Abstract 2255: Patient pharmacodynamic biomarker and pk evaluation results from an ongoing phase I dose-escalation study of q702, an axl, mer and csf1r kinase inhibitor in patients with advanced solid tumors

Background: Axl, Mer and CSF1 receptor tyrosine kinases play vital roles in promoting the immunosuppressive tumor microenvironment (TME) by affecting myeloid functions (e.g., tumor associated macrophage [TAM], myeloid derived suppression cell [MDSC]) and promoting epithelial-to-mesenchymal transition (EMT). Thus, simultaneous inhibition of Axl, Mer and CSF1R may be an effective strategy for TME modification. Q702 is a novel Axl/Mer/CSF1R kinase inhibitor that affects the immune components (modulating TAM and MDSC populations, inducing CD8+ T cell infiltration and increasing IFN-ɣ in CD8+ T cell) as well as changes in malignant cells such as increasing MHC I on the tumor cells of syngeneic mouse models. These nonclinical results suggest that Q702 monotherapy or Q702 combination with conventional therapies may have considerable potential as a novel treatment strategy for patients with advanced solid tumors.

Methods: This is a Phase 1, Multicenter, Open-label, Dose-Escalation, Safety, Pharmacodynamic, Pharmacokinetic Study of Q702 with a Cohort Expansion at the recommended phase 2 dose (RP2D) in Patients with Advanced Solid Tumors (NCT04648254). Q702 was administered orally for seven days every other week. Peripheral blood samples were obtained on days 1,8,15, and 21. Axl, Mer and CSF1R target engagement is assessed by the quantifications of soluble Axl, Mer and M-CSF in plasma by Luminex xMAP® technology or ELISA. The pharmacodynamic biomarker changes are measured by flow cytometry for immune cell population shifts and IFN-ɣ levels in specific immune cells.

Results: PK and PD biomarker samples from 22 patients with various tumor types (e.g. colon, pancreas, esophageal) from the dose escalation phase (4 mg to 240 mg) have been analyzed. Pharmacokinetic studies demonstrated dose proportional increase in Cmax and AUClast of Q702 and its two active metabolites which have activity against Axl and/or CSF1R. Axl and CSF1R target engagement by Q702 treatment is observed in a dose dependent manner. From the 60 mg cohort, target engagement for Axl and CSF1R reached a inhibitory level that was observed in nonclinical models. In the pharmacodynamic biomarker analysis, IFN-ɣ in CD8+ T cells and non-T cell populations is increased. Monocytes and M-MDSC population are decreased in peripheral blood.

Conclusion: Up to 240 mg, Q702 has demonstrated the intended pharmacologic activity with acceptable safety profile. In biomarker analysis, immune modulation activity is exerted by Axl/Mer/CSF1R inhibition. Further assessment of pharmacokinetics, pharmacodynamics, safety and antitumor activity will be performed at the expansion phase at the RP2D in patients with selected advanced tumors.

Citation Format: Bae Jung Choi, Devalingam Devalingam, Angela Alistar, Anthony El-Khoueiry, Alain Mita, Hwankyu Kang, Jinho Choi, Hyunji Ahn, Jeongjun Kim, Seung-Joo Lee, Yeong-In Yang, Jiye Ahn, Borami Jeon, Jaeseung Kim, Kiyean Nam. Patient pharmacodynamic biomarker and pk evaluation results from an ongoing phase I dose-escalation study of q702, an axl, mer and csf1r kinase inhibitor in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2255.

Abstract 5532: Increasing racial and ethnic diversity of phase 1 solid tumor clinical trials through enrollment at a safety net hospital

Background: Racial minorities are under-represented in oncology clinical trials. African Americans and Hispanic/Latinos account for 13% and 18% of the US population, respectively, but in 2018 these groups combined were only 8% of oncology trial subjects. Disproportionate enrollment can limit how generalizable trial outcomes may be and can perpetuate healthcare disparities. The majority of clinical trial enrollment occurs at large academic cancer centers that may not reflect the diverse general cancer patient population in the US. Los Angeles County/University of Southern California Medical Center (LAC+USC) is a large safety net hospital that serves a racially and ethnically diverse patient population.

Methods: We developed a database of all adult patients (pts) enrolled in phase I solid tumor trials at LAC+USC from 2015 - 2022. The data collected includes baseline demographics (age, gender, race, ethnicity, primary language, tumor histology), type of therapeutic intervention, radiologic response per RECIST 1.1, duration of treatment, and survival. Progression-free survival was defined as time from enrollment in the study until progression, discontinuation of treatment, or death. Disease control rate (DCR) was defined as pts with best response of CR, PR, or SD.

Results: 120 pts with solid tumors were enrolled in phase 1 trials at LAC+USC from 2015-2022. Median age was 58 (range 26-78); 58% female; ECOG 0-1 (99%), 2 (1%). 73 patients (61%) were Hispanic, 27 (23%) Asian/Pacific Islander, 9 (8%) non-Hispanic (NH) White, 5 (4%) were NH Black, and 6 (5%) were unknown. 70% of pts had a primary language other than English: 56% Spanish. The most common tumor types were colorectal (16%), hepatocellular (13%), non-small cell lung (12%), head and neck (11%), and ovarian (11%). Trial interventions included chemotherapy (19%), immunotherapy (35%), targeted therapy (54%), and 10% required biomarker selection. The disease control rate (DCR) was 58/120 (48%): 2 pts had CR, 9 pts had PR, and 47 pts had SD. 4-month progression-free survival (PFS) was 42/120 (35%), and 6-month PFS was 27/120 (23%). 90-day survival was confirmed in 101/120 (84%) of patients.

Discussion: A racially diverse population can be successfully enrolled in early phase oncology trials at a safety net hospital. Patient populations that are underrepresented nationally in clinical trials had robust enrollment and comprised the majority of participation (88%) in this setting. Almost half of patients derived clinical benefit (48% DCR) from trial participation. Creating an infrastructure to enroll patients to phase 1 clinical trials at a safety net hospital may be a successful strategy to improve racial and ethnic diversity.

Citation Format: Varun Roy, Esther Lee, Ming Li, Xiomara Menendez, Elena Nieves, Rebecca Umayam, Nicole Jensen, Lorraine Martinez, Diana Hanna, Jorge Nieva, Anthony El-Khoueiry, Jacob Thomas. Increasing racial and ethnic diversity of phase 1 solid tumor clinical trials through enrollment at a safety net hospital. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5532.

Association of Body Mass Index With the Safety Profile of Nivolumab With or Without Ipilimumab

Importance

Increased survival with immune checkpoint inhibitors has been reported for patients with obesity vs a normal body mass index (BMI). However, the association of obesity with the safety of immune checkpoint inhibitors warrants study.

Objective

To investigate associations between BMI and immune-related adverse events (irAEs) among patients with advanced cancers treated with nivolumab monotherapy and nivolumab plus ipilimumab combination therapy.

Design, Setting, and Participants

This study was a retrospective pooled analysis of 3772 patients from 14 multicenter CheckMate clinical trials across 8 tumor types. Patients with advanced cancers received nivolumab, 3 mg/kg (n = 2746); nivolumab, 3 mg/kg, plus ipilimumab, 1 mg/kg (n = 713); or nivolumab, 1 mg/kg, plus ipilimumab, 3 mg/kg (n = 313). Baseline BMI was categorized as normal weight or underweight (<25), overweight (25 to <30), or obese (≥30) according to World Health Organization criteria. The studies began patient enrollment between February 9, 2012, and May 21, 2015, and patients were followed up to database lock on May 1, 2019. Data analysis was conducted from May 1 to September 1, 2019.

Interventions

Nivolumab, 3 mg/kg; nivolumab, 3 mg/kg, plus ipilimumab, 1 mg/kg; and nivolumab, 1 mg/kg, plus ipilimumab, 3 mg/kg.

Main Outcomes and Measures

Odds ratios (ORs) and 95% CIs for incidence of any-grade and grade 3 or 4 irAEs were calculated for patients with obesity vs normal weight or underweight BMI in the overall cohort and in subgroups based on patient and tumor characteristics. Analyses for nivolumab plus ipilimumab cohorts were exploratory.

Results

A total of 3772 patients were included, 2600 were male (69%), and median age was 61 years (range, 18-90 years). For patients receiving monotherapy with nivolumab, 3 mg/kg (n = 2746), the incidence of any-grade irAEs was higher in patients with obesity (n = 543) vs those with normal weight or underweight BMI (n = 1266; OR, 1.71; 95% CI, 1.38-2.11). Incidence of grade 3 or 4 irAEs did not differ between patients with obesity and those with normal weight or underweight BMI (OR, 1.21; 95% CI, 0.92-1.61). Risk of any-grade and grade 3 or 4 irAEs appeared consistent with that in the overall population across all subgroups evaluated except for a higher likelihood of grade 3 or 4 irAEs among female patients with obesity vs normal weight or underweight BMI (OR, 1.73; 95% CI, 1.07-2.79). For patients receiving nivolumab plus ipilimumab, the incidence of irAEs appeared consistent across BMI categories.

Conclusions and Relevance

Obesity appeared to be associated with an increased incidence of any-grade irAEs among patients treated with nivolumab monotherapy and with grade 3 or 4 irAEs among female patients only. These findings may inform the monitoring of patients at high risk of developing irAEs.

DNMT and EZH2 inhibitors synergize to activate therapeutic targets in hepatocellular carcinoma

The development of more effective targeted therapies for hepatocellular carcinoma (HCC) patients due to its aggressiveness is urgently needed. DNA methyltransferase inhibitors (DNMTis) represented the first clinical breakthrough to target aberrant cancer epigenomes. However, their clinical efficacies are still limited, in part due to an "epigenetic switch" in which a large group of genes that are demethylated by DNMTi treatment remain silenced by polycomb repressive complex 2 (PRC2) occupancy. EZH2 is the member of PRC2 that catalyzes the placement of H3K27me3 marks. EZH2 overexpression is correlated with poor HCC patient survival. We tested the combination of a DNMTi (5-aza-2'-deoxycytidine, DAC) and the EZH2 inhibitor (EZH2i) GSK126 in human HCC cell lines on drug sensitivity, DNA methylation, nucleosome accessibility, and gene expression profiles. Compared with single agent treatments, all HCC cell lines studied showed increased sensitivity after receiving both drugs concomitant with prolonged anti-proliferative changes and sustained reactivation of nascently-silenced genes. The increased number of up-regulated genes after combination treatment correlated with prolonged anti-proliferation effects and increased nucleosome accessibility. Combination treatments also activate demethylated promoters that are repressed by PRC2 occupancy. Furthermore, 13-31% of genes down-regulated by DNA methylation in primary HCC tumors were reactivated through this combination treatment scheme in vitro. Finally, the combination treatment also exacerbates anti-tumor immune responses, while most of these genes were downregulated in over 50% of primary HCC tumors. We have linked the anti-tumor effects of DAC and GSK126 combination treatments to detailed epigenetic alterations in HCC cells, identified potential therapeutic targets and provided a rationale for treatment efficacy for HCC patients.

