Predictive biomarkers for the efficacy of nivolumab as ≥ 3rd-line therapy in patients with advanced gastric cancer: a subset analysis of ATTRACTION-2 phase III trial

Purpose

The phase 3 ATTRACTION-2 study demonstrated that nivolumab monotherapy improved survival compared to placebo in patients with pretreated advanced gastric cancer (AGC). However, the efficacy of nivolumab seems to be limited to a subset of patients.

Materials and methods

The predictive values of blood neutrophil–lymphocyte ratio (NLR), serum Na, PD-L1 expression, MSI status, tumor EBV infection, and tumor mutation burden (TMB) were investigated in patients with AGC refractory to ≥2 lines of chemotherapy enrolled from Asan Medical Center in ATTRACTION-2 study.

Results

All 45 patients were analyzed; nivolumab (n = 28) and placebo (n = 17) groups. The objective response rate, median progression-free survival (PFS), and overall survival (OS) were 16.7%, 1.6 months, and 8.1 months in nivolumab group and 0%, 1.6 months and 6.5 months in placebo group. When comparing nivolumab with the placebo group, tumor PD-L1 expression, blood NLR, and serum Na were significant predictive factors of PFS and OS. A multivariate analysis revealed that PD-L1 ( +) and low NLR (≤ 2.9, median) were associated with better PFS. In the nivolumab group, PD-L1 ( +), low NLR, and normal Na (≥ 135 mmol/L) were associated with higher response and disease control rates, while tumor EBV infection and TMB were not.

Conclusion

Tumor PD-L1 expression, blood NLR, and serum Na could be predictive biomarkers for the efficacy of nivolumab in previously treated cases of AGC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09488-2.

Assessment of hyperprogression versus the natural course of disease development with nivolumab with or without ipilimumab versus placebo in phase III, randomized, controlled trials

BACKGROUND

Retrospective studies have suggested a potential risk of hyperprogressive disease (HPD) in patients receiving immune checkpoint inhibitors (ICIs). We compared the incidence of HPD during treatment with nivolumab±ipilimumab versus natural tumor progression with placebo in post hoc analyses of two randomized, double-blind clinical trials.

METHODS

ATTRACTION-2 randomized patients with advanced gastric or gastroesophageal junction cancer (GC/GEJC) and progression on ≥2 prior regimens to nivolumab 3 mg/kg Q2W or placebo. CheckMate 451 randomized patients with extensive-disease small cell lung cancer (ED SCLC) and ongoing complete/partial response or stable disease after first-line chemotherapy to nivolumab 240 mg Q2W, nivolumab 1 mg/kg+ipilimumab 3 mg/kg Q3W for four doses then nivolumab 240 mg Q2W, or placebo. Patients receiving ≥1 dose of study drug and with tumor scans at baseline and the first on-treatment evaluation were included in the HPD analyses. HPD definitions were ≥20%, ≥50%, and ≥100% increase in target lesion sum of the longest diameters (SLD) at the first on-treatment assessment.

RESULTS

In the ATTRACTION-2 HPD-evaluable population, 243 patients received nivolumab and 115 placebo. Fewer patients receiving nivolumab versus placebo had increases in SLD ≥20% (33.7% vs 46.1%) and ≥50% (6.2% vs 11.3%); similar proportions had increases in SLD ≥100% (1.6% vs 1.7%). In the CheckMate 451 HPD-evaluable population, 177 patients received nivolumab, 179 nivolumab+ipilimumab, and 175 placebo. Fewer patients receiving nivolumab or nivolumab+ipilimumab versus placebo had increases in SLD ≥20% (27.1%, 27.4% vs 45.7%), ≥50% (10.2%, 11.2% vs 22.3%), and ≥100% (2.8%, 2.8% vs 6.3%).

CONCLUSIONS

Nivolumab±ipilimumab was not associated with an increased rate of progression versus placebo in patients with GC, GEJC, or ED SCLC, suggesting that previous reports of HPD may reflect the natural disease course in some patients rather than ICI-mediated progression.

TRIAL REGISTRATION NUMBER

NCT02538666; NCT02267343.

Association of magnitude and consistency of PD-L1 expression and other variables associated with benefit from immune checkpoint inhibition (ICI): Systematic review and meta-analysis of 14 phase 3 trials in advanced gastroesophageal cancer (GEC)

344

Background: ICI with anti-PD-1 therapy was approved by the US FDA as 1st/2nd-line treatment of advanced GEC regardless of PD-L1 status. It is argued that patients (pts) with PD-L1-low GEC do not benefit from ICI. To avoid spurious exclusion of pts, we systematically reviewed phase 3 trials to assess the magnitude and consistency of PD-L1 to predict benefit from ICI. We also examined other potential predictive factors to understand their magnitude and consistency in comparison with PD-L1 status. Methods: MEDLINE, Embase, Scopus, Web of Science, and Cochrane Central Register were searched for all randomized clinical trials (RCT; 2000-2021) in advanced GEC comparing ICI, alone or with chemotherapy, vs standard of care (SOC). The primary endpoint was overall survival (OS). Study screening, data abstraction, and bias assessment were done independently by two reviewers per PRISMA guidelines. The mean HR for ICI vs SOC was calculated by random effects model. The predictive value of a factor was quantified using relative magnitude and consistency (table). Results: 14 RCTs at low risk of bias were included (N = 9,210 pts; KN62, CM649, CM648, ESCORT1st, KN590, ATT4, JAV100, KN181, KN61, ATT3, ESCORT, RATIONALE302, JAV300, ATT2). 6 trials were 1st-line, 8 were after 1st-line. Treatment comparisons were ICI + chemo vs chemo (6 trials), ICI vs chemo (9 trials), and ICI vs placebo (1 trial). ICI was always anti-PD-1/-L1 (1 trial also had anti-CTLA-4). Table shows primary results. To enable head to head comparisons, subgroup analyses of trials containing both levels of a factor or having similar design were done and generally yielded consistent results. Conclusions: PD-L1 CPS is the strongest predictive biomarker, after MSI, for OS benefit from ICI-containing therapy vs SOC. Additional research on gender is warranted.[Table: see text]

