Nivolumab in sorafenib-naive and sorafenib-experienced patients with advanced hepatocellular carcinoma: 5-year follow-up from CheckMate 040

BACKGROUND

Patients with advanced hepatocellular carcinoma (aHCC) have a poor prognosis and high mortality. Nivolumab monotherapy demonstrated clinical benefit with an acceptable safety profile in patients with aHCC in the CheckMate 040 study. Five-year follow-up of the sorafenib-naive and sorafenib-experienced groups of CheckMate 040 is presented here.

PATIENTS AND METHODS

Patients received nivolumab monotherapy at dose levels of 0.1-10.0 mg/kg (dose-escalation phase) or 3 mg/kg (dose-expansion phase) every 2 weeks until disease progression or unacceptable toxicity. Primary endpoints were safety and tolerability (dose escalation), and objective response rate (ORR) by blinded independent central review (BICR) and by investigator as per RECIST version 1.1 (dose expansion).

RESULTS

Eighty sorafenib-naive and 154 sorafenib-experienced patients were treated. Minimum follow-up in both groups was 60 months. ORR as per BICR was 20% [95% confidence interval (CI) 12% to 30%] and 14% (95% CI 9% to 21%) in the sorafenib-naive and sorafenib-experienced groups, respectively. Responses occurred regardless of HCC etiology or baseline tumor cell programmed death-ligand 1 (PD-L1) expression levels. Median overall survival (OS) was 26.6 months (95% CI 16.6-30.6 months) and 15.1 months (95% CI 13.0-18.2 months) in sorafenib-naive and sorafenib-experienced patients, respectively. The 3-year OS rates were 28% in the sorafenib-naive and 20% in the sorafenib-experienced groups; 5-year OS rates were 14% and 12%, respectively. No new safety signals were identified; grade 3/4 treatment-related adverse events were observed in 33% and 21% of patients in the sorafenib-naive and sorafenib-experienced groups, respectively. Biomarker analyses showed that baseline PD-L1 expression ≥1% was associated with higher ORR and longer OS compared with PD-L1 <1%. In the sorafenib-naive group, patients with OS ≥3 years exhibited higher baseline CD8 T-cell density compared with those with OS <1 year.

CONCLUSION

With 5 years of follow-up, nivolumab monotherapy continued to provide durable clinical benefit with manageable safety in sorafenib-naive and sorafenib-experienced patients with aHCC.

CALGB 80802 (Alliance): Impact of Sorafenib with and without Doxorubicin on Hepatitis C Infection in Patients with Advanced Hepatocellular Carcinoma

Sorafenib blocks nonstructural protein 5A (NS5A)-recruited c-Raf-mediated hepatitis C virus (HCV) replication and gene expression. Release of Raf-1-Ask-1 dimer and inhibition of Raf-1 via sorafenib putatively differ in the presence or absence of doxorubicin. Cancer and Leukemia Group B (CALGB) 80802 (Alliance) randomized phase III trial of doxorubicin plus sorafenib versus sorafenib in patients with advanced hepatocellular carcinoma (HCC), showed no improvement in median overall survival (OS). Whether HCV viral load impacts therapy and whether any correlation between HCV titers and outcome based on HCV was studied. In patients with HCV, HCV titer levels were evaluated at baseline and at multiple postbaseline timepoints until disease progression or treatment discontinuation. HCV titer levels were evaluated in relation to OS and progression-free survival (PFS). Among 53 patients with baseline HCV data, 12 patients had undetectable HCV (HCV-UN). Postbaseline HCV titer levels did not significantly differ between treatment arms. One patient in each arm went from detectable to HCV-UN with greater than 2 log-fold titer levels reduction. Aside from these 2 HCV-UN patients, HCV titers remained stable on treatment. Patients who had HCV-UN at baseline were 3.5 times more likely to progress and/or die from HCC compared with HCV detectable (HR = 3.51; 95% confidence interval: 1.58-7.78; P = 0.002). HCV titer levels remained unchanged, negating any sorafenib impact onto HCV titer levels. Although an overall negative phase III study, patients treated with doxorubicin plus sorafenib and sorafenib only, on CALGB 80802 had worse PFS if HCV-UN. Higher levels of HCV titers at baseline were associated with significantly improved PFS.

SIGNIFICANCE

Sorafenib therapy for HCC may impact HCV replication and viral gene expression. In HCV-positive patients accrued to CLAGB 80802 phase III study evaluating the addition of doxorubicin to sorafenib, HCV titer levels were evaluated at baseline and different timepoints. Sorafenib did not impact HCV titer levels. Despite an improved PFS in patients with detectable higher level HCV titers at baseline, no difference in OS was noted.

Phase 1 study of GSK3368715, a type I PRMT inhibitor, in patients with advanced solid tumors

BACKGROUND

GSK3368715, a first-in-class, reversible inhibitor of type I protein methyltransferases (PRMTs) demonstrated anticancer activity in preclinical studies. This Phase 1 study (NCT03666988) evaluated safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of GSK3368715 in adults with advanced-stage solid tumors.

METHODS

In part 1, escalating doses of oral once-daily GSK3368715 (50, 100, and 200 mg) were evaluated. Enrollment was paused at 200 mg following a higher-than-expected incidence of thromboembolic events (TEEs) among the first 19 participants, resuming under a protocol amendment starting at 100 mg. Part 2 (to evaluate preliminary efficacy) was not initiated.

RESULTS

Dose-limiting toxicities were reported in 3/12 (25%) patients at 200 mg. Nine of 31 (29%) patients across dose groups experienced 12 TEEs (8 grade 3 events and 1 grade 5 pulmonary embolism). Best response achieved was stable disease, occurring in 9/31 (29%) patients. Following single and repeat dosing, GSK3368715 maximum plasma concentration was reached within 1 h post dosing. Target engagement was observed in the blood, but was modest and variable in tumor biopsies at 100 mg.

CONCLUSION

Based on higher-than-expected incidence of TEEs, limited target engagement at lower doses, and lack of observed clinical efficacy, a risk/benefit analysis led to early study termination.

TRIAL REGISTRATION NUMBER

NCT03666988.

Nivolumab Plus Cabozantinib With or Without Ipilimumab for Advanced Hepatocellular Carcinoma: Results From Cohort 6 of the CheckMate 040 Trial

PURPOSE

To investigate the safety and efficacy of nivolumab plus cabozantinib with or without ipilimumab in patients with advanced hepatocellular carcinoma.

METHODS

In cohort 6 of the multicohort, open-label, phase I/II CheckMate 040 study, patients who were treatment-naive, sorafenib-intolerant, or had progressed on sorafenib were randomly assigned 1:1 to nivolumab 240 mg once every 2 weeks plus cabozantinib 40 mg once daily (doublet arm); or nivolumab 3 mg/kg every 2 weeks plus cabozantinib 40 mg once daily with ipilimumab 1 mg/kg once every 6 weeks (triplet arm). Primary objectives were safety and tolerability, objective response rate, and duration of response by investigator assessment per RECIST v1.1. Secondary objectives included progression-free survival (by blinded independent central review) and overall survival.

RESULTS

Seventy-one patients were randomly assigned: 36 to the doublet arm and 35 to the triplet arm. After 32.0-month median follow-up, objective response rate (95% CI) was 17% (6 to 33) and 29% (15 to 46) in the doublet and triplet arms, respectively. Median (95% CI) duration of response was 8.3 (6.9 to not estimable) months in the doublet arm and not reached (0.0 to not estimable) in the triplet arm. Median progression-free survival was 5.1 and 4.3 months, and median overall survival was 20.2 and 22.1 months for the doublet and triplet arms, respectively. Grade 3-4 treatment-related adverse events occurred in 50% and 74% of patients and treatment-related adverse events leading to discontinuation were reported for 11% and 23% in the doublet and triplet arms, respectively. There were no treatment-related deaths in either arm.

CONCLUSION

Nivolumab plus cabozantinib with or without ipilimumab showed encouraging preliminary antitumor activity and had consistent safety profiles with those established for the individual drugs in patients with advanced hepatocellular carcinoma.

Adjuvant Chemoradiation in Patients with Lymph Node-Positive Biliary Tract Cancers: Secondary Analysis of a Single-Arm Clinical Trial (SWOG 0809)

BACKGROUND

SWOG 0809 is the only prospective study of adjuvant chemotherapy followed by chemoradiation focusing on margin status in patients with extrahepatic cholangiocarcinoma (EHCC) and gallbladder cancer (GBCA); however, the effects of adjuvant therapy by nodal status have never been reported in this population.

METHODS

Patients with resected EHCC and GBCA, stage pT2-4, node-positive (N+) or margin-positive (R1) who completed four cycles of chemotherapy followed by radiotherapy were included. Cox regression was used to compare overall survival (OS), disease-free survival (DFS), local recurrence, and distant metastasis by nodal status. DFS rates were compared with historical data via a one-sample t-test.

RESULTS

Sixty-nine patients [EHCC, n = 46 (66%); GBCA, n = 23 (33%)] were evaluated, with a median age of 61.7 years and an R0 rate of 66.7% and R1 rate of 33.3%. EHCC versus GBCA was more likely to be N+ (73.9% vs. 47.8%, p = 0.03). Nodal status did not significantly impact OS (hazard ratio [HR] 1.98, 95% confidence interval [CI] 0.86-4.54, p = 0.11) or DFS (HR 1.63, 95% CI 0.77-3.44, p = 0.20). Two-year OS was 70.6% for node-negative (N0) disease and 60.9% for N+ disease, while 2-year DFS was 62.5% for N0 tumors and 49.8% for N+ tumors. N+ versus N0 tumors showed higher rates of distant failure (42.2% vs. 25.0%, p = 0.04). The 2-year DFS rate in N+ tumors was significantly higher than in historical controls (49.8% vs. 29.7%, p = 0.004).

CONCLUSIONS

Adjuvant therapy is associated with favorable outcome independent of nodal status and may impact local control in N+ patients. These data could serve as a benchmark for future adjuvant trials, including molecular-targeted agents.

RELATIVITY-106: A phase 1/2 trial of nivolumab (NIVO) + relatlimab (RELA) in combination with bevacizumab (BEV) in first-line (1L) hepatocellular carcinoma (HCC)

TPS636

Background: The current standard of care for 1L treatment of patients with advanced/metastatic HCC is atezolizumab + BEV, which demonstrated significantly prolonged progression-free survival (PFS) and overall survival (OS) compared to sorafenib in treatment-naïve patients. However, only 29.8% of patients show objective responses and additional therapy options are needed in the 1L setting. Programmed death-1 (PD-1) and lymphocyte-activation gene 3 (LAG-3) are distinct inhibitory immune checkpoint pathways that synergistically reduce T-cell function. RELA is a first-in-class human immunoglobulin G4 LAG-3-blocking antibody that binds to LAG-3 and restores the effector function of T cells. Dual checkpoint inhibition of the PD-1 and LAG-3 pathways with NIVO + RELA has the potential to boost immune surveillance in HCC. Preclinical data presume that BEV, a human vascular endothelial growth factor inhibitor, reverses abnormal vascularization to allow NIVO + RELA to inhibit hypoxia-induced programmed cell death ligand 1 and LAG-3 expression and enhance depth of response and OS in HCC. Here we describe the RELATIVITY-106 study investigating the triplet therapy of NIVO + RELA + BEV in the 1L treatment of advanced/metastatic HCC. Methods: RELATIVITY-106 (NCT05337137) is a phase 1/2, randomized, double-blind, placebo-controlled trial to assess the safety and efficacy of NIVO + RELA + BEV compared with NIVO + BEV in treatment-naïve patients with advanced/metastatic HCC. Key inclusion criteria include age ≥ 18 years; histologic confirmation of advanced/metastatic HCC in patients naïve to systemic therapy for advanced/metastatic HCC (prior neoadjuvant or adjuvant immunotherapy permitted if recurrence occurs ≥ 6 months after treatment completion); Child-Pugh A; and ECOG performance status 0 or 1. Key exclusion criteria include known fibrolamellar HCC, sarcomatoid HCC, or mixed hepatocellular cholangiocarcinoma; prior allogenic stem cell or solid organ transplantation; untreated symptomatic central nervous system metastases; clinically significant ascites; increased risk of bleeding; significant vascular disease or inadequately controlled hypertension; and major surgical procedure within 4 weeks prior to study treatment. Primary endpoints include incidence of dose-limiting toxicities assessed for up to 6 weeks and PFS by blinded independent central review (BICR) per RECIST v1.1 in all randomized patients in phase 1 and phase 2, respectively. Secondary endpoints include overall response rate (ORR) by BICR and OS in all randomized patients; ORR and PFS by BICR and OS in all randomized LAG-3-positive patients (≥ 1% by immunohistochemistry); and safety. Key exploratory endpoints include pharmacokinetics and immunogenicity assessed by antidrug antibody positivity. The study, initiated in May 2022, is currently enrolling globally. Clinical trial information: NCT05337137 .

Results from a phase 1a/1b study of botensilimab (BOT), a novel innate/adaptive immune activator, plus balstilimab (BAL; anti-PD-1 antibody) in metastatic heavily pretreated microsatellite stable colorectal cancer (MSS CRC)

LBA8

Background: BOT promotes optimized T cell priming, activation and memory formation by strengthening antigen presenting cell/T cell co-engagement. As an Fc-enhanced next-generation anti–CTLA-4 antibody, BOT also promotes intratumoral regulatory T cell depletion and reduces complement fixation. We present results from patients with MSS CRC treated with BOT + BAL in an expanded phase 1a/1b study; NCT03860272. Methods: Patients (pts) with metastatic MSS CRC received BOT 1 or 2 mg/kg every 6 weeks (Q6W) + BAL 3 mg/kg every 2 weeks. Crossover from monotherapy to combination therapy was permitted (rescue) as well as fixed-dosing (150 mg BOT Q6W + 450 mg BAL every 3 weeks). Results: Fifty-nine combination pts were evaluable for efficacy/safety (treated as of 19 May 2022 with ≥1 Q6W imaging assessment), including one rescue and one fixed-dose pt. Median pt age was 57 (range, 25-83), 58% were female, and 76% received at least three prior lines of therapy including prior immunotherapy (34%). Median follow-up was 6.4 months (range, 1.6-29.5). In all pts, objective response rate (ORR) was 22% (95% CI, 12-35), disease control rate (DCR) was 73% (95% CI, 60-84), and median duration of response (DOR) was not reached (NR), with 9/13 responses ongoing. The 12-month overall survival (OS) rate was 61% (95% CI, 42-75), with median OS NR. Of the 13 responders, 9 had RAS mutations (7 KRAS, 2 NRAS), 0 had BRAF mutations, 0/10 had a TMB of ≥10 mutations/Mb, and 1/7 was PD-L1 positive (≥1% combined positive score). A subgroup analysis was conducted by the dose of BOT received . In 1 mg/kg pts (n=8), ORR was 38% (3/8; 95% CI, 9-76) and DCR was 100% (8/8; 95% CI, 63-100); in 2 mg/kg pts (n=50), ORR was 20% (10/50; 95% CI, 10-34) and DCR was 70% (35/50; 95% CI, 55-82). All grade treatment-related adverse events (TRAEs) occurred in 88% of pts, including grade 3 in 32%, and grade 4 in 2% of pts. Diarrhea/colitis was the only grade 3/4 TRAE occurring in more than three pts (15% grade 3, 2% grade 4). The most common grade 3 TRAEs outside of diarrhea/colitis were fatigue (5%) and pyrexia (5%). There were no grade 5 TRAEs reported. Fifteen percent of pts had a TRAE leading to discontinuation of BOT alone and 12% had a TRAE leading to discontinuation of both BOT + BAL. Conclusions: In heavily pretreated metastatic MSS CRC pts, BOT + BAL continues to demonstrate promising clinical activity with durable responses and was well tolerated with no new immune-mediated safety signals. A larger pt set, analyses by subgroup, and additional translational data will be presented at the meeting. A randomized phase 2 trial in MSS CRC pts is enrolling (NCT05608044). Clinical trial information: NCT03860272 .

