Trial in progress: A phase 2, multicenter, open-label study of DKN-01 in combination with tislelizumab and chemotherapy as 1L therapy in patients with unresectable, locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma (G/GEJ; DisTinGuish)

TPS484

Background: Advanced G/GEJ cancer is a major cause of cancer-related mortality requiring novel therapies. DKN-01 is a humanized mAb that binds and neutralizes DKK1. DKK1 plays a major role in WNT-pathway regulation and is overexpressed in multiple cancers. DKK1 expression is associated with poor prognosis, an immunosuppressive tumor microenvironment, and resistance to chemotherapy in G/GEJ cancer. The non-randomized Part A of DisTinGuish demonstrated durable clinical benefit in patients with G/GEJ adenocarcinoma. Higher response rates were observed in patients with high tumoral DKK1 expression, when DKN-01 was administered in combination with an anti-PD1 mAb, tislelizumab, and chemotherapy1,2. Furthermore, in Part B, durable responses were seen in 2L patients with DKK1-high G/GEJ cancers treated with a chemotherapy-free doublet regimen, DKN-01 plus tislelizumab1. Part C will evaluate the efficacy of this chemoimmunotherapy combination in a randomized fashion in treatment-naïve G/GEJ adenocarcinoma patients. Methods: Part C is an ongoing, global, randomized phase 2 open-label study evaluating DKN-01 in combination with tislelizumab + chemotherapy (CAPOX or mFOLFOX6) vs tislelizumab + chemotherapy in patients with advanced G/GEJ adenocarcinoma. Patients are randomized 1:1 and stratified by DKK1 and PD-L1 expression. Approximately 160 patients will be enrolled from 5 different countries. Key inclusion criteria include patients with HER2 negative, G/GEJ adenocarcinoma who have received no prior systemic treatment in the unresectable locally advanced/metastatic setting and can provide tumor tissue to document PD-L1 CPS and DKK1 expression, as performed at a central lab. Key exclusion criteria include prior treatment with anti-PD1/L1/L2. The primary endpoint is PFS according to RECIST v1.1 as assessed by the investigator in patients with DKK1-high tumors. Key secondary and exploratory end points include PFS, OS, ORR, DoR in patients with tumors with any level of DKK1 expression, as assessed by both investigator and by blinded, central review. Recruitment is ongoing. Clinical trial information: NCT04363801 . References SJ Klempner, et al. DKN-01 and tislelizumab ± chemotherapy as a first-line (1L) and second-line (2L) investigational therapy in advanced gastroesophageal adenocarcinoma (GEA): DisTinGuish Trial. JCO 40, no. 4_suppl, 2022, 292-292.  SJ Klempner, et al. DKN-01 and Tislelizumab + Chemotherapy as First-line (1L) Investigational Therapy in Advanced Gastroesophageal Adenocarcinoma (GEA): DisTinGuish Trial. ESMO Annual Meeting September 2022. Clinical trial information: NCT04363801 .

Rationale 305: Phase 3 study of tislelizumab plus chemotherapy vs placebo plus chemotherapy as first-line treatment (1L) of advanced gastric or gastroesophageal junction adenocarcinoma (GC/GEJC)

286

Background: In a phase 2 study, tislelizumab (TIS), an anti-PD-1 monoclonal antibody, plus chemotherapy demonstrated durable antitumor activity as 1L in Chinese GC/GEJC patients (Xu et al, 2020). RATIONALE 305 (NCT03777657) was a global, double-blind, phase 3 study comparing 1L TIS plus investigator-chosen chemotherapy (TIS+ICC) vs placebo plus ICC (P+ICC) in GC/GEJC patients. Results from the interim analysis (IA) in the PD-L1+ population are presented; ITT population outcomes will be presented after final analysis. Methods: Adults with previously untreated, unresectable locally advanced or metastatic GC/GEJC, regardless of PD-L1 expression, were randomized (1:1) to receive TIS (200 mg IV Q3W) plus ICC (oxaliplatin [130 mg/m² IV Q3W] and oral capecitabine [1,000 mg/m² BID, Days 1-14 Q3W] or cisplatin [80 mg/m² IV Q3W] and 5-fluorouracil [800 mg/m²/day IV, Days 1-5 Q3W]) or P+ICC. Randomization was stratified by region, PD-L1 expression, peritoneal metastasis, and ICC. Patients with known HER2-positive status were excluded. RATIONALE 305 had dual primary endpoints of OS in the PD-L1+ and ITT analysis set; PD-L1+ was defined as PD-L1 TAP score ≥5% (VENTANA SP263 assay) assessed by blinded independent central laboratory. Secondary endpoints include PFS, ORR and DoR per RECIST 1.1, HRQoL, and safety profile. The prespecified IA was conducted after ~70% of total OS events had occurred. Results: Of 546 PD-L1+ patients enrolled from 13 counties/regions (73.8 % Asia; 26.2% Europe/ North America), 274 were randomized to receive TIS+ICC and 272 to receive P+ICC. As of 8 Oct 2021, median follow-up was 11.8 (TIS+ICC) and 11.7 mo (P+ICC). TIS+ICC showed statistically significant and clinically meaningful OS improvement vs P+ICC (HR 0.74 [95% CI: 0.59-0.94], mOS 17.2 vs 12.6 mo; 1-sided P= .0056). Compared with P+ICC, TIS+ICC also had longer PFS (mPFS 7.2 vs 5.9 mo; HR 0.67 [95% CI: 0.55-0.83]), higher ORR (50.4% vs 43.0%), and more durable response (mDoR 9.0 vs 7.1 mo). Patients treated with TIS+ICC reported better HRQoL than patients treated with P+ICC, as indicated by EORTC-QLQ-C30 global health status and physical functioning scores as well as the QLQST022 index score. No new safety signals were observed with TIS+ICC or P+ICC. While TEAEs leading to discontinuation of any treatment were higher with TIS+ICC than P+ICC (22.4% vs 12.1%), incidence rates of grade ≥3 TEAEs (64.7% vs 62.9%), serious TEAEs (42.3% vs 36.8%), and TEAEs leading to death (8.8% vs 7.7%) were comparable between both arms. Conclusions: In RATIONALE 305, TIS+ICC provided significant and clinically meaningful improvement in OS vs P+ICC with well acceptable safety as 1L in PD-L1+ patients with advanced GC/GEJC. These data suggest this combination is a new 1L option for this patient population. Clinical trial information: NCT03777657 .

Nivolumab (NIVO) plus chemotherapy (chemo) vs chemo as first-line (1L) treatment for advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma (GC/GEJC/EAC): 3-year follow-up from CheckMate 649