Phase 3 randomized, open-label, multicenter study of tremelimumab (T) and durvalumab (D) as first-line therapy in patients (pts) with unresectable hepatocellular carcinoma (uHCC): HIMALAYA

379

Background: A single priming dose of T (anti-CTLA-4) added to D (anti-PD-L1) in the STRIDE (Single T Regular Interval D) regimen, formerly T300+D, showed encouraging clinical activity and limited toxicity in a phase 2 uHCC study (Study 22, NCT02519348), suggesting single exposure to T is sufficient to improve upon D activity. HIMALAYA (NCT03298451) evaluated the efficacy and safety of STRIDE or D vs sorafenib (S) in uHCC. Methods: HIMALAYA is an open-label, multicenter, phase 3 study, in which pts with uHCC and no prior systemic therapy were initially randomized to STRIDE (T 300 mg plus D 1500 mg [one dose] plus D 1500 mg every 4 weeks [Q4W]), D (1500 mg Q4W), S (400 mg twice daily), or T 75 mg Q4W (4 doses) plus D 1500 mg Q4W (T75+D). Recruitment to T75+D ceased after a planned analysis of Study 22 showed T75+D did not meaningfully differ from D. The primary objective was overall survival (OS) for STRIDE vs S. The secondary objective was OS noninferiority (NI) of D to S (NI margin: 1.08). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR; RECIST v.1.1), duration of response (DoR), and safety. Results: In total, 1171 pts were randomized to STRIDE (N=393), D (N=389), or S (N=389). At data cutoff (DCO), the primary objective was met: OS was significantly improved for STRIDE vs S (hazard ratio [HR], 0.78; 96% confidence interval [CI], 0.65–0.92; p=0.0035; Table). D met the objective of OS NI to S (HR, 0.86; 96% CI, 0.73–1.03). ORRs were higher for STRIDE (20.1%) and D (17.0%) than for S (5.1%). No new safety signals were identified. Grade 3/4 treatment-related adverse events (TRAEs) occurred in 25.8% (STRIDE), 12.9% (D), and 36.9% (S) of pts. Grade 3/4 hepatic TRAEs occurred in 5.9% (STRIDE), 5.2% (D), and 4.5% (S) of pts. No TRAE of esophageal varices hemorrhage occurred. Rates of TRAEs leading to discontinuation were 8.2% (STRIDE), 4.1% (D), and 11.0% (S). Conclusions: HIMALAYA was the first large phase 3 trial with a diverse, representative uHCC population and extensive long-term follow-up to assess both mono- and combination immunotherapy. D was noninferior to S with favorable safety. The combination of a single priming dose of T plus D in STRIDE displayed superior efficacy and a favorable benefit-risk profile vs S. STRIDE is a proposed, novel, first-line standard of care systemic therapy for uHCC. Clinical trial information: NCT03298451. [Table: see text]

Safety and efficacy of durvalumab plus bevacizumab in unresectable hepatocellular carcinoma: Results from the phase 2 study 22 (NCT02519348)

436

Background: The phase 2 Study 22 trial (NCT02519348) investigated durvalumab (anti-programmed cell death ligand-1 [PD-L1] antibody) and tremelimumab (anti-cytotoxic T-lymphocyte associated antigen 4 antibody) as monotherapy, or durvalumab in combination with tremelimumab or bevacizumab (anti-vascular endothelial growth factor [VEGF] antibody), for the treatment of patients with unresectable hepatocellular carcinoma (uHCC). Results of Study 22 that evaluated durvalumab and tremelimumab as monotherapy or in combination were reported previously. PD-L1 inhibition plus VEGF inhibition with bevacizumab may exhibit an additive effect to improve clinical activity. Herein, we report results from a single-arm cohort of Study 22, evaluating durvalumab plus bevacizumab as first-line treatment in patients with uHCC. Methods: Patients with uHCC who had not received any prior systemic therapy were administered durvalumab 1120 mg plus bevacizumab 15 mg/kg once every 3 weeks. Adequate endoscopic therapy according to institutional standards was required for patients with a history of gastrointestinal bleeding for >12 months or those at high risk for esophageal varices. The primary endpoint was safety. Secondary endpoints included confirmed objective response rate (ORR; assessed by blinded independent central review [BICR] according to RECIST v1.1), duration of response (DoR; RECIST v1.1 by BICR) and overall survival (OS). Results: At the data cut-off (November 6, 2020), 47 patients were allocated to receive treatment. Median total treatment duration was 6.2 months (durvalumab) and 4.1 months (bevacizumab). Thirty-three (70.2%) patients experienced an adverse event possibly related to treatment (TRAE). Grade 3 or 4 TRAEs occurred in 4 (8.5%) patients; serious TRAEs occurred in 5 (10.6%) patients, including gastric ulcer perforation, ascites, and liver tumor rupture, possibly related to bevacizumab, and raised creatinine and pneumonitis, possibly related to durvalumab. There were 3 (6.4%) discontinuations and no deaths associated with TRAEs. Objective responses (RECIST 1.1 by BICR) were confirmed in 10 patients (ORR, 21.3%; 95% CI, 10.7–35.7); median DoR (RECIST 1.1 by BICR) was not reached. Median OS was not reached (95% CI, 12.52 months–non-estimable). Conclusions: Durvalumab plus bevacizumab was well tolerated and showed promising clinical activity in patients with uHCC. Durvalumab with or without bevacizumab in combination with transarterial chemoembolization is being investigated as locoregional therapy in patients with HCC not amenable to curative treatment in the phase 3 EMERALD-1 study (NCT03778957), and durvalumab with or without bevacizumab is being investigated in patients with HCC at high risk of recurrence after curative treatment in the phase 3 EMERALD-2 study (NCT03847428). Clinical trial information: NCT02519348.

[The prospects of DNA damage repair variants guiding platinum compounds in the treatment of triple negative breast cancer]

Triple negative breast cancer (TNBC) is prone to recurrence and metastasis, which is the subtype of poorest prognosis. Chemotherapy is the main treatment, although there is lack of effective adjuvant chemotherapy regimens. The unsatisfactory efficacy of chemotherapy has been a bottleneck in improving the outcome of TNBC. Platinum compounds act directly on DNA to kill tumor cells, and they have a stronger killing effect on tumor cells carrying DNA damage repair (DDR) defects, which is an important entry point to improve the efficacy of TNBC. Biomarkers for predicting the efficacy of platinum drugs in TNBC treatment have always been a hot topic. The DDR pathway contains a large number of related genes, and recent studies have shown that deficiencies in the DDR pathway may be associated with the efficacy of platinum drugs, which is expected to be a biomarker for predicting the efficacy of platinum drugs in breast cancer treatment.