IMbrave151: A phase 2, randomized, double-blind, placebo-controlled study of atezolizumab with or without bevacizumab in combination with cisplatin plus gemcitabine in patients with untreated, advanced biliary tract cancer

491

Background: VEGF blockade coupled with cytotoxic chemotherapy can promote an immune-permissive tumor microenvironment that can augment response to PD-L1 inhibition. IMbrave151 (NCT04677504) is a randomized, double-blind, global Phase II study evaluating the efficacy of atezolizumab (atezo), bevacizumab (bev) and cisplatin and gemcitabine (CisGem) as first-line treatment for patients with advanced biliary tract cancer (aBTC). Methods: Patients with previously untreated aBTC were randomized 1:1 to receive atezo (1200 mg every 3 weeks [q3w]) + bev (15 mg/kg q3w) or placebo + CisGem (cisplatin 25 mg/m2 and gemcitabine 1000 mg/m2 on Days 1 and 8 q3w) for up to 8 cycles, followed by atezo (1200 mg q3w) + bev (15 mg/kg q3w) or placebo until disease progression or unacceptable toxicity. Patients were stratified by disease status, geographic region and primary tumor location. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), duration of response (DOR), disease control rate and safety. No formal hypothesis testing was performed. Results: In total, 162 patients were randomized to receive either atezo + bev + CisGem (n=79) or atezo + placebo + CisGem (n=83). Median age 63 years, Asia/Rest of World (43/57%), ECOG PS 0/1 (53/48%), intrahepatic/extrahepatic cholangiocarcinoma and gallbladder (54/19/27%), and metastatic/locally advanced stage (82/18%). The HR for PFS was 0.76 (95% CI: 0.51, 1.14). Median PFS was 8.4 months for atezo + bev + CisGem and 7.9 months for atezo + placebo + CisGem; the 6-month PFS rates were 78% and 63%, respectively. The confirmed ORR was 24% for atezo + bev + CisGem and 25% for atezo + placebo + CisGem. DOR ≥6 months was 89% for atezo + bev + CisGem vs 47% for atezo + placebo + CisGem. The incidence of Grade 3 or 4 adverse events was 73% and 74% with atezo + bev + CisGem and atezo + placebo + CisGem, respectively. Median OS is not reached. Conclusions: Both combinations of IMbrave151 showed a manageable safety profile. The aggregate of data suggests that combining atezo with bev and chemotherapy may provide clinical benefit in a subset of patients with aBTC. Follow-up is ongoing for OS. Clinical trial information: NCT04677504 .

First-in-human study of an OX40 (ivuxolimab) and 4-1BB (utomilumab) agonistic antibody combination in patients with advanced solid tumors

BACKGROUND

Ivuxolimab (PF-04518600) and utomilumab (PF-05082566) are humanized agonistic IgG2 monoclonal antibodies against OX40 and 4-1BB, respectively. This first-in-human, multicenter, open-label, phase I, dose-escalation/dose-expansion study explored safety, tolerability, pharmacokinetics, pharmacodynamics, and antitumor activity of ivuxolimab+utomilumab in patients with advanced solid tumors.

METHODS

Dose-escalation: patients with advanced bladder, gastric, or cervical cancer, melanoma, head and neck squamous cell carcinoma, or non-small cell lung cancer (NSCLC) who were unresponsive to available therapies, had no standard therapy available or declined standard therapy were enrolled into five dose cohorts: ivuxolimab (0.1-3 mg/kg every 2 weeks (Q2W)) intravenously plus utomilumab (20 or 100 mg every 4 weeks (Q4W)) intravenously. Dose-expansion: patients with melanoma (n=10) and NSCLC (n=20) who progressed on prior anti-programmed death receptor 1/programmed death ligand-1 and/or anti-cytotoxic T-lymphocyte-associated antigen 4 (melanoma) received ivuxolimab 30 mg Q2W intravenously plus utomilumab 20 mg Q4W intravenously. Adverse events (AEs) were graded per National Cancer Institute Common Terminology Criteria for Adverse Events V.4.03 and efficacy was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) V.1.1 and immune-related RECIST (irRECIST). Paired tumor biopsies and whole blood were collected to assess pharmacodynamic effects and immunophenotyping. Whole blood samples were collected longitudinally for immunophenotyping.

RESULTS

Dose-escalation: 57 patients were enrolled; 2 (3.5%) patients with melanoma (0.3 mg/kg+20 mg and 0.3 mg/kg+100 mg) achieved partial response (PR), 18 (31.6%) patients achieved stable disease (SD); the disease control rate (DCR) was 35.1% across all dose levels. Dose-expansion: 30 patients were enrolled; 1 patient with NSCLC achieved PR lasting &gt;77 weeks. Seven of 10 patients with melanoma (70%) and 7 of 20 patients with NSCLC (35%) achieved SD: median (range) duration of SD was 18.9 (13.9-49.0) weeks for the melanoma cohort versus 24.1 (14.3-77.9+) weeks for the NSCLC cohort; DCR (NSCLC) was 40%. Grade 3-4 treatment-emergent AEs were reported in 28 (49.1%) patients versus 11 (36.7%) patients in dose-escalation and dose-expansion, respectively. There were no grade 5 AEs deemed attributable to treatment. Ivuxolimab area under the concentration-time curve increased in a dose-dependent manner at 0.3-3 mg/kg doses.

CONCLUSIONS

Ivuxolimab+utomilumab was found to be well tolerated and demonstrated preliminary antitumor activity in selected groups of patients.

TRIAL REGISTRATION NUMBER

NCT02315066.

Abstract CT549: Randomized Phase II trial of two different nutritional approaches for patients receiving treatment for their advanced pancreatic cancer

Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by stromal fibrosis, hypoxia, and nutritional deprivation. PDAC tumors grow aggressively, diagnosis is typically made after metastasis and the disease remains associated with poor outcomes. The triplet chemotherapy regimen of gemcitabine, nab-paclitaxel with cisplatin was associated with a median overall survival of 16.4 months in patients with metastatic pancreatic cancer in the first-line setting (Jameson et al., 2020). Nutritional, metabolic interventions offer an opportunity to fundamentally change the tumor microenvironment and improve outcomes for patients. A medically supervised ketogenic diet (MSKD) defined as lower carbohydrate, lower protein, and higher fat can significantly reduce glucose and insulin and increase metabolically active ketone bodies. A ketogenic diet combined with triplet chemotherapy (gemcitabine, nab-paclitaxel, cisplatin) was shown to inhibit murine pancreatic KPC tumor growth and to triple the survival benefit of chemotherapy alone. The ketogenic diet combined with triple chemotherapy was associated with glucose depletion, altered TCA substrate usage, and NADH elevation.

Methods: In this Phase II randomized clinical trial (NCT04631445), we are evaluating a medically supervised ketogenic diet (MSKD) versus a standard diet when combined with the triplet therapy in patients with treatment-naive advanced pancreatic cancer. The primary endpoint is progression free survival for triplet therapy while on MSKD or non-MSKD. Secondary endpoints include disease control rate (PR+ CR+ SD for at least 9 weeks), change in CA 19-9 (or CA125, or CEA if not expressers of CA 19-9), average insulin levels, HbA1c, body weight, a comparison of gut microbial diversity, changes in serum metabolites and quality of life via the EORTC QLQ-C30 assessment. Unlike prior ketogenic intervention studies, the MSKD is being supported by a continuous care nutrition intervention through Virta Health Corp, that offers tracking of daily ketone and glucose levels, a web-based software application, education, and communication with a remote care team to ensure sustained nutritional ketosis. A total of 40 patients with untreated metastatic PDAC are planned for enrollment, 20 randomized to each arm. The trial opened for accrual November 2020.

Citation Format: Diana Hanna, Gayle S. Jameson, Drew W. Rasco, Angela Alistar, Richard C. Frank, Anthony B. El-Khoueiry, Julia E. Wiedmeier, Caroline Roberts, Brandon Fell, Sarah Hallberg, Denise Roe, Derek Cridebring, Joshua Rabinowitz, Stephen Thomas Gately, Daniel D. Von Hoff. Randomized Phase II trial of two different nutritional approaches for patients receiving treatment for their advanced pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT549.

First-in-human phase 1/2 dose escalation and expansion study evaluating first-in-class eIF4A inhibitor zotatifin in patients with solid tumors

3081

Background: Zotatifin (eFT226) is a first in class, potent and sequence selective inhibitor of RNA helicase eIF4A1 that promotes stable mRNA:eIF4A:drug ternary complex at specific polypurine motifs within the 5’-UTR, preventing ribosome docking and thus, efficient translation of select transcripts. In preclinical models zotatifin treatment simultaneously down-regulated translation of numerous oncogenes with complex 5’ mRNA structures, including ERBB2, FGFR1/2, EGFR, KRAS, and CCND1. Methods: Patients (pts) with select advanced solid tumors harboring mutations/amplification of ERBB2, FGFR1, FGFR2, EGFR, or KRAS or with pancreatic cancer were enrolled into 3+3 dose escalation portion of the protocol (Part 1), and indication specific expansions continue to enroll at recommended phase 2 dose (RP2D; Part 2). The primary endpoints of Part 1 include determination of safety, tolerability, and maximum tolerated dose (MTD)/RP2D; additional endpoints include characterization of pharmacokinetic, pharmacodynamic (including from blood-based assay during escalation and from pre- and on-treatment biopsy at/near MTD with reverse phase protein array (RPPA)), and initial efficacy. Results: As of cut-off date Jan 13, 2022, Dose escalation phase (Part 1) included 37 patients treated with zotatifin at dose levels: 0.005, 0.01, 0.02, 0.035 mg/Kg IV weekly, and 0.035, 0.05, 0.07, 0.1 mg/kg IV 2 weeks-on and 1 week-off. DLTs were observed in 3 patients: Gr 2 thrombocytopenia (0.035 mg/kg weekly), Gr 3 anemia (0.1 mg/kg) and Gr 3 gastrointestinal bleed resulting in anemia (0.1 mg/kg). MTD/RP2D is 0.07 mg/Kg IV 2 weeks-on and 1 week-off. The most common treatment emergent adverse events (TEAEs) in Part 1 include: fatigue, anemia, diarrhea and dyspnea. The most common AEs at RP2D (n = 16 pts; Part 1 and Part 2) include: anemia (25% all gr 1 or 2), fatigue (25% all gr 1 or 2) and dyspnea (19%; 13% Gr 3) diarrhea (13%, all Gr 1 or 2). Pharmacokinetics were generally linear and dose proportional and exposures at MTD/RP2D are consistent with target pharmacologic levels in preclinical models. Blood based biomarkers showed dose- and time- dependent evidence of target engagement. Pre- and on-treatment biopsy data in expansion patients showed decreased expression of target proteins. No patient in dose escalation experienced an objective tumor response; initial efficacy data from Part 2 and at RP2D will be presented. Conclusions: eIF4A inhibitor zotatifin achieves pharmacologically relevant exposures with on-target AEs that are manageable at the MTD, with evidence of target knockdown from on-treatment biopsies. Part 2 indication-specific expansions (including in ER+ FGFR-amplified MBC as single agent, ER+ MBC in combination with fulvestrant and abemaciclib, and KRAS NSCLC in combination with sotorasib) are on-going. Clinical trial information: NCT04092673.

The combination of CD16A/EGFR innate cell engager, AFM24, with SNK01 autologous natural killer cells in patients with advanced solid tumors

TPS2675

Background: Natural killer (NK) cells are a critical component of the innate immune system involved in the eradication of transformed cells via antibody-dependent cellular cytotoxicity (ADCC). For treatment of solid tumors autologous NK cell transfer represents a promising treatment strategy, with ex vivo expansion and activation enhancing the specificity and anti-tumor activity of NK cells. The efficacy of this approach may be enhanced through the addition of tumor-targeting antibodies, augmenting NK cell-mediated ADCC. Innate Cell Engagers (ICE) are bispecific antibodies that target a tumor cell-surface antigen and bind to CD16A expressed on NK cells. AFM24 is a novel ICE that targets epidermal growth factor receptor (EGFR), which is often overexpressed in solid tumors. The Phase 1 study of AFM24 monotherapy showed patients had a manageable safety profile, and SNK01 monotherapy has also shown to be well-tolerated in patients with rapidly progressive solid tumors. This study seeks to investigate AFM24 in combination with SNK01 autologous NK cells in patients with advanced EGFR+ solid tumors. Methods: An ongoing Phase 1/2a open-label, non-randomized, multicenter, dose escalation (Phase 1) and dose expansion (Phase 2a) study was initiated in November 2021 (NCT05099549) to evaluate the safety, tolerability and efficacy of AFM24 in combination with SNK01 NK cells in EGFR+ solid tumors. The primary aim of the Phase 1 study is to determine the maximum tolerated dose and/or recommended Phase 2 dose (RP2D) of AFM24 in combination with SNK01 at a fixed dose NK cells using a standard 3+3 design. Eligible patients must have advanced or metastatic disease with positive immunohistochemical staining for EGFR in >1% of tumor cells and be refractory to standard-of-care treatment. Treatment begins with a safety lead-in phase with a single dose of AFM24 7 days prior to combination therapy. AFM24 will be administered at an escalating dose as weekly intravenous (IV) infusions; the starting dose (160 mg) and dose escalations for each cohort are based on results from the ongoing AFM24 monotherapy trial (NCT04259450). SNK01 NK cells will be given at a fixed dose (4.0 x109 cells) as a weekly IV infusion concomitantly with AFM24. Patients will receive combination therapy until disease progression, intolerable toxicity, patient withdrawal or termination at the investigator’s discretion. Phase 2 will then establish the overall response rate (as per RECIST v1.1) of combination therapy in patients with treatment refractory, advanced or metastatic squamous cell carcinoma of the head and neck, non-small cell lung cancer, or colorectal cancer as the primary endpoint. Efficacy will also be assessed by assessing progression-free and overall survival. Secondary endpoints for both phases include treatment-emergent adverse events, serious adverse events, pharmacokinetics and immunogenicity. Clinical trial information: NCT05099549.

Optimization of Voyager V1 (VV1) oncolytic virus systemic delivery in combination with cemiplimab and ipilimumab in patients with melanoma and non–small cell lung cancer (NSCLC)

TPS9595

Background: There is a need for novel immunotherapies to address the patient population that never or no longer responds to immune checkpoint inhibitors (CPI). VV1 is an oncolytic vesicular stomatitis virus engineered to express human interferon beta (IFNβ) to enhance cellular anti-tumor immune responses and tumor selectivity. Phase 1 studies demonstrated VV1 anti-tumor activity in several malignancies with or without a CPI. We are exploring ways to optimize VV1 efficacy in combination with cemiplimab, an anti-PD1 antibody approved for lung, basal and squamous cell skin cancers. Recent clinical data support a 5-fold higher dose of VV1 than was previously explored, and pre-clinical data show synergy between the oncolytic and an anti-CTLA4 antibody, in addition to cemiplimab, supporting exploration of a triplet. What was originally a five-arm study of intravenous (IV) VV1 in combination with IV cemiplimab has been amended to focus on 2 means of optimizing efficacy: use of a higher dose of VV1 and triplet combination in proof-of-concept populations. Methods: We are now enrolling pts with advanced melanoma (after progression on anti-PD1) and plan to include 1st-line NSCLC pts with PD-L1 expression ≥50%. The study is first exploring the preliminary anti-tumor activity, safety, and immunogenic activity of the combination of IV VV1 at a dose of 1.0 x 1011 TCID50 once on D1 followed by IV cemiplimab Q3W starting on D8, or the same regimen with an additional intratumoral injection of VV1 1.0 x 109 TCID50 once on D1 for pts with accessible lesions. Pts receive IV cemiplimab Q3W until confirmed disease progression or intolerable toxicity. Once at least 6 pts have been treated with acceptable safety across the 2 melanoma doublet cohorts using this higher dose of VV1, a 3rd melanoma cohort will open to add a single dose of ipilimumab 50 mg on D1 (all IV triplet). Once 6 melanoma pts have received the triplet safely, the 1st-line NSCLC cohort will open. All cohort decisions are guided by a Data Review Committee. Cohorts will be expanded based on a Simon 2-stage design using a type I error rate of 0.05 and power of 85%. Null ORR is 10% with a target of 35% for 2nd line melanoma and null ORR is 40% in 1st line NSCLC with a target of 70%. Each melanoma cohort will require a response in ≥2 of 10 pts in the 1st stage to add 11 more in the 2nd stage, while NSCLC will first need 5/9 evaluable pts to respond, then an additional 13 to complete the design. Response is assessed at week 7 then Q9W per RECIST v1.1. The study includes serial biopsies in ≥3/10 pts in Stage 1 of each of the IV melanoma cohorts (doublet and triplet therapy), all pts in Stage 2 of these IV melanoma cohorts, and all pts in both Stage 1 and Stage 2 of the IV/IT melanoma cohort, to permit a thorough investigation of the impact of the 3 immunotherapies under investigation. The study is currently ongoing in the USA. Clinical trial information: NCT04291105.