Abstract IA19: Impact of single checkpoint inhibitors and biomarkers of response

Single agent anti PD-1 antibodies have shown consistent safety and efficacy for the treatment of advanced hepatocellular carcinoma (HCC). Response rates range between 15 and 20% and the rate of grade 3 and 4 adverse events is generally below 25%. Recently, the HIMALAYA trial showed that durvalumab was non-inferior to sorafenib for first-line treatment of HCC. Further, Keynote-394 showed that pembrolizumab improved survival compared to placebo in second line treatment of HCC. Nivolumab was evaluated in a dedicated cohort of Checkmate 040 in patients with child pugh B cirrhosis and determined to have a manageable safety profile, similar to that in child pugh A. Given the fact that immunotherapy-based combinations are the current standard of care for advanced HCC, and given the absence of biomarkers for patient selection, the use of single agent anti PD-1 or PD-L1 antibodies in advanced first line HCC treatment is limited to patients who are not candidates for combination therapy or patients with compromised liver function. Single agent anti PD-1/PD-L1 antibodies are being evaluated in the adjuvant setting and in combination with liver directed therapy. Emerging biomarker data suggest an association between T cell inflammation signature and outcome with single agent anti PD-1 and PD-L1 agents. Further research is needed to validate the early biomarker data.

Citation Format: Anthony El-Khoueiry. Impact of single checkpoint inhibitors and biomarkers of response [abstract]. In: Proceedings of the AACR Special Conference: Advances in the Pathogenesis and Molecular Therapies of Liver Cancer; 2022 May 5-8; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(17_Suppl):Abstract nr IA19.

Abstract 2145: Genomic and transcriptomic analyses related to the clinical efficacy of first-line nivolumab in advanced hepatocellular carcinoma from the phase 3 CheckMate 459 trial

In the phase 3 CheckMate 459 study (NCT02576509), first-line nivolumab (NIVO) treatment demonstrated higher overall response rate (ORR) and a favorable safety profile, but no significant improvement in overall survival (OS) compared with sorafenib (SORA) in patients with advanced hepatocellular carcinoma (HCC). Here, we report exploratory biomarker analyses from the trial with a potential to identify patients who may benefit from NIVO. Archival or fresh tumor samples were collected before treatment and subjected to whole exome sequencing (WES) (400/730: 55%) for genetic alterations including high microsatellite instability (MSI-H) and WNT/beta-catenin pathway components, as well as whole transcriptome RNA sequencing (469/730: 64%) for analysis of individual genes, inflammation signatures and Gene Set Enrichment Analysis (GSEA). Associations between biomarkers and best overall response (BOR), progression free survival (PFS) and OS were evaluated at a minimum follow-up of 33·6 months. RNA sequencing analysis demonstrated that high Gajewski inflammation gene signature score of ≥0.47 (30% of tumors) was associated with an improvement in BOR (p=0.0043), PFS (p=0.00065) and OS (p=0.0073) within the NIVO arm only. Upon comparison of NIVO versus SORA, only patients whose tumors were inflammation high demonstrated NIVO benefit for BOR (p=0.017), PFS (p=0.0063) and OS (p=0.037). Responses to NIVO were associated with higher expression of CD8A, CD8B, PDCD1 (PD-1) and other inflammation-associated genes within the tumor (false discovery rate, FDR&lt;0.01). GSEA of 50 hallmark gene sets for ORR showed that responders to NIVO and SORA were enriched in similar gene sets such as inflammatory response, interferon alpha/gamma response, E2F targets and G2M checkpoint (FDR&lt;0.01). In contrast, GSEA for OS showed inflammatory response and IL6-JAK-STAT3 signaling gene sets were associated with benefit from NIVO, but shorter OS for SORA (FDR&lt;0.01). WES analysis demonstrated that the prevalence of MSI-H was low (12/400: 3%) and insufficient to confirm relationship to clinical outcomes (no radiographic responses observed in 9 NIVO- and 3 SORA-treated patients). Alterations within beta-catenin gene were not associated with survival outcomes for NIVO. Overall, patients with advanced HCC whose tumors had high Gajewski inflammation gene signature demonstrated improved outcomes with NIVO versus SORA. NIVO responders had higher expression of individual inflammation-associated genes. Expression of inflammatory response and IL6-JAK-STAT3 signaling gene sets showed association with longer OS for NIVO, but not SORA. These exploratory analyses support further studies of tumor inflammation-related biomarkers to identify patients most likely to benefit from PD-1 inhibition in advanced HCC.

Citation Format: Jaclyn Neely, Jin Yao, Masatoshi Kudo, Richard S. Finn, Bruno Sangro, Ignacio Melero, Anthony El-Khoueiry, Marina Tschaika, Damir Begic, Ashwin Sama, Parul Doshi, Thomas Yau, Robin Kate Kelley. Genomic and transcriptomic analyses related to the clinical efficacy of first-line nivolumab in advanced hepatocellular carcinoma from the phase 3 CheckMate 459 trial [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 2145.

Abstract CT201: Ceralasertib and olaparib in the treatment of homologous recombination repair (HRR)-deficient platinum-sensitive ovarian cancer after progression on PARP inhibitors

Background: The majority of BRCA-mutant or HRR-deficient ovarian cancers are initially sensitive to PARP inhibitors (PARPis) but eventually develop resistance. The most commonly reported PARPi resistance mechanisms are (1) reversal of HRR deficiency through (a) reversion mutations in BRCA or other HRR genes (eg, RAD51C/D) or (b) DNA end resection rewiring with loss of 53BP1, REV7, or Shieldin complex components; or (2) stabilization of stalled replication forks through loss of PTIP or EZH2, preventing nuclease recruitment. The only confirmed PARPi resistance mechanism in the clinic to date is reversion mutations.

Combined ATR and PARP inhibition is an attractive strategy that may overcome PARPi resistance, as has been shown in PARPi-resistant cell lines and patient-derived xenograft models (Yazinski et al Genes Dev 2017; Murai et al Oncotarget 2016; Kim et al Nat Commun 2020; data on file, AstraZeneca). The PARPi olaparib 300 mg twice daily (BID) continuously in combination with the ATR inhibitor ceralasertib 160 mg daily on days 1-7 of a 28-day cycle has demonstrated promising activity in the CAPRI study in patients with ovarian cancer who had progressed on PARPis (Wethington et al J Clin Oncol 2021). However, preclinical models of PARPi resistance suggest that a higher dose or duration of ceralasertib with a lower dose of olaparib may be more beneficial (data on file, AstraZeneca).

Methods: D5330C00004 (NCT02264678) is a multicenter, modular, phase 1 study assessing ceralasertib in combination with other anti-cancer agents in adults with advanced solid malignancies. In Module 2, a lower dose of olaparib (150 mg BID continuous) and a longer duration of ceralasertib (80 mg BID, days 1-14 of a 28-day cycle) is now being explored in 2 expansion cohorts in patients with platinum-sensitive, high-grade, serous or endometrioid ovarian, fallopian tube, or primary peritoneal cancer with deleterious or suspected deleterious germline or somatic BRCA or RAD51C/D mutations, or HRR deficiency by Myriad MyChoice® or FoundationOne® CDx (F1CDx) assays. Patients will have progressed on prior PARPis after ≥6 months in the maintenance or treatment setting (≥12 months after first-line maintenance). Cohort 1 is enrolling ~30 patients immediately after progression on a PARPi; Cohort 2 is recruiting ~30 PARPi-treated patients after intervening platinum-based chemotherapy. Study endpoints include safety, tumor response by RECIST 1.1, and duration of response. Exploratory analyses include genomic and functional analysis of HRR restoration in tumor and circulating tumor DNA, and analysis of replication fork stability in organoid cultures established from mandatory fresh tumor biopsy samples. Recruitment began in July 2021 with the first patient dosed in August 2021.

Citation Format: Geoffrey I. Shapiro, Bristi Basu, Anthony El-Khoueiry, Sophie Postel-Vinay, Seock-Ah Im, Sun Young Rha, Claire F. Friedman, Antoine Italiano, Yong Man Kim, Myong Cheol Lim, Rene Roux, Joyce F. Liu, Elhan Sanai, Simon A. Smith, Claire Smith, Sarah El Farhi, Alan Lau, Natalia Lukashchuk, Emma Dean, Matthew G. Krebs. Ceralasertib and olaparib in the treatment of homologous recombination repair (HRR)-deficient platinum-sensitive ovarian cancer after progression on PARP inhibitors [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 CT201.

Abstract CT183: First-in-human study of MEDI1191 (mRNA encoding IL-12) plus durvalumab in patients (pts) with advanced solid tumors

Background: IL-12 is a key mediator of antitumor immune response. In preclinical models, IT IL-12 mRNA led to IFNγ release and CD8+ T cell-dependent tumor regression and potentiated PD-L1 blockade. MEDI1191, a lipid nanoparticle-formulated mRNA encoding IL-12 delivered by IT injection, drives IL-12 production and enhances antitumor immune response with improved tolerability. We hypothesized that combining MEDI1191 with PD-L1 blockade would augment antitumor immunity in vivo. Here we report updated results from the dose-escalation phase of the first-in-human study of IT MEDI1191 and IV durvalumab (D; anti-PD-L1) for advanced/metastatic solid tumors (NCT03946800).

Methods: In this multicenter, open-label study, MEDI1191 was dosed sequentially (seq, Part 1A) or concurrently (conc, Part 1B) with D. In Part 1A, MEDI1191 was given IT on Days 1 and 22 followed by D 1500 mg on day 43 and then Q4W IV. In Part 1B, MEDI1191 was given IT on Days 1, 29, 57 and then Q8W, along with D on Day 1 and then Q4W. Treatment continued until progression or unacceptable toxicity for up to 2 years. Eligible adult pts had any solid tumor with cutaneous or subcutaneous lesions suitable for IT injection and progression on standard therapy for recurrent/metastatic disease. Primary objectives were safety and tolerability and determination of maximum tolerated dose (MTD); secondary objectives included preliminary antitumor activity by RECIST v1.1.