INTRIGUE: A phase III, randomized, open-label study to evaluate the efficacy and safety of ripretinib versus sunitinib in patients with advanced gastrointestinal stromal tumor previously treated with imatinib

359881

Background: Sunitinib is approved for advanced gastrointestinal stromal tumor (GIST) after imatinib failure. Ripretinib, a broad-spectrum KIT and PDGFRA switch-control tyrosine kinase inhibitor (TKI), is indicated for the treatment of adult patients (pts) with GIST who received prior treatment with 3 or more TKIs, including imatinib. We compared the efficacy and safety of ripretinib vs sunitinib in pts with advanced GIST who progressed on or were intolerant to imatinib. Methods: This multicenter, global, randomized, open-label phase 3 study (NCT03673501) enrolled adult pts with GIST who progressed on or had intolerance to imatinib. Pts were randomized 1:1 to ripretinib 150 mg once daily (QD) or sunitinib 50 mg QD (4 wks on/2 wks off). Randomization was stratified by KIT mutational status and imatinib intolerance. The primary endpoint was progression-free survival (PFS) by independent radiologic review (IRR) using modified RECIST version 1.1. Key secondary endpoints were objective response rate (ORR) by IRR and overall survival (OS). Hierarchical testing was performed for primary and key secondary endpoints in a prespecified sequence; testing pts with a KIT exon 11 primary mutation (Ex11 intention-to-treat [ITT] population) preceded the all-patient (AP) ITT population. Data cutoff was 1 Sep 2021; final analyses of PFS and ORR and the first interim analysis of OS were conducted. Results: A total of 453 pts were randomized to ripretinib (n = 226; Ex11 ITT, n = 163) or sunitinib (n = 227; Ex11 ITT, n = 164). Median age was 60 yrs (range 18–88) and most pts were white (66.2%) males (62.0%). PFS was not statistically different between ripretinib and sunitinib in the Ex11 ITT (hazard ratio [HR] 0.88, 95% CI 0.66, 1.16; P = 0.36; median 8.3 vs 7.0 mos) or in the AP populations (HR 1.05, 95% CI 0.82, 1.33; P = 0.72; median 8.0 vs 8.3 mos). ORR was numerically higher for ripretinib vs sunitinib in the Ex11 ITT (23.9% vs 14.6%; difference 9.3%, 95% CI 0.7, 17.8; nominal P = 0.03) and AP ITT populations (21.7% vs 17.6%; difference 4.2%, 95% CI −3.2, 11.5; nominal P = 0.27). OS data was highly immature; median OS was not reached in either arm. Fewer pts in the ripretinib arm experienced Grade 3-4 (G3-4) treatment-emergent adverse events (TEAEs) vs sunitinib (41.3% vs 65.6%). Among G3-4 TEAEs with a difference ≥5% between arms, ripretinib had fewer events vs sunitinib (hypertension [8.5% vs 26.7%], palmar-plantar erythrodysesthesia [1.3% vs 10.0%], neutropenia [0% vs 6.3%], and neutrophil count decreased [0% vs 7.2%]). Conclusions: The PFS in both arms was longer than PFS achieved by sunitinib in its pivotal phase 3 trial. While the PFS for ripretinib did not meet the primary endpoint of superiority vs sunitinib, meaningful clinical activity and fewer G3-4 TEAEs were observed in pts with advanced GIST treated with ripretinib after imatinib failure. Clinical trial information: NCT03673501.

Insertion-deletion rate is a qualitative aspect of the tumor mutation burden associated with the clinical outcomes of gastric cancer patients treated with nivolumab

BACKGROUND

We aimed to investigate the clinical implications of the tumor mutation burden (TMB) and insertion-deletion (indel) rate in gastric cancer patients treated with nivolumab.

METHODS

A total of 105 patients with advanced gastric cancer who were treated with nivolumab as third or later line of therapy were included as the study population. The indel rate was defined as the proportion of indels making up the TMB.

RESULTS

The median age was 58 (32-78 years), and 65 (61.9%) were men. Patients with TMB > 18.03/Mb showed superior progression-free survival (PFS) and overall survival (OS) compared to those with TMB ≤ 18.03/Mb. Patients with a high indel rate (> 40%) had a favorable PFS and OS compared to those with a lower indel rate (≤ 40%) (P = 0.009 and P = 0.007, respectively). The association between a high indel rate and favorable PFS and OS was prominent in a subgroup with TMB > 18.03/Mb (P < 0.001 and P = 0.007 for PFS and OS, respectively), but not in that with TMB ≤ 18.03/Mb. All five patients with deficient-MMR fell into the category of 'TMB > 18.03/Mb with an indel rate of > 40%. TMB ≥ 18.03/Mb with an indel rate of > 40% was independently associated with a favorable PFS (hazard ratio [HR] 0.07, P = 0.012) and OS (HR 0.09, P = 0.023).

CONCLUSION

TMB and indel rate should be jointly considered to better predict survival outcomes of gastric cancer patients treated with nivolumab. Our findings deserve further investigation and validation in future studies.

Exploration of predictors of benefit from nivolumab monotherapy for patients with pretreated advanced gastric and gastroesophageal junction cancer: post hoc subanalysis from the ATTRACTION-2 study

BACKGROUND

The phase 3 ATTRACTION-2 study demonstrated that nivolumab monotherapy was superior to placebo for patients with pretreated advanced gastric or gastroesophageal junction cancer, but early progression of tumors in some patients was of concern.

METHODS

This post hoc analysis statistically explored the baseline characteristics of the ATTRACTION-2 patients and extracted a single-factor and double-factor combinations associated with early disease progression or early death. In the extracted patient subgroups, the 3-year restricted mean survival times of progression-free survival and overall survival were compared between the nivolumab and placebo arms.