First-in-human study of SRF388, a first-in-class IL-27 targeting antibody, as monotherapy and in combination with pembrolizumab in patients with advanced solid tumors

2501

Background: The immunoregulatory cytokine IL-27 upregulates inhibitory immune checkpoint receptors (eg, PD-L1, TIGIT) and downregulates proinflammatory cytokines (eg, IFNγ, TNFα). SRF388 is a fully human IgG1 blocking antibody to IL-27 with potential to promote immune activation in the tumor microenvironment. A phase 1 study was conducted to establish the preliminary safety of SRF388 and to identify recommended phase 2 doses (RP2D) suitable for monotherapy and combination expansions (NCT04374877). Methods: The dose-escalation study (accelerated single patient followed by standard 3+3) enrolled patients (pts) with advanced treatment-refractory solid tumors. Upon RP2D selection, monotherapy and combination expansions opened for treatment-refractory clear cell renal cell cancer (ccRCC), hepatocellular cancer (HCC), and non-small cell lung cancer. SRF388 was administered IV every 4 weeks (wks) as monotherapy and every 3 wks with pembrolizumab. Tumor response was assessed by RECIST1.1. Results: The monotherapy dose-escalation enrolled 29 pts with doses ranging from 0.003 to 20 mg/kg. Median age was 64 years. Most pts were female (62%) with ECOG PS of 1 (72%). Approximately 80% had prior PD-(L)1 blockade, and 48% had ≥4 prior therapies. Treatment-related adverse events (TRAEs) occurred in 21%, and all were low grade. Fatigue was the only TRAE reported in ≥10% (n = 3). No dose-limiting toxicities (DLTs) or Grade ≥3 TRAEs were observed. Median time on study was 9 wks (range 0–59). One patient with highly treatment-refractory NSCLC experienced a confirmed partial response (PR) at 8 wks that was durable for 20 wks. Nine pts (31%) experienced disease stabilization at 8 wks, with 6 of 9 exhibiting durable disease control at 6 months. Of the 7 pts with ccRCC in the dose-escalation portion of the trial, 3 (43%) experienced durable disease control for ≥20 wks (range: 20-32). With doses up to 20 mg/kg, SRF388 PK remain linear with an estimated T1/2 of 10-12 days. PK characteristics and safety profile support dosing every 3 or 4 wks. Based on safety, tolerability, PK, peripheral pSTAT1 inhibition, and preliminary efficacy, 10 mg/kg was selected as the RP2D. Both the pembrolizumab safety cohort (n = 10) and Stage 1 of the ccRCC monotherapy expansion (n = 17) have fully enrolled. Of the 10 evaluable pts with ccRCC, 1 confirmed monotherapy PR has been reported, enabling Stage 2 initiation. Changes in several serum cytokines and chemokines were observed after SRF388 administration, including expected increase in circulating IL-27 levels. Conclusions: Results of IL-27 pathway blockade with a first-in-class therapeutic demonstrates that SRF388 has good tolerability with encouraging preliminary antitumor activity as a monotherapy. Updated data, including safety and clinical outcomes as well as correlative biomarker analyses, will be presented. Clinical trial information: NCT04374877.

Single center real-world treatment and outcomes in patients with hepatocellular carcinoma receiving immunotherapy

e16134

Background: Immune checkpoint inhibitor (ICI) based therapy has emerged as a therapeutic option in hepatocellular carcinoma (HCC), both in combination (IC-C) and as single agent (IC-SA). Approvals were based on clinical trials with strict eligibility criteria limiting generalizability to the entire spectrum of clinical practice. Survival outcomes have not been evaluated in a real-world population and there is no established post ICI treatment standard. Methods: Patients (pts) with advanced HCC treated with ICI across lines of therapy were included in this retrospective study. Data regarding demographics, comorbidities, HCC etiology, liver function (Child Pugh Score [CPS] and ALBI Grade [G]), tumor burden, AFP, treatments, reason for discontinuation (dc) and outcomes were collected. Descriptive statistics and survival analysis were performed using Stata with cox regression analysis. Results: The cohort consisted of 138 pts: median age 63 years (24,95); 83% male; 38% Hispanic/Latino, 27% Asian, 17% Non-Hispanic White, 4% Black and 14% other/unknown. Etiology of cirrhosis: 16% Hepatitis B, 38% Hepatitis C, 12% alcohol liver disease, 9% NAFLD and 24 % mixed/other; Baseline CPS were 74% CPA, 23% CPB, and 2% CPC; ALBI Scores were G1 in 35%, G2 in 53%, and G3 in 12% pts; 62% had extrahepatic disease and/or portal invasion; AFP was ≥ 400ng/mL in 30% of pts. 88% of pts had prior local therapy. For the entire cohort, first line systemic therapy consisted of 52% ICI (18% IC-C and 34% IC-SA) and 48% TKI. mOS was 12 months (mo) (0,74) for first line ICI group and 19.5 mo (3,78) in those with first line TKI. In CPA pts, first line therapy was 51% ICI (24% IC-C and 27% IC-SA) and 39% TKI. 79% of CPA patients received ≥ 2 lines of therapy with second line consisting of 65% ICI and 20% TKI. First line therapy for pts with CPB cirrhosis was 58% ICI (2% IC-C and 55% IC-SA) and 42% TKI. 55% of CPB patients received ≥ 2 lines of therapy and second line therapy for CPB pts included 71% ICI and 18% TKI. mOS was 18 mo in CPA pts and 10 mo in CPB pts. Cirrhosis related complications resulted in treatment discontinuation in 2% of CPA pts vs. 14% of CPB pts. On multivariable analysis, Asian ethnicity (HR 0.41 p = 0.006), CPS (HR 1.64 p = 0.027), and number of treatment lines (HR 0.74 p = 0.005) were associated with OS. Conclusions: This single institution real-world cohort highlights the reality of sequential therapy in pts with advanced HCC. Survival outcomes in our CPA cohort are comparable to data from recent phase 3 trials. The survival in our CPB cohort in a tertiary care setting compares favorably with available data from clinical trials and suggests the feasibility of sequential and effective anti-cancer therapy in this population. Liver function, Asian ethnicity, and number of treatment lines are independent predictors of OS in this cohort of HCC patients receiving ICI. Prospective studies related to optimal treatment sequence and to CPB pts are needed.

A phase 1/2a open label, multicenter study to assess the safety, tolerability, pharmacokinetics, and efficacy of AFM24 in patients with advanced solid cancers: Study design and rationale

TPS2672

Background: AFM24 is a first-in-class, tetravalent, bispecific, fragment crystallizable-silenced antibody that targets epidermal growth factor receptor-expressing (EGFR+) solid tumors. Of its 4 binding sites, 2 are specific for EGFR, and 2 are specific for CD16A, the Fcγ receptor expressed by natural killer (NK) cells and macrophages. The primary mode of action of AFM24 is not to inhibit EGFR signaling, but to redirect NK cells and macrophages to EGFR+ tumor cells to induce antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), respectively. Preclinical studies showed AFM24 induced killing of EGFR+ tumor cell lines, and the activity was independent of EGFR cell surface expression level. A favorable safety profile was also demonstrated in cynomolgus monkeys. Therefore, AFM24 may utilize the patients’ innate immunity to redirect and activate immune cells, overcoming resistance to current therapies and offering a favorable safety profile. An ongoing Phase 1/2a, first-in-human study (NCT04259450) is evaluating AFM24 in patients with locally advanced or metastatic, treatment refractory solid tumors that are known to express EGFR. The Phase 1 dose escalation study was designed to establish the maximum tolerated dose and/or the recommended Phase 2 dose (RP2D) of AFM24 and evaluated the safety, efficacy, immunogenicity, pharmacokinetic (PK) and pharmacodynamic (PD) responses. AFM24 was administered intravenously once weekly until disease progression, intolerable toxicity, patient withdrawal, or termination at the investigator’s discretion. AFM24 had a well-managed safety profile and the RP2D was established. Methods: In parallel to the continuing dose escalation phase, the Phase 2a dose expansion study was initiated, and the first patient was enrolled in January 2022. This study will assess AFM24 at the RP2D of 480 mg in patients with different EGFR-expressing tumors and will follow a Simon’s two-stage design; the trial will progress to the second stage unless the null hypothesis, that the true tumor response rate is below a specified value, is confirmed at the end of stage one. Eligible patients must have positive histological or cytological staining of EGFR in > 1% of tumor cells. The primary endpoint is to establish the overall response rate (assessed by the investigator per RECIST v1.1) in three disease-specific cohorts. These comprise patients with clear cell renal cell carcinoma (ccRCC), KRAS wild-type colorectal cancer (KRASwt CRC), and EGFR-mutant non-small cell lung cancer (EGFRmut NSCLC). Secondary endpoints include treatment-emergent adverse events, serious adverse events, PK, PD, and immunogenicity. Clinical trial information: NCT04259450.

First-in-human study of PC14586, a small molecule structural corrector of Y220C mutant p53, in patients with advanced solid tumors harboring a TP53 Y220C mutation

3003

Background: The p53 tumor suppressor protein is a transcription factor that acts to maintain genome stability in response to cellular stress. Spontaneous mutation of the TP53 gene leading to inactivation of the p53 protein is the most common mutational event across all human cancers. PC14586 is a novel, small molecule structural corrector that binds selectively to p53 Y220C mutant protein and restores the p53 wildtype conformation and transcriptional activity, resulting in potent preclinical antitumor activity. This Phase 1 multicenter dose escalation study assesses PC14586 safety, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary efficacy in patients (pts) with advanced solid tumors that harbor the TP53 Y220C mutation. Methods: Eligible adult pts with locally advanced or metastastic TP53 Y220C mutant solid tumors received increasing doses of oral PC14586 using the modified Toxicity Probability Interval design to estimate toxicity and to determine maximum tolerated dose and recommended phase 2 dose. Plasma PK was characterized using standard methods. Preliminary efficacy was assessed by RECIST v1.1. Reporting of interim results was approved by the study’s Safety Review Committee. Results: As of 08 Feb 2022, 29 pts (62% female, median age 62 years) with a variety of TP53 Y220C mutant solid tumor types (median number of prior lines of therapy 3; range 1 to 8) were treated in 7 dose cohorts of PC14586: 150 mg QD (3 pts), 300 mg QD (3 pts), 600 mg QD (4 pts), 1150 mg QD (5 pts), 2000 mg QD (7 pts), 2500 mg QD (4 pts) and 1500 mg BID (3 pts). PC14586 was generally well-tolerated; treatment-related AEs were observed in 79% of pts that were all Grade 1/2 in severity except 2 Grade 3 AEs (alanine aminotransferase increased and neutrophil count decreased). The most common AEs (≥15% of pts) were nausea (34%), vomiting (24%), fatigue (21%), and aspartate aminotransferase increased (17%). There were no dose limiting toxicities and enrollment continues. PK analysis showed dose proportional increases in Cmax and AUC. Amongst 21 efficacy evaluable pts, PRs were observed in 5 pts: 1 small cell lung and 1 breast with confirmed PR (cPR), both ongoing; 1 colorectal with unconfirmed PR (uPR), and 2 prostate with uPR and ongoing. In the 3 highest dose cohorts (total daily dose 2000 to 3000 mg), there were 3 PRs (2 uPR, 1cPR) and 7 SD out of 10 efficacy evaluable pts (all ongoing). Observations of decreasing p53 Y220C circulating tumor DNA and decreasing numbers of circulating tumor cells in pts further support on-target anti-tumor activity of PC14586. Conclusions: Enrollment to a Phase 1 study is feasible in a TP53 mutation selective population. PC14586 is safe and tolerated up to 3000 mg daily. Preliminary efficacy was achieved in heavily pretreated pts. Additional safety, PK, PD and efficacy data will be reported at the annual meeting. Clinical trial information: NCT04585750.

Effect of intratumoral INT230-6 on tumor necrosis and promotion of a systemic immune response: Results from a multicenter phase 1/2 study of solid tumors with and without pembrolizumab (PEM) [Intensity IT-01; Merck KEYNOTE-A10]

2520

Background: INT230-6 is a new product with a unique dual anti-cancer mechanism. The drug is comprised of cisplatin (CIS) and vinblastine (VIN) co-formulated with an amphiphilic molecule that enables drug dispersion throughout a tumor and passive diffusion into cancer cells following intratumoral (IT) delivery. A neoadjuvant study in breast cancer confirms that a single injection can kill 95% of an injected tumor and recruit TILs. Methods: INT230-6 treatments are Q2W for up to 5 treatments followed by maintenance dosing every 9 weeks. Dose is set by the tumor’s longest diameter or volume. One arm received INT230-6 plus PEM 200mg IV Q3W. Biopsies from injected tumor are taken pretreatment and Day 28 for immunohistochemistry (IHC) analysis. Results: Sixty-two subjects received INT230-6 alone (median age 61, with 4 prior treatments), and 21 INT230-6 + PEM (median age 70, with 3 prior treatments). To these subjects over 575 image guided INT230-6 IT injections were given (320 to visceral tumors such as lung, liver, pancreas). Doses ranged from 0.14 to 175mL (87.5 mg of CIS, 17.5 mg VIN - higher than typical IV doses). Pharmacokinetic data shows > 95% of the INT230-6 active agents remain in the tumor. The most common ( > 25%) adverse events (AEs) related to INT230-6 were localized pain (58%), nausea (40%), and fatigue (29%). The most common AEs attributed to the PEM combination were nausea (62%), localized pain (57%), vomiting (57%), decreased appetite (43%), fatigue (43%) and constipation (29%). The incidence of grade 3 AEs for the INT230-6 arm was 11% and for the PEM combination was 14%. There were no related grade 4 or 5 AEs in the INT230-6 arm; and one grade 4 neutrophil count decrease was seen on the PEM combination. There were no dose limiting adverse events. No patient discontinued therapy due to toxicities related to either drug or injection procedure. The monotherapy arm enrolled patients from 17 tumor types; while the PEM combo recruited primarily pancreatic, CRC, triple negative breast, or bile duct cancer. IHC results confirm a marked reduction in proliferating tumor cells with influx of CD4 and CD8 T-cells. Seven of the INT230-6 monotherapy patients had non injected tumor shrinkage in 9 visceral/deep lesions. Estimated median overall survival (mOS) was over 1 year for both arms. Conclusions: In this clinical trial, deep and superficial tumor injections into patients with widely metastatic disease was feasible and well tolerated. Biopsies confirm the dual anti-cancer mechanism, and study patients live longer than would be expected for these refractory populations. INT230-6’s rapid tumor killing and immune activation properties may offer an alternative to control refractory patients (even those that are chemotherapy refractory) and the product is moving into randomized controlled registration trials. Clinical trial information: NCT03058289.