291

Background: NIVO + chemo demonstrated superior overall survival (OS) and clinically meaningful progression-free survival (PFS) benefit vs chemo and an acceptable safety profile in previously untreated patients (pts) with advanced GC/GEJC/EAC, leading to approvals in multiple countries including the US. NIVO + chemo continued to demonstrate clinically meaningful improvement in efficacy after 2 years of follow-up. We present efficacy and safety analyses from NIVO + chemo vs chemo from the 3-year follow-up of CheckMate 649. Methods: Adults with previously untreated, unresectable advanced, or metastatic GC/GEJC/EAC were enrolled, regardless of programmed death ligand 1 (PD-L1) expression. Pts with known HER2-positive status were excluded. Randomized pts received NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO + ipilimumab, or chemo. Dual primary endpoints for NIVO + chemo vs chemo were OS and PFS by blinded independent central review (BICR) in pts with PD-L1 combined positive score (CPS) ≥ 5. Results: 581 pts were concurrently randomized to NIVO + chemo or chemo. With 36-month (mo) minimum follow-up, NIVO + chemo continued to demonstrate OS and PFS benefit vs chemo in pts with PD-L1 CPS ≥ 5 and all randomized pts. The objective response rate (ORR) per BICR in pts with PD-L1 CPS ≥ 5 who had measurable lesions at baseline was 60% (95% CI 55–65) with NIVO + chemo vs 45% (95% CI 40–50) with chemo; in all randomized pts, ORR per BICR was 58% (95% CI 54–62) with NIVO + chemo vs 46% (95% CI 42–50) with chemo. Responses were more durable with NIVO + chemo vs chemo in pts with PD-L1 CPS ≥ 5 (median [m] duration of response [mDOR] 9.6 mo [95% CI 8.2–12.4] vs 7.0 mo [95% CI 5.6–7.9], respectively) and in all randomized pts (mDOR 8.5 mo [95% CI 7.7–9.9] vs 6.9 mo [95% CI 5.8–7.2], respectively). OS benefit with NIVO + chemo was observed across most prespecified subgroups. No new safety signals were identified. A summary of treatment-related adverse events (TRAEs) is shown here. Conclusions: After 3 years of follow-up, NIVO + chemo continued to demonstrate clinically meaningful long-term survival benefit with an acceptable safety profile, further supporting its use as a standard 1L treatment in previously untreated pts with advanced GC/GEJC/EAC. Clinical trial information: NCT02872116 . [Table: see text]

Randomized phase 2 study of DKN-01 plus FOLFIRI/FOLFOX and bevacizumab versus FOLFIRI/FOLFOX and bevacizumab as second-line treatment of advanced colorectal cancer (DeFianCe)

TPS275

Background: Colorectal cancer is the third most prevalent cancer, and the prognosis of patients with advanced metastatic (mCRC) is poor. The efficacy of standard of care (SOC) second-line chemotherapy combinations with anti-vascular endothelial growth factor (VEGF) therapies remains modest. Previously treated advanced mCRC that is microsatellite stable (MSS/pMMR) represents nearly 95% of the metastatic population and remains a high unmet medical need. DKN-01 is a humanized IgG4 monoclonal antibody (mAb) targeted against Dickkopf-related protein 1 (DKK1), a regulator of the Wnt signaling pathway. DKK1 has been identified as a potential oncogenic driver in CRC and has been correlated with 5FU resistance. Therefore, DKK1 expression is a potential predictive biomarker for chemotherapeutic resistance in CRC. Methods: This is a phase 2 randomized, open-label, two-part, multicenter study with a safety run-in to evaluate safety and efficacy of DKN-01 plus FOLFIRI/FOLFOX and bevacizumab versus SOC [FOLFIRI/FOLFOX and bevacizumab] as second-line treatment of advanced mCRC patients. In Parts A and B, approximately 150 advanced MSS, BRAF Wild Type mCRC patients with radiographic progression during or following 1 prior line of systemic treatment will be enrolled in the study. Part A is a safety run-in with DKN-01 plus FOLFIRI/FOLFOX and bevacizumab in at least 20 safety evaluable patients. In Part B, approximately 130 patients will be randomized 1:1 to either the experimental (DKN-01 plus FOLFIRI/FOLFOX and bevacizumab) or control arm (FOLFIRI/FOLFOX and bevacizumab), using a central stratified block randomization scheme and stratified based on DKK1 RNAscope tumor percentage score (TPS) (≥1% vs <1%). Primary endpoint is progression free survival and secondary endpoints include overall response rate, duration of response, overall survival and incidence of ≥Grade 3 related treatment-related adverse events (TRAEs). Exploratory endpoints will include evaluation of efficacy outcomes based upon tumoral DKK1 expression. Recruitment is ongoing. Clinical trial information: NCT05480306 .

Trial in progress: Phase 1b/3 study of bemarituzumab + mFOLFOX6 + nivolumab versus mFOLFOX6 + nivolumab in previously untreated advanced gastric and gastroesophageal junction (GEJ) cancer with FGFR2b overexpression (FORTITUDE-102)

TPS4165

Background: Fibroblast growth factor receptor 2b (FGFR2b) is overexpressed in approximately 30% of non-human epidermal growth factor receptor 2 (non-HER2) positive gastric cancer (Wainberg, 2021). Bemarituzumab is a first-in-class monoclonal antibody that specifically blocks FGFR2b, inhibiting downstream tumor proliferation and enhancing antibody dependent cellular cytotoxicity (Catenacci, 2020; Xiang, 2021). In the phase 2 FIGHT study (Wainberg, 2021; Catenacci, 2021), progression-free survival (PFS) was improved (HR, 0.68; 95% CI, 0.44-1.04; p = 0.07) and a 5.7 month longer median overall survival (OS) was observed (19.2 months vs 13.5 months; HR, 0.60; 95% CI, 0.38-0.94) with bemarituzumab + mFOLFOX6 vs placebo + mFOLFOX6. Preclinical studies indicate that bemarituzumab modulates the tumor microenvironment to sensitize tumors to anti-PD1 monoclonal antibodies (Powers, 2016; Xiang, 2021) providing rationale for combination with nivolumab. Methods: FORTITUDE-102 (NCT05111626) is a phase 1b/3 study in patients (pts) with unresectable locally advanced or metastatic gastric or GEJ adenocarcinoma not amenable to curative therapy. Part 1 is an open-label safety lead-in; Part 2 is a double-blind, placebo-controlled study to evaluate efficacy and safety. Approximately 702 pts ≥18 years will be enrolled (Part 1, ̃20; Part 2, ̃682). Key eligibility criteria include Eastern Cooperative Oncology Group performance status 0-1, evaluable disease per RECIST v1.1, adequate hematologic and organ function, and no contraindication to receive mFOLFOX6 chemotherapy or nivolumab; for part 2, IHC-confirmed FGFR2b overexpression by central testing is required and no prior treatment for metastatic or unresectable disease allowed except 1 dose of mFOLFOX6 ± nivolumab. Key exclusion criteria include positive HER2 status and untreated or symptomatic CNS metastasis and leptomeningeal disease. Pts on bemarituzumab will receive 15 mg/kg every 2 weeks (Q2W) with an additional 7.5 mg/kg dose on cycle 1 day 8. mFOLFOX6 + nivolumab will be at a fixed dose Q2W. The dose-limiting toxicity (DLT) period is 28 days; observed safety data will influence additional enrollment to Part 1, de-escalation of bemarituzumab, or the recommended phase 3 dose (RP3D). For Part 1, primary endpoints are DLTs and adverse events; secondary endpoints include OS, PFS, and objective response (OR). For Part 2, pts will be randomized 1:1 to mFOLFOX6 + nivolumab Q2W plus either bemarituzumab at RP3D or placebo. Primary endpoint for Part 2 is OS; secondary endpoints include PFS, OR, and safety. The concurrent phase 3 FORTITUDE-101 study (NCT05052801) will evaluate bemarituzumab + mFOLFOX6 vs placebo + mFOLFOX6. Clinical trial information: NCT05111626.