Results: Starting in May 2019, 31 pts received seq MEDI1191 with D (Part 1A cohorts 0.1-12 μg; n=20) or conc MEDI1191 with D (Part 1B cohorts 1.0-3.0 μg; n=11); 23 pts had received prior anti-PD-1/PD-L1 therapy. Most common tumor types were melanoma, n=8; head and neck cancer, n=4; and breast cancer, n=4. At the data cutoff of Dec 7, 2021, there were no dose-limiting toxicities and no MTD was identified. One pt (3.2%) had a Gr ≥3 MEDI1191-related AE (Gr 3 pyrexia, resolved within 24 hr) and 1 (3.2%) had a MEDI1191-related serious AE (SAE; Gr 2 confusion). Two pts had Gr 3 D-related AEs (6.5%, pyrexia also related to MEDI1191 and pruritus; each n=1); none had a D-related SAE. There were no Gr 4 related AEs. 3 pts had partial responses (PR): 1 with head and neck cancer (unconfirmed, off study) and 2 with anti-PD-1 resistant melanoma (1 confirmed, &gt;12 months on treatment; 1 unconfirmed, off study); 10 pts had stable disease (including the 2 unconfirmed PRs). Among pts with available biomarker data (up to 3 μg in Part 1A and 1 μg in Part 1B), MEDI1191 increased serum IL-12 in 15/17 pts, increased CD8+ T cell tumor infiltration by &gt;2-fold in 8/14 pts and increased tumor PD-L1 expression in 6/14 pts.

Conclusions: IT MEDI1191 plus systemic anti-PD-L1 was safe and feasible. Preliminary antitumor efficacy and pharmacodynamics, including tumor CD8+ T cell recruitment, were consistent with expected mechanism of action. Pts with injectable deep visceral and superficial lesions are being recruited.

Citation Format: Benedito A. Carneiro, Dmitriy Zamarin, Thomas Marron, Inderjit Mehmi, Sandip P. Patel, Vivek Subbiah, Anthony El-Khoueiry, David Grand, Kirema Garcia-Reyes, Sanjay Goel, Phillip Martin, Jixin Wang, Yuling Wu, Steven Eck, Benjamin Ridgway, Nairouz Elgeioushi, Jim Eyles, Nicholas Durham, Analia Azaro, Omid Hamid. First-in-human study of MEDI1191 (mRNA encoding IL-12) plus durvalumab in patients (pts) with advanced solid tumors [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 CT183.

Abstract CT149: A phase 1/2a first-in-human study of AFM24, a CD16A/epidermal growth factor (EGFR) bispecific Innate Cell Engager (ICE®), in patients with locally advanced or metastatic EGFR-expressing solid tumors: Preliminary findings from the dose-escalation phase

AFM24 is a first-in-class, tetravalent, bispecific ICE® that binds to EGFR on tumor cells and CD16A on natural killer (NK) cells and macrophages, inducing antibody-mediated cytotoxicity and antibody-mediated phagocytosis, respectively. Preclinical in vitro and in vivo studies have demonstrated AFM24 can induce killing of EGFR+ solid tumor cell lines, independently of EGFR mutational status; toxicology testing in cynomolgus monkeys revealed a favorable safety profile. An ongoing phase 1/2a study (NCT04259450) is evaluating the safety, efficacy, immunogenicity, pharmacokinetic (PK) and pharmacodynamic responses of AFM24 in patients with locally advanced or metastatic, treatment refractory solid tumors that are known to express EGFR. AFM24 is administered intravenously Q1W until disease progression, intolerable toxicity, investigator’s discretion or patient withdrawal. As of 29 Oct 2021, 29 patients (median [range] age 58 [29-81] years; number of prior therapies 4 [2-8]), predominantly with colorectal- (CRC, 16/29; 10 KRAS mutant) and non-small cell lung cancer (NSCLC, 7/29; 6 EGFR mutant), were treated with AFM24 across six dose levels (14-480 mg flat). The median number of AFM24 doses administered was 8, range 1-29. The most frequently reported (≥20% of patients) AFM24-related treatment-emergent adverse events (TEAEs) were infusion-related reactions (IRR, 20/29), nausea (7/29) and headache (6/29). There were no on-study deaths; two patients had serious TEAEs (one Grade 3 IRR and one Grade 2 hypoxia) and five patients had transient and reversible Grade 3-4 TEAEs (two Grade 3 IRRs, one Grade 3 hypertension, three ≥Grade 3 lymphocytopenia) attributed to AFM24, respectively. There was one dose-limiting toxicity at 40 mg (Grade 3 IRR). Best objective response was stable disease in 8/24 response-evaluable patients; three patients had stable disease for ≥4 months (two CRC, one NSCLC). Dose-proportional PK between 320 and 480 mg indicated saturation of target-mediated elimination. CD16A receptor occupancy (CD16ARO) on circulating blood cells was correlated with exposure and seemed to level off at 480 mg. Estimated intra-tumoral AFM24 concentrations and CD16ARO were in the range associated with maximum tumor cell killing in vitro. TNF-α, IFN-γ and IL-10 increased over time; other cytokines including IL-6 showed only transient increases. AFM24 has a well-managed safety profile and shows pharmacodynamic activity at doses of 320-480 mg. In parallel to continued dose escalation, expansion in disease specific cohorts has been launched at 480 mg. Other studies are evaluating AFM24 in combination with atezolizumab, and in combination with autologous NK cells holding the potential to activate the innate immune response to fight EGFR+ cancer.

Citation Format: Anthony El-Khoueiry, Juanita Lopez, Omar Saavedra, Mark Awad, Jacob Thomas, Crescens Tiu, Elena Garralda, Bettina Rehbein, Gabriele Hintzen, Kerstin Pietzko, Christa Raab, Erich Rajkovic, Paulien Ravenstijn, Michael Emig. A phase 1/2a first-in-human study of AFM24, a CD16A/epidermal growth factor (EGFR) bispecific Innate Cell Engager (ICE®), in patients with locally advanced or metastatic EGFR-expressing solid tumors: Preliminary findings from the dose-escalation phase [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 CT149.

Molecular pathogenesis and systemic therapies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the most prevalent and deadliest cancers. The poor outcome associated with HCC is dramatically changing due to the advent of effective systemic therapies. Here we discuss the molecular pathogenesis of HCC, molecular classes and determinants of heterogeneity. In addition, effective single-agent and combination systemic therapies involving immunotherapies as standard of care are analyzed. Finally, we propose a flowchart of sequential therapies, explore mechanisms of resistance and address the need for predictive biomarkers.

Abstract P5-16-13: Safety and efficacy of INT230-6, a potential first-in-class intratumoral therapy, in monotherapy and in combination with pembrolizumab: Results from the IT-01 study [KEYNOTE-A10] in subjects with locally advanced, unresectable and metastatic breast cancer

Background: INT230-6 is a novel formulation of cisplatin and vinblastine with an amphiphilic cell penetration enhancer that has been shown to enhance dispersion of the drug throughout tumors and allow diffusion into cells when given intratumorally. INT230-6 is being evaluated in monotherapy and in combination with immune checkpoint inhibitors (ICIs) in subjects with various advanced solid tumors, including advanced breast cancer. Methods: This phase 1/2 study evaluated INT230-6 in superficial and deep tumors with INT230-6 Q2W intratumoral injections for 5 doses alone or in combination with 200mg pembrolizumab IV Q3W for 2 years. Total INT230-6 injected in a subject ranged from 0.89 to 649 mL over 5 INT230-6 dosing sessions in each subject, except one subject who had only 2 dosing sessions. Subjects who had completed treatment in dose escalation cohorts were eligible for retreatment; and one subject was retreated with INT230-6 in multiple arms of the study. Advanced breast cancer subjects with an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or below who have failed one or more approved therapies, or have no alternate approved therapy, were enrolled. Subjects must have adequate organ function and measurable disease by RECIST 1.1 criteria including one target tumor for injection. Tumor response using RECIST 1.1 was evaluated at 12 weeks from the first INT230-6 dose and then every 8 weeks. Tumor biopsies were taken prior to INT230-6 dosing on day 0 and on day 28 post dose. Results: 7 advanced triple negative breast cancer subjects (4 monotherapy, 3 pembrolizumab combination) were evaluable as of June 1, 2021. The median age was 56 (range 46-82) years old, with a median of 8 (2, 17) prior systemic therapies for metastatic disease. The intratumoral INT230-6 dose was up to 164 mL (82 mg of CIS, 16.4mg VIN) to tumors in a single dosing session. With INT230-6, 133-200% more volume is injected into the tumor and pharmacokinetics (PK) analysis shows that 95% of INT230-6 active agents remain in the tumor. Accordingly, assessment of tumor response using RECIST principles may be challenging, and even stable disease may represent a large decrease in viable tumor cells as indicated by biopsy evaluations. The most common (&gt;20%) related treatment related adverse events (AE) were localized tumor related pain (71%), nausea (57%), anemia (29%), fatigue (29%), neck pain (29%), and vomiting (29%). AEs were mostly low grade and only one subject experienced grade 3 anemia (13%). There were no related grade 4 or 5 AEs or serious AEs. Disease control rate (DCR), defined as the percent of patients with a complete response, partial response, or stable disease at the first radiologic assessment, was 57%. Median overall survival was 12 months. Pre- and post- biopsy at 28 days after two INT230-6 doses (n= 3 evaluable, monotherapy, and combination with pembrolizumab) showed a 55% decrease in Ki67 and 69% reduction in viable cancer cells. In addition, multiplex immunofluorescence (n= 3 evaluable, combination with pembrolizumab) showed an influx of activated CD4 and CD8 T cells and in some cases a reduction in FoxP3 T-reg cells.. Conclusion: INT230-6 is a potential first-in-class intratumoral therapy for advanced breast cancer being developed in monotherapy and in combination with ICIs. There is a favorable safety profile in this population, similar to the broader metastatic solid tumor population presented elsewhere. There are early signs of cancer cell death in injected tumors and immune activation in heavily pre-treated patients. A Phase 2 expansion cohort of INT230-6 in combination with ICIs is ongoing. In addition, INT230-6 in being studied in a separate randomized Phase 2 neoadjuvant breast cancer study.

Citation Format: Philippe Bedard, Lillian L Siu, Jacob Thomas, Diana Hanna, Anthony J Olszanski, Nilofer Azad, Giles Whalen, Matthew Ingham, Syed Mahmood, Lewis H Bender, Ian B Walters, Anthony El-Khoueiry. Safety and efficacy of INT230-6, a potential first-in-class intratumoral therapy, in monotherapy and in combination with pembrolizumab: Results from the IT-01 study [KEYNOTE-A10] in subjects with locally advanced, unresectable and metastatic breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-16-13.