AFM24 in combination with atezolizumab in patients with advanced EGFR-expressing solid tumors: Phase 1/2a study design and rationale

TPS2673

Background: Innate Cell Engagers (ICE) are bispecific molecules that bind both a tumor cell-surface antigen and to CD16A expressed on natural killer (NK) cells and macrophages, inducing antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), respectively. As epidermal growth factor receptor (EGFR) is often overexpressed in several types of solid tumors, this provides an ideal tumor-cell surface antigen which may be targeted using ICE molecules. AFM24 is a first in class, tetravalent, bispecific, novel ICE targeting EGFR. By binding to EGFR on tumor cells and CD16A on innate immune cells, AFM24 may utilize a patient’s innate immunity to induce ADCC/ADCP towards tumor cells. Anti-programmed death-ligand 1 (PD-L1) immune checkpoint inhibitors, which enhance the anti-tumor activity of a patient’s adaptive immunity, have also demonstrated efficacy as monotherapy and are playing an increasingly prominent role in treatments. The combination of AFM24 and the PD-L1 inhibitor, atezolizumab, may therefore represent a rational new treatment modality, enhancing both the innate and adaptive immune responses to target EGFR+ tumor cells. Methods: An ongoing Phase 1/2a open-label, non-randomized, multicenter, dose escalation (Phase 1) and dose expansion (Phase 2a) study was initiated in November 2021 (NCT05109442) to evaluate the safety, tolerability and efficacy of AFM24 in combination with atezolizumab. The primary aim of the Phase 1 study is to determine the maximum tolerated dose and the recommended Phase 2 dose (RP2D) of AFM24. Eligible patients must have advanced histologically confirmed EGFR+ disease and confirmed disease progression after treatment with ≥1 prior therapy. Patients undergo a safety lead-in phase with AFM24 as a single agent 7 days before receiving the combination therapy. A standard 3+3 design will be used to determine the RP2D. Escalating doses of AFM24 will be given to each cohort as weekly intravenous (IV) infusions; the starting dose and at least two planned dose escalations are based on results from the ongoing AFM24 monotherapy trial (NCT04259450). Atezolizumab will be given at a fixed dose of 840 mg as a biweekly IV infusion. Patients will receive AFM24 and atezolizumab treatment until disease progression, intolerable toxicity, patient withdrawal, or termination at the investigator’s discretion. The Phase 2a study will then establish the overall response rate (as per RECIST v1.1) and safety of combination therapy in patients with advanced/ metastatic, or treatment refractory gastric, esophagogastric, hepatocellular, hepatobiliary, pancreatic, or non-small cell lung cancer. For both phases, secondary endpoints include treatment-emergent adverse events, serious adverse events, pharmacokinetics, pharmacodynamics, and immunogenicity. Clinical trial information: NCT05109442.

A first-in-human, phase 1 study of ASTX029, a dual-mechanism inhibitor of ERK1/2, in relapsed/refractory solid tumors

9085

Background: Aberrant activation of the RAS-RAF-MEK-ERK pathway is common in human cancers. This is an open-label Phase 1 study of ASTX029, a dual-mechanism extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor, in subjects with relapsed/refractory solid tumors (NCT03520075). Methods: The primary objective is to identify a recommended Phase 2 dose. Subjects with relapsed/refractory solid tumors were eligible for Phase 1A with any molecular feature and for Phase 1B if the tumor demonstrated RAS or BRAF mutations. ASTX029 was administered orally daily on a continuous basis in 21-day cycles. Phase 1A was a modified 3+3 dose-escalation design based on dose-limiting toxicity (DLT) events. Phase 1B subjects were treated at the recommended dose for expansion (RDE) based on emerging safety, pharmacokinetic (PK), and pharmacodynamic (PD) data. Disease response was evaluated by RECIST v1.1. Results: 76 subjects were treated with at least one dose of ASTX029 in Phase 1A (n = 56) and Phase 1B (n = 20). In Phase 1A, ASTX029 was evaluated from 10 mg to 280 mg daily. Two subjects experienced grade 2 central serous retinopathy (CSR) within a few days of dosing at the 280 mg daily dose level (one event was declared a DLT). Both subjects recovered to baseline within days of dose interruption. CSR is an expected AE based on the class of drugs. At the selected RDE dose level of 200 mg daily, the mean PK exposure was 109% of target exposure (13,022 ng*hr/ml), defined as the level expected to have biological activity based on mouse models. As of the data cut-off of February 7, 2022, the most frequent grade ≥2 AEs experienced by subjects (≥5%) assessed as related to ASTX029 included ocular AEs (n = 6: all Grade 2); nausea (n = 7: all Grade 2); diarrhea (n = 6: 5 Grade 2, 1 Grade 3); fatigue (n = 4: all Grade 2); rash (n = 4, 3 Grade 2, 1 Grade 3). There were 52 serious AEs, all unrelated to ASTX029 except for one subject with Grade 3 malaise. Four subjects had a partial response, including KRAS-G12A BRAF-D549N non-small cell lung cancer (NSCLC; Phase 1A: 120 mg treated 20.0 months); KRAS-G12D pancreatic cancer (Phase 1A: 200 mg treated 2.1 months); KRAS-G13D NSCLC (Phase 1B; treated 10.6 months); KRAS-G12S NSCLC (Phase 1B; treated 10.4 months and ongoing). In all, two partial responses were observed out of 3 NSCLC subjects enrolled in Phase 1B. Phospho-ERK and phospho-RSK were evaluated for PD effect on fresh tumor biopsies obtained at baseline and cycle 2. A PD effect and decreased cell proliferation (Ki-67) were observed in 6 of 9 and 3 of 8 evaluable Phase 1B samples, respectively. The most common reason for ASTX029 discontinuation was disease progression. Conclusions: This Phase 1 study of the ERK1/2 inhibitor ASTX029 has identified a dose level of 200 mg daily continuously for investigation in the Phase 2 study. PK and PD data suggest target exposures are achieved with preliminary clinical activity, especially in KRAS-mutated NSCLC. Clinical trial information: NCT03520075.

INT230-6 monotherapy and in combination with ipilimumab (IPI) across a broad spectrum of refractory soft tissue sarcomas (STS) [Intensity IT-01; BMS#CA184-592]

11515

Background: INT230-6 is a novel intratumoral (IT) agent with a dual anti-cancer mechanism (tumor cytoreduction while stimulating antigen presentation and recruitment of T-cells). The drug is comprised of cisplatin (CIS) and vinblastine (VIN) co-formulated with an amphiphilic molecule that enables drug dispersion throughout tumors and passive diffusion into cancer cells following IT delivery. In the neoadjuvant setting, a single injection can cause necrosis in > 95% of the tumor and recruit TILs. Combining with anti-CTLA-4 improved responses in preclinical models. Methods: INT230-6 dose is set by the tumor’s longest diameter and is proportional to the injected disease volume. INT230-6 is administered IT Q2W for 5 treatment sessions followed by maintenance every 9 weeks as monotherapy or with IPI 3mg/kg IV Q3W for 4 doses. Biopsies from injected tumors are obtained pretreatment and Day 28 for immunoprofiling. Results: 22 subjects with various advanced STS histologies with a median age of 64 and a median of 3 prior systemic therapies were enrolled (11 INT230-6 alone, 11 IPI combination). There were 178 image-guided IT INT230-6 injections (107 to deep tumors) at INT230-6 doses ranging from 5 to 242 mL (121mg CIS, 24.2mg VIN, doses which vastly exceed the usual IV doses of these drugs). PK analysis showed that > 95% of drug agents remain in the tumor. The most common (> 25%) all-grade related adverse events (AEs) in evaluable monotherapy subjects (n = 10) were pain (80%), decreased appetite (40%), nausea (40%), anemia (30%), fatigue (30%) and vomiting (30%). Tolerability was similar for the combination with IPI. Most events were low grade. The incidence of grade 3 AEs for the INT230-6 arm was 30% and for the IPI combination was 10%. There were no related grade 4 or 5 AEs in either cohort. RECIST metrics may not accurately reflect clinical benefit with this treatment given large volumes of INT230-6 is repeatedly injected into a tumor and local inflammation may occur. Paired biopsies showed reduction in proliferating tumor cells and an increase in T-cell infiltrates. The disease control rate at the first imaging timepoint for evaluable INT230-6 subjects (n = 9) was 56% and for evaluable IPI combination (n = 5) was 80%. Abscopal effects were seen in 2 monotherapy subjects, though most uninjected tumors were not tracked. The estimated 1-year overall survival was 88% for the IPI combo and 60% for the monotherapy cohort. Conclusions: IT INT230-6 is well tolerated as monotherapy and combined with IPI. STS, which is typically not sensitive to immunotherapy, may be amenable to INT230-6 or IPI combo to create antigens and promote a systemic immune response. Preliminary efficacy using INT230-6 alone is encouraging and will be evaluated in a global phase 3 trial. Further evaluation is needed to determine whether the addition of IPI may improve patient outcomes. Clinical trial information: NCT03058289.

Phase I study of HFB200301, a first-in-class TNFR2 agonist monoclonal antibody in patients with solid tumors selected via Drug Intelligent Science (DIS)

TPS2670

Background: Tumor necrosis factor receptor-2 (TNFR2) is expressed on effector CD8+ T cells, CD4+ T cells, T regulatory cells, natural killer cells, and myeloid cells. Targeting TNFR2 is anticipated to yield effective anti-tumor immunity by stimulating T-cell and NK-cell activation and proliferation in the tumor microenvironment. HFB200301 is a first-in-class anti-TNFR2 agonistic monoclonal antibody that triggers both innate and adaptive immune stimulation by binding to a specific epitope on TNFR2. HFB200301 has demonstrated dose-dependent anti-tumor activity in human TNFR2 knock-in mice bearing MC38 and Hepa1-6 syngeneic tumors. Methods: HFB200301 is being evaluated in a first-in-human, open-label, multi-center, dose escalation and expansion study in adult patients with advanced solid tumors. A single-cell immune profiling platform, DIS, was deployed to identify unique tumor-infiltrating T cell signatures that could help optimize patient selection for HFB200301 treatment. It is hypothesized that the presence of an effector T cell subpopulation that express both TNFR2 and CD8A in solid tumors may represent a tumor microenvironment favorable to TNFR2 agonism. The following cancer indications have been identified based on the prevalence of a TNFR2 high/CD8 high signature: Epstein-Barr Virus positive (EBV+) gastric cancer, clear cell renal cell carcinoma (ccRCC), cutaneous melanoma, testicular germ cell tumor (TGCT), soft tissue sarcoma (STS), and PD-L1+ cancers: cervical cancer, pleural mesothelioma, lung adenocarcinoma, and head and neck squamous cell carcinoma (HNSCC). The escalation portion of the study explores increasing doses in cohorts of up to six patients, utilizing mTPI-2 design to determine recommended dose(s) for expansion (RDE(s)). Based on pharmacokinetic modeling to maximize HFB200301 activity, 60-minute intravenous infusions of HFB200301 are administered every 4 weeks. Once RDE(s) is determined, expansion into three indication-specific cohorts is planned to determine the recommended phase 2 dose (RP2D). Key eligibility criteria include histologically documented advanced or metastatic solid tumors in the above listed indications. Patient enrollment opened in February 2022 in the USA, with plans for additional clinical sites in Spain and China. The primary objective is to identify the RDE, characterize safety and tolerability of HFB200301, and determine RP2D. Secondary objectives include pharmacokinetic parameters, preliminary evidence of anti-tumor efficacy (e.g., ORR, DCR, DOR) and pharmacodynamic evaluation (e.g., T cell subsets) in the blood and in the tumor. Furthermore, a potential predictive biomarker signature derived based on the DIS single-cell immune profiling approach will be investigated retrospectively. Clinical trial information: NCT05238883.

Quality of life assessment of cabozantinib in patients with advanced hepatocellular carcinoma in the CELESTIAL trial

BACKGROUND

The CELESTIAL trial (NCT01908426) demonstrated overall survival benefit for cabozantinib versus placebo in patients with advanced hepatocellular carcinoma (aHCC) who had received prior sorafenib treatment. This analysis of CELESTIAL compared the impact of cabozantinib versus placebo on health-related quality of life (HRQoL).

MATERIALS AND METHODS

Health status was assessed using the EuroQol five-dimension five-level (EQ-5D-5L) questionnaire over the 800-day follow-up period. EQ-5D-5L health states were mapped to health utility scores using reference values for the UK population. Quality-adjusted life years (QALYs) were calculated for each treatment group as the area under the curve for the plot of health utility score over time. The between-treatment group difference in restricted mean QALYs was calculated by generalized linear models and adjusted for baseline differences. A difference of 0.08 in health utility score (or in QALY) was deemed a minimally important difference and to be clinically significant.

RESULTS

At week 5, the difference in mean health utility score between cabozantinib and placebo was -0.097 (95% confidence interval [95% CI]: -0.126, -0.067; p ≤ 0.001). Between-group differences in health utility scores diminished over time and were generally non-significant. The cabozantinib group accrued more QALYs than the placebo group over follow-up. Differences in mean QALYs (cabozantinib minus placebo) were statistically and clinically significant, ranging from +0.092 (95% CI: 0.016, 0.169) to +0.185 (95% CI: 0.126, 0.243) in favour of cabozantinib, depending on the reference value set used.

CONCLUSIONS

These HRQoL findings support a positive benefit-risk profile for cabozantinib in previously treated patients with aHCC.

Safety and efficacy of cabozantinib for patients with advanced hepatocellular carcinoma who advanced to Child–Pugh B liver function at study week 8: a retrospective analysis of the CELESTIAL randomised controlled trial

Background

Patients with hepatocellular carcinoma (HCC) and Child–Pugh B liver cirrhosis have poor prognosis and are underrepresented in clinical trials. The CELESTIAL trial, in which cabozantinib improved overall survival (OS) and progression-free survival (PFS) versus placebo in patients with HCC and Child–Pugh A liver cirrhosis at baseline, was evaluated for outcomes in patients who had Child–Pugh B cirrhosis at Week 8.

Methods

This was a retrospective analysis of adult patients with previously treated advanced HCC. Child–Pugh B status was assessed by the investigator. Patients were randomised 2:1 to cabozantinib (60 mg once daily) or placebo.

Results

Fifty-one patients receiving cabozantinib and 22 receiving placebo had Child–Pugh B cirrhosis at Week 8. Safety and tolerability of cabozantinib for the Child–Pugh B subgroup were consistent with the overall population. For cabozantinib- versus placebo-treated patients, median OS from randomisation was 8.5 versus 3.8 months (HR 0.32, 95% CI 0.18–0.58), median PFS was 3.7 versus 1.9 months (HR 0.44, 95% CI 0.25–0.76), and best response was stable disease in 57% versus 23% of patients.

Conclusions

These encouraging results with cabozantinib support the initiation of prospective studies in patients with advanced HCC and Child–Pugh B liver function.

Clinical Trial Registration: NCT01908426.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09453-z.