INTEGRATE IIb: A randomized phase III open label study of regorafenib + nivolumab versus standard chemotherapy in refractory advanced gastroesophageal cancer (AGOC)

TPS366

Background: Advanced Gastro-oesophageal Carcinoma (AGOC) has a poor prognosis, and there is no established standard treatment following failure of first- and second-line chemotherapy. Regorafenib (BAY 73-4506) is an investigational oral multi-targeted tyrosine kinase inhibitor (TKI) which targets angiogenic (VEGF, TIE-2), stromal (PDGF-β), and oncogenic (RAF, RET and KIT) receptor tyrosine kinases, and has shown activity in this setting. Single agent regorafenib prolonged progression free survival (PFS) versus placebo across all regions/subgroups in the INTEGRATE randomised phase 2 trial. Current options in refractory AOGC involves sequencing through chemotherapy with the latest active agent approved being trifluridine/tipiracil, TAS-102. Promising activity in refractory AOGC has been seen with the combination of regorafenib & nivolumab. INTEGRATE IIb–will compare the effectiveness of the combination of regorafenib & nivolumab in pre-treated patients with AGOC to current standard chemotherapy. Methods: Randomised phase III, open label study with 2:1 randomisation (RegoNivo : standard chemotherapy) and stratification by: Geographic region (Asia vs. Rest of World); Prior VEGF inhibitors (Yes vs No); Prior immunotherapy (Yes vs No). RegoNivo arm will receive 90mg (3x30mg) of regorafenib days 1-21 of each 28-day treatment cycle with intravenous nivolumab 240 mg day 1 of each 14 day cycle until disease progression or prohibitive adverse events as per protocol. The control arm will receive the investigator’s choice of the following chemotherapy; a taxane (paclitaxel or docetaxel), irinotecan or oral trifluridine/tipiracil (TAS102). Primary endpoint: OS. Secondary endpoints: PFS, response rate, quality of life, toxicity, exploratory correlative biomarkers. Clinical trial information: NCT04879368.

Nivolumab (NIVO) plus chemotherapy (chemo) versus chemo as first-line (1L) treatment for advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma (GC/GEJC/EAC): Expanded efficacy, safety, and subgroup analyses from CheckMate 649

240

Background: CheckMate 649 is a randomized, global phase 3 study of 1L programmed death-1 (PD-1) inhibitor–based therapies in advanced non-HER2-positive GC/GEJC/EAC that demonstrated superior overall survival (OS) with NIVO + chemo vs chemo, leading to approvals in the US and other countries. Clinically meaningful long-term survival benefit with NIVO + chemo vs chemo was observed with 24 months (mo) of minimum follow-up in all randomized patients (pts) for both OS (HR 0.79 [95% CI 0.71–0.88]) and progression-free survival (PFS; HR 0.79 [95% CI 0.70–0.89]; Janjigian YY et al; ESMO 2021). We present expanded analyses of NIVO + chemo vs chemo with minimum follow-up of 24 mo. Methods: Adults with previously untreated, unresectable advanced or metastatic GC/GEJC/EAC were enrolled regardless of PD-ligand (L)1 expression. Pts with known HER2-positive status were excluded. Pts were randomized to NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO 1 mg/kg + IPI 3 mg/kg Q3W (4 doses, then NIVO 240 mg Q2W), or chemo. Dual primary endpoints were OS and PFS (per blinded independent central review) in pts with PD-L1 combined positive score (CPS) ≥ 5 for NIVO + chemo vs chemo. Hierarchically tested secondary endpoints included OS in NIVO + chemo vs chemo (PD-L1 CPS ≥ 1, then all randomized). Results: Of 2031 pts, 1581 were randomized to NIVO + chemo or chemo. In all randomized pts, 41% of pts (NIVO + chemo) and 44% of pts (chemo) received subsequent therapy. Median PFS2 (time from randomization to progression after subsequent systemic therapy, initiation of second subsequent systemic therapy, or death, whichever is earlier) was 12.2 (95% CI 11.3–13.5) mo with NIVO + chemo and 10.4 (95% CI 9.7–11.2) mo with chemo (HR 0.75 [95% CI 0.67–0.84]). 51% of pts (NIVO + chemo) and 43% of pts (chemo) had > 50% reduction from baseline in tumor burden, while 24% and 17% had > 80% reduction, respectively. The HR (95% CI) for OS was 0.66 (0.56–0.77) among pts with a PD-L1 CPS ≥ 10 (median OS for NIVO + chemo vs chemo: 15.0 [95% CI 13.7–16.7] vs 10.9 [95% CI 9.8–11.9] mo). OS benefit was observed with NIVO + chemo vs chemo across multiple additional subgroups, and these data will be presented. No new safety signals were identified. The majority of the treatment-related adverse events with potential immunologic etiology were grade 1 or 2 and grade 3 or 4 events were reported in ≤ 5% of pts in both treatment arms. Conclusions: NIVO + chemo continued to demonstrate clinically meaningful efficacy and an acceptable safety profile with longer follow-up, further supporting the use of NIVO + chemo as a standard 1L therapy in previously untreated pts with advanced GC/GEJC/EAC. Clinical trial information: NCT02872116.

Health-related quality of life (HRQOL) in patients (pts) with advanced gastric cancer/gastroesophageal junction cancer (GC/GEJC) or esophageal adenocarcinoma (EAC): Results of nivolumab plus chemotherapy (NIVO+chemo) versus chemo from CheckMate 649

167

Background: CheckMate 649 (NCT02872116) is a randomized, open label phase 3 study in first line (1L) treatment of pts with advanced GC/GEJC/EAC. Primary analysis results showed statistically significant improvement in overall survival (OS) for NIVO+chemo vs. chemo in all randomized pts. We present HRQOL results for these pts, included as an exploratory study objective. Methods: HRQOL was assessed using EQ-5D-3L (EQ-5D) and Functional Assessment of Cancer Therapy–Gastric Cancer (FACT-Ga). Assessments were performed at baseline (BL), every 6 weeks during treatment and during follow-up. Change from BL EQ-5D Visual Analog Scale (VAS), Utility Index (UI) and FACT-Ga scores were analyzed using mixed models. Time to first symptom deterioration (TTSD), time until definitive deterioration (TuDD), and time to improvement (TTI) were estimated with Kaplan-Meier estimators and stratified Cox models; deterioration/improvement was based on prespecified meaningful change thresholds. Results: 1581 pts were randomized to NIVO+chemo (n = 789) or chemo (n = 792). Among 1359 pts with BL and post-BL patient-reported outcomes (NIVO+chemo, n = 693; chemo, n = 666), BL scores for FACT-Ga total were similar between treatment groups. Least squares mean differences from BL favored NIVO+chemo at most visits for EQ-5D, FACT-Ga total, and Gastric Cancer Subscale (GaCS), and were comparable for other subscales (not shown). TTI generally favored NIVO+chemo (most HR > 1) but was not significantly different between arms. TTSD was longer in NIVO+chemo arm compared with chemo alone (all HRs < 1), except for Emotional Well-Being (WB); only GaCS and FACT-Ga total were significantly different between arms. TuDD showed statistically significant delays in deterioration (HR with CI < 1) for all scores expect Social WB. Conclusions: Compared with chemo alone, the addition of NIVO to chemo maintained HRQoL with a decreased risk of symptom deterioration in patients with previously untreated advanced or metastatic GC/GEJC/EAC. Together with improved OS, these data support NIVO+chemo as a new 1L standard treatment for GC/GEJC/EAC. Clinical trial information: NCT02872116. [Table: see text]

Early-onset stage II/III colorectal adenocarcinoma in the IDEA database: Treatment adherence, toxicities, and outcomes from adjuvant fluoropyrimidine and oxaliplatin