Abstract P02-02: First results of RLY-4008, a potent and highly selective FGFR2 inhibitor in a first-in-human study in patients with FGFR2-altered cholangiocarcinoma and multiple solid tumors

INTRODUCTION: Oncogenic FGFR2 alterations (fusions/rearrangements, amplifications, mutations) are key drivers in cholangiocarcinoma (CCA) and multiple solid tumors. Current pan-FGFR inhibitor (FGFRi) therapy is limited by off-isoform toxicity and acquired FGFR2 kinase domain resistance mutations. RLY-4008 is a highly selective and potent oral inhibitor designed to target both FGFR2 driver and resistance mutations. We initiated a first-in-human study in advanced solid tumors patients (pts) to define the safety, pharmacokinetics (PK) and efficacy of RLY-4008 (NCT04526106). METHODS: Adult pts received RLY-4008 QD or BID on a 4-week cycle following a BOIN escalation design. Adverse events (AEs), PK, ctDNA and anti-tumor activity (RECIST 1.1) were assessed. RESULTS: As of 16AUG21, 45 pts (35 CCA; 10 other) have been treated with RLY-4008 at total daily doses of 30-200 mg (18 pts BID; 27 pts QD). 44 pts had oncogenic FGFR2 alterations (26 fusions/13 mutations/5 amplifications). The median number of prior anti-neoplastic therapies was 3 (range 1-15). 94% (33/35) of CCA pts had prior chemotherapy and 69% (24/35) had prior FGFRi. 56% (9/16) CCA pts with prior FGFRi and evaluable ctDNA had ≥1 FGFR2 resistance mutation at baseline, most commonly at positions 549 (8/9), 617 (3/9), or 564 (2/9). RLY-4008 had rapid absorption (Tmax 1-7h), half-life to support QD dosing (18-34 h), dose-dependent exposure (AUC; Cmax) and predicted FGFR2 occupancy &gt;85% across dose levels. The MTD has not been defined, and QD dose exploration continues to select the optimal biologically efficacious dose. AEs occurring in &gt;20% of pts include stomatitis (49%), palmar-plantar erythrodysesthesia (PPE, 38%), dry mouth (29%), and nail toxicities (22%), majority of which were ≤Gr 2. 6 pts had Gr 1-2 retinopathy, which resolved in all cases. 5 AEs were considered dose limiting toxicities: 4 in BID (rash/PPE/mucositis/hyperbilirubinemia) and 1 in QD (retinopathy). No Gr 4/5 drug-related AEs were seen. 25 pts remain on treatment (range 1-37 weeks). RLY-4008 showed broad anti-tumor activity across dose levels and FGFR2 alterations with radiographic tumor reductions of ≥10% in 59% pts (19/32; -11% to -83%). Activity was seen in FGFRi-naïve, FGFR2-fusion+ CCA with PRs in 50% of pts (3/6, 2 confirmed and 1 pending confirmation; -56% to -83%). Activity was also seen in FGFRi pre-treated FGFR2-fusion+ CCA pts (N=16) with 16 SD, including 9 pts with tumor reduction ≥10% (from -12% to -35%). Of the FGFRi pre-treated FGFR2-fusion+ CCA patients with detectable FGFR2 resistance mutations in ctDNA at baseline, 78% (7/9) were undetectable at C2D1. CONCLUSION: RLY-4008 demonstrates promising safety, tolerability, and clinical activity in FGFR2-altered solid tumor pts, including those who progressed on prior FGFRi therapy. Consistent with the FGFR2-selective mechanism, minimal off-isoform toxicity (FGFR1-hyperphosphatemia; FGFR4-diarrhea) was seen. These encouraging data validate selective targeting of FGFR2 and suggest that RLY-4008 has potential to overcome resistance to FGFRi.

Citation Format: Lipika Goyal, Mitesh Borad, Vivek Subbiah, Amit Mahipal, Suneel Kamath, Kabir Mody, Robin Katie Kelley, Richard Kim, Vaibhav Sahai, Anthony El-Khoueiry, Efrat Dotan, Oleg Schmidt-Kittler, Jinshan Shen, Kai Yu Jen, Alicia Deary, Wei Guo, Mahesh Padval, Cori Ann J. Sherwin, Charles Ferte, Beni Wolf, Alison M. Schram. First results of RLY-4008, a potent and highly selective FGFR2 inhibitor in a first-in-human study in patients with FGFR2-altered cholangiocarcinoma and multiple solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P02-02.

501 Survival and immune response data from intratumoral INT230–6 alone (IT-01) and with pembrolizumab [KEYNOTE-A10] in subjects with locally advanced, unresectable and metastatic solid tumors

Background

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, as monotherapy and in combination with pembrolizumab (PEM). 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 improves these responses in mouse models.

Methods

IT-01 is an open-label phase 1/2 study, currently enrolling adult subjects with solid tumors in phase 2. The study assesses the safety and efficacy of INT230-6 IT Q2W up to 5 doses as monotherapy or with PEM 200mg Q3W. Biopsies from injected tumor are taken pretreatment and Day 28 for immunohistochemistry (IHC) analysis.

Results

Fifty-seven INT230-6, two INT230-6 then PEM combination, and thirteen INT230-6 + PEM combination subjects were enrolled having a median of 4 prior therapies (0, 10). Median age was 62. 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 (contains higher amounts than typical IV chemo doses). PK shows that 95% of INT230-6 active agents remain in the tumor.1 The most common (>25%) related adverse events (AEs) for INT230-6 alone were localized pain (59%), nausea (37%), and fatigue (29%). Safety profile of the PEM combination was similar. There were no related grade 4 or 5 AEs in either arm. The median overall survival (mOS) estimated with removal of <2cm3 and >700cm3 tumor burdens was 433 days for monotherapy (n=51) and 513 days for PEM combination (n=12), which compares favorably to results seen in basket studies of patients having similar prognostic factors (ECOG, LDH, # of metastatic sites).2 IHC results indicate influx of CD4 and CD8 T-cells in injected lesions. No meaningful changes were observed in circulating inflammatory cytokines. Abscopal effects in the monotherapy arm were observed in 15 visceral/deep lesions in 11 patients, primarily who received an INT230-6 dose >50% of their total tumor burden (TTB).

Conclusions

INT230-6 is well tolerated when administered IT as monotherapy and combined with PEM. Data suggests that INT230-6 prolongs survival compared to published basket studies in patients with similar prognostic factors. IHC and abscopal results indicate dosing INT230-6 may also activate a T-cell mediated immune response.

Acknowledgements

N/A

Trial Registration

NCT# 03058289

References

Owelien. Historical PK data from IV administration. J Cancer Res 1977; 8.

Abstract. Wagner M, et al. Validation of the Royal Marsden Hospital (RMH) prognostic score in 100 patients with advanced sarcoma enrolled in early phase clinical trials at a major cancer center. JCO 2015. https://ascopubs.org/doi/abs/10.1200/jco.2015.33.15_suppl.10558

Ethics Approval

The protocol was approved by an institutional review board, independent ethics committee, or research ethics board at each institution. All subjects or their legally acceptable representative provided written informed consent before screening. The study was designed, undertaken, and reported in accordance with the Declaration of Helsinki, and is registered with clinicaltrial.gov with registration no NCT03058289.

479 AGEN1181, an Fc-enhanced anti-CTLA-4 antibody, alone and in combination with balstilimab (anti-PD-1) in patients with advanced solid tumors: Initial phase I results

Background

AGEN1181 is a novel anti-CTLA-4 antibody with enhanced FcyR-dependent functionality, engineered to bind high and low binding alleles of FcyRIIIA, promoting superior T cell priming, memory responses, and depletion of intratumoral T regulatory cells. Further, AGEN1181 avoids complement recruitment, predictive of better tolerability. Here we report initial safety and efficacy findings from a phase I/Ib study of AGEN1181 as monotherapy and in combination with balstilimab (BAL; anti-PD-1).

Methods

Eligible patients (pts) had advanced solid tumors refractory to standard therapies. AGEN1181 was dosed Q3W (0.1–3 mg/kg) or Q6W (1–2 mg/kg) as monotherapy, or Q6W (0.1–2 mg/kg) in combination with BAL Q2W (3 mg/kg).

Results

As of July 16th 2021, 102 pts received AGEN1181 (43 monotherapy, 59 combination). Median age, 63 years (29–83); 50.5% with ≥3 prior lines of therapy. MTD not yet reached with AGEN1181 dosing up to 3 mg/kg Q3W as monotherapy and 2 mg/kg in combination with BAL. The most common treatment-related adverse events (TRAEs) of any grade were fatigue (34.3%), diarrhea (32.4%), and nausea (19.6%) with grade ≥3 events in 21.6% (diarrhea/colitis, 11.8%, fatigue, 2.9%). Notably, no immune-related hypophysitis or pneumonitis has been observed. Discontinuation from AGEN1181 due to TRAEs occurred in 15% of pts. Grade 5 TRAEs occurred in two pts (colitis [chronic], intestinal perforation). The disease control rate in evaluable pts (completed ≥1 on-treatment scan) defined as best overall response of CR, PR, or SD ≥6 weeks was 48.1% for AGEN1181 monotherapy ≥1 mg/kg (1 CR, 3 PR, 9 SD) and 70% for combination (3 PR, 6 unconfirmed PR [uPR], 19 SD). Monotherapy responders include individual pts with MSS endometrial cancer (CR), PD-1-relapsed/refractory cervical cancer (PR), PD-1-relapsed/refractory melanoma (PR), and pancreatic cancer (PR). Enrollment is continuing in several disease expansion cohorts with combination therapy. For MSS CRC, 2 PR, 2 uPR, and 7 SD have been seen in 17 evaluable ≥1 mg/kg patients to date. In the ovarian cohort (n=6), 2 PRs and 3 SD are noted. Additional combination responders include one PR and uPR in MSS endometrial cancer, two uPRs in visceral angiosarcoma (uPRs) and one uPR in PD-1-relapsed/refractory NSCLC (uPR); the majority of the responses are recent and ongoing.

Conclusions

AGEN1181 alone and in combination with BAL demonstrates favorable tolerability and compelling clinical activity, notably in poorly immunogenic tumor types and PD-1-refractory pts. These results underscore the significant potential of AGEN1181 to expand benefit of anti-CTLA-4 therapy to a broader patient population.

Trial Registration

NCT03860272

Ethics Approval

The study obtained ethics approval at each participating center (UT Health Sciences Center at San Antonio, University of Colorado Cancer Center, St John’s Cancer Institute, and HonorHealth under WIRB Study number 1256391; USC Norris Comprehensive Cancer Center, Beth Israel Deaconess Medical Center, and MD Anderson Cancer Center, approval numbers HS19-00277, 19–132, and 140346, respectively). All patients provided written informed consent in accordance with federal, local, and institutional guidelines.