Single-center real-world treatment and outcomes in patients with hepatocellular carcinoma receiving immunotherapy

401

Background: Immune checkpoint inhibitor (ICI) based therapy has emerged as a therapeutic option in hepatocellular carcinoma (HCC). Approvals were based on clinical trials with strict eligibility criteria limiting generalizability to clinical practice. Further, there is no established post ICI treatment standard. Methods: Patients (pts) with advanced HCC treated with ICI as single agent (ICI-SA) or in combination (ICI-C) across lines of therapy were included in this retrospective study. Results: The cohort consisted of 118 pts: median age 63 years (24, 88); 84% male; 35% Hispanic/Latino, 26% Asian, 19% Non-Hispanic White, 5% Black and 15% unknown. Etiology of cirrhosis: 13% Hepatitis B, 45% Hepatitis C, 16 % alcohol liver disease, 10% NAFLD and 16 % mixed/other; 73% had baseline Child Pugh (CP) A, 25% had CP-B, and 2% had CP-C; ALBI Scores were ≤ -2.60 in 32%, 2.60 < and ≤-1.39 in 48%, and ≥-1.39 in 19% pts; 62% had extrahepatic disease and/or portal invasion; AFP was ≥ 400 ng/mL in 25% of pts. 81% of pts had prior local therapy. First line systemic therapies were: TKIs in 52 pts (44%), ICI-SA in 42 (36%), ICI-C in 15 (13%), clinical trial agent (CTA) in 8 (7%) and chemotherapy in 1 (1%), with a median duration (dur) of 4 months (95% CI 2.3 to 4). Ninety one (77%) and 61 pts (52%) received ≥ 2 or 3 lines of therapy, respectively. Fifty seven pts had ICI-SA and 14 ICI-C in second line or beyond. Median dur of ICI therapy was 4 months (95% CI 3-5) for all lines. Post-ICI therapies included 11% ICI, 30% CTA and 59% TKIs. TKIs included sorafenib (46%), cabozantinib (27%), lenvatinib (15%), and regorafenib (27%). For the 118 pt cohort, mOS was 14 months (95% CI 12-19). For pts treated with ICI in first line, mOS was 11 months (0, 74); post-ICI mOS was 6 months (95% CI 3-9) and mPFS was 3 months (95% CI 2-3). Thirty one pts received a TKI post ICI; mOS for this subset was 19 months (15, 22); mOS from start of TKI post ICI was 6.5 months (4, 12). On multivariable regression analysis, ALBI score was associated with OS (HR 1.63, p=0.02, CI: 1.08-2.27). Conclusions: Pts with advanced HCC and CP-A or B cirrhosis are able to receive sequential systemic therapy including ICI. Survival outcomes in this cohort are impacted by the inclusion of patients with more compromised liver function and less restrictive pt selection compared to clinical trials. Usage of TKIs post ICI is feasible with suggestion of clinical activity but this is an area in need of prospective studies.

A phase Ib study of guadecitabine and durvalumab in patients with advanced hepatocellular carcinoma, pancreatic adenocarcinoma, and biliary cancers

574

Background: Pancreatic (PC) and biliary cancers (BC) are cold tumors with limited activity of single agent immune checkpoint inhibitors. DNA methyltransferase inhibitors (DNMTi) have immunomodulatory effects manifested by upregulation of interferon pathways and expression of endogenous retroviral signatures. We performed a phase Ib study of the DNMTi guadecitabine (G) and durvalumab (D) in patients (pts) with hepatocellular carcinoma, PC and BC. We report initial results from the PC and BC cohorts. Methods: This is a phase Ib study to establish the maximum tolerated dose (MTD) of the combination (dose escalation; 3+3 design) and evaluate the objective response rate (ORR) in expansion cohorts of PC and BC. G was given at escalating doses of 30 mg/m2 and 45 mg/m2 subQ for 5 days q 28 days. D was given at 1500 mg IV on day 8 of each cycle. Expansion was started at the MTD. Eligibility criteria included ECOG 0-1, ANC ≥ 1,500, platelets > 100,000, albumin ≥ 2.5 g/dL, total bilirubin ≤ 2.5 x upper limit of normal, failure of ≥ 1 prior line of therapy for advanced disease. Prior anti PD-1/PDL-1 was not allowed. Tumor biopsies were performed during screening and on cycle 3 day 1. Results: A total of 11 pts were treated in dose escalation; 3 at dose level 1, and 8 (6 evaluable for DLT) at dose level 2. Given lack of dose-limiting toxicities, MTD was the highest planned dose of G at 45 mg/m2. 24 pts with PC and 23 pts with BC were treated in dose escalation and expansion. For the PC cohort: median age was 66 (43, 93), 29% female, 67% ECOG 1, and median number of prior therapies 2 (1,3). For the BC cohort: median age was 61 (41, 85), 52% female, 78% ECOG 1, and median number of prior therapies 1 (1,3). All grade treatment related AEs in ≥10% of pts were neutropenia (55%), leukopenia (50%), anemia (33%), fatigue (33%), thrombocytopenia (17%), nausea (15%), and anorexia (10%). Grade 3/4 AEs in ≥10% of pts were neutropenia (40%), leukopenia (35%), and anemia (13%). There was 1(5%) PR in PC cohort lasting > 24 mo and ongoing and 1(5%) in BC cohort lasting 12 mo; both were in MSS pts. SD was noted in 7/24 (29%) PC and 5/23 (22%) BC pts, 8 of which lasted ≥4 mo. Median PFS for PC and BC was 2.1 mo [1.9, 3.8] and 1.9 mo [1.4, 2] respectively. Median OS for PC and BC was 4.4 mo [3.4, NR] and 8.6 mo [6.4, NR]. Six and 12 mo OS rates are 38% [21, 66] and 27% [13, 56] for PC; 69% [52, 91] and 35% [19, 63] for BC. 4% of PC pts and 42% of BC pts received another therapy after progression. Conclusions: The combination of G and D has a manageable safety profile in pts with advanced PC and BC; grade 3/4 AEs were limited to myelosuppression. The combination had limited clinical activity based on ORR and PFS in this unselected, pretreated population; however, a subset of pts appeared to derive prolonged clinical benefit, and OS rates were comparable to standard second line chemotherapy, despite a minority of pts receiving subsequent treatment. Biomarker analyses are ongoing. Clinical trial information: NCT03257761.

Randomized phase II trial of two different nutritional approaches for patients receiving treatment for their advanced pancreatic cancer

TPS637

Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by stromal fibrosis, hypoxia, and nutritional deprivation. PDAC tumors grow aggressively, diagnosis is typically made after metastasis and the disease remains associated with poor outcomes. The triplet chemotherapy regimen of gemcitabine, nab-paclitaxel with cisplatin was associated with a median overall survival of 16.4 months in patients with metastatic pancreatic cancer in the first-line setting (Jameson et al., 2020). Nutritional, metabolic interventions offer an opportunity to fundamentally change the tumor microenvironment and improve outcomes for patients. A ketogenic diet defined as lower carbohydrate, lower protein, and higher fat can significantly reduce glucose and insulin and increase metabolically active ketone bodies and has been evaluated in patients with a variety of solid tumors (Weber et al, 2020). Recently, a ketogenic diet combined with triplet chemotherapy was shown to inhibit murine pancreatic KPC tumor growth and significantly prolong animal survival over chemotherapy alone. Tumor growth inhibition was associated with glucose depletion, altered TCA substrate usage, and NADH elevation. Methods: In this Phase II randomized clinical trial (NCT04631445), we are evaluating a medically supervised ketogenic diet (MSKD) versus a standard diet when combined with the triplet therapy in patients with treatment-naive advanced pancreatic cancer. The primary endpoint is progression free survival for triplet therapy while on MSKD or non-MSKD. Secondary endpoints include disease control rate (PR+ CR+ SD for at least 9 weeks), change in CA 19-9 (or CA125, or CEA if not expressers of CA 19-9), average insulin levels, HbA1c, body weight, a comparison of gut microbial diversity, changes in serum metabolites and quality of life via the EORTC QLQ-C30 assessment. Unlike prior ketogenic intervention studies, the MSKD is being supported by a continuous care nutrition intervention through Virta Health Corp, that offers tracking of daily ketone and glucose levels, a web-based software application, education, and communication with a remote care team to ensure sustained nutritional ketosis. A total of 40 patients with untreated metastatic PDAC are planned for enrollment, 20 randomized to each arm. The trial opened for accrual November 2020. Clinical trial information: NCT04631445.

Phase I/II study of regorafenib (rego) and pembrolizumab (pembro) in refractory microsatellite stable colorectal cancer (MSSCRC)

15

Background: Immune check point inhibitors (ICI) are ineffective in MSSCRC. Combination of ICI with targeted agents has the potential to alter the tumor microenvironment and render these tumors vulnerable to ICI. We report the results of the multicenter study of rego and pembro in a diverse patient population with advanced MSSCRC. Methods: This was an investigator-initiated study and enrolled patients (pts) who had failed/were intolerant of chemotherapy at 3 sites. A 3+3 design was used for phase I to evaluate escalating doses of rego (80,120,160, days 1-14/21) in combination with pembro (200m/q3weeks). The primary endpoint was dose limiting toxicities during the first cycle. For phase II, pts received rego at the recommended phase II dose (RP2D) with pembro. The primary endpoint was progression free survival (PFS). Secondary endpoints were overall survival (OS) and objective response rate (ORR). The study was powered to show an improvement in PFS from 1.9 months (CORRECT data) to 2.85 months. Estimated sample size for phase II was 63 pts. Results: Study started in 7/2019 and accrual completed in 7/2021. Of 73 pts, 10 enrolled in phase I and 63 in phase II. RP2D of rego was 80 mg, days 1-14/21, and 70 pts treated at that dose. As of Sep 14, 11 pts remain on treatment. At baseline, median age was 54 years (23-81), 51% female, 53% white, 19% Asian, 12% black, and 11% Hispanic, median prior lines of therapy 2 (1-5), primary tumor location rectosigmoid/rectal 13%, KRAS mutated 68%, BRAF mutated 5%. Liver metastases was present in 78% of the pts. There was no grade 4 toxicity. The most common grade 3 toxicities were rash (20%), followed by hand-foot syndrome and HTN (7%). Dose modification was required in 14%. The most common reason for discontinuation was disease progression (85%), followed by withdrawal of consent (12%). With a median follow up of 5.3 (range:0.6-24.4) months, median PFS was 2.0 (1.8 -3.5) months, and median OS was 10.9 (5.3-NR) months. In 16 pts (23%), with non-liver metastatic disease PFS was 4.3 (1.9-8.4) months. No objective response was observed. Stable disease was observed in 49% of pts, median duration of stable disease was 2 (0.2-18.8) months. Conclusions: This is the largest trial of combination of ICI + rego in MSSCRC reported to date. The trial didn’t meet its primary endpoint, though the median OS is provocative. Analysis of biomarkers for identification of pts with longer duration of benefit is ongoing. Clinical trial information: NCT03657641.

Molecular profile of hepatocellular carcinoma (HCC) in older versus younger adults: Does age matter?

477

Background: HCC is increasingly prevalent in older adults with rising incidence and an aging population worldwide. Retrospective studies show older patients with HCC may have an increased survival compared to younger patients. However, data is lacking regarding the genomic and biologic differences, that if identified, would potentially change how we treat this disease in younger vs. older patients. Hence, there is a need to better characterize the molecular landscape of the disease in an age-specific manner. We analyzed the association of age with genomic alterations and therapeutic response to sorafenib in a cohort of advanced HCC that had undergone comprehensive molecular profiling. Methods: 487 HCC samples (excluding variants) were analyzed using Next Generation Sequencing (592 gene panel, NextSeq), Whole Exome and Whole Transcriptome Sequencing (NovaSeq), and IHC at Caris Life Sciences (Phoenix, AZ). PD-L1 positivity was determined by IHC (SP-142 clone, cutoff ≥1, 1%). Tumor mutational burden (TMB) was a measure of total somatic mutations per Mb. Immune cell populations were determined by Microenvironment Cell Population (MCP) counter analysis of RNA expression data. Overall survival (OS) calculated from tissue collection to last contact and time on treatment (TOT) with sorafenib were extracted from insurance claims and calculated using Kaplan-Meier curves. Statistical analysis was done using Chi-square, Fisher Exact and Wilcoxon rank sum tests, with p values adjusted for multiple comparisons and q<0.05. Results: Differences in the molecular landscape of HCC stratified by patient age were assayed using a ternary classification based on 1 standard deviation from the mean age (mean age=65; <53: A1 (n=51), 53-77: A2 (n=361), >77: A3 (n=75)). With age, mutational frequencies in CTNNB1 (A1=13.04%, A2=33.43%, A3=38.24%) and TERT (A1=25%, A2=68.84%, A3=76.92%) increased, while ATM (A1=6.52%, A2=0.93%, A3=1.49%) decreased (p<0.05, q>0.05). There were fold increases in median TMB (A2/A1=1.33, A3/A1=1.33, p<0.01), LAG3 (A2/A1=1.75, A3/A1=1.93 p<0.01), CTLA4 (A2/A1=2.05, A3/A1=2.15, p<0.05) expression; median cell fractions of CD8+ T cells (A2/A1=1.37, A3/A1=1.50, p<0.05) & B cells (A3/A1=3.01 p<0.05) increased while cancer associated fibroblasts (A1/A2=0.62, A1/A3=0.69, p<0.01) decreased with age. PD-L1 was not statistically significant. While there was no change in OS, reduced TOT with sorafenib was observed in patients aged>65 (p=0.013). Conclusions: Increased alterations in oncogenic drivers and estimates of CD8+ T cells and B cells were observed in the elderly population with HCC. The enhanced presence of co-inhibitory molecules suggests potential immune evasion. While we observed reduced TOT with sorafenib, additional studies are needed to elucidate the impact of molecular alterations on outcomes with sorafenib and newer therapies (i.e. immunotherapy) in older adults.

LEAP-012 trial in progress: Transarterial chemoembolization (TACE) with or without lenvatinib plus pembrolizumab for intermediate-stage hepatocellular carcinoma (HCC)

TPS494

Background: Limited treatment options are available for patients with intermediate HCC. Lenvatinib, a potent multikinase inhibitor, and pembrolizumab, a PD-1 inhibitor, are approved first- and second-line therapies for advanced HCC, respectively. The LEAP-012 study (NCT04246177) is investigating lenvatinib plus pembrolizumab in combination with TACE versus placebo plus TACE in patients with intermediate-stage HCC. Methods: LEAP-012 is a randomized, double-blind, phase 3 study. Adults with confirmed HCC localized to the liver without portal vein thrombosis and not amenable to curative treatment, ≥1 measurable lesion per RECIST v1.1, Eastern Cooperative Oncology Group performance status of 0 or 1, and no previous systemic treatment for HCC are eligible. Patients will be randomly assigned to receive lenvatinib 8 mg (body weight < 60 kg) or 12 mg (body weight ≥60 kg) orally once daily plus pembrolizumab 400 mg intravenously (IV) every 6 weeks (Q6W) plus TACE or placebo orally once daily plus placebo IV Q6W plus TACE. Response will be assessed by imaging every 9 weeks; safety will be assessed throughout the study and up to 90 days after the end of treatment. Dual primary end points are overall survival and progression-free survival (PFS) per RECIST v1.1 by blinded independent central review (BICR). Secondary end points are PFS, objective response rate (ORR), disease control rate (DCR), duration of response (DOR), and time to progression (TTP) per modified RECIST by BICR; ORR, DCR, DOR, and TTP per RECIST v1.1 by BICR; and safety. Exploratory end points are PFS, ORR, DCR, DOR, TTP, and time from randomization to second/subsequent disease progression after initiation of new anticancer therapy or death from any cause, whichever occurs first, per RECIST v1.1 by investigator review, identification of molecular biomarkers, and health-related quality of life. Recruitment began in April 2020, and the planned sample size is 950 patients. The results of the LEAP-012 study will show the clinical benefit of adding lenvatinib plus pembrolizumab to the current standard of care TACE for patients with intermediate-stage HCC not amenable to curative treatment. Clinical trial information: NCT04246177.

A Phase I, Open-Label, Dose-Escalation Study of the OX40 Agonist Ivuxolimab in Patients with Locally Advanced or Metastatic Cancers

PURPOSE

Stimulation of effector T cells is an appealing immunotherapeutic approach in oncology. OX40 (CD134) is a costimulatory receptor expressed on activated CD4⁺ and CD8⁺ T cells. Induction of OX40 following antigen recognition results in enhanced T-cell activation, proliferation, and survival, and OX40 targeting shows therapeutic efficacy in preclinical studies. We report the monotherapy dose-escalation portion of a multicenter, phase I trial (NCT02315066) of ivuxolimab (PF-04518600), a fully human immunoglobulin G2 agonistic monoclonal antibody specific for human OX40.