3517

Background: Incidence of early-onset colorectal cancer (eoCRC, age < 50) is steadily increasing. Decisions on adjuvant treatment (adjTx) regimen and duration should consider tx adherence, toxicity (tox) and expected outcomes in a population with life-expectancy longer than late onset CRC (loCRC, age ≥ 50). Methods: Individual patient data from stage II/III patients (pts) from 6 randomised trials in the IDEA database were used to compare characteristics, tx adherence, and adverse events of eoCRC to loCRC. To reduce the confounder of non-cancer-related deaths due to age/co-morbidities, time-to-recurrence (TTR) and cancer-specific survival (CSS) were compared by stratified Gay k-sample test. 5-year cancer-specific mortality (CSM) rate were estimated by adjusted cumulative incidence function. 3-year relapse-free survival (RFS) rate were compared by stratified and adjusted COX models. Results: Out of 16,349 pts included, 1564 (9.6%) were eoCRC. Compared to loCRC, eoCRC had lower percent of male pts (51% vs 57%, p < 0.01) better performance status (PS0 86% vs 80%, p < 0.01), similar T stage distribution (% T1-3/T4: 76/24 vs 77/23, p = 0.97), higher rate of N2 disease (24% vs 22%, p < 0.01), more likely to complete pre-planned duration of adjTx (83.2% vs 78.2%, p < 0.01) and received a higher tx intensity especially with 6 month tx (mean oxaliplatin dose intensity 75% vs 72%, p < 0.01; capecitabine 85% vs 78%, p < 0.01; 5FU 85% vs 82% p < 0.01). Gastrointestinal tox was more common in eoCRC (any grade nausea 58% vs 45%, p < 0.01; any grade vomiting 22% vs 16%, p < 0.01); haematological tox was more frequent in loCRC (62% vs, 69%, p = < 0.01); any grade neuropathy rate was similar (75%). Significant interaction was found between age and T stage for TTR (p = 0.04). Clinical outcome estimates and comparisons are shown in Table. Notably, high risk stage III (T4/N2) eoCRC had significantly lower 3-y RFS rate (54% vs 64%, HRadj 0.74, p < 0.01). Conclusions: eoCRC have better tx adherence than loCRC, as expected. While in high risk stage II and low risk stage III, cancer-specific outcomes are not different, in high risk stage III young age is negatively prognostic and associated with significantly higher relapse rate and risk of CRC death; this is despite a higher administered adjTx-intensity, suggesting a more aggressive disease biology. Clinical trial information: NCT00749450 (SCOT); NCT00646607 (TOSCA); NCT01150045 (CALGB/SWOG 80702); NCT00958737 (IDEA France) [Table: see text]

Adjuvant nivolumab (NIVO) in resected esophageal or gastroesophageal junction cancer (EC/GEJC) following neoadjuvant chemoradiotherapy (CRT): Expanded efficacy and safety analyses from CheckMate 577

4003

Background: In CheckMate 577 (NCT02743494), NIVO demonstrated a significant and clinically meaningful improvement in disease-free survival (DFS; primary endpoint) vs placebo (PBO) and was well tolerated in patients (pts) with resected (R0) stage II/III EC/GEJC who received neoadjuvant CRT and had residual pathologic disease. Median DFS doubled with NIVO vs PBO (22.4 vs 11.0 months; HR 0.69; 96.4% CI 0.56–0.86; P = 0.0003). Serious treatment-related adverse events (TRAEs) and TRAEs leading to discontinuation were reported for < 10% of pts with NIVO and 3% with PBO. Methods: Pts were randomized 2:1 to NIVO 240 mg or PBO Q2W for 16 weeks, followed by NIVO 480 mg or PBO Q4W. Here, we present additional efficacy, safety, and quality-of-life (QoL) data from CheckMate 577. Results: 794 pts were randomized (NIVO, 532; PBO, 262). Distant recurrence was reported for 29% vs 39% and locoregional recurrence for 12% vs 17% of pts in the NIVO vs PBO groups, respectively. Median distant metastasis-free survival was 28.3 vs 17.6 months with NIVO vs PBO (HR 0.74; 95% CI 0.60–0.92). Median progression-free survival 2 (PFS2; time from randomization to progression after subsequent systemic therapy, initiation of second subsequent systemic therapy, or death, whichever is earlier) was not reached with NIVO vs 32.1 months with PBO (HR 0.77; 95% CI 0.60–0.99). TRAEs with potential immunologic etiology (select TRAEs; sTRAEs) reported for NIVO are presented in the table. Results for the FACT-ECS and FACT-G7 showed similar trends for QoL improvement from baseline for NIVO and PBO during treatment and maintained benefit post-treatment. Conclusions: Adjuvant NIVO demonstrated clinically meaningful efficacy, an acceptable safety profile, and maintained QoL, providing further support for its use as a new standard of care for pts with resected EC/GEJC who received neoadjuvant CRT with residual pathologic disease. Clinical trial information: NCT02743494. [Table: see text]

First-line (1L) nivolumab (NIVO) plus chemotherapy (chemo) versus chemo in advanced gastric cancer/gastroesophageal junction cancer/esophageal adenocarcinoma (GC/GEJC/EAC): Expanded efficacy and safety data from CheckMate 649

4002

Background: CheckMate 649 is the largest randomized, global phase 3 study of 1L programmed death (PD)-1 inhibitor–based therapy in GC/GEJC/EAC. 1L NIVO + chemo demonstrated superior overall survival (OS) vs chemo, with progression-free survival (PFS) benefit and an acceptable safety profile in pts whose tumors expressed PD-ligand (L)1 at combined positive score (CPS) ≥ 5 and ≥ 1, and in all randomized pts (Moehler et al. Ann Oncol 2020). We report additional data for all randomized pts. Methods: Eligible pts had previously untreated, unresectable advanced or metastatic GC/GEJC/EAC. Known HER2-positive pts were excluded. Pts were randomized to receive NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO + ipilimumab, or chemo. Dual primary endpoints for NIVO + chemo vs chemo were OS and PFS by blinded central review in PD-L1 CPS ≥ 5 pts. Hierarchically tested secondary endpoints were OS in PD-L1 CPS ≥ 1 and all randomized pts. Results: At 12-month minimum follow-up for 1581 randomized pts, NIVO + chemo had a statistically significant OS benefit vs chemo (HR 0.80 [99.3% CI 0.68–0.94; P = 0.0002]) in all randomized pts; PFS benefit was also seen (HR 0.77 [95% CI 0.68–0.87]). OS benefit was observed in multiple prespecified subgroups, consistent with the primary population. Grade 3–4 treatment-related adverse events (TRAEs) were reported in 59% (NIVO + chemo) and 44% (chemo) of pts. TRAEs with potential immunologic etiology (select TRAEs; sTRAEs) are shown in the table. Pts in the NIVO + chemo arm had decreased risk of symptom deterioration on treatment vs those in the chemo arm (HR 0.77 [95% CI 0.63–0.95; P = 0.0129]). Tolerability as measured by the FACT-Ga GP5 item was similar in both treatment groups. Conclusions: The addition of NIVO to chemo demonstrated improved OS and PFS benefit in all randomized pts, along with an acceptable safety profile and maintained tolerability as well as QoL, providing further support for NIVO + chemo as a standard 1L treatment for advanced GC/GEJC/EAC. Clinical trial information: NCT02872116. [Table: see text]

EORTC 1707 VESTIGE: Adjuvant immunotherapy in patients with resected gastric cancer following preoperative chemotherapy with high risk for recurrence (ypN+ and/or R1)—An open-label randomized controlled phase II study