536 Intratumoral INT230–6 shows a favorable safety profile and early signs of efficacy in advanced soft tissue sarcoma with monotherapy and in combination with ipilimumab [Intensity IT-01; BMS#CA184–592]

Background

Study IT-01 evaluates INT230-6, a novel formulation of cisplatin (CIS) and vinblastine (VIN) with an amphiphilic cell penetration enhancer designed for intratumoral (IT) administration, as monotherapy or in combination with ipilimumab (IPI). 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. Further, the addition of IPI has shown to improve INT230-6 responses in preclinical models.1

Methods

IT-01 is an open-label phase 1/2 study, currently enrolling adult subjects with locally advanced, unresectable or metastatic solid tumors, including soft tissue sarcoma (STS). The study assesses the safety and efficacy of INT230-6 administered IT Q2W up to 5 treatment sessions as monotherapy or with IPI 3mg/kg IV Q3W for 4 doses. Biopsies from injected tumor are taken pretreatment and Day 28 for immunohistochemistry (IHC) analysis.

Results

22 subjects with STS (14 INT230-6 monotherapy, 8 IPI combination) have been enrolled with a median age was 65, having a median of 4 (2,10) prior therapies. INT230-6 doses of up to 175 mL (87.5 mg of CIS, 17.5 mg VIN) were injected in one or more tumors at a single dosing session, which contains doses exceeding the typical IV doses of the cytotoxic drugs.2 PK analysis estimates that 95% of INT230-6 active agents remain in the tumor. The most common (>25%) related adverse events (AEs) in evaluable monotherapy subjects (n=13) were localized pain (77%), fatigue (39%), decreased appetite (31%), and nausea (31%). The most common (>25%) related AEs in evaluable IPI subjects (n=4) were anemia (50%), fatigue (50%), pruritus (50%), and rash maculo-papular (50%). There were no related grade 4 or 5 AEs in either cohort.The median overall survival (OS) estimate for the monotherapy population (n=14) has not been reached with a median follow-up of 425 days, which compares favorably to results seen in basket studies of patients with similar prognostic factors (ECOG, LDH, # of metastatic sites).3 4 IHC results indicate influx of CD4 and CD8 T-cells without meaningful changes in circulating inflammatory cytokines. Abscopal effects in the monotherapy arm were observed in multiple lesions in 4 subjects. OS data for the 8 IPI combination subjects is immature.

Conclusions

IT INT230-6 is well tolerated when administered as monotherapy and combined with IPI in STS subjects. INT230-6 monotherapy survival compares favorably to published basket studies in STS with similar prognostic factors. IHC and abscopal effects indicate dosing may activate a T-cell mediated immune response.

Trial Registration

NCT # 03058289

References

Bloom AC, et al. Intratumorally delivered formulation, INT230-6, containingpotent anticancer agents induces protective T cell immunity and memory. OncoImmunology 2019.

Owelien. Historical PK data from IV administration. J Cancer Res 1977; 8.

Livingston J, et al. Validation of prognostic scoring and assessment of clinical benefit for patients with bone sarcomas enrolled in phase I clinical trials. Oncotarget 2016;7: 64421–64430. https://www.oncotarget.com/article/10910/

Abstract M, et al. Validation of the Royal Marsden Hospital (RMH) prognostic score in 100 patients with advanced sarcoma enrolled in early phase clinical trials at a major cancer center. JCO 2015. https://ascopubs.org/doi/abs/10.1200/jco.2015.33.15_suppl.10558Wagner

Ethics Approval

The protocol was approved by an institutional review board, independent ethics committee, or research ethics board at each institution. All subjects or their legally acceptable representative provided written informed consent before screening. The study was designed, undertaken, and reported in accordance with the Declaration of Helsinki, and is registered with clinicaltrial.gov with registration no NCT03058289.

Phase I, First-in-Human Study of the Probody Therapeutic CX-2029 in Adults with Advanced Solid Tumor Malignancies

PURPOSE

PROCLAIM-CX-2029 is a phase I first-in-human study of CX-2029, a Probody-drug conjugate targeting CD71 (transferrin receptor 1) in adults with advanced solid tumors. Although the transferrin receptor is highly expressed across multiple tumor types, it has not been considered a target for antibody-drug conjugates (ADCs) due to its broad expression on normal cells. CX-2029 is a masked form of a proprietary anti-CD71 antibody conjugated to monomethyl auristatin E, designed to be unmasked in the tumor microenvironment by tumor-associated proteases, therefore limiting off-tumor toxicity and creating a therapeutic window for this previously undruggable target.

PATIENTS AND METHODS

This was a dose-escalation, multicenter trial to evaluate the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of CX-2029. The primary endpoint was to determine the maximum tolerated dose (MTD) and cycle 1 dose-limiting toxicity (DLT). CX-2029 was administered i.v. every 3 weeks.

RESULTS

Forty-five patients were enrolled in eight dose levels. No DLTs were reported in the dose escalation through 4 mg/kg. At 5 mg/kg, there were two DLTs (febrile neutropenia and pancytopenia). Following expansion of the 4 mg/kg dose to six patients, two additional DLTs were observed (infusion-related reaction and neutropenia/anemia). Both the 4 and 5 mg/kg doses were declared above the maximum tolerated dose. The recommended phase II dose is 3 mg/kg. The most common dose-dependent hematologic toxicities were anemia and neutropenia. Confirmed partial responses were observed in three patients, all with squamous histologies.

CONCLUSIONS

The Probody therapeutic platform enables targeting CD71, a previously undruggable ADC target, at tolerable doses associated with clinical activity.See related commentary by Oberoi and Garralda, p. 4459.

Infigratinib (BGJ398) in previously treated patients with advanced or metastatic cholangiocarcinoma with FGFR2 fusions or rearrangements: mature results from a multicentre, open-label, single-arm, phase 2 study

BACKGROUND

Treatment options are sparse for patients with advanced cholangiocarcinoma after progression on first-line gemcitabine-based therapy. FGFR2 fusions or rearrangements occur in 10-16% of patients with intrahepatic cholangiocarcinoma. Infigratinib is a selective, ATP-competitive inhibitor of fibroblast growth factor receptors. We aimed to evaluate the antitumour activity of infigratinib in patients with locally advanced or metastatic cholangiocarcinoma, FGFR2 alterations, and previous gemcitabine-based treatment.

METHODS

This multicentre, open-label, single-arm, phase 2 study recruited patients from 18 academic centres and hospitals in the USA, Belgium, Spain, Germany, Singapore, Taiwan, and Thailand. Eligible participants were aged 18 years or older, had histologically or cytologically confirmed, locally advanced or metastatic cholangiocarcinoma and FGFR2 fusions or rearrangements, and were previously treated with at least one gemcitabine-containing regimen. Patients received 125 mg of oral infigratinib once daily for 21 days of 28-day cycles until disease progression, intolerance, withdrawal of consent, or death. Radiological tumour evaluation was done at baseline and every 8 weeks until disease progression via CT or MRI of the chest, abdomen, and pelvis. The primary endpoint was objective response rate, defined as the proportion of patients with a best overall response of a confirmed complete or partial response, as assessed by blinded independent central review (BICR) according to Response Evaluation Criteria in Solid Tumors, version 1.1. The primary outcome and safety were analysed in the full analysis set, which comprised all patients who received at least one dose of infigratinib. This trial is registered with ClinicalTrials.gov, NCT02150967, and is ongoing.

FINDINGS

Between June 23, 2014, and March 31, 2020, 122 patients were enrolled into our study, of whom 108 with FGFR2 fusions or rearrangements received at least one dose of infigratinib and comprised the full analysis set. After a median follow-up of 10·6 months (IQR 6·2-15·6), the BICR-assessed objective response rate was 23·1% (95% CI 15·6-32·2; 25 of 108 patients), with one confirmed complete response in a patient who only had non-target lesions identified at baseline and 24 partial responses. The most common treatment-emergent adverse events of any grade were hyperphosphataemia (n=83), stomatitis (n=59), fatigue (n=43), and alopecia (n=41). The most common ocular toxicity was dry eyes (n=37). Central serous retinopathy-like and retinal pigment epithelial detachment-like events occurred in 18 (17%) patients, of which ten (9%) were grade 1, seven (6%) were grade 2, and one (1%) was grade 3. There were no treatment-related deaths.

INTERPRETATION

Infigratinib has promising clinical activity and a manageable adverse event profile in previously treated patients with locally advanced or metastatic cholangiocarcinoma harbouring FGFR2 gene fusions or rearrangements, and so represents a potential new therapeutic option in this setting.

FUNDING

QED Therapeutics and Novartis.

Pharmacokinetics and safety of niraparib in patients with moderate hepatic impairment

PURPOSE

The purpose of this study is to characterize niraparib pharmacokinetics (PK) and safety in patients with normal hepatic function (NHF) versus moderate hepatic impairment (MHI).

METHODS

Patients with advanced solid tumors were stratified by NHF or MHI (National Cancer Institute-Organ Dysfunction Working Group criteria [bilirubin > 1.5-3 × upper limit of normal and any aspartate aminotransferase elevation]). In the PK phase, all patients received one 300 mg dose of niraparib. In the extension phase, patients with MHI received niraparib 200 mg daily; patients with NHF received 200 or 300 mg based on weight (< 77 kg, ≥ 77 kg)/platelets (< 150,000/µL, ≥ 150,000/µL). PK parameters included maximum concentration (C_max), area under the curve to last measured concentration (AUC_last) and extrapolated to infinity (AUC_inf). Safety was assessed in both phases. Exposure-response (E-R) modeling was used to predict MHI effects on exposure and safety of niraparib doses ≤ 200 mg or 300/200 mg or 200/100 mg weight/platelet regimens.

RESULTS

In the PK phase (NHF, n = 9; MHI, n = 8), mean niraparib C_max was 7% lower in patients with MHI versus NHF. Mean exposure (AUC_last, AUC_inf) was increased by 45% and 56%, respectively, in patients with MHI without impacting tolerability. In the extension phase (NHF, n = 8; MHI, n = 7), the overall safety profile was consistent with previous trials. In patients with MHI, E-R modeling predicted niraparib 200 mg reduced Grade ≥ 3 thrombocytopenia incidence, whereas a 200/100 mg regimen yielded exposures below efficacy-associated levels in 15% of patients.

CONCLUSION

These findings support adjusting the 300 mg niraparib starting dose to 200 mg QD in patients with MHI.

TRIAL REGISTRATION

NCT03359850; registered December 2, 2017.

Etiology and Outcomes of Hepatocellular Carcinoma in an Ethnically Diverse Population: The Multiethnic Cohort

BACKGROUNDS

HCC incidence varies by race/ethnicity. We characterized racial differences in underlying etiology, presentation, and survival in the linkage of Multiethnic Cohort Study with SEER and Medicare claims.

METHODS

HCC characteristics, treatment, and underlying etiology in participants were obtained. Deaths were ascertained using state death certificates and the National Death Index. Risk factors were collected via questionnaires. Cox models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for death.