PATIENTS AND METHODS

Adult patients (N = 52) with selected locally advanced or metastatic cancers received ivuxolimab 0.01 to 10 mg/kg. Primary endpoints were safety and tolerability. Secondary/exploratory endpoints included preliminary assessment of antitumor activity and biomarker analyses.

RESULTS

The most common all-causality adverse events were fatigue (46.2%), nausea (28.8%), and decreased appetite (25.0%). Of 31 treatment-related adverse events, 30 (96.8%) were grade ≤2. No dose-limiting toxicities occurred. Ivuxolimab exposure increased in a dose-proportionate manner from 0.3 to 10 mg/kg. Full peripheral blood target engagement occurred at ≥0.3 mg/kg. Three (5.8%) patients achieved a partial response, and disease control was achieved in 56% of patients. Increased CD4⁺ central memory T-cell proliferation and activation, and clonal expansion of CD4⁺ and CD8⁺ T cells in peripheral blood were observed at 0.1 to 3.0 mg/kg. Increased immune cell infiltrate and OX40 expression were evident in on-treatment tumor biopsies.

CONCLUSIONS

Ivuxolimab was generally well tolerated with on-target immune activation at clinically relevant doses, showed preliminary antitumor activity, and may serve as a partner for combination studies.

Outcomes Based on Plasma Biomarkers for the Phase 3 CELESTIAL Trial of Cabozantinib versus Placebo in Advanced Hepatocellular Carcinoma

INTRODUCTION

Cabozantinib, an inhibitor of MET, AXL, and VEGF receptors, significantly improved overall survival (OS) and progression-free survival (PFS) versus placebo in patients with previously treated advanced hepatocellular carcinoma (HCC). In this exploratory analysis, outcomes were evaluated according to plasma biomarker levels.

METHODS

Baseline plasma levels were evaluated for MET, AXL, VEGFR2, HGF, GAS6, VEGF-A, PlGF, IL-8, EPO, ANG2, IGF-1, VEGF-C, and c-KIT for 674/707 randomized patients; and Week 4 levels were evaluated for MET, AXL, VEGFR2, HGF, GAS6, VEGF-A, PlGF, IL-8, and EPO for 614 patients. OS and PFS were analyzed by baseline levels as dichotomized or continuous variables and by on-treatment changes at Week 4 as continuous variables; biomarkers were considered potentially prognostic if p < 0.05 and predictive if p < 0.05 for the interaction between treatment and the biomarker. Multivariable analyses adjusting for clinical covariates were also performed.

RESULTS

In the placebo group, high levels of MET, HGF, GAS6, IL-8, and ANG2 and low levels of IGF-1 were associated with shorter OS in univariate and multivariable analyses; these associations were also observed for MET, IL-8, and ANG2 in the cabozantinib group. Hazard ratios for OS and PFS favored cabozantinib over the placebo at low and high baseline levels for all biomarkers. No baseline biomarkers were predictive of a treatment benefit. Cabozantinib promoted pharmacodynamic changes in several biomarkers, including increases in VEGF-A, PlGF, AXL, and GAS6 levels and decreases in VEGFR2 and HGF levels; these changes were not associated with OS or PFS.

CONCLUSION

Cabozantinib improved OS and PFS versus placebo at high and low baseline concentrations for all biomarkers analyzed. Low baseline levels of MET, HGF, GAS6, IL-8, and ANG2 and high levels of IGF-1 were identified as potential favorable prognostic biomarkers for survival in previously treated advanced HCC. Although cabozantinib promoted pharmacodynamic changes in several biomarkers, these changes were not associated with survival.

Final Overall Survival Efficacy Results of Ivosidenib for Patients With Advanced Cholangiocarcinoma With IDH1 Mutation: The Phase 3 Randomized Clinical ClarIDHy Trial

Question

Does ivosidenib treatment improve overall survival outcomes vs placebo among patients with chemotherapy-refractory cholangiocarcinoma with IDH1 mutation?

Findings

In this phase 3 randomized clinical trial including 187 previously treated patients with advanced cholangiocarcinoma with IDH1 mutation, ivosidenib treatment resulted in numerically improved overall survival benefits vs placebo, despite a high rate of crossover. Ivosidenib preserved certain quality of life subscales and was well tolerated.

Meaning

The combined efficacy data and tolerable safety profile, as well as corroborating quality of life data, support the clinical benefit of ivosidenib relative to placebo in cholangiocarcinoma with IDH1 mutation, which has an unmet need for new treatments.

Importance

Isocitrate dehydrogenase 1 (IDH1) variations occur in up to approximately 20% of patients with intrahepatic cholangiocarcinoma. In the ClarIDHy trial, progression-free survival as determined by central review was significantly improved with ivosidenib vs placebo.

Objective

To report the final overall survival (OS) results from the ClarIDHy trial, which aimed to demonstrate the efficacy of ivosidenib (AG-120)—a first-in-class, oral, small-molecule inhibitor of mutant IDH1—vs placebo for patients with unresectable or metastatic cholangiocarcinoma with IDH1 mutation.

Design, Setting, and Participants

This multicenter, randomized, double-blind, placebo-controlled, clinical phase 3 trial was conducted from February 20, 2017, to May 31, 2020, at 49 hospitals across 6 countries among patients aged 18 years or older with cholangiocarcinoma with IDH1 mutation whose disease progressed with prior therapy.

Interventions

Patients were randomized 2:1 to receive ivosidenib, 500 mg, once daily or matched placebo. Crossover from placebo to ivosidenib was permitted if patients had disease progression as determined by radiographic findings.

Main Outcomes and Measures

The primary end point was progression-free survival as determined by blinded independent radiology center (reported previously). Overall survival was a key secondary end point. The primary analysis of OS followed the intent-to-treat principle. Other secondary end points included objective response rate, safety and tolerability, and quality of life.

Results

Overall, 187 patients (median age, 62 years [range, 33-83 years]) were randomly assigned to receive ivosidenib (n = 126; 82 women [65%]; median age, 61 years [range, 33-80 years]) or placebo (n = 61; 37 women [61%]; median age, 63 years [range, 40-83 years]); 43 patients crossed over from placebo to ivosidenib. The primary end point of progression-free survival was reported elsewhere. Median OS was 10.3 months (95% CI, 7.8-12.4 months) with ivosidenib vs 7.5 months (95% CI, 4.8-11.1 months) with placebo (hazard ratio, 0.79 [95% CI, 0.56-1.12]; 1-sided P = .09). When adjusted for crossover, median OS with placebo was 5.1 months (95% CI, 3.8-7.6 months; hazard ratio, 0.49 [95% CI, 0.34-0.70]; 1-sided P < .001). The most common grade 3 or higher treatment-emergent adverse event (≥5%) reported in both groups was ascites (11 patients [9%] receiving ivosidenib and 4 patients [7%] receiving placebo). Serious treatment-emergent adverse events considered ivosidenib related were reported in 3 patients (2%). There were no treatment-related deaths. Patients receiving ivosidenib reported no apparent decline in quality of life compared with placebo.

Conclusions and Relevance

This randomized clinical trial found that ivosidenib was well tolerated and resulted in a favorable OS benefit vs placebo, despite a high rate of crossover. These data, coupled with supportive quality of life data and a tolerable safety profile, demonstrate the clinical benefit of ivosidenib for patients with advanced cholangiocarcinoma with IDH1 mutation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02989857

Efficacy and safety of cabozantinib for patients with advanced hepatocellular carcinoma based on albumin-bilirubin grade

Background

Albumin-bilirubin (ALBI) grade is an objective measure of liver function for patients with hepatocellular carcinoma (HCC). The tyrosine kinase inhibitor cabozantinib is approved for patients with advanced HCC who have received prior sorafenib based on the phase 3 CELESTIAL trial (NCT01908426). Cabozantinib improved overall survival (OS) and progression-free survival (PFS) versus placebo in patients with previously treated HCC.

Methods

Patients were randomised 2:1 to receive cabozantinib 60 mg or placebo orally every day. Clinical outcomes in patients with ALBI grade 1 or 2 at baseline were evaluated in CELESTIAL. ALBI scores were retrospectively calculated based on baseline serum albumin and total bilirubin, with an ALBI grade of 1 defined as  ≤ −2.60 score and a grade of 2 as a score of > −2.60 to  ≤ −1.39.

Results

Cabozantinib improved OS and PFS versus placebo in both ALBI grade 1 (hazard ratio [HR] [95% CI]: 0.63 [0.46–0.86] and 0.42 [0.32–0.56]) and ALBI grade 2 (HR [95% CI]: 0.84 [0.66–1.06] and 0.46 [0.37–0.58]) subgroups. Adverse events were consistent with those in the overall population. Rates of grade 3/4 adverse events associated with hepatic decompensation were generally low and were more common among patients in the ALBI grade 2 subgroup.

Discussion

These results provide initial support of cabozantinib in patients with advanced HCC irrespective of ALBI grade 1 or 2.

Trial registration number

ClinicalTrials.gov number, NCT01908426.

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of hepatocellular carcinoma

Patients with advanced hepatocellular carcinoma (HCC) have historically had few options and faced extremely poor prognoses if their disease progressed after standard-of-care tyrosine kinase inhibitors (TKIs). Recently, the standard of care for HCC has been transformed as a combination of the immune checkpoint inhibitor (ICI) atezolizumab plus the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab was shown to offer improved overall survival in the first-line setting. Immunotherapy has demonstrated safety and efficacy in later lines of therapy as well, and ongoing trials are investigating novel combinations of ICIs and TKIs, in addition to interventions earlier in the course of disease or in combination with liver-directed therapies. Because HCC usually develops against a background of cirrhosis, immunotherapy for liver tumors is complex and oncologists need to account for both immunological and hepatological considerations when developing a treatment plan for their patients. To provide guidance to the oncology community on important concerns for the immunotherapeutic care of HCC, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline (CPG). The expert panel drew on the published literature as well as their clinical experience to develop recommendations for healthcare professionals on these important aspects of immunotherapeutic treatment for HCC, including diagnosis and staging, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence- and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with HCC.

CheckMate 040 cohort 5: A phase I/II study of nivolumab in patients with advanced hepatocellular carcinoma and Child-Pugh B cirrhosis

BACKGROUND & AIMS

Patients with advanced hepatocellular carcinoma (aHCC) and Child-Pugh B liver function are often excluded from clinical trials. In previous studies, overall survival for these patients treated with sorafenib was ∼3-5 months; thus, new treatments are needed. Nivolumab, alone or in combination with ipilimumab, is conditionally approved in the United States to treat patients with aHCC who previously received sorafenib. We describe nivolumab monotherapy outcomes in patients with Child-Pugh B status.

METHODS

This phase I/II, open-label, non-comparative, multicentre trial (27 centres) included patients with Child-Pugh B (B7-B8) aHCC. Patients received intravenous nivolumab 240 mg every 2 weeks until unacceptable toxicity or disease progression. Primary endpoints were objective response rate (ORR) by investigator assessment (using Response Evaluation Criteria in Solid Tumors v1.1) and duration of response. Safety was assessed using National Cancer Institute Common Terminology Criteria for Adverse Events v4.0.

RESULTS

Twenty-five sorafenib-naive and 24 sorafenib-treated patients began treatment between November 2016 and October 2017 (median follow-up, 16.3 months). Investigator-assessed ORR was 12% (95% CI 5-25%) with 6 patients responding; disease control rate was 55% (95% CI 40-69%). Median time to response was 2.7 months (interquartile range, 1.4-4.2), and median duration of response was 9.9 months (95% CI 9.7-9.9). Treatment-related adverse events (TRAEs) were reported in 25 patients (51%) and led to discontinuation in 2 patients (4%). The most frequent grade 3/4 TRAEs were hypertransaminasemia (n = 2), amylase increase (n = 2), and aspartate aminotransferase increase (n = 2). The safety of nivolumab was comparable to that in patients with Child-Pugh A aHCC.

CONCLUSIONS

Nivolumab showed clinical activity and favourable safety with manageable toxicities, suggesting it could be suitable for patients with Child-Pugh B aHCC.

LAY SUMMARY

In patients with advanced hepatocellular carcinoma, almost all systemic therapies require very good liver function, i.e. Child-Pugh A status. The evidence from this study suggests that nivolumab shows clinical activity and an acceptable safety profile in patients with hepatocellular carcinoma with Child-Pugh B status who have mild to moderate impairment of liver function or liver decompensation that might rule out other therapies. Further studies are warranted to assess the safety and efficacy of nivolumab in this patient population.

CLINICAL TRIAL NUMBER

NCT01658878.

IMbrave 151: a randomized phase II trial of atezolizumab combined with bevacizumab and chemotherapy in patients with advanced biliary tract cancer

Background:

Biliary tract cancers (BTCs) are heterogenous, highly aggressive tumors that harbor a dismal prognosis for which more effective treatments are needed. The role of cancer immunotherapy in BTC remains to be characterized. The tumor microenvironment (TME) of BTC is highly immunosuppressed and combination treatments are needed to promote effective anticancer immunity. Vascular endothelial growth factor (VEGF) drives immunosuppression in the TME by disrupting antigen presentation, limiting T-cell infiltration, or potentiating immune-suppressive cells. Many VEGF-regulated mechanisms are thought to be relevant to repressed antitumor immunity in BTC, making dual targeting of VEGF and programmed cell death protein 1 (PD-1)/PD-L1 pathways a rational approach. Gemcitabine and Cisplatin (Gem/Cis) can also modulate anticancer immunity through overlapping and complementary mechanisms to those regulated by VEGF. Anti-PD-L1/VEGF inhibition, coupled with chemotherapy, may potentiate antitumor immunity leading to enhanced clinical benefit.

Methods:

IMbrave 151 is a randomized, double-blind, placebo-controlled, multicenter, international phase II study to evaluate atezolizumab (a PD-L1 inhibitor) in combination with chemotherapy (gemcitabine and cisplatin) and bevacizumab (an anti-VEGF monoclonal antibody) as a first-line treatment for advanced BTC. Approximately 150 patients with previously untreated, advanced BTC will be randomized to either Arm A (atezolizumab + bevacizumab + Gem/Cis) or Arm B (atezolizumab + placebo + Gem/Cis). Randomization is stratified by the presence of metastatic disease, primary tumor location, and geographic region. The primary efficacy endpoint is investigator-assessed progression-free survival (PFS) per RECIST 1.1. Secondary endpoints include objective response rate (ORR), duration of response (DoR), disease control rate (DCR), overall survival (OS), and safety and patient reported outcomes (PROs). Tissue, blood, and stool samples will be collected at baseline and on-treatment in order to perform correlative biomarker analyses.

Discussion:

IMbrave 151 represents the first randomized study to evaluate combined PD-L1/VEGF blockade on a chemotherapy backbone in BTC.

Trial registration:

NCT identifier: NCT04677504; EUDRACT number: 2020-003759-14

Second-line cabozantinib after sorafenib treatment for advanced hepatocellular carcinoma: a subgroup analysis of the phase 3 CELESTIAL trial

Objective

In the phase 3 CELESTIAL trial, cabozantinib improved overall survival (OS) and progression-free survival (PFS) compared with placebo in patients with previously treated advanced hepatocellular carcinoma (HCC). This subgroup analysis evaluated cabozantinib in patients who had received sorafenib as the only prior systemic therapy.

Methods

CELESTIAL randomised (2:1) patients with advanced HCC and Child–Pugh class A liver function to treatment with cabozantinib (60 mg daily) or placebo. Eligibility required prior treatment with sorafenib, and patients could have received ≤2 prior systemic regimens. The primary endpoint was OS. Outcomes in patients who had received sorafenib as the only prior therapy were analysed by duration of prior sorafenib (<3 months, 3 to <6 months and ≥6 months).