TPS4156

Background: Gastroesophageal adenocarcinoma (GEA) patients with metastatic lymph nodes (ypN+) or a microscopically incomplete surgical resection (R1) following neoadjuvant chemotherapy are at high risk of disease recurrence. Current practice is to continue with the same perioperative chemotherapy used prior to surgery, despite these suboptimal outcomes. Adjuvant immunotherapy with nivolumab has shown efficacy in poor risk GEA patients following chemoradiotherapy and surgery in the CheckMate 577 trial, and nivolumab and ipilimumab have demonstrated activity in advanced GEA. We hypothesise that high risk (ypN+ and/or R1) post resection GEA patients who are treated with nivolumab and ipilimumab will have better disease free survival than patients who continue with standard post-operative chemotherapy. Methods: VESTIGE is an ongoing, international, open label randomized phase II study designed to evaluate the efficacy of adjuvant nivolumab plus ipilimumab versus standard post-operative chemotherapy in high risk (ypN+ and/or R1) post resection GEA patients. Eligible patients (n=240) will be randomised 1:1 to receive post-operative adjuvant chemotherapy (identical regimen as pre-operatively) or nivolumab 3mg/kg IV q2w plus ipilimumab 1mg/kg IV q6w x 1 year. Key inclusion criteria include ypN+ and/or R1 status following neoadjuvant chemotherapy plus surgery and an adequate pre-specified surgical resection. The primary endpoint of the study is disease free survival, with secondary endpoints of overall survival, safety, toxicity and quality of life. Since start of recruitment in August 2019, the trial has recruited 85 of 240 patients at 18 sites in the Czech Republic, France, Germany, Israel, Italy, Norway, Poland, Spain, and United Kingdom. The VESTIGE translational research programme includes collection of pre-treatment biopsies, post-chemotherapy resection specimens and serial liquid biopsy on treatment to explore biomarkers predictive of immune checkpoint blockade efficacy. Clinical trial information: NCT03443856.

Health-related quality of life (HRQOL) in patients (pts) with advanced gastric cancer/gastroesophageal junction cancer (GC/GEJC) or esophageal adenocarcinoma (EAC): Interim results of nivolumab plus chemotherapy (N+C) versus (C) from CheckMate 649

4066

Background: CheckMate 649 (NCT02872116) is a randomized, open label phase 3 study in first line (1L) GC/GEJC/EAC. Prespecified interim results showed statistically significant improvement in overall survival (OS) and progression-free survival (PFS) for N+C vs C in all randomized pts and pts whose tumors expressed programmed death-ligand 1 combined positive score (CPS) ≥ 5. We present interim HRQOL results for CPS ≥ 5 pts, included as exploratory in the study. Methods: HRQOL was assessed using EQ-5D-3L (EQ-5D) and Functional Assessment of Cancer Therapy–Gastric Cancer (FACT-Ga). Assessments were performed at baseline (BL), every 6 weeks during treatment, and during follow-up. Change from BL EQ-5D Visual Analog Scale (VAS), Utility Index (UI) and FACT-Ga scores were analyzed using mixed models. Time to first symptom deterioration (TTSD), time until definitive deterioration (TuDD), and time to improvement (TTI) were estimated with Kaplan-Meier estimators and stratified Cox models; deterioration/improvement was based on prespecified meaningful change thresholds. Results: 1,581 pts were randomized to N+C (n = 789) and C (n = 792); of those, 955 pts had CPS ≥ 5 (N+C [n = 473] and C [n = 482]). Among 821 pts with BL and post BL PROs (N+C [n = 421] and C [n = 400]), BL scores for FACT-Ga total were similar for N+C and C. Least-squares mean differences from BL favored N+C at most visits for EQ-5D and FACT-Ga total and GaCS, and were comparable for other FACT subscales (data not shown). TTI largely favored N+C (most hazard ratios (HR) > 1) but was not significantly different between treatments. For TTSD, pts treated with N+C had decreased risk of deterioration (HR < 1) in EQ-5D UI, FACT-Ga total, and GaCS. TuDD showed statistically significant delays in deterioration (HR with confidence intervals [CI] < 1) for all scores. Conclusions: Pts with 1L GC/GEJC/EAC experienced better HRQOL with N+C compared with C alone. Change from BL in EQ-5D and FACT-Ga total and GaCS favored N+C at most visits. N+C decreased deterioration risk compared to C with OS and PFS improvement, suggesting favorable benefits in 1L GC/GEJC/EAC pts with CPS ≥ 5. Clinical trial information: NCT02872116. [Table: see text]

Margetuximab (M) combined with anti-PD-1 (retifanlimab) or anti-PD-1/LAG-3 (tebotelimab) +/- chemotherapy (CTX) in first-line therapy of advanced/metastatic HER2+ gastroesophageal junction (GEJ) or gastric cancer (GC)

TPS264

Background: Trastuzumab (T), a monoclonal antibody (mAb) targeting HER2, is standard of care 1st-line therapy for advanced HER2+ GEJ/GC patients. M, an investigational Fc-engineered anti-HER2 mAb, targets the same HER2 epitope but with higher affinity for both 158V (high binding) and 158F (low binding) alleles of activating Fc receptor CD16A. Data suggest margetuximab coordinately enhances both innate and adaptive immunity, including antigen-specific T-cell responses to HER2. PD-1 and LAG-3 are T-cell checkpoint molecules that suppress T-cell function. Retifanlimab (also known as MGA012 or INCMGA00012) is a humanized, hinge-stabilized, IgG4 Κ anti-PD-1 mAb blocking binding of PD-L1 or PD-L2 to PD-1. Tebotelimab (also known as MGD013) is a humanized Fc-bearing bispecific tetravalent DART® protein that binds to both PD-1 and LAG-3, inhibiting their respective ligand binding. We previously reported that a CTX-free regimen of M+PD-1 blockade was well tolerated in GEJ/GC patients, and induced a 44% objective response rate (ORR) in a double-positive biomarker population. This was 2- to 3-fold greater than in historical controls with checkpoint inhibitors alone. This registration-directed trial assesses efficacy, safety, and tolerability of M+checkpoint inhibition ± CTX in metastatic/locally advanced, treatment-naïve, HER2+ GEJ/GC patients. Methods: This is a 2-cohort, adaptive open-label phase 2/3 study (NCT04082364). The first single arm, CTX-free cohort A, evaluates M+retifanlimab in HER2+ (immunohistochemistry [IHC] 3+) and PD-L1+ (excluding microsatellite instability high) patients. After 40 patients are evaluated for response/safety, additional patients will be enrolled if the threshold for continuation is met. In randomized cohort B, HER2+ (IHC 3+ or 2+/fluorescent in situ hybridization+) patients are enrolled irrespective of PD-L1 status. Part 1 of cohort B randomizes patients to 1 of 4 arms (50 patients each): control arm (T+CTX) or 1 of 3 experimental arms (M+CTX; M+CTX+retifanlimab; M+CTX+tebotelimab). CTX is investigator’s choice XELOX or mFOLFOX-6. Part 2 of cohort B consists of control (T+CTX) vs 1 experimental arm (M+CTX) + either retifanlimab or tebotelimab, depending on results from part 1; with 250 patients each. The primary efficacy endpoint for cohort A (both parts) is ORR per RECIST 1.1; for cohort B part 2 it is overall survival. Clinical trial information: NCT04082364.