RESULTS

Two single factors (age and peritoneal metastasis) were extracted as independent predictors of early progression, but none of them, as a single factor, stratified patients into two subgroups with significant differences in restricted mean survival time. In contrast, two double-factor combinations (serum sodium level and white blood cell count; serum sodium level and neutrophil-lymphocyte ratio) stratifying patients into two subgroups with significant differences in the restricted mean survival time were extracted. Additional exploratory analysis of a triple-factor combination showed that patients aged < 60 years with peritoneal metastasis and low serum sodium levels (approximately 7% of all patients) might receive less benefit from nivolumab, and patients aged ≥ 60 years with no peritoneal metastasis and normal serum sodium levels might receive higher benefit.

CONCLUSIONS

A combination of age, peritoneal metastasis, and serum sodium level might predict benefit from nivolumab as salvage therapy in advanced gastric or gastroesophageal junction cancer patients, especially less benefit for patients having all three risk factors.

New prognostic model for patients with advanced gastric cancer: Fluoropyrimidine/platinum doublet for first-line chemotherapy

BACKGROUND

New prognostic factors have been reported in patients with metastatic or recurrent gastric cancer (MRGC), necessitating modifications to the previous prognostic model.

AIM

To develop a new model, MRGC patients who received fluoropyrimidines/ platinum doublet chemotherapy between 2008 and 2015 were analyzed.

METHODS

A total of 1883 patients was divided into a training set (n = 937) and an independent validation set (n = 946).

RESULTS

Multivariate analysis showed that the following six factors were associated with poor overall survival (OS) in the training set: Eastern Cooperative Oncology Group performance score ≥ 2 and bone metastasis (2 points each), peritoneal metastasis, high alkaline phosphatase level, low albumin level, and high neutrophil-lymphocyte ratio (1 point each). A prognostic model was developed by stratifying patients into good (0-1 point), moderate (2-3 points), and poor (≥ 4 points) risk groups. In the validation set, the median OS of the three risk groups was 15.8, 10.1, and 5.7 mo, respectively, and those differences were significant (P < 0.001).

CONCLUSION

We identified six factors readily measured in clinical practice that are predictive of poor prognosis in patients with MRGC. The new model is simpler than the old and more easily predicts OS.

Pembrolizumab versus paclitaxel for previously treated advanced gastric or gastroesophageal junction cancer (KEYNOTE-063): A randomized, open-label, phase 3 trial in Asian patients

Background

KEYNOTE‐063 (NCT03019588) investigated pembrolizumab versus paclitaxel as second‐line therapy in Asian patients with advanced programmed death ligand 1 (PD‐L1)–positive (combined positive score ≥1) gastric/gastroesophageal junction (GEJ) cancer.

Methods

This randomized, open‐label, phase 3 study was conducted at 36 medical centers in China (mainland), Malaysia, South Korea, and Taiwan. Patients were randomly assigned 1:1 to 200 mg of pembrolizumab intravenously every 3 weeks for ≤2 years or 80 mg/m² of paclitaxel intravenously every week. Primary end points were overall survival (OS) and progression‐free survival (PFS). Secondary end points were objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 and safety.

Results

Between February 16, 2017, and March 12, 2018, 94 patients were randomly assigned (47 pembrolizumab/47 paclitaxel) after screening; enrollment was stopped on March 12, 2018, based on the results of the global KEYNOTE‐061 study, and patients were followed until the last patient's last visit. Median OS was 8 months (95% confidence interval [CI], 4‐10 months) with pembrolizumab versus 8 months (95% CI, 5‐11 months) with paclitaxel (hazard ratio [HR], 0.99; 95% CI, 0.63‐1.54). Median PFS was 2 months (95% CI, 1‐3 months) with pembrolizumab versus 4 months (95% CI, 3‐6 months) with paclitaxel (HR, 1.62; 95% CI, 1.04‐2.52). ORR was 13% for pembrolizumab versus 19% for paclitaxel. Any‐grade treatment‐related adverse events occurred in 28 pembrolizumab‐treated patients (60%) and 42 paclitaxel‐treated patients (96%); grades 3 to 5 events occurred in 5 patients (11%) and 28 patients (64%), respectively.

Conclusions

Definitive conclusions about the efficacy of second‐line pembrolizumab in Asian patients with advanced PD‐L1–positive gastric/GEJ cancer are limited because of insufficient power, but pembrolizumab was well tolerated in this patient population. Efficacy followed a trend similar to that observed in the phase 3 KEYNOTE‐061 trial.

In this small sample of Asian patients with advanced PD‐L1–positive (combined positive score [CPS] ≥1) gastric/gastroesophageal junction (GEJ) cancer enrolled in the randomized, open‐label, phase 3 KEYNOTE‐063 study, definitive conclusions on clinical outcomes are limited; however, second‐line pembrolizumab monotherapy seems to be well tolerated in this patient population. These findings are consistent with those of the larger global KEYNOTE‐061 study in patients with CPS ≥1 gastric/GEJ cancer.

Adjuvant Imatinib Treatment for 5-Years vs 3-Years in Patients with Ruptured Localized Gastrointestinal Stromal Tumor: A Retrospective Analysis

Purpose

Three years of adjuvant imatinib is the standard treatment for resected gastrointestinal stromal tumors (GISTs) with rupture, but the recurrence rate is prominently high. We aimed to investigate the efficacy and safety of 5-year adjuvant imatinib compared with 3-year treatment in patients with a ruptured GIST following surgical resection.

Materials and Methods

A total of 51 patients were included in the analysis. The assessment of GIST rupture was based on Nishida’s classification. Twenty patients who were diagnosed before November 2013 were treated with 5 years of imatinib, and 31 patients who were diagnosed after November 2013 were treated with 3 years of imatinib. We retrospectively compared the clinical outcomes of the two groups.

Results

Baseline characteristics and the incidence of the adverse events were generally comparable between the two groups. During a median follow-up duration of 43.8 months and 104.2 months in the 3- and 5-year group, 8 and 9 patients had a disease recurrence, respectively. The 5-year group showed better recurrence-free survival (RFS) than the 3-year group. In multivariate analysis, low mitotic index was a significant independent favorable prognostic factor for RFS, while 5-year imatinib treatment was marginally associated with a favorable RFS.