Results

Of patients who had received only prior sorafenib, 331 were randomised to cabozantinib and 164 to placebo; 136 patients had received sorafenib for <3 months, 141 for 3 to <6 months and 217 for ≥6 months. Cabozantinib improved OS relative to placebo in the overall second-line population who had received only prior sorafenib (median 11.3 vs 7.2 months; HR=0.70, 95% CI 0.55 to 0.88). This improvement was maintained in analyses by prior sorafenib duration with longer duration generally corresponding to longer median OS—median OS 8.9 vs 6.9 months (HR=0.72, 95% CI 0.47 to 1.10) for prior sorafenib <3 months, 11.5 vs 6.5 months (HR=0.65, 95% CI 0.43 to 1.00) for 3 to <6 months and 12.3 vs 9.2 months (HR=0.82, 95% CI 0.58 to 1.16) for ≥6 months. Cabozantinib also improved PFS in all duration subgroups. Safety data were consistent with the overall study population.

Conclusion

Cabozantinib improved efficacy outcomes versus placebo in the second-line population who had received only prior sorafenib irrespective of duration of prior sorafenib treatment, further supporting the utility of cabozantinib in the evolving treatment landscape of HCC.

Clinical trial number

NCT01908426.

First-in-human study of highly selective FGFR2 inhibitor, RLY-4008, in patients with intrahepatic cholangiocarcinoma and other advanced solid tumors

TPS4165

Background: Oncogenic activation of FGFR2 via genomic rearrangement, gene amplification, or point mutation in advanced solid tumors provides the opportunity for rapid clinical development of highly selective FGFR2 inhibitors using a precision oncology approach to deliver clinical benefit to genomically-defined patient (pt) populations. Unfortunately, this opportunity remains largely unrealized as current, non-selective small molecule inhibitors (pan-FGFRi) suffer from off-isoform toxicity (FGFR1-hyperphosphatemia; FGFR4-diarrhea) and on-target acquired resistance leading to only modest efficacy primarily limited to FGFR2-fusion+ intrahepatic cholangiocarcinoma (ICC). RLY-4008 is a novel, oral FGFR2 inhibitor designed to overcome the limitations of pan-FGFRi by potently and selectively targeting primary oncogenic FGFR2 alterations and acquired resistance mutations. We initiated a first-in-human (FIH) precision oncology study of RLY-4008 in advanced solid tumor pts with FGFR2 alterations with primary objectives to define the maximum tolerated dose/recommended phase 2 dose (MTD/RP2D) and adverse event (AE) profile of RLY-4008 and key secondary objectives to assess FGFR2 genotype in blood and tumor tissue, pharmacokinetics (PK), and anti-tumor activity. Methods: This is a global, multi-center, FIH dose escalation/expansion study of RLY-4008 (NCT04526106) in adult pts who have unresectable or metastatic solid tumors with FGFR2 alteration per local assessment, ECOG performance status 0-2, measurable or evaluable disease per RECIST 1.1, and who are refractory, intolerant, or declined standard therapy including pan-FGFRi. FGFR2 alteration will be confirmed retrospectively by central laboratory assessment. For the dose escalation (Ñ50), RLY-4008 is administered QD/BID on a continuous schedule with 4-week cycles according to a Bayesian Optimal Interval design that allows accelerated dose titration, additional accrual to dose levels declared tolerable, and exploration of alternative schedules if warranted. The MTD is determined via logistic regression of the dose limiting toxicity rate across all dose levels and an RP2D less than the MTD may be considered based on observed AEs, PK, and anti-tumor activity. Following dose escalation, the dose expansion (Ñ75) will treat pts with RLY-4008 at the MTD/RP2D and includes 5 groups with any prior therapy (except group 2): 1. FGFR2 fusion+ ICC pts; 2. FGFR2 fusion+ ICC pts with no prior FGFRi; 3. FGFR2 fusion+ pts with other solid tumors; 4. FGFR2-mutation+ solid tumor pts and 5. FGFR2-amplified solid tumor pts. The primary endpoints are MTD/RP2D and AE profile; key secondary endpoints are FGFR2 genotype in blood and tumor tissue, PK parameters; overall response rate, and duration of response per RECIST 1.1. US enrollment began SEP2020 and Europe/Asia start-up is underway. Clinical trial information: NCT04526106.

Phase II trial of soluble EphB4-albumin in combination with PD-1 antibody (pembrolizumab) in relapsed/refractory head neck squamous cell carcinoma

6016

Background: EphB4 receptor tyrosine kinase and its ligand EphrinB2 are highly induced in head neck squamous cell carcinoma (HN SCC) tumor cells and vessels, particularly in HPV negative tumors. Each are predictors for poor survival with worse prognosis when both are induced. EphB4 provides tumor cell survival and EphrinB2 inhibits immune cell invasion. Soluble EphB4-Alb blocks bidirectional signaling, enhances immune cell recruitment alone and when combined with PD-1 antibody. Methods: A phase II trial of sEphB4-Alb combined with pembrolizumab accrued HN SCC patients after failure of one or more prior regimens. IHC positivity for p16 was used as a surrogate for HPV infection. Treatment regimen was sEphB4-Alb 10 mg/kg weekly IV infusion with pembrolizumab 200 mg IV infusion every three weeks. Study endpoints were toxicity, overall response rates (ORR) and overall survival (OS). Response to therapy was based on RECIST 1.1 criteria. Patient tumor samples were collected at baseline with a 2nd biopsy at week 8 on therapy, for tissue analysis of PD-L1, EphrinB2 and other biomarkers. Results: Twenty-four patients were accrued to the phase II trial combination of sEphB4-Alb and pembrolizumab. Age, sex, prior treatment, HPV status, and response data are summarized in the table below. The most common toxicity was hypertension with 8 patients experiencing grade 3 HTN. No grade 4 or above toxicities were observed. Among HPV negative cases, partial and complete responses were observed in 6 of 14 patients (43%) with complete response (CR) observed in 3 of 6 responders. Additionally, rapid response was observed in 3 of 14 HPV negative patients. Response was associated with increase in immune markers on 2nd biopsy. Median overall and progression-free survival in all patients was 12.6 months and 8.6 months, respectively. Conclusions: 1. sEphB4-Alb was well tolerated in combination with PD-1 antibody. 2. sEphB4-Alb was associated with increased immune response to tumor, when combined with PD-1 antibody. 3. sEphB4-Alb appears to have substantial activity (including complete remission) when combined with PD-1 antibody in relapsed/refractory HPV negative HN SCC. Clinical trial information: NCT03049618. [Table: see text]

Does adjuvant chemoradiation benefit patients with lymph node-positive biliary tract cancer? A secondary analysis of SWOG S0809

4104

Background: Biliary tract cancers are rare tumors with a median overall survival (OS) of 16 months for node-positive (N+) and 37 months for node-negative (N0) disease despite resection. Lymph node status is a known strong prognostic factor for local recurrence with an average estimated 2-year disease-free survival (DFS): 65.5% for N0 and 29.7% for N+ tumors. The Phase II Intergroup Trial S0809 showed that adjuvant capecitabine and gemcitabine followed by radiotherapy and concurrent capecitabine improved OS in patients with extrahepatic cholangiocarcinoma (EHCC) and gallbladder cancer (GBC) compared to historical controls. We hypothesized that nodal status is a prognostic factor for local recurrence in this patient population who received adjuvant therapy. Methods: This analysis included patients with stage pT2-4, N+ or positive margin EHCC or GBC. Treatment included four cycles of gemcitabine (1,000 mg/m2 intravenously on days 1 and 8) and capecitabine (1,500 mg/m2 per day on days 1 to 14) every 21 days followed by concurrent capecitabine (1,330 mg/m2 per day) and radiotherapy (45 Gy to regional lymphatics; 52.5 to 59.4 Gy to tumor bed). S0809 patients who did not receive radiotherapy were excluded from analysis. Correlations between nodal status, resection margin, and other clinicopathological factors, patterns of recurrence and survival were analyzed, and Cox regression models were used to estimate the prognostic significance of nodal status. A Z-test was used to compare DFS rates between these patients and historical data. Results: A total of 69 patients [EHCC n = 46 (66%); GBCA n = 23 (33%)] were evaluated with a median age of 61.7 (26.1-80.6). The majority of N0 patients were female (17/24, 70.8%), whereas most N+ patients were male (25/45, 55.6%; p < 0.04). Distribution of R0 (66.7%) and R1 (33.3%) resections was similar in the N0 and N+ groups. Thirty-four patients with EHCC had N+ disease (73.9%) compared with 11 patients with GBCA (47.8%, p = 0.03). Nodal status did not significantly impact OS (HR = 2.03, 95% CI 0.92-4.49, p = 0.08) or DFS (HR = 1.75, 95% CI 0.85-3.59, p = 0.13). Two-year OS was 70.6% for N0 and 60.9% for N+ disease (p = 0.11). Nodal status was not significantly associated with 2-year DFS: 62.5% for N0 and 49.8% for N+ (p = 0.20). N+ vs N0 tumors showed higher rates of distant failure (51.1% vs 25.0%, p < 0.04), but similar local recurrence (17.8% vs 12.5%, p = 0.88). The observed 2-year DFS in patients with N+ tumors was significantly longer compared to the historical rate of 29.7% (p = 0.004). Conclusions: This combination adjuvant treatment regimen following curative resection for EHCC and GBCA provides favorable outcomes regardless of nodal status. These data suggest that adjuvant chemoradiation may positively impact local control in N+ patients. These findings need to be validated in future clinical trials. Clinical trial information: NCT00789958.

A phase 1 trial of FID-007, a novel nanoparticle paclitaxel formulation, in patients with solid tumors

3021

Background: FID-007 (FID) consists of paclitaxel encapsulated in a polyethyloxazoline (PEOX) polymer excipient designed to enhance PK, biodistribution, and tolerability. In addition to allowing the drug to remain in solution until it can enter a cancer cell, the PEOX nanoparticle preferentially delivers paclitaxel to the tumor through the leaky hyperpermeable vasculature. In xenograft studies, FID reduced or limited tumor growth in multiple tumor types including lung, gastric, breast, pancreatic, and ovarian cancer. FID was more effective at lower or comparable taxane doses with fewer side effects. We present the first-in-human trial of FID. Methods: The study is evaluating the safety, PK, and efficacy of FID in pts with advanced solid tumors. The primary objective is to determine the MTD and RP2D. Pts received FID in doses between 15mg/m2 and 125mg/m2 using a standard 3+3 dose escalation design. FID was given IV on Days 1, 8, and 15 of a 28-day cycle. Eligibility included ECOG 0-2, adequate organ function, and no more than 3 prior lines of cytotoxic therapy for advanced disease. Results: Twenty-five pts were treated across 6 dose levels. Median age was 62 (44-76). ECOG PS was 2 in 1 pt and 1 in 64%. Median number of cycles was 2 (1-16). There were 2 DLTs of grade 3 rash at 100 mg/m2. Given the transient nature of the rash and response to topical therapy, DLT definition was modified to exclude grade 3 rash that lasts ≤ 7 days and additional patients were treated at 100 mg/m2 which was deemed tolerable. There was 1 DLT of grade 3 neutropenia at 125 mg/m2. All grade treatment related adverse events (TRAEs) in ≥ 25% of pts were rash (64%), alopecia (52%), pruritus (44%), anemia (44%) leukopenia, fatigue (40% each), dysgeusia, anorexia, nausea (32% each), and neutropenia (28%). Grade 3/4 TRAEs occurring in > 1 pt were anemia (20%), neutropenia, leukopenia, and maculopapular rash (16%). There were no treatment discontinuations due to toxicity. Twenty-two pts were evaluable for response by RECIST 1.1 with a PR rate of 14% (PR in pancreatic, biliary tract and NSCLC) and disease control rate of 59%. PK is linear and dose proportional. There is no paclitaxel accumulation after weekly dosing, and the t1/2 is between 18-26 hours. Conclusions: FID has a manageable safety profile with MTD not reached. Accrual is continuing at 125 mg/m2. PK is linear, dose proportional and comparable to that of nab-paclitaxel. There is preliminary evidence of anti-tumor activity in heavily pre-treated pts across different tumor types. Enrollment in dose escalation continues. Combination studies with immunotherapeutic agents are planned. Clinical trial information: NCT03537690.

A phase 1/2 study of intratumoral INT230-6 alone (IT-01) or in combination with pembrolizumab [KEYNOTE-A10] in adult subjects with locally advanced, unresectable and metastatic solid tumors refractory to therapy

2592

Background: Study IT-01 (KEYNOTE-A10) evaluates INT230-6, a novel formulation of cisplatin (CIS) and vinblastine (VIN) with an amphiphilic cell penetration enhancer designed for intratumoral (IT) administration, alone or in combination with pembrolizumab (PEM), an antibody to PD-1. INT230-6 dosing is set by a tumor’s volume. In preclinical studies, INT230-6 increases drug dispersion throughout the tumor, allows drug diffusion into cancer cells and recruits dendritic, CD4 and CD8 T cells. The addition of PEM has been shown to improve these responses in models. Phase 1 data indicated INT230-6 alone induced tumor regression in both injected and non-injected lesions. Considering the large volume of drug injected and retained in the tumor, coupled with immune infiltration on biopsies, RECIST response methodology may not capture the benefit of INT230-6 treatment. Methods: IT-01 is an open-label phase 1/2 study, currently enrolling adult subjects with solid tumors in phase 2. INT230-6 was administered IT Q2W for 5 doses alone or with PEM 200mg Q3W. The study seeks to assess the safety and efficacy of IT INT230-6 alone and in combination with PEM. Results: 67 subjects have been enrolled (58 mono and 12 INT230-6 + PEM (3 started in mono, then received combo)) having a median of 3 prior therapies (0, 10). Median age was 60 (42, 85). 20+ cancer types were accrued; breast cancer and sarcoma were the most frequent. Over 500 image guided INT230-6 IT injections were given (253 to deep tumors) at doses of 0.3 to 172mL (86 mg CIS, 17.2 mg VIN) in a single session, which are higher amounts than typical IV doses. PK shows that 95% of INT230-6 active agents remain in the tumor. The most common (> 20%) related TEAEs for INT230-6 alone were localized pain (57%), nausea (36%), fatigue (29%) and vomiting (24%); with grade 3 TEAEs (> 1) of localized pain (5%) and anemia (3%). The safety in the combination was similar. There were no related grade 4 or 5 TEAEs. In evaluable monotherapy subjects (n = 43), the disease control rate (DCR) was 65% vs. 100% in PEM subjects (n = 5). Given the range of dose and entering tumor burden, an exploratory analysis of dose relative to tumor burden (TB) showed that subjects receiving a dose of INT230-6 < 50% of their reported TB (n = 30) had a mOS of 3.5 months. While in subjects receiving a dose of INT230-6 to ≥50% of TB (n = 37), mOS has not yet been reached after a median follow up of 9.5 months (HR: 0.26 (0.13,0.51)). Conclusions: INT230-6 is well tolerated when administered IT as monotherapy and combined with PEM. Given the challenge in assessing overall response rate following IT delivery, an exploratory analysis suggests prolonged survival for subjects receiving an INT230-6 dose ≥50% of their tumor burden compares favorably to the < 50% group and to literature accounting for prognostic factors (ECOG, LDH, # of metastatic sites). Clinical trial information: 03058289.