Checkmate 577:Health-related quality of life (HRQoL) in a randomized, double-blind phase III study of nivolumab (NIVO) versus placebo (PBO) as adjuvant treatment in patients (pts) with resected esophageal or gastroesophageal junction cancer (EC/GEJC)

167

Background: NIVO is the first adjuvant therapy to provide a statistically significant and clinically meaningful improvement in disease-free survival (DFS) versus PBO in resected EC/GEJC following neoadjuvant chemoradiotherapy as demonstrated by CheckMate 577. NIVO was well tolerated with an acceptable safety profile. This analysis provides additional information on the exploratory HRQoL endpoints in this clinical trial. Methods: The effect of NIVO versus PBO on HRQoL, including general and disease-related symptoms, functioning, disease burden, and overall QoL, was assessed using FACT-E and EQ-5D-3L patient-reported outcome (PRO) questionnaires administered at baseline (BL), every 4 weeks during the 12-month treatment period, and at post-treatment follow-up visits (up to 2 years after last dose). Longitudinal change from BL in PRO scores over 12 months was assessed using descriptive statistics. Additionally, mixed model for repeated measures and time to deterioration analyses evaluated the difference between treatment with NIVO and PBO (data not shown). Results: 794 pts with EC/GEJC were randomized 2:1 to NIVO (n = 532) or PBO (n = 262). PRO completion rates were ≥ 95% at BL and ~ 90% at 12 months on treatment. Mean (SD) BL HRQoL scores were similar between treatment arms for the FACT-E total score (NIVO: 133.40 [20.97]; PBO: 134.03 [20.40]); esophageal cancer subscale (ECS; NIVO: 50.2 [9.3]; PBO: 50.1 [8.9]); EQ-5D Visual Analogue Scale (NIVO: 70.4 [22.3]; PBO: 69.1 [24.1]); and EQ-5D Utility Index (NIVO: 0.820 [0.179]; PBO: 0.831 [0.163]) based on the UK value set. Descriptive analyses showed a trend for increases from baseline at most time points through week 49 for both NIVO and PBO treatment groups for FACT-E total score, ECS, and EQ-5D Visual Analogue Scale and Utility Index. Conclusions: Preliminary results from CheckMate 577 demonstrated that pts on NIVO treatment showed trends of improvement in both esophageal-specific and general HRQoL. Similar trends were also observed in pts treated with PBO over 1 year. Pts treated with NIVO did not experience a reduction in HRQoL, further supporting clinical data to demonstrate treatment benefit and tolerability for adjuvant NIVO in pts with resected EC/GEJC. Clinical trial information: NCT02743494.

Gender representation in authorship in later-phase systemic clinical trials in biliary tract cancer (BTC)

348

Background: The proportion of females in medicine is increasing (approx. 50% in medical school/workforce), but disparities in female authorship in oncology research publications exist; female corresponding authorship reportedly ranges from 7.2-39.1% in oncology clinical trials (Ludmir et al 2019). This study aimed to describe and assess factors associated with female first and senior authorship in later phase systemic clinical trials in BTC and to identify any changes over time. Methods: Embase/Medline were used to identify final primary trial publications in BTC (2000-2020) (excluding phase I (PI) (expected to move to later phase), mixed tumour site trials, reviews, editorials and trial-in-progress publications). Gender was determined by inspection of names, google search and author communication. Chi-square tests and log regression were used to assess factors associated with female first and senior authorship, including changes over time (STATA16). Results: Of 501 publications, 163 met inclusion criteria; 80% single-arm PII and 15% and 5% randomised PII and PIII respectively; 73% enrolled ≤50 patients. Tumour primary sites were all BTC: 86%, cholangiocarcinoma: 8%, gallbladder cancer: 6%; 80% involved chemotherapy, 13% targeted therapy and 5% localised/systemic combinations; 65% were in first-line (1L) advanced setting, 17% post 1L, 13% advanced non-specified and 5% neo-adjuvant/adjuvant. Forty-eight percent received industry funding and 65% met primary end-point. Sixty-four percent were published post ABC-02 (Valle et al 2010). Publication impact factor (IF) was ≤5 in 50% and >20 in 12%. Median number of authors in all publications was 11. Geographic location of all first and senior authors were Asia (42%/42%), Europe (29%/29%), USA (24%/22%) and other (4%/6%), respectively. Median individual trial female author representation was 25%; there were no female authors in 12% of trials. Overall, female first and senior author representation was 21% and 11%, respectively. Median position of first female author was second. In publications with IF ≤20 and >20, there were 22% and 16% female first and 13% and 0% female senior authors, respectively. The phase of trial, journal IF, industry funding, or whether met primary end-point did not impact female first or senior author representation (all P>.05). There were more female senior authors associated with “other” geographic locations (40% in 10 trials) (P=.016) vs Asia (7%), Europe (8%) and USA (14%). There were no significant changes in female first or senior author representation over time (‘00-05: 21%/18%, ‘06-10: 27%/5%, ‘11-15: 15%/15%, ‘16-20: 22%/9%, P=.738, and P=.508 respectively). Conclusions: Female first and senior author representation in later phase systemic clinical trial publications in BTC is low and has not changed significantly over time. The underlying reasons for this imbalance need to be better understood and addressed.

Progression-free survival (PFS) as a surrogate endpoint for overall survival (OS) in advanced/recurrent gastric cancer (AGC) treatment: Individual-patient-data (IPD) based meta-analysis of randomized trials

e16506

Background: In 2013, the GASTRIC (Global Advanced/Adjuvant Stomach Tumor Research through International Collaboration) evaluated the surrogacy of PFS based on IPD of 4,069 patients from 20 randomized trials of AGC. Treatment effects on PFS and on OS were only moderately correlated, and we could not validate PFS as a surrogate endpoint for OS. More recent trials, with refined inclusion criteria and higher standards for evaluating progression, may allow for a more accurate estimate of the correlation. The 2nd round of the GASTRIC sought to re-evaluate the surrogacy of PFS for OS in AGC. Methods: The GASTRIC database was updated with trials published after 2010 which used RECIST (Response Evaluation Criteria in Solid Tumors). Since the proportional hazards assumption was questionable for PFS, we primarily used mean-time ratio as a treatment effect measure, estimated by using the log-logistic model. Using the meta-analytic approach, correlations between PFS and OS at the individual level (Rindiv), and between treatment effects on PFS and on OS at the trial level (Rtrial), were estimated using Spearman’s rank-correlation and estimation-error-adjusted regression, respectively. Surrogate threshold effect was estimated as well. Results: We analyzed 10,912 patient data (1st round 4,069 patients from 20 trials and 2nd round 6,843 patients from 17 trials). Overall, moderate correlations were found at the individual level (Rindiv = 0.75, 95%CI = 0.75 to 0.76 in Hougaard copula) and at the trial level (Rtrial = 0.77, 95%CI = 0.32 to 1.00), respectively. Surrogate threshold effect was equal to 1.29, i.e., observing 29% increase in mean PFS time would predict a significant increase of the OS time. In the subgroup of patients with measurable disease in the 2nd round dataset (4,866 patients), Rtrial was higher and equal to 0.93 (95%CI = 0.70 to 1.00), with STE equal to 1.21. These results were same for 1st and 2nd line trials. Conclusions: The meta-analysis indicates a strong correlation between treatment effects (expressed as log-mean-ratios) on PFS and OS in patients with measurable disease.