Conclusion

Five years of adjuvant imatinib treatment in patients with ruptured GIST was associated with favorable survival outcomes with manageable toxicity profiles. Our findings warrant validation and confirmation in future studies.

402 Pegasus GI, a platform study of SAR444245 (THOR-707, a pegylated recombinant non-alpha IL2) with anti-cancer agents of participants with advanced and metastatic gastrointestinal cancer

Background

SAR444245 (THOR-707) is a recombinant human IL-2 molecule that includes a PEG moiety irreversibly bound to a novel amino acid via click chemistry to block the alpha-binding domain while retaining near-native affinity for the beta/gamma subunits. In animal models, SAR444245 showed anti-tumor benefits, but with no severe side effects, both as single agent and when combined with anti-PD1 comparing with historical data from aldesleukin. Preclinical study demonstrated SAR444245 enhances ADCC function of cetuximab. The HAMMER trial, which is the FIH study, shows preliminary encouraging clinical results: initial efficacy and safety profile with SAR444245 monotherapy and in combination with pembrolizumab or with cetuximab support a non-alpha preferential activity, validating preclinical models. The Pegasus GI Ph 2 study will evaluate the clinical benefit of SAR444245 in combination with pembrolizumab or cetuximab for the treatment of participants with advanced or metastatic gastrointestinal cancer [esophageal squamous cell carcinoma (ESCC), gastric cancer (GC) or gastro-esophageal junction adenocarcinoma (GEJ), Hepatocellular carcinoma (HCC) or colorectal cancer (CRC)]

Methods

Pegasus GI will enroll approximately 280 patients in 7 separate cohorts concurrently (4 cohorts) or sequentially (3 cohorts). In cohort A, 2–3 line (L) ESCC participants who have progressed after checkpoint inhibitor (CPI)-based therapy will receive SAR444245 + pembrolizumab. In cohorts B1, B2 & B3 participants with GC and GEJ cancers will receive SAR444245 + pembrolizumab. Cohort B1 & B2 will enroll 1–3L CPI-naïve patients. Cohort B3 will enroll 2-4L patients post CPI-based therapy). In cohort C, 2–3L HCC participants who have progressed after CPI-based therapy will receive SAR444245 + pembrolizumab. In cohorts D1 and D2, 3–6L CRC participants will receive SAR444245 + pembrolizumab (any RAS) or SAR444245 + cetuximab (RAS-wild type)SAR444245 is administered IV at a dose of 24 ug/kg Q3W until disease progression or completion of 35 cycles. Pembrolizumab is administered as per label, Q3W for up to 35 cycles. Cetuximab is administered per label, QW until PD.The study primary objective is to determine the antitumor activity of SAR444245 in combination with other anticancer therapies. Secondary objectives are to assess safety profile, other indicators of antitumor activity, the pharmacokinetic profile and immunogenicity of SAR444245. The study will be conducted in the US, France, Germany, Spain, Italy, Belgium, Netherlands, Poland, Russia, South Korea and China

Acknowledgements

The Pegasus GI study is sponsored by Sanofi

Ethics Approval

All applicable ECs are obtained

Consent

All participant consents are obtained

Avapritinib Versus Regorafenib in Locally Advanced Unresectable or Metastatic GI Stromal Tumor: A Randomized, Open-Label Phase III Study

PURPOSE

Primary or secondary mutations in KIT or platelet-derived growth factor receptor alpha (PDGFRA) underlie tyrosine kinase inhibitor resistance in most GI stromal tumors (GISTs). Avapritinib selectively and potently inhibits KIT- and PDGFRA-mutant kinases. In the phase I NAVIGATOR study (NCT02508532), avapritinib showed clinical activity against PDGFRA D842V-mutant and later-line KIT-mutant GIST. VOYAGER (NCT03465722), a phase III study, evaluated efficacy and safety of avapritinib versus regorafenib as third-line or later treatment in patients with unresectable or metastatic GIST.

PATIENTS AND METHODS

VOYAGER randomly assigned patients 1:1 to avapritinib 300 mg once daily (4 weeks continuously) or regorafenib 160 mg once daily (3 weeks on and 1 week off). Primary end point was progression-free survival (PFS) by central radiology per RECIST version 1.1 modified for GIST. Secondary end points included objective response rate, overall survival, safety, disease control rate, and duration of response. Regorafenib to avapritinib crossover was permitted upon centrally confirmed disease progression.

RESULTS

Four hundred seventy-six patients were randomly assigned (avapritinib, n = 240; regorafenib, n = 236). Median PFS was not statistically different between avapritinib and regorafenib (hazard ratio, 1.25; 95% CI, 0.99 to 1.57; 4.2 v 5.6 months; P = .055). Overall survival data were immature at cutoff. Objective response rates were 17.1% and 7.2%, with durations of responses of 7.6 and 9.4 months for avapritinib and regorafenib; disease control rates were 41.7% (95% CI, 35.4 to 48.2) and 46.2% (95% CI, 39.7 to 52.8). Treatment-related adverse events (any grade, grade ≥ 3) were similar for avapritinib (92.5% and 55.2%) and regorafenib (96.2% and 57.7%).

CONCLUSION

Primary end point was not met. There was no significant difference in median PFS between avapritinib and regorafenib in patients with molecularly unselected, late-line GIST.

Prognostic value of natural killer cell activity for patients with HER2 + advanced gastric cancer treated with first-line fluoropyrimidine-platinum doublet plus trastuzumab

BACKGROUND

We aimed to evaluate the prognostic value of natural killer (NK) cell activity for patients with HER2 + advanced gastric cancer (AGC) treated with first-line fluoropyrimidine-platinum doublet plus trastuzumab.

METHODS

Forty-one patients with HER2 + AGC who received fluoropyrimidine-platinum doublet plus trastuzumab as first-line treatment were prospectively enrolled. NK cell activity was evaluated using the NK Vue®.

RESULTS

The median age was 63.5 years, and 31 patients (75.6%) were male. Patients with low baseline NK cell activity (≤ median, n = 21) were associated worse progression-free survival (PFS) and overall survival (OS) compared with patients with high baseline NK cell activity (> median, n = 20) with a median PFS of 4.21 vs. 9.53 months (P < 0.001), and median OS of 8.15 months vs. 17.82 months (P = 0.025), respectively. In the multivariate analysis, low baseline NK cell activity was independently associated with poor PFS (HR 4.35, P = 0.007). NK cell activity recovered to a normal range in nine patients (47.4%) with a low baseline NK cell activity (n = 19) after two cycles of treatment. The median PFS and OS among patients with recovered NK cell activity were significantly better than that among patients with persistently low NK cell activity (PFS, P = 0.038; OS, P = 0.003).