RESULTS

Among 359 cases, the average age at diagnosis was 75.1. The most common etiology was hepatitis C (HCV) (33%), followed by nonalcoholic fatty liver disease (NAFLD) (31%), and different by ethnicity (p < 0.0001). African Americans (AA) (59.5%) and Latinos (40.6%) were more likely to be diagnosed with HCV-related HCC. In Japanese Americans (33.1%), Native Hawaiians (39.1%), and whites (34.8%), NAFLD was the most common etiology. Receipt of treatment varied across ethnic groups (p = 0.0005); AA had the highest proportion of no treatment (50.0%), followed by Latinos (45.3%), vs. whites (15.2%). HCC (72.2%) was the most common cause of death. In a multivariate analysis, AA (HR = 1.87; 95% CI: 1.06-3.28) had significantly higher mortality compared to whites.

CONCLUSIONS

We found significant ethnic differences in HCC underlying etiology, receipt of treatment, and outcome. The findings are important for reducing disparities.

Comparative Efficacy of Atezolizumab plus Bevacizumab and Other Treatment Options for Patients with Unresectable Hepatocellular Carcinoma: A Network Meta-Analysis

BACKGROUND

Most phase 3 clinical trials of systemic therapy for first-line unresectable hepatocellular carcinoma (HCC) have failed, with the exception of SHARP, REFLECT, and IMbrave150. We conducted indirect comparisons of therapies evaluated for first-line HCC treatment.

SUMMARY

We conducted a systematic review and meta-analysis of treatments for adults with locally advanced or metastatic unresectable HCC and no prior systemic treatment, including atezolizu-mab plus bevacizumab, sorafenib, lenvatinib, nivolumab, selective internal radiotherapy (SIRT), transarterial chemoembolization, and placebo or best supportive care. Randomized controlled trials published from January 1, 2007, to March 12, 2020, were retrieved from MEDLINE and Embase. Qualitative assessment of heterogeneity evaluated study designs, populations, and outcomes. Indirect comparisons used generalized linear models with random effects within a Bayesian framework and informative priors. We calculated relative efficacy estimates with 95% credible intervals (CrIs) and Bayesian posterior probability estimates of atezolizumab-bevacizumab being superior to other treatments. Nine clinical studies with a total of 3,897 participants were identified from 8,783 records and used to build the all-trials evidence network. Indirect comparisons suggested an improved overall survival (OS) with atezolizumab-bevacizumab versus lenvatinib (odds ratio, 0.63 [95% CrI 0.39-1.04]; with 97% Bayesian posterior probability of being superior), nivolumab (0.68 [95% CrI 0.41-1.14]; 94%), sorafenib (0.59 [95% CrI 0.39-0.87]; 99%), SIRT (0.51 [95% CrI 0.32-0.82]; 100%), or placebo/best supportive care (0.40 [95% CrI 0.25-0.64]; 100%).

KEY MESSAGES

Within the context of indirect comparisons, analyses of OS favored atezolizumab-bevacizumab versus other treatment options for patients with locally advanced or metastatic unresectable HCC.

Association of inflammatory biomarkers with clinical outcomes in nivolumab-treated patients with advanced hepatocellular carcinoma

BACKGROUND & AIMS

Nivolumab, a programmed death (PD)-1 (PD-1) inhibitor, led to durable responses, manageable safety, and increased survival in patients with advanced hepatocellular carcinoma (HCC). In our retrospective analysis, we studied the immunobiology and potential associations between biomarkers and outcomes with nivolumab in HCC.

METHODS

Fresh and archival tumour samples from dose-escalation and dose-expansion phases of the CheckMate 040 trial were analysed by immunohistochemistry and RNA sequencing to assess several inflammatory gene expression signatures, including CD274 (PD-ligand 1 [PD-L1]), CD8A, LAG3, and STAT1. Biomarkers were assessed for association with clinical outcomes (best overall response by blinded independent central review per RECIST v1.1 and overall survival [OS]).

RESULTS

Complete or partial tumour responses were observed in PD-L1-positive and PD-L1-negative patients treated with nivolumab monotherapy. Median OS was 28.1 (95% CI 18.2-n.a.) vs. 16.6 months (95% CI 14.2-20.2) for patients with tumour PD-L1 ≥1% vs. <1% (p = 0.03). Increased CD3 and CD8 showed a non-significant trend towards improved OS (both p = 0.08), and macrophage markers were not associated with OS. Tumour PD-1 and PD-L1 expression were associated with improved OS (p = 0.05 and p = 0.03, respectively). An inflammatory gene signature consisting of 4 genes was associated with improved objective response rate (p = 0.05) and OS (p = 0.01).

CONCLUSIONS

PD-1 and PD-L1 expression, biomarkers of inflammation, and inflammatory gene signatures trended with improved survival and response. While further confirmation within a larger phase III trial is needed to evaluate predictive value of these biomarkers, these exploratory analyses suggest that anti-tumour immune response may play a role in the treatment benefit of nivolumab in HCC.

LAY SUMMARY

Certain tests may be used to provide a picture of how a tumour is escaping the immune system, allowing it to continue to grow and create more tumours. Therapies such as nivolumab are designed to help the immune system fight the tumour. These tests may be used to determine how effective such therapies will be in the treatment of advanced liver cancer.

NCT NUMBER

NCT01658878.

Phase II Trial of Neoadjuvant Bevacizumab with Modified FOLFOX7 in Patients with Stage II and III Rectal Cancer

LESSONS LEARNED

Neoadjuvant bevacizumab with modified FOLFOX7 without radiation failed to meet the goal of pathological complete response rate; however, the low number of recurrence and disease-free survival in this population, with predominantly stage III, is encouraging and worth further exploration. The racial distribution of the patient population, as well as a wait time of more than 4 weeks after last chemotherapy, may have contributed to the findings.

BACKGROUND

Combination chemotherapy in lieu of radiation in rectal adenocarcinoma is under exploration in multiple trials. We evaluated the efficacy of neoadjuvant FOLFOX + bevacizumab in patients (pts) with clinical stage II and III disease.

METHODS

Pts received six cycles of bevacizumab (5 mg/kg) and modified FOLFOX7 (oxaliplatin 85 mg/m² , leucovorin 20 mg/m² , and fluorouracil [5-FU] 2,400 mg/m² ). Surgical resection was performed 6-8 weeks after completion of treatment and upon confirmation of nonmetastatic disease. We employed a Simon two-stage design and required three pathological complete responses (pCR) in the first 18 pts, with a prespecified pCR rate of 25% before moving to the next stage.

RESULTS

Seventeen pts enrolled; 65% at stage III. Median age was 57 (35-79), 65% were male, 47% were Hispanic, 35% were white, and 18% were Asian. All pts but one completed six cycles of therapy. One pCR was observed (6%), and 11 of 17 (65%) pts had pathological downstaging. One patient experienced systemic recurrence and remains on treatment. Probability of disease-free survival (DFS) at 5 years is 0.94 (SE, 0.06).

CONCLUSION

The study failed to meet the required three pCRs in the first 18 pts. The DFS in this population is encouraging and supports the hypothesis that select pts with rectal cancer may be spared from radiation.

Abstract D104: Presentation, treatment, and survival of hepatocellular carcinoma (HCC) in a diverse population: Experience of a single transplant center

Background: HCC has pathognomonic imaging and predominantly non-surgical treatment paradigms. Most patients do not have histological diagnosis, an integral part of case identification for population based cancer registries. The unique patterns of diagnosis and treatment may hamper population-based study of HCC outcomes and patterns of care. We examined racial differences in the HCC underlying etiology, presentation, treatment, and outcome in a diverse patient population in a single transplant center. Methods: HCC patients who were diagnosed/treated at Norris Comprehensive Cancer Center between 2003-2018 were identified from cancer registry. Registry data including vital status were linked with medical records. Demographics, stage at diagnosis [Barcelona Clinic Liver Cancer stage (BCLC) and Tumor Node Metastasis (TNM)], underlying etiology [hepatitis C (HCV), hepatitis B (HBV), nonalcoholic steatohepatitis (NASH), alcoholic liver disease], treatment information, and vital status were retrieved. The chi-square test was used to compare characteristics of patients by race. Multivariable Cox’s models were used to identify factors associated with overall survival. Results: A total of 619 patients (152 non-Hispanic whites (NHW), 285 Hispanics, 158 Asians, and 24 African Americans) were included in the analysis. The median follow-up was 27.0 months. The average age at diagnosis was 63 years, and 76% of patients were male. Underlying etiology varied significantly across racial groups (P&lt;0.0001); HCV was the most common etiology in African Americans (79%), NHW (70%), and Hispanics (52%), while HBV was the main etiology in Asians (54%). The proportion of NASH-related HCC was 13% in Hispanics, 8% in NHW, 4% in African Americans, and 3% in Asians. There was no significant difference in TNM stage at presentation, however, compared to NHW (36%), Asians (48%) and Hispanics (52%) were more likely to be diagnosed with Barcelona stage A (P≤0.021). Median AFP values at presentation was highest in African Americans and lowest in Hispanics (P heterogeneity ≤0.033). Only 7% of patients received no treatment, 49, 26, and 19% of patients received locoregional, systemic, or transplant respectively. There was no difference in access to these treatments by race, despite significant differences in the insurance status. In the multivariate analyses, higher stage at presentation, NASH-related HCC, and non-transplant treatment were associated with worse survival. Surveillance for HCC showed trend for improved survival (P=0.057). Conclusion: Among patients with appropriate and similar access to care prognosis of HCC is driven by stage, underlying etiology, and curative treatment. Surveillance may improve survival in patients with appropriate access to care.

Citation Format: Afsaneh Barzi, Ravi Patel, Varsha Tulpule, Robert Albertian, Bo Yu, Gwendolyn Lynch, Anthony El-Khoueiry, Songren Wang, Veronica Wendy Setiawan. Presentation, treatment, and survival of hepatocellular carcinoma (HCC) in a diverse population: Experience of a single transplant center [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D104.

Diagnosis and management of toxicities of immune checkpoint inhibitors in hepatocellular carcinoma

Immune checkpoint inhibitors (ICIs) have reshaped cancer therapy. ICIs enhance T cell activation through various mechanisms and may help reverse the exhausted phenotype of tumour-infiltrating lymphocytes. However, disrupting the key role that checkpoint molecules play in immune homeostasis may result in autoimmune complications. A broad range of immune-related adverse events (irAEs) involve almost every organ but mostly affect the skin, digestive system, lung, endocrine glands, nervous system, kidney, blood cells, and musculoskeletal system. They are usually manageable but can be life-threatening. The incidence of irAEs is not very different in patients with hepatocellular carcinoma (HCC) compared to other tumour types, although there is a trend towards a higher incidence of hepatic irAEs. HCC usually develops on a background of cirrhosis with associated systemic manifestations. Extrahepatic organ dysfunction in cirrhosis may cause signs and symptoms that overlap with irAEs or increase their severity. Available guidelines for the management of irAEs have not specifically considered the assessment of toxicities in the context of patients with liver cancer and cirrhosis. This review addresses the toxicity profile of ICIs in patients with HCC, focusing on the challenges that the underlying liver disease poses to their diagnosis and management. Challenges include late recognition, inadequate work-up and delayed treatment, overdiagnosis and inappropriate interruption of ICIs, complications caused by immunosuppressive therapy, and increased cost. A specific algorithm for the management of hepatic irAEs is provided.