Neoadjuvant chemoradiation (CRT) for locally advanced rectal cancer (LARC) with or without oxaliplatin (OX): Individual patient data (IPD) meta-analysis of three randomized controlled trials (RCTs) with subgroup analyses of age cohorts

4074

Background: Neoadjuvant CRT with fluoropyrimidine (FP) is standard treatment for LARC, which is increasing in younger patients (pts). RCTs examining the addition of OX are still controversial. A post hoc analysis of the CAO/ARO/AIO-04 trial showed significant benefit in pts < 60y. We hypothesised that younger pts with LARC might have improved outcomes with OX-CRT. Methods: Systematic review and IPD meta-analysis were performed. Data from 3 RCTs (CAO/ARO/AIO-04, ACCORD-12, PETACC-6) testing the addition of OX to standard FP-based CRT in LARC were available (of 9 RCTs identified). Primary endpoint: disease-free survival (DFS), secondary endpoints: pathologic complete response (pCR), overall survival (OS). Analyses were by intention to treat (ITT), stratified by trial. Age cut-offs were 60y and 50y. Given the focus on young age a multivariate analysis evaluating all possible confounders was not intended in the current work. Results: IPD from 2914 pts were included (48.5% of available literature). Median age was 63; 70% were male; 79% had a performance status = 0; 72% were stage ≥III. In ITT (Hazard Ratio [HR] 0.88, 95%CI 0.77-1.01, p = 0.06), DFS was not significantly improved by the addition of OX (Table). In < 60y (n = 1166, 40% total), DFS was significantly improved by OX (HR 0.77, 95%CI 0.62-0.96, p = 0.02). In < 50y (n = 350, 12% total) there was a numerically better DFS, although not significant (HR 0.73, 95%CI 0.49-1.08, p = 0.12). Interaction test between age and DFS was non-significant (60y p = 0.11; 50y p = 0.44). In ITT, OX increased pCR from 13% to 16% (Odds Ratio [OR] 1.28, 95%CI 1.04-1.57, p = 0.024 [stratified by trial]), without significant interaction with age (60y p = 0.11, 50y p = 0.74). No OS benefit was demonstrated (HR 0.97, 95%CI 0.82-1.15, p = 0.75). Conclusions: This first IPD meta-analysis of three RCTs evaluating the addition of OX to CRT did not show significant interaction of OX with age. However, we confirm a signal for DFS benefit in pts < 60y and a non-significant increment in DFS in < 50 y although this analysis may be underpowered. Stage-stratified analyses and feasibility/toxicity data in age cohorts will be presented. [Table: see text]

Results of the JAVELIN Gastric 100 phase 3 trial: avelumab maintenance following first-line (1L) chemotherapy (CTx) vs continuation of CTx for HER2− advanced gastric or gastroesophageal junction cancer (GC/GEJC)

278

Background: We report the primary analysis of JAVELIN Gastric 100, which compared avelumab (anti–PD-L1) maintenance after 1L CTx vs continued CTx in patients (pts) with GC/GEJC. Methods: In this global, open-label, phase 3 trial (NCT02625610), eligible pts had previously untreated, unresectable, locally advanced/metastatic (LA/M) HER2− GC/GEJC. Pts without progressive disease (PD) after 12 weeks of 1L oxaliplatin/fluoropyrimidine induction were randomized 1:1 to avelumab 10 mg/kg Q2W switch maintenance or continued CTx, stratified by region (Asia vs non-Asia). Primary endpoint was overall survival (OS) post induction in all randomized or PD-L1+ (≥1% of tumor cells, 73-10 assay) pts. Results: 805 pts received induction CTx and 499 pts were randomized (avelumab, n = 249; CTx, n = 250). At data cutoff (Sep 13, 2019), minimum follow-up was 18 months. In the avelumab and CTx arms, median OS post induction/randomization was 10.4 months (95% CI 9.1-12.0) vs 10.9 months (95% CI 9.6-12.4), hazard ratio (HR) 0.91 (95% CI 0.74-1.11; p = 0.1779); 24-month OS rates were 22.1% (95% CI 16.8-28.0) vs 15.5% (95% CI 10.8-20.9), respectively. The HR for OS in PD-L1+ pts (n = 54) was 1.13 (95% CI 0.57-2.23). No OS trend was seen in Asian pts (n = 114; HR 0.90 [95% CI 0.59-1.36]) or other subgroups, except for a potential benefit with avelumab in pts with no metastatic sites at randomization (n = 60; HR 0.52 [95% CI 0.28-0.98]). Progression-free survival was similar between arms (HR 1.04 [95% CI 0.85-1.28]). In the avelumab vs CTx arms, objective response rates (post randomization only) were 13.3% (95% CI 9.3-18.1) vs 14.4% (95% CI 10.3-19.4), and 12-month rates for duration of response were 62.3% (95% CI 40.9-77.9) vs 28.4% (95% CI 13.2-45.7), respectively. Treatment-related adverse event rates (all grades/grade ≥3) were 61.3%/12.8% with avelumab and 77.3%/32.8% with CTx. Conclusions: Avelumab maintenance showed clinical activity and favorable safety vs continued CTx in pts with LA/M GE/GEJC; however, JAVELIN Gastric 100 did not meet its primary objective of demonstrating superior OS in the randomized or PD-L1+ population. Clinical trial information: NCT02625610.

Margetuximab (M) combined with anti-PD-1 (MGA012) or anti-PD-1/LAG-3 (MGD013) +/- chemotherapy (CTX) in first-line therapy of advanced/metastatic HER2+ gastroesophageal junction (GEJ) or gastric cancer (GC)

TPS468

Background: Trastuzumab (T), a monoclonal antibody (mAb) targeting HER2, is standard of care palliative 1st-line therapy for advanced HER2+ GEJ/GC patients (pts). M, an Fc-engineered anti-HER2 mAb, targets the same HER2 epitope but with higher affinity for both 158V (high binding) and 158F (low binding) alleles of activating Fc receptor CD16A. M coordinately enhanced both innate and adaptive immunity, including antigen-specific T-cell responses to HER2. PD-1 and LAG-3 are T-cell checkpoint molecules that suppress T-cell function. MGA012 (INCMGA00012) is a humanized, hinge-stabilized, IgG4 κ anti-PD-1 mAb blocking binding of PD-L1 or PD-L2 to PD-1. MGD013 is a humanized Fc-bearing bispecific tetravalent protein that binds to both PD-1 and LAG-3, inhibiting their respective ligand binding. We previously reported that a CTX-free regimen of M+PD-1 blockade was well tolerated in GEJ/GC pts, and induced a 30% objective response rate (ORR). This was 2- to 3-fold greater than in historical controls with checkpoint inhibitors alone. This registration-directed trial assesses efficacy, safety, and tolerability of M+checkpoint inhibition ± CTX in metastatic/locally advanced, treatment-naïve, HER2+ GEJ/GC pts. Methods: This is a 2-cohort, adaptive open-label phase 2/3 study. The first single arm, CTX-free cohort A evaluates M+MGA012 in HER2+ (immunohistochemistry [IHC] 3+) and PD-L1+ (excluding microsatellite instability high) pts. After 40 pts are evaluated for response/safety, 60 more pts will be enrolled if the threshold for continuation is met. In randomized cohort B, HER2+ (IHC 3+ or 2+/fluorescent in situ hybridization+) pts are enrolled irrespective of PD-L1 status. Part 1 randomizes pts to 1 of 4 arms (50 pts each): control arm (T+CTX) or 1 experimental arm (M+CTX; M+CTX+MGA012; M+CTX+MGD013). CTX is investigator’s choice XELOX or mFOLFOX-6. Part 2 consists of control (T+CTX) vs 1 experimental arm (M+CTX) + either MGA012 or MGD013, depending on results from part 1; with 250 pts each. The primary efficacy endpoint for cohort A (both parts) is ORR per RECIST 1.1; for cohort B part 2 it is overall survival.