CONCLUSION

Our results demonstrated the prognostic value of baseline NK cell activity for patients with HER2 + AGC treated with fluoropyrimidine-platinum doublet plus trastuzumab. The association between treatment outcomes and dynamic changes in NK cell activity suggests that NK cell treatment may improve treatment outcomes, especially for patients with low baseline NK cell activity.

Safety, Efficacy, and Pharmacodynamics of Tremelimumab Plus Durvalumab for Patients With Unresectable Hepatocellular Carcinoma: Randomized Expansion of a Phase I/II Study

This phase I/II study evaluated tremelimumab (anticytotoxic T-lymphocyte–associated antigen-4 monoclonal antibody) and durvalumab (antiprogrammed death ligand-1 monoclonal antibody) as monotherapies and in combination for patients with unresectable hepatocellular carcinoma (HCC), including a novel regimen featuring a single, priming dose of tremelimumab (ClinicalTrials.gov identifier: NCT02519348).

Abstract 2187: Circulating tumor DNA (ctDNA) gene sequencing results from prospective screening of patients with newly diagnosed metastatic gastric and gastroesophageal adenocarcinoma (GEA) for the bemarituzumab FIGHT randomized trial using a plasma NGS assay

Background: Metastatic GEA is a molecularly heterogeneous disease with limited therapeutic options. It is the third most common cause of cancer death globally. Targeted therapies against HER2 positive and microsatellite instability-high (MSI-H) GEA have improved overall survival. There has not been a prospective evaluation of the prevalence of potentially actionable molecular targets in a global population with newly diagnosed advanced-stage GEA.

Methods: As part of the global FIGHT study of bemarituzumab (NCT03694522), patients with newly diagnosed advanced stage GEA that was not known to be HER2 positive were screened using the PGDx elioTM Plasma Resolve Investigation Use Only assay. This next generation sequencing (NGS) hybrid-capture assay was developed to include coding and select noncoding regions of 33 cancer-related genes. Circulating cell free DNA (cfDNA) extracted from plasma samples was used as input. FGFR2-amplification positive clinical samples were identified in a primary report for enrollment in the trial. Variant calls for translocations, amplifications and SNVs/indels were reported for informational use only.

Results: Of the 721 samples submitted for analyses, 661 had sufficient cfDNA to proceed with the assay, 51 samples failed to generate sufficient sequencing data to be interpreted based upon quality cutoffs. Of the 610 remaining samples 5% were amplified for FGFR2. Of these 610 samples, 496 (82%) individual patient samples were tested for additional molecular changes with 29 failing to generate sufficient sequencing data; leaving 467 patient samples with evaluable data. 81% of patients had at least one gene aberration. Of the 8 genes evaluated for amplification, the most common to least commonly amplified were MYC (10%), EGFR (7%), ERBB2 (7%), MET (7%), FGFR2 (5%), CCND1 (4%), and CD274 (1%). No KIT amplification was reported. The most frequently mutated genes among the 33 examined were p53, ARID1A, PIK3CA, BRCA2, KRAS, CDH1, APC, ATM, BRCA1 and FGFR2. Other identified mutations in genes of interest for which targeted therapies exist include mutations in NTRK1 (n=8) and ROS1 (n=15). Screening for 5 gene fusions identified fusions in 15 patients with 12 involving FGFR2.

Conclusions: This is the largest prospective global survey of genetic abnormalities using targeted ctDNA testing in newly-diagnosed advanced-stage GEA in patients whose tumors were not known to be HER2 positive. Using a multi-gene panel NGS approach to identify patients with FGFR2 amplification by ctDNA, other potentially clinically actionable genetic abnormalities were identified.

Citation Format: Daniel Catenacci, Yoon-Koo Kang, Peter Enzinger, Giovanni G. Cardellino, Raquel Guardeno Sanchez, Aaron Q. Xu, Allie Tappe, Michelle Y. Sun, Siddhartha Mitra, Derek Murphy, Ian Misner, Steven Smith, Zev Wainberg. Circulating tumor DNA (ctDNA) gene sequencing results from prospective screening of patients with newly diagnosed metastatic gastric and gastroesophageal adenocarcinoma (GEA) for the bemarituzumab FIGHT randomized trial using a plasma NGS assay [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2187.

PRODIGY: A Phase III Study of Neoadjuvant Docetaxel, Oxaliplatin, and S-1 Plus Surgery and Adjuvant S-1 Versus Surgery and Adjuvant S-1 for Resectable Advanced Gastric Cancer

Adjuvant chemotherapy after D2 gastrectomy is standard for resectable locally advanced gastric cancer (LAGC) in Asia. Based on positive findings for perioperative chemotherapy in European phase III studies, the phase III PRODIGY study (ClinicalTrials.gov identifier: NCT01515748) investigated whether neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) followed by surgery and adjuvant S-1 could improve outcomes versus standard treatment in Korean patients with resectable LAGC.

Phase IA/IB study of single-agent tislelizumab, an investigational anti-PD-1 antibody, in solid tumors

Background

The programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1) axis plays a central role in suppressing antitumor immunity; axis dysregulation can be used by cancer cells to evade the immune system. Tislelizumab, an investigational monoclonal antibody with high affinity and binding specificity for PD-1, was engineered to minimize binding to FcγR on macrophages to limit antibody-dependent phagocytosis, a potential mechanism of resistance to anti-PD-1 therapy. The aim of this phase IA/IB study was to investigate the safety/tolerability, antitumor effects and optimal dose and schedule of tislelizumab in patients with advanced solid tumors.

Methods

Patients (aged ≥18 years) enrolled in phase IA received intravenous tislelizumab 0.5, 2, 5 or 10 mg/kg every 2 weeks; 2 or 5 mg/kg administered every 2 weeks or every 3 weeks; or 200 mg every 3 weeks; patients in phase IB received 5 mg/kg every 3 weeks. Primary objectives were to assess tislelizumab’s safety/tolerability profile by adverse event (AE) monitoring and antitumor activity using RECIST V.1.1. PD-L1 expression was assessed retrospectively with the VENTANA PD-L1 (SP263) Assay.