A first-in-human study of AO-176, a highly differentiated anti-CD47 antibody, in patients with advanced solid tumors

2516

Background: AO-176 is a humanized IgG2 antibody that specifically targets CD47. Expressed by multiple tumor types, CD47 binds to signal regulatory protein a (SIRPa) on phagocytes, including macrophages and dendritic cells. The CD47-SIRPa complex results in a “don’t eat me” signal that allows the tumor to escape removal by the innate immune system, disabling the generation of an adaptive immune response. The differentiated mechanisms of action of AO-176 include promotion of phagocytosis, direct tumor cell killing through programmed cell death type III and induction of damage associated molecular patterns/immunogenic cell death, preferentially binding to tumor cells vs. normal cells, and enhanced binding at an acidic pH as found in tumor microenvironments. AO-176 has negligible binding to RBCs. Methods: In a phase 1/2 first-in-human study (NCT03834948) of AO-176, pts with advanced solid tumors associated with high CD47 expression and an ECOG PS of 0-1 were enrolled into escalating dose cohorts of AO-176 given IV every 7 days. Objectives included evaluation of safety, dose-limiting toxicity (DLT) and recommended phase 2 dose (RP2D), antitumor activity, pharmacokinetic (PK) parameters and exploratory biomarkers. Results: As of 4 Jan 2021, 27 pts were enrolled (median age 64 years; 67% female; 67% ECOG PS 1; median [range] of 4 [1-7] prior therapies for metastatic disease). Dose levels of 1, 3, 10, 20 and 20 (using step-up dosing) mg/kg were evaluated in >250 infusions. Most common (>10%) treatment-related adverse events (TRAEs) of any grade were thrombocytopenia and infusion-related reaction (IRR) (33% each), anemia (22%) with no evidence of hemolysis, nausea (19%), and fatigue (15%). The only G3+ TRAE occurring in >10% of pts was asymptomatic, brief thrombocytopenia (22%). No platelet transfusions were given. DLTs included IRRs in 2 pts dosed at 20 mg/kg, and asymptomatic thrombocytopenia and a cerebrovascular accident in 1 pt each in the 20 mg/kg step-up cohort. The RP2D was 10 mg/kg. Implementation of additional pre-medication and a 6-hr infusion duration in cycle 1 eliminated subsequent IRRs. Dexamethasone tapering and shortening of the infusion duration to 2 hrs was successful in all pts after cycle 1. Interim PK analysis of AO-176 demonstrated consistent exposure with linear PK. The T1/2 was ̃5 days. One pt with endometrial carcinoma who had not responded to any of 4 prior systemic regimens had a confirmed PR and remains on study for >1 year. 7 pts had SD as a best response, with 2 pts (endometrial carcinoma, gastric cancer) on study for >6 mos. Conclusions: AO-176 is a well-tolerated, differentiated anti-CD47 therapeutic. Durable anti-tumor activity was observed. Evaluations of AO-176 in combination with paclitaxel in pts with select solid tumors (NCT03834948) and as a single-agent in pts with multiple myeloma (NCT04445701) are ongoing. Clinical trial information: NCT03834948.

Early results of intratumoral INT230-6 alone or in combination with ipilimumab in subjects with advanced sarcomas

11557

Background: Patients have limited treatment options following initial chemotherapy failure. INT230-6, a novel formulation of cisplatin (CIS) and vinblastine (VIN) with an amphiphilic cell penetration enhancer, is designed for intratumoral (IT) administration. Study IT-01 (BMS # CA184-592, NCT 03058289) evaluates INT230-6 alone or in combination with ipilimumab (IPI), an antibody to CTLA-4. INT230-6 dosing is set by a % of the volume of the tumor to be injected. The product has been shown to disperse throughout an injected tumor and diffuse into cancer cells. Cell death leads to recruitment of dendritic and T cells, the effect of which may be augmented by CTLA-4 inhibition as evidenced by increased efficacy of the combination in preclinical models. Historically, checkpoint inhibitors have limited activity in sarcoma. Considering the large volume of drug injected and retained in the tumor, coupled with immune infiltration on biopsies, RECIST response methodology may not capture the benefits of INT230-6 treatment. Methods: IT-01 is an open-label phase 1/2 study that is enrolling adult subjects with locally advanced, unresectable or metastatic sarcoma. INT230-6 was administered IT Q2W for 5 doses alone or with IPI 3mg/kg IV Q3W for 4 doses. The study objectives are to assess the safety and efficacy of IT INT230-6 alone and in combination with IPI. Results: 16 heterogenous sarcoma subjects (13 monotherapy, 3 IPI combination) having a median of 3 prior therapies (0, 8) were enrolled to date. The INT230-6 dose was up to 145 mL (72.5 mg of CIS, 14.5 mg VIN) in a single session (an amount of each agent in excess of standard IV doses). The most common ( > 20%) related TEAEs in sarcoma subjects (n = 16) were localized pain (63%), fatigue (38%), decreased appetite (31%), nausea (31%), and vomiting (25%) most of which were low grade; with only grade 3 TEAE above 5% being anemia (13%). There were no related grade 4 or 5 TEAEs. In 11 evaluable monotherapy subjects, the disease control rate (DCR = CR+PD+SD) was 82%. Basket studies of sarcomas, including chordoma, with Royal Marsden Hospital index (RMHI) scores of 2 or higher report median overall survival (mOS) of 4 months. In this study 75% of monotherapy subjects had a RMHI score of 2 and preliminary estimates of mOS was 21.3 (4.67, NA) months. Pilot immunohistochemistry analysis of 5 paired (pre- and 28 days post-dose) biopsy samples showed substantial tumor necrosis, reduction of viable cancer, a decreased cancer proliferation as measured by Ki67, and increased TILs. Conclusions: Preliminary data shows that INT230-6 administered intratumorally alone or in combination with ipilimumab is well-tolerated in this small, heterogenous sarcoma population. The preclinical cancer cell death and immune infiltration mechanism of action appears to translate to sarcoma subjects. There are early signs of efficacy, DCR and potentially OS, that need to be confirmed in randomized studies. Clinical trial information: 03058289.

Updated results of a phase 1b study of regorafenib (REG) 80 mg/day or 120 mg/day plus pembrolizumab (PEMBRO) for first-line treatment of advanced hepatocellular carcinoma (HCC)

4078

Background: REG, a multikinase inhibitor, and PEMBRO, an anti-PD-1 mAb, are approved as monotherapies in advanced HCC after progression on sorafenib. This phase 1b dose-finding study investigated first-line REG plus PEMBRO in advanced HCC. Methods: Patients (pts) in the first cohort received a starting REG dose of 120 mg/day orally for 3 weeks (wks) on/1 wk off, which could be escalated (160 mg) or reduced (80 mg) in later cohorts, plus a fixed dose of PEMBRO 200 mg IV every 3 wks. Due to a high dose modification rate in the REG 120 mg cohort, an exploratory REG 80 mg cohort was introduced. Primary objective was safety and tolerability; secondary aims were to assess the maximum tolerated dose (MTD), recommended phase 2 dose, and anti-tumor activity. Results: 35 pts started on REG 120 mg/day and 22 on REG 80 mg/day. Median age was 66 yrs (range 29–81), 84% of pts were male, 70%/30% had ECOG PS 0/1, 26%/74% were BCLC stage B/C, 100% were C–P A, 46% had extrahepatic spread, and 32% had macrovascular invasion. MTD of REG was 120 mg/day. Grade (Gr) 3/4 treatment-emergent adverse events (TEAE) occurred in 86% of pts on REG 120 mg and 50% on REG 80 mg (Table). Most common Gr 3/4 TEAE for REG 120 mg/80 mg were AST increased (23%/9%), lipase increased (20%/5%), ALT increased (17%/9%), and hypertension (17%/9%). TEAE led to REG/PEMBRO dose reductions or interruptions in 71%/57% of pts on REG 120 mg and 59%/45% on REG 80 mg. Median treatment duration (range) was 3.0 months (mo; 0.2–20.5) for REG 120 mg and 3.5 mo (0.03–24.4) for PEMBRO, and 3.5 mo (0.7–10.8) for REG 80 mg and 3.5 mo (0.8–11.3) for PEMBRO. Of 32 evaluable pts on REG 120 mg, 10 (31%) had a partial response (PR) and 18 (56%) had stable disease (SD); disease control rate (DCR) was 88% (RECIST v1.1). Of 22 pts on REG 80 mg, 4 (18%) had a PR and 16 (73%) had SD; DCR was 91%. As of 17 Dec 2020, 16 pts remain on treatment (REG 120 mg n = 5; REG 80 mg n = 11); median follow up was 11.7 mo and 6.9 mo, respectively. REG pharmacokinetic exposure was as expected for 80 mg and 120 mg doses. Flow cytometry analysis of sequential peripheral blood showed changes in subsets of T-cells and monocytes, which may contribute to clinical benefit. Conclusions: First-line REG plus PEMBRO in advanced HCC showed no new safety signals and encouraging anti-tumor activity (DCR ̃90%). The REG 80 mg cohort appeared to have lower rates of dose reductions and interruptions due to TEAE vs REG 120 mg. Efficacy data for the REG 80 mg cohort are preliminary due to short follow-up. Clinical trial information: NCT03347292. [Table: see text]

Initial findings of the first-in-human phase I study of AGEN2373, a conditionally active CD137 agonist antibody, in patients (pts) with advanced solid tumors

2634

Background: CD137 is a member of the tumor necrosis factor receptor superfamily that functions as a potent co-stimulator of both adaptive and innate immune cells, thus making it an attractive target for cancer immunotherapy. The development of first-generation anti-CD137 antibodies has been hampered by limited clinical activity or dose-limiting hepatotoxicity. AGEN2373 is a novel, conditionally active CD137 agonist antibody designed to selectively enhance tumor immunity while mitigating side effects associated with systemic activation of CD137. Here we report the initial findings from the first-in-human evaluation of AGEN2373 in pts with advanced solid cancers. Methods: Pts received AGEN2373 on day 1 of a 28-day cycle (Q4W dosing), with cycles repeated until progression, intolerable toxicity or investigator/patient decision. Dose-escalation followed a standard 3+3 scheme, with planned dosing of 0.03, 0.06, 0.3, 1.0, 2.0, and 3.0 mg/kg. The primary objective was to determine the safety, tolerability, and dose-limiting toxicity (DLT) of AGEN2373 as monotherapy. Secondary objectives included pharmacokinetics (PK) and preliminary clinical activity. Adverse events (AEs) were reported per CTCAE v5.0 and DLTs evaluated within a 28-day window. For PK analyses, serum AGEN2373 concentrations determined using a validated bioanalytical assay and simultaneously analyzed by an NLME model. Antitumor activity was assessed using RECIST v1.1. Results: As of January 21 2021, 19 pts (median age 54.4 years, range 33-74; 11 men, 8 women; 7 with prior immunotherapy) have been treated with AGEN2373 Q4W at escalating doses from 0.03 – 2.0 mg/kg across 5 cohorts. Eleven pts (57.9%) experienced treatment-related AEs; none were grade 3 or higher. The most common events were fatigue (4 pts, 21.1%) and nausea (2 pts, 10.6%). No DLTs have been observed. Importantly, no drug-related elevations in liver transaminases (ALT, AST) or bilirubin beyond 1 grade have been seen. AGEN2373 PK were consistent with linear elimination. Prolonged disease stabilization as best response occurred in 5 pts (26.3%; range, 6-41 weeks); three of which were seen in heavily pretreated pts with metastatic leiomyosarcoma, including one who had progressed on prior combination checkpoint immunotherapy. Enrollment into the 3.0 mg/kg cohort is continuing. Conclusions: AGEN2373 demonstrates good tolerability in pts with advanced solid tumors, with a safety profile characterized by a lack of hepatotoxicity frequently observed with CD137-targeting antibodies. These findings underscore the suitability of AGEN2373 as a potential partnering agent for other immunomodulatory agents, including planned expansion as combination therapy with balstilimab (anti-PD-1). Clinical trial information: NCT04121676.

Multimodal profiling of biliary tract cancers to detect potentially actionable biomarkers and differences in immune signatures between subtypes

4023

Background: Biliary tract cancers (BTC) are increasingly subtyped by molecular alterations, but little is known about the relationship between gain-of-function mutations and the RNA transcript expression of immune-related pathways. Methods: A sample of retrospective, clinicogenomic and transcriptomic data from de-identified records of patients with BTC in the Tempus database was selected. We then investigated the relationship between the mutational landscape and immune-related RNA signatures of different anatomic and genomic BTC subtypes. Results: The cohort included 455 samples of intrahepatic bile duct (IH) (n=267), gallbladder (GB) (n=153), and extrahepatic bile duct (EH) (n=35) cancer subtypes. Across all subtypes, we detected alterations in TP53 (43.8%), ARID1A (19.8%), KMT2C (18.2%), BAP1 (14.6%), KRAS (12.7%), TERT (12.0%), IDH1 (11.4%), KMT2D (11.0%), LRP1B (11.0%), and PBRM1 (10.7%), along with FGFR2 fusions (2.6%). Potentially actionable biomarkers ( FGFR2 and NTRK1-3 fusions, IDH1 and BRAFV600E mutations, tumor mutational burden [TMB]>10, HER2 expression, and/or microsatellite instability) were identified in 21.1% of all BTC and 28.6% of IH samples. Mutually exclusive alterations observed between subtypes were TP53 & BAP1, KRAS & BAP1, TP53 & IDH1, KRAS & IDH1, and SMAD4 & BAP1 ( P < 0.001 for all). GB was more inflamed based on RNA signatures and classical immune biomarkers, including PD-L1 and TMB. RNA signature analyses revealed a higher expression of immune-related pathways in GB than IH ( P = 0.001) with no differences in comparison with EH. PD-L1 expression and continuous TMB were elevated in GB versus the other anatomical subtypes. Significant associations were noted between particular genetic mutations and immune profiling features (table). Conclusions: BTC subtypes are diverse in DNA alterations, RNA inflammatory signatures, and immune markers. Notably, potentially actionable biomarkers were identified in a sizable portion of the cohort and varied significantly between subtypes. These results provide guidance for targeted therapy development and support the use of multimodal immune profiling for BTC. For example, GB-specific clinical trials may be considered due to the relative increase in immune-related biomarkers observed in GB and the historically limited success of BTC trials.[Table: see text]

A phase 1, multicenter, open-label, dose-escalation, safety, pharmacodynamic, pharmacokinetic study of Q702 with a cohort expansion at the RP2D in patients with advanced solid tumors

TPS2673

Background: Immune checkpoint inhibitors directly targeting T cell activation have been successfully used in the treatment of various malignancies, nevertheless, the durable ORRs are low for certain indications. The low ORRs have been attributed to the immune suppressive tumor microenvironment (TME), composed of innate immune suppressive components such as tumor associated macrophages (TAM) and myeloid-derived suppression cells (MDSC). The potential contributions of innate immune modulation to anti-tumor immunity, suggest the need for the novel strategies to elicit a more efficient/robust immune response against the targeted malignant cells. Axl, Mer and CSF1R receptor tyrosine kinases play vital roles in promoting an immune suppressive TME by affecting TAM and MDSC populations and by decreasing antigen presentation on tumor cells. Q702 is a novel Axl/Mer/CSF1R inhibitor, able to modulate the TAM and MDSC population leading to CD8+ T cell activation and to increase antigen presentation of the tumor cells in syngeneic animal models. Q702, as a monotherapy, shows significant tumor growth inhibition in multiple syngeneic tumor models, and demonstrates synergistic effects with anti-PD-1 treatment particularly in high myeloid containing tumor models. Interestingly, intermittent administration of Q702 monotherapy demonstrates a more favorable immune cell population changes, possibly through preventing immune exhaustion secondary to negative feedback with continuous activation. These results suggest that Q702 monotherapy or in combination with existing therapies have a good potential to become a novel treatment strategy for patients with advanced solid tumors. Methods: “A Phase 1, Multicenter, Open-label, Dose-Escalation, Safety, Pharmacodynamic, Pharmacokinetic Study of Q702 with a Cohort Expansion at the RP2D in Patients with Advanced Solid Tumors. (NCT04648254)” is open and recruiting patients at 4 US investigative sites. Patients with histologically or cytologically confirmed advanced or metastatic solid tumors, that have progressed following SOC or for which there is no SOC which confers clinical benefit are being enrolled in this study. The study follows a standard dose escalation. The study will enroll up to 78 patients. The primary endpoint is to establish safety, PK profile and define the recommended phase 2 dose. The secondary and exploratory endpoints include establishing pharmacokinetic/pharmacodynamic relationship, potential biomarkers and preliminary anti-tumor activity. Clinical trial information: NCT04648254.