Mandatory Research Biopsy Requirements Delay Initiation of Clinical Trials

Background: There has been an increasing requirement for fresh tumor tissue to enroll in clinical trials in order to look for specific biomarkers. This has been shown to increase screening duration and increase screen failure rates. It was important to corroborate these results in other centers. Methods: This study is a non-randomized retrospective analysis of patients in one subset of patients seen by research nurses who operated in the standard head/neck and lung team not including patients in the phase 1 program. All patients were enrolled in clinical trials from January 16, 2013 to May 28, 2018 at USC Norris Comprehensive Cancer Institute in Los Angeles. Patients who were required to give fresh research biopsies prior to intervention were part of the research biopsy group. Results: In total, 76 patients were analyzed in this study. Thirty-three patients were in the research biopsygroup and 43 patients were in the no biopsy group. Trials that required a fresh biopsy had a longer median screening duration (30 vs. 14 days) than trials that did not require a biopsy (p < 0.0001). Conclusions: Our study shows that requiring biopsies prior to clinical trial treatment results in a statistically significant delay in treatment. The informed consent forms that were part of clinical trials involving mandatory research biopsies did not reflect this delay in treatment. However, these delays did not result in a statistically significant decrease in number of days on trial or days until progression of disease.

Abstract 3183: Initial safety of AFP SPEAR T-cells in patients with advanced hepatocellular carcinoma

Background: Genetically engineered affinity-enhanced autologous SPEAR T-cells (AFPc332T-cells) directed towards the HLA-A*02-restricted AFP peptide FMNKFIYEI are being tested in an ongoing Phase 1 trial to evaluate safety and antitumor activity in patients with hepatocellular carcinoma (HCC) (NCT03132792).

Methods: This is a first-in-human study in HCC patients not amenable to transplant, resection, or loco-regional therapy and failed/intolerant/refused standard of care treatment. Patients must be HLA-A*02:01+ or 02:642+. Patients must have AFP expression by immunohistochemistry at ≥1+ in ≥20% HCC tumor cells or serum AFP ≥400 ng/ml and ≤5% IHC AFP in non-cancerous liver tissue. Up to 24 patients will be enrolled using a modified 3+3 design. Lymphodepletion is with fludarabine 20 mg/m2/day and cyclophosphamide 500 mg/m2/day on days -7 to -5. The initial transduced cell dose is 0.1×109 cells; additional doses are 1×109 and 5×109. Cohort expansion will occur at maximum tolerated dose and may allow doses up to 10×109 transduced cells. Dose-limiting toxicities (DLTs) are adjudicated by a Safety Review Committee.

Results: As of 21Sep18, 2 patients were treated with 0.1×109 AFP SPEAR T-cells. Both had cytopenias related to lymphodepleting chemotherapy. Neither experienced cytokine release syndrome or SAEs during initial hospitalization. Liver chemistries show no AFPc332T-related hepatotoxicity. AFPc332T-cells were detected in both patients. One patient had grade 1 cognitive disturbance on day 8. This patient had SAEs of biliary obstruction at week 9 treated with stenting, and abdominal pain at week 12; neither was considered related to AFPc332T. Post-treatment imaging shows stable disease at week 12 by RECIST v1.1. Serum AFP was 12665 ng/ml at baseline, 29616 ng/ml at week 2, and 16,489 at week 12. Week 8 tumor biopsy showed diffuse tissue necrosis with cholestasis suspicious for necrotic tumor cells. No viable tissue was present. Immunostaining for CD3 showed numerous T-cells and T-cell aggregates within the necrotic tissue. The 2nd patient had no SAEs reported; post-treatment imaging is pending.

Conclusions: AFP SPEAR T-cells at the 0.1×109 cell dose show no evidence of on target or off target toxicity in the first 2 patients. No protocol defined DLTs were reported. Current data support continued investigation of AFPc332T-cells. Updated data will be presented.

Citation Format: Lipika Goyal, Matthew Frigault, Tim Meyer, Lynn G. Feun, Jordi Bruix, Anthony El-Khoueiry, Petr Hausner, Bruno Sangro, Theodore T. Pierce, Elliot Norry, Sulabha Ranganathan, Rafael G. Amado, Richard S. Finn. Initial safety of AFP SPEAR T-cells in patients with advanced hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3183.

Abstract 2675: Assessment of inflammation biomarkers in relation to clinical outcomes in nivolumab-treated patients with advanced hepatocellular carcinoma in CheckMate 040

Introduction: Nivolumab (NIVO), a programmed death-1 (PD-1) inhibitor, demonstrated durable responses, manageable safety, and promising long-term survival in patients (pts) with advanced hepatocellular carcinoma (HCC), regardless of etiology, with/without prior sorafenib treatment in CheckMate 040 (El-Khoueiry, Lancet 2017). NIVO is approved in several countries for the treatment of sorafenib-experienced pts with advanced HCC. We report findings on additional exploratory biomarker analyses from NIVO-treated pts with advanced HCC from CheckMate 040.

Methods: In CheckMate 040, pts with advanced HCC received NIVO monotherapy in the phase 1/2 dose-escalation (ESC; 0.1–10 mg/kg) and dose-expansion (EXP; 3 mg/kg) phases every two weeks, regardless of programmed death ligand 1 (PD-L1) status and HCC etiology. For pts in the ESC and EXP phases receiving NIVO 3 mg/kg, baseline tumor biopsy samples were analyzed using immunohistochemistry for the following markers: expression of PD-L1, PD-1, T-cell markers (CD3, CD4, CD8, FOXP3), and macrophages (CD68, CD163). Baseline tumor biopsy samples from a subset of pts in the ESC and EXP phases were evaluated using RNA sequencing to assess inflammatory signatures. Results were correlated with clinical outcomes: response (complete response [CR] + partial response [PR] vs stable disease [SD] or progressive disease [PD]) and overall survival (OS). Associations with characteristics such as etiology and geographical region (non-Asia vs Asia) were also assessed. The data cutoff date was June 2018.

Results: In pts with evaluable data (n = 184), increased tumor cell PD-L1 expression was significantly associated with response (CR+PR vs SD [P = 0.00009]; CR+PR vs PD [P = 0.0007]) and OS (P = 0.03). Increased PD-1 expression was also significantly associated with response (CR+PR vs SD [P = 0.05]; CR+PR vs PD [P = 0.009]) and OS (P = 0.05). Of the T-cell markers assessed, CD3 expression was significantly associated with response (n = 182, CR+PR vs SD; P = 0.05). In pts positive for CD3 or CD8, there was a trend towards improved survival (P = 0.08). No association between CD68- and CD163-expression and clinical outcomes was observed. For the subset of pts for whom RNA sequencing data was available (n = 37), the median Bristol-Myers Squibb (BMS) inflammatory signature score was significantly higher in pts with a PR vs SD (P = 0.05) and was correlated with improved OS (P = 0.01). For all of the inflammation markers assessed, there was no association with HCC etiology or geographical region.

Conclusions: In pts with advanced HCC, improved survival and response to nivolumab may be associated with higher PD-L1, PD-1 and CD3 expression, and higher BMS inflammatory signature scores. These data support the role of PD-1 inhibition in the treatment of HCC. Further investigation of these biomarkers is required.

Citation Format: Ignacio Melero, Jaclyn Neely, Bruno Sangro, Richard Finn, Ghassan K. Abou-Alfa, Ann-Lii Cheng, Thomas Yau, Junji Furuse, Joong-Won Park, Samir Wadhawan, Hao Tang, Christine Delacruz, Carlos Baccan, Zach Boyd, Anthony El-Khoueiry. Assessment of inflammation biomarkers in relation to clinical outcomes in nivolumab-treated patients with advanced hepatocellular carcinoma in CheckMate 040 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2675.

Adjuvant Therapy for Resected Biliary Tract Cancer: ASCO Clinical Practice Guideline

PURPOSE

To develop an evidence-based clinical practice guideline to assist in clinical decision making for patients with resected biliary tract cancer.

METHODS

ASCO convened an Expert Panel to conduct a systematic review of the literature on adjuvant therapy for resected biliary tract cancer and provide recommended care options for this patient population.

RESULTS

Three phase III randomized controlled trials, one phase II trial, and 16 retrospective studies met the inclusion criteria.

RECOMMENDATIONS

Based on evidence from a phase III randomized controlled trial, patients with resected biliary tract cancer should be offered adjuvant capecitabine chemotherapy for a duration of 6 months. The dosing used in this trial is described in the qualifying statements, while it should be noted that the dose of capecitabine may also be determined by institutional and regional practices. Patients with extrahepatic cholangiocarcinoma or gallbladder cancer and a microscopically positive surgical resection margin (R1 resection) may be offered chemoradiation therapy. A shared decision-making approach is recommended, considering the risk of harm and potential for benefit associated with radiation therapy for patients with extrahepatic cholangiocarcinoma or gallbladder cancer. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines .

Integrative Epigenetic Analysis Reveals Therapeutic Targets to the DNA Methyltransferase Inhibitor Guadecitabine (SGI-110) in Hepatocellular Carcinoma

There is an urgent need to develop more effective therapies for hepatocellular carcinoma (HCC) because of its aggressiveness. Guadecitabine (SGI-110) is a second-generation DNA methyltransferase inhibitor (DNMTi), which is currently in clinical trials for HCC and shows greater stability and performance over first-generation DNMTis. In order to identify potential therapeutic targets of SGI-110 for clinical trials, HCC cell lines (SNU398, HepG2, and SNU475) were used to evaluate the effects of transient SGI-110 treatment by an integrative analysis of DNA methylation, nucleosome accessibility, gene expression profiles, and its clinical relevance by comparison to The Cancer Genome Atlas (TCGA) HCC clinical data. Each HCC cell line represents a different DNA methylation subtype of primary HCC tumors based on TCGA data. After SGI-110 treatment, all cell lines were sensitive to SGI-110 with prolonged antiproliferation effects. Expression of up-regulated genes, including tumor suppressors, was positively correlated with nucleosome accessibility and negatively correlated with gene promoter DNA methylation. Alternatively, expression of down-regulated genes, such as oncogenes, was negatively correlated with nucleosome accessibility and positively correlated with gene body DNA methylation. SGI-110 can also act as a dual inhibitor to down-regulate polycomb repressive complex 2 (PRC2) genes by demethylating their gene bodies, resulting in reactivation of PRC2 repressed genes without involvement of DNA methylation. Furthermore, it can up-regulate endogenous retroviruses to reactivate immune pathways. Finally, about 48% of frequently altered genes in primary HCC tumors can be reversed by SGI-110 treatment.