Results

Between May 2015 and October 2017, 451 patients (n=116, IA; n=335, IB) were enrolled. Fatigue (28%), nausea (25%) and decreased appetite (20%) were the most commonly reported AEs. Most AEs were grade 1–2 severity; anemia (4.9%) was the most common grade 3–4 AE. Treatment-related AEs led to discontinuation in 5.3% of patients. Grade 5 AEs were reported in 14 patients; 2 were considered related to tislelizumab. Pneumonitis (2%) and colitis (1%) were the most common serious tislelizumab-related AEs. As of May 2019, 18% of patients achieved a confirmed objective response in phase IA and 12% in phase IB; median follow-up duration was 13.6 and 7.6 months, respectively. Pharmacokinetics, safety and antitumor activity obtained from both phase IA and IB determined the tislelizumab recommended dose; ultimately, tislelizumab 200 mg intravenous every 3 weeks was the dose and schedule recommended to be taken into subsequent clinical trials.

Conclusions

Tislelizumab monotherapy demonstrated an acceptable safety/tolerability profile. Durable responses were observed in heavily pretreated patients with advanced solid tumors, supporting the evaluation of tislelizumab 200 mg every 3 weeks, as monotherapy and in combination therapy, for the treatment of solid tumors and hematological malignancies.

Trial registration number

NCT02407990.

Phase I study of H3B-6527 in hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC)

4090

Background: Evidence suggests that hyperactivated fibroblast growth factor 4 (FGFR4) signaling pathway leads to enhanced tumor growth. Targeting FGFR4 may have therapeutic benefit in tumors with altered FGF19 signaling. A phase I study (NCT02834780) was undertaken to assess H3B-6527, a highly selective covalent FGFR4 inhibitor, in patients with HCC/ICC. Methods: Adults with advanced HCC/ICC, ECOG PS 0-1, well compensated liver function, who progressed after > one prior therapy, received H3B-6527 po daily (QD) or twice-daily (bid) on a 21-day cycle following a 3+3 design. Doses ranged from 300-2000mg QD or 500-700mg BID. Patients in dose escalation were treated regardless of FGF19 status. Patients in expansion had FGF19+ tumors by mRNA testing. Adverse events (AEs), and pharmacokinetics (PK) were assessed. Response was determined by RECIST 1.1/mRECIST imaging every 6 weeks. Results: Study enrollment is complete at 128 patients. Ninety HCC patients were treated (QD = 48, bid = 42). ICC enrollment was suspended after 38 patients due to limited efficacy. No dose-limiting toxicities were seen and no grade 4-5 treatment related AEs have been observed. Recommended Phase II dose for H3B-6527 is 1000mg QD based upon safety, efficacy, and PK data. Grade 3 TEAEs have occurred in 12.5% of patients on QD dosing. Treatment related TEAEs were seen in 62.5% of patients on the QD schedule, with diarrhea (45.8%), fatigue (12.5%), and nausea (12.5%) most frequent. Drug discontinuation due to AEs for QD dosing was 8.3%. Interim data analysis shows that, for HCC patients with >2 prior lines of therapy treated on QD schedule, overall survival was 10.6m, progression-free survival 4.1m, overall response rate 16.7% (all partial responses), and clinical benefit rate 45.8% (responders + durable stable disease >17 weeks). H3B-6527 Cmax and AUC were lower at 300 mg dose but then similar across 500–2000 mg doses. Following oral administration of 1000 mg fasted, H3B-6527 plasma concentration reached peak at a Tmax of ̃2-3 hours and then decayed exponentially, with terminal half-life of ̃4-5 hours. There was no accumulation following QD dose. Dosing with food did not meaningfully change H3B-6527 plasma exposure. Conclusions: H3B-6527 was well tolerated and demonstrated a favorable toxicity and safety profile and encouraging clinical activity in heavily pretreated HCC patients. Final trial results will be presented at conference. Clinical trial information: NCT02834780.

Zanidatamab, an anti-HER2 bispecific antibody, plus chemotherapy with/without tislelizumab as first-line treatment for patients with advanced HER2-positive breast cancer or gastric/gastroesophageal junction adenocarcinoma: A phase 1B/2 trial-in-progress

TPS2656

Background: Zanidatamab is a novel HER2-targeted antibody that binds two distinct extracellular domains of HER2, allowing for multiple mechanisms of action including enhanced binding, clustering, receptor internalization and downregulation; this results in inhibition of ligand-dependent and -independent proliferation and potent activation of antibody-dependent cellular cytotoxicity. Zanidatamab monotherapy is well tolerated and has shown promising anti-tumor activity in patients (pts) with pre-treated advanced HER2-positive cancers, and was well tolerated in a Phase I trial (NCT02892123). Tislelizumab is an investigational anti-programmed death-1 (PD-1) antibody engineered to minimize binding of FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, which is a potential mechanism of T-cell clearance and resistance to anti-PD-1 therapy. Tislelizumab is well tolerated and has anti-tumor activity alone and in combination with chemotherapy in pts with advanced solid tumors. The highly immunogenic nature of HER2 tumors has led to the development of therapies combining anti-HER2 therapies with immune checkpoint blockade. Methods: This open-label, two cohort Phase 1B/2 study (NCT04276493) is designed to evaluate zanidatamab as a first-line therapy with chemotherapy in pts with HER2-positive metastatic breast cancer (mBC; cohort 1) or with chemotherapy + tislelizumab in pts with HER2-positive advanced gastric/gastroesophageal junction adenocarcinoma (GC/GEJC; cohort 2). Weight-based dosing (cohorts 1a and 2a) and flat dosing (cohorts 1b and 2b) regimens of zanidatamab are being investigated. In cohort 1 (n = 20), pts with treatment-naïve HER2-positive (IHC3+ or ISH amplified) mBC will receive intravenous (IV) zanidatamab 30 mg/kg (cohort 1a) or 1800 mg (cohort 1b), plus IV docetaxel 75 mg/m2 once every 3 weeks (Q3W). In cohort 2 (n = 30), treatment-naïve pts with HER2-positive (IHC3+ or IHC2+ with ISH amplification) advanced GC/GEJC will receive IV zanidatamab 30 mg/kg (cohort 2a), or 1800 mg (pts < 70kg; cohort 2b) or 2400 mg (pts ≥ 70kg; cohort 2b), plus IV tislelizumab 200 mg and chemotherapy (CAPOX regimen: oral capecitabine 1000 mg/m2 twice daily [days 1–14] and IV oxaliplatin 130 mg/m2 [day 1]) Q3W. For cohort 2 there is a six pt safety lead-in phase, followed by dose expansion after approval by the safety monitoring committee. Primary endpoints are the safety profile and objective response rate. Secondary endpoints include duration of response, time to response, progression-free survival, disease control rate, and overall survival. Clinical trial information: NCT02892123.