Tislelizumab plus chemotherapy versus placebo plus chemotherapy as first-line therapy in patients with locally advanced unresectable or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma

TPS458

Background: First-line standard of care in patients with locally advanced or metastatic G/GEJ adenocarcinoma is fluoropyrimidine- and platinum (plat)-based combination chemotherapy. Despite improved chemotherapy regimens, outcomes remain poor and survival is low. Tislelizumab, an investigational humanized IgG4 monoclonal antibody with high affinity and binding specificity for PD-1, was engineered to minimize binding of FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy. Previous reports from early phase studies suggested tislelizumab, as a single agent and combined with chemotherapy, was generally well tolerated and had antitumor activity in patients with advanced solid tumors, including G/GEJ cancer. Methods: This randomized, placebo-controlled phase 3 study (NCT03777657) is designed to evaluate plat/fluoropyrimidine + tislelizumab vs plat/fluoropyrimidine + placebo as first-line therapy for patients with locally advanced or metastatic G/GEJ adenocarcinoma. Adult patients (n≈720) from ~160 centers will be randomized 1:1 to receive tislelizumab (200 mg IV Q3W) or placebo in combination with chemotherapy. Oxaliplatin (130 mg/m² IV Q3W) + capecitabine (1000 mg/m2 orally BID for 2 weeks) or cisplatin (80 mg/m² IV Q3W) + 5-fluorouracil (800 mg/m2/day IV on Days 1-5 Q3W) will be used as backbone chemotherapy on an individual basis. Chemotherapy will be administered for up to 6 cycles; capecitabine maintenance therapy is optional for patients who received capecitabine and oxaliplatin. Progression-free and overall survival are primary endpoints of the study. Secondary endpoints will include overall response rate, quality-of-life outcomes, and the safety/tolerability profile of combination therapy. Exploratory endpoints include disease control rate, time to response, and an analysis of potential predictive biomarkers including PD-L1 expression; the VENTANA PD-L1 (SP263) assay will be used for PD-L1 expression analysis. This study is actively enrolling. Clinical trial information: NCT03777657.

Regorafenib with TAS-102 (REGOTAS) in metastatic colorectal cancer patients who progressed after at least two standard therapies: Efficacy and safety results of a multicenter phase I study (REMETY)

158

Background: The multi-kinase inhibitor regorafenib (REGO) and oral fluoropyrimidine TAS-102 (TAS) show efficacies as single agents in treatment of refractory metastatic CRC patients (pts). We conducted a conventional 3+3 dose finding to determine a recommended phase II dose (RP2D) of its combination REGOTAS and efficacy in 3-4.-line. Methods: Eligible patients with ECOG 0-1, measurable mCRC, not amenable to surgery had at least 3rd-line treatments. Prior fluoropyrimidine-based and anti-VEGF (R) combinations were mandatory, and anti-EGFR for RAS WT tumors. TAS was given on days 1-5 and 8-12 (28-days cycle); REGO on days 2-22 (dose levels see table below). The following major AE categories were used to define DLTs if they occurred during the first 2 treatment cycles: any grade ≥3 non-hematologic toxicity (except vomiting, nausea, non-significant lab abnormalities), grade ≥3 hematological toxicities, grade ≥3 bleeding. Tumor response was assessed Q8W as per RECIST1.1. EudraCT 2016-001968-11; NCT03305913. Results: All observed toxicities were consistent with safety profile of individual IMPs. 6 pts were enrolled into each DL1 and DL2 (n=12 in total). One DLT was observed in 1/6 pts in DL1; 2 DLTs in 2/6 pts in DL2. All DLTs were only grade 3 hypertension was well manageable, causality was attributed to REGO. No DLT resulted in treatment discontinuation. Results indicate a RP2D of 25mg/m² TAS-102 BID + 120mg REGO daily. No remissions were observed. Overall disease control rate (DCR) after 8 weeks was promising with 58.3% (DCR of 33.3% for DL1 and 83.3% in DL2) and remarkably better as historical data with 41/44% for REGO/TAS102 alone, respectively (Lancet 2013/NEJM 2015). Conclusions: Toxicities of REGOTAS were consistent with safety profiles of REGO and TAS alone. No additional DLTs were attributed to REGOTAS. Thus, the risk-benefit assessment of REGOTAS was positive. DCR was clinically quite meaningful. Mature PFS and OS will be presented at the meeting. Clinical trial information: NCT03305913.

[Table: see text]

EORTC 1707 VESTIGE: Adjuvant immunotherapy in patients with resected gastric cancer following preoperative chemotherapy with high risk for recurrence (ypN+ and/or R1): An open-label randomized controlled phase II study

TPS467

Background: Gastroesophageal adenocarcinoma patients with metastatic lymph nodes (ypN+) or a microscopically incomplete surgical resection (R1) following neoadjuvant chemotherapy are at high risk of disease recurrence. Current practice is to continue with the same perioperative chemotherapy used prior to surgery, despite these suboptimal outcomes. Immune checkpoint blockade with nivolumab and ipilimumab has demonstrated activity in advanced gastroesophageal adenocarcinoma. We hypothesise that high risk (ypN+ and/or R1) post resection gastroesophageal adenocarcinoma patients who are treated with nivolumab and ipilimumab will have better disease free survival than patients who continue with standard post-operative chemotherapy. Methods: VESTIGE is an ongoing, international, open label randomized phase II study designed to evaluate the efficacy of adjuvant nivolumab plus ipilimumab versus standard post-operative chemotherapy in high risk (ypN+ and/or R1) post resection gastroesophageal adenocarcinoma patients. Eligible patients (n=240) will be randomised 1:1 to receive post-operative adjuvant chemotherapy (identical regimen as pre-operatively) or nivolumab 3mg/kg IV q2w plus ipilimumab 1mg/kg IV q6w x 1 year. Key inclusion criteria include ypN+ and/or R1 status following neoadjuvant chemotherapy plus surgery and an adequate pre-specified surgical resection. The primary endpoint of the study is disease free survival, with secondary endpoints of overall survival, safety, toxicity and quality of life. The trial will recruit 240 patients at 24 number of sites in the Czech Republic, France, Germany, Israel, Italy, Norway, Poland, Portugal, Spain, and United Kingdom. Recruitment commenced July 2019 and is anticipated to take 30 months. The VESTIGE translational research programme includes collection of pre-treatment biopsies, post-chemotherapy resection specimens and serial liquid biopsy on treatment to explore biomarkers predictive of immune checkpoint blockade efficacy. Clinical trial information: NCT03443856.

A phase III study of futibatinib (TAS-120) versus gemcitabine-cisplatin (gem-cis) chemotherapy as first-line (1L) treatment for patients (pts) with advanced (adv) cholangiocarcinoma (CCA) harboring fibroblast growth factor receptor 2 (FGFR2) gene rearrangements (FOENIX-CCA3)

TPS600

Background: Pts with adv CCA have poor survival outcomes, and chemotherapy offers limited survival benefit (5-year survival rates, 5–10%; median overall survival [OS], 8–12 months). FGFR2 gene rearrangements are known to be early drivers of oncogenesis in ~15% of pts with intrahepatic (i) CCA. Futibatinib, an oral, highly selective, irreversible FGFR1-4 inhibitor has shown antitumor activity against a broad spectrum of FGFR-deregulated tumors in preclinical studies. In a previous study, futibatinib demonstrated clinical activity and tolerability in heavily pretreated pts with adv CCA harboring FGFR2 gene rearrangements. This phase 3 trial (FOENIX-CCA3) is designed to evaluate futibatinib vs gem-cis as 1L therapy for pts with adv iCCA harboring FGFR2 rearrangements. Methods: FOENIX-CCA3 is a multicenter, open-label, randomized phase 3 study that will be conducted in pts with metastatic or