CONCLUSION

Our integrative analysis has successfully linked the antitumor effects of SGI-110 to detailed epigenetic alterations in HCC cells, identified potential therapeutic targets, and provided a rationale for combination treatments of SGI-110 with immune checkpoint therapies.

Abstract 779: Integrative analysis reveals therapeutic targets to the DNA methyltransferase inhibitor SGI-110 in hepatocellular carcinoma

Objective There is an urgent need for developing more effective therapies for Hepatocellular carcinoma (HCC) because of its aggressiveness. Guadecitabine (SGI-110) is a second-generation DNA methyltransferase inhibitor (DNMTi) currently in clinical trials for HCC and shows greater stability and performance over first generation DNMTi. The aim of this study is to identify potential therapeutic targets of SGI-110 for clinical trials.

Design HCC cell lines (SNU398, HepG2 and SNU475) were used to evaluate effects of SGI-110 by an integrative analysis of DNA methylation, nucleosome accessibility and gene expression profiles following the transient SGI-110 treatment and its clinic relevant by comparing HCC clinic data from TCGA.

Results These HCC cell lines represent the three DNA methylation subtypes of primary HCC tumors based on TCGA data. After SGI-110 treatment, all cell lines were sensitive to SGI-110 with prolonged anti-proliferation effects. Up-regulated genes including tumor suppressors were positively correlated with nucleosome accessibility and negatively correlated with gene promoter DNA methylation, while the down-regulated genes, such as oncogenes, were negatively correlated with nucleosome accessibility and positively correlated with gene body DNA methylation. Furthermore, SGI-110 down-regulated PRC2 complex genes by demethylating their gene bodies, resulting in re-activation of PRC2 repressed gene promoters which are independent on DNA methylation. In addition, SGI-110 up-regulated endogenous retroviruses (ERVs) to reactivate immune pathways. Finally, about 45% of frequently altered genes in primary HCC tumors can be re-shaped into a “normal like” expression status through the treatment.

Conclusion Our integrative analysis has successfully linked the anti-tumor effects of SGI-110 to detailed epigenetic alterations in HCC cells and identified potential therapeutic targets. We also provide rationale of combination treatment with immune checkpoint therapies.

Citation Format: Minmin Liu, Toshinori Hinoue, Wanding Zhou, Hitoshi Ohtani, Anthony El-Khoueiry, John Daniels, Casey O'Connell, Tanya B. Dorff, Daniel J. Weisenberger, Gangning Liang. Integrative analysis reveals therapeutic targets to the DNA methyltransferase inhibitor SGI-110 in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 779.

A Randomized Phase II Open-Label Multi-Institution Study of the Combination of Bevacizumab and Erlotinib Compared to Sorafenib in the First-Line Treatment of Patients with Advanced Hepatocellular Carcinoma

OBJECTIVES

To investigate the clinical efficacy and tolerability of the combination of bevacizumab (B) and erlotinib (E) compared to sorafenib (S) as first-line treatment for patients with advanced hepatocellular carcinoma (HCC).

METHODS

A total of 90 patients with advanced HCC, Child-Pugh class A-B7 cirrhosis, and no prior systemic therapy were randomly assigned (1: 1) to receive either 10 mg/kg B intravenously every 14 days and 150 mg E orally daily (n = 47) (B+E) or 400 mg S orally twice daily (n = 43). The primary endpoint was overall survival (OS). Secondary endpoints included event-free survival (EFS), objective response rate based on Response Evaluation Criteria in Solid Tumors (RECIST 1.1), time to progression, and safety and tolerability.

RESULTS

The median OS was 8.55 months (95% CI: 7.00-13.9) for patients treated with B+E and 8.55 months (95% CI: 5.69-12.2) for patients receiving S. The hazard ratio (HR) for OS was 0.92 (95% CI: 0.57-1.47). The median EFS was 4.37 months (95% CI: 2.99-7.36) for patients receiving B+E and 2.76 months (95% CI: 1.84-4.80) for patients receiving S. The HR for EFS was 0.67 (95% CI: 0.42-1.07; p = 0.09), favoring B+E over S. When OS was assessed among patients who were Child-Pugh class A, the median OS was 11.4 months (95% CI: 7.5-15.7) for patients treated with B+E (n = 39) and 10.26 months (95% CI: 5.9-13.0) for patients treated with S (n = 38) (HR = 0.88; 95% CI: 0.53-1.46).

CONCLUSIONS

There was no difference in efficacy between the B+E and S arms, although the safety and tolerability profile tended to favor B+E over S based on competing risk analysis.

Combination epigenetic therapy in metastatic colorectal cancer (mCRC) with subcutaneous 5-azacitidine and entinostat: a phase 2 consortium/stand up 2 cancer study

Purpose

Therapy with demethylating agent 5-azacitidine and histone deacetylase inhibitor entinostat shows synergistic re-expression of tumor-suppressor genes and growth inhibition in colorectal (CRC) cell lines and in vivo studies.

Experimental Design

We conducted a phase II, multi-institutional study of the combination in metastatic CRC patients. Subcutaneous azacitidine was administered at 40 mg/m2 days 1-5 and 8-10 and entinostat was given 7 mg orally on days 3 and 10. An interim analysis indicated toxicity crossed the pre-specified safety boundary but was secondary to disease. A 2^nd cohort with added eligibility restrictions was accrued: prior therapies were limited to no more than 2 or 3 (KRAS-mutated and KRAS-wildtype cancers, respectively) and <30% of liver involvement. The primary endpoint was RECIST response. Serial biopsies were performed at baseline and after 2 cycles of therapy.

Results

Forty-seven patients were enrolled (24:Cohort 1, 23:Cohort 2). Patients were heavily pre-treated (median prior therapies 4: Cohort 1 and 2.5: cohort 2). No responses were observed. Median progression-free survival was 1.9 months; overall survival was 5.6 and 8.3 months in Cohorts 1 and 2, respectively. Toxicity was tolerable and as expected. Unsupervised cluster analysis of serial tumor biopsies suggested greater DNA demethylation in patients with PFS above the median.

Conclusion

In this first trial of CRC patients with combination epigenetic therapy, we show tolerable therapy without significant clinical activity as determined by RECIST responses. Reversal of hypermethylation was seen in a subset of patients and correlated with improved PFS.

Abstract P5-21-32: AZD5363 in combination with fulvestrant in AKT1-mutant ER-positive metastatic breast cancer

Background: E17K is the most common activating AKT1 mutation and was shown to be a therapeutic target in this multipart Phase 1 study of AZD5363 (NCT01226316), an oral and selective pan-AKT kinase inhibitor, in patients (pts) with AKT1-mutant (AKT1m) advanced solid tumors. In heavily pretreated AKT1m (E17K) ER+ metastatic breast cancer (MBC) pts, monotherapy achieved an objective response rate (ORR) of 20% and a median progression-free survival of 5.5 months (95% CI, 2.9−6.9). Suppression of PI3K-AKT signaling results in induction of ER-dependent transcription, potentially limiting the response to single-agent PI3K/AKT inhibitors. We explored the hypothesis that simultaneous inhibition of AKT and ER signaling would enhance antitumor efficacy in AKT1m ER+ MBC.

Methods: In an expansion of this study, we administered oral AZD5363 400 mg twice daily, 4 days on 3 days off, and fulvestrant 500 mg, to AKT1m (detected in tumor tissue by local screening and/or plasma BEAMing) ER+ HER2– MBC pts, enrolled into a fulvestrant-naïve (FN) or fulvestrant-resistant (FR) cohort (max 24 pts/cohort). Key objectives included safety and efficacy by RECIST v1.1. We report results of a planned interim analysis conducted when 12 pts/cohort reached maturity for assessment of 24-week clinical benefit rate (CBR), defined as the percentage of responders plus those with stable disease (SD) ≥24 weeks.Data cut-off occurred in June 2017.

Results: At the time of analysis, 24 AKT1m pts (23 E17K, 1 E40K) had received treatment. FN had more visceral disease (83.3% vs 66.7%) and ER+/PR– status (25% vs 8.3%) than FR. Median number of prior anticancer regimens was 4.5 (range 1–9) and 6 (2–11) in FN and FR, respectively, with more chemotherapy (CT) and less hormone therapy (HT) exposure in FN vs FR [3 (0–5) vs 2 (0–6) and 2 (0–4) vs 4 (2–6) prior CT and HT, respectively]. Prior palbociclib was received by 1 (8.3%) and 4 (33.3%) pts in FN and FR, respectively. Clinical efficacy is detailed below; CBR was 33% and 42% in FN and FR, respectively (Table 1). There was 1 unconfirmed partial response in patients treated with prior palbociclib and 3 SD. At data cut-off, 18 pts had discontinued treatment: progressive disease, n=12; adverse events (AEs), n=2; other reasons, n=4. AEs were observed in all 24 pts, most commonly diarrhea (71%), nausea (63%), vomiting and decreased appetite (29%). Grade ≥3 AEs occurred in 13 (54%) pts, most frequently maculopapular rash (n=3), nausea, hyperglycemia and back pain (all n=2). Dose reduction due to AEs occurred in 3 pts.

Table 1. Clinical efficacy FNFREligible for interim data cut-off, n1212ORR, n (%)2 (17)4 (33)CBR, n (%)4 (33)5 (42)Confirmed response (complete/partial response), n (%)2 (17)4 (33)SD ≥24 weeks, n (%)2 (17)1 (8)

Conclusions: AZD5363 plus fulvestrant is clinically active in AKT1m ER+ MBC pts, including in pts with demonstrated prior resistance to fulvestrant. Comparatively lower efficacy was observed in the FN cohort; factors that may have potentially contributed (eg disease characteristics) will be explored. cfDNA and genomic data will also be presented.

Citation Format: Smyth LM, Oliveira M, Ciruelos E, Tamura K, El-Khoueiry A, Mita A, You B, Renouf DJ, Sablin M-P, Lluch A, Mayer IA, Bando H, Yamashita H, Ambrose H, de Bruin E, Carr TH, Corcoran C, Foxley A, Lindemann JPO, Maudsley R, Pass M, Rutkowski A, Schiavon G, Banerji U, Scaltriti M, Taylor BS, Chandarlapaty S, Baselga J, Hyman DM. AZD5363 in combination with fulvestrant in AKT1-mutant ER-positive metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-32.

Abstract P5-21-05: Withdrawn

This abstract was withdrawn by the authors.