FIGHT: A randomized, double-blind, placebo-controlled, phase II study of bemarituzumab (bema) combined with modified FOLFOX6 in 1L FGFR2b+ advanced gastric/gastroesophageal junction adenocarcinoma (GC)

4010

Background: Bema is a first-in-class humanized IgG1 monoclonal antibody selective for fibroblast growth factor receptor 2b (FGFR2b). Results from the FIGHT study showed an improvement in progression-free survival (PFS), overall survival (OS), and overall response rate with the addition of bema to mFOLFOX6 in FGFR2b+, non HER2+ GC. This report provides updated analyses of patient (pt) subgroups, additional data on ocular adverse events (AEs), and the median OS result for the bema+mFOLFOX6 combination. Methods: Pts were treated with mFOLFOX6 and randomized 1:1 to bema (15 mg/kg) or placebo (pbo) every 2 weeks (wks) with an additional 7.5 mg/kg bema/pbo dose on cycle 1 day 8. Eligible pts had unresectable locally advanced or metastatic GC not known to be HER2+, and had FGFR2b overexpression (any 2+/3+ staining) by centrally performed immunohistochemistry (IHC+) or FGFR2 amplification by circulating tumor DNA (ctDNA+). Results: Of the 155 pts who were randomized, 149 (96%) were FGFR2b+ by IHC, 26 (17%) by ctDNA, and 20 (13%) by both. 96 pts (62%) had tumors with FGFR2b IHC 2+/3+ in ≥10% of tumor cells. The proportion of pts with ctDNA+ or with ≥5% or ≥10% tumor cells FGFR2b+ by IHC was similar across geographic regions. Bema showed a benefit vs pbo across pre-specified subgroups including age, gender, geographic region, and prior adjuvant therapy. Patients with FGFR2b overexpression irrespective of ctDNA gene amplification benefited from bema: IHC+/ctDNA- PFS hazard ratio (HR) 0.63 (95% CI 0.4, 0.99), OS HR 0.66 (95% CI 0.39, 1.12); IHC+/ctDNA+ PFS HR 0.15 (95% CI 0.02, 1.18), OS HR 0.10 (95% CI 0.01, 0.83). Frequency and severity of ocular AEs were similar for the overall enrolled population and for pts with ≥5% or ≥10% FGFR2b+ by IHC. Corneal AEs in the bema arm increased in frequency and severity over time; 10.5% (0% G3) wk 1-8 vs 44.1% (15.3% G3) wk ≥25. Following discontinuation of study treatment, subsequent anti-cancer therapy was balanced in the 2 arms (bema 53%; pbo 49%). With a median follow-up of 12.5 months (mo), the bema arm had a median OS of 19.2 mo (95%CI: 13.6, not reached) vs 13.5 mo (95%CI: 9.3, 15.9) for placebo (HR:0.60 95%CI: 0.38, 0.94) for the intent-to-treat population; for the subset of pts with ≥10% FGFR2b+ by IHC, the median OS for bema was 25.4 mo (95%CI: 13.8, not reached) vs 11.1 mo (95% CI: 8.4, 13.8) for placebo (HR: 0.41 95%CI: 0.23, 0.74). Conclusions: The addition of bema to mFOLFOX6 improved the OS of 1L FGFR2b+ GC pts vs mFOLFOX6 alone. Outcomes favored bema across pre-specified subgroups. Pts with overexpression of FGFR2b even without ctDNA amplification demonstrated a benefit from the addition of bema to mFOLFOX6, supporting further evaluation of bema in tumors with FGFR2b overexpression without the requirement for gene amplification. Clinical trial information: NCT03694522.

Serum alpha-fetoprotein and clinical outcomes in patients with advanced hepatocellular carcinoma treated with ramucirumab

BACKGROUND

Post hoc analyses assessed the prognostic and predictive value of baseline alpha-fetoprotein (AFP), as well as clinical outcomes by AFP response or progression, during treatment in two placebo-controlled trials (REACH, REACH-2).

METHODS

Serum AFP was measured at baseline and every three cycles. The prognostic and predictive value of baseline AFP was assessed by Cox regression models and Subpopulation Treatment Effect Pattern Plot method. Associations between AFP (≥ 20% increase) and radiographic progression and efficacy were assessed.

RESULTS

Baseline AFP was confirmed as a continuous (REACH, REACH-2; p < 0.0001) and dichotomous (≥400 vs. <400 ng/ml; REACH, p < 0.01) prognostic factor, and was predictive for ramucirumab survival benefit in REACH (p = 0.0042 continuous; p < 0.0001 dichotomous). Time to AFP (hazard ratio [HR] 0.513; p < 0.0001) and radiographic (HR 0.549; p < 0.0001) progression favoured ramucirumab. Association between AFP and radiographic progression was shown for up to 6 (odds ratio [OR] 5.1; p < 0.0001) and 6-12 weeks (OR 1.8; p = 0.0065). AFP response was higher with ramucirumab vs. placebo (p < 0.0001). Survival was longer in patients with an AFP response than patients without (13.6 vs. 5.6 months, HR 0.451; 95% confidence interval, 0.354-0.574; p < 0.0001).

CONCLUSIONS

AFP is an important prognostic factor and a predictive biomarker for ramucirumab survival benefit. AFP ≥ 400 ng/ml is an appropriate selection criterion for ramucirumab.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, REACH (NCT01140347) and REACH-2 (NCT02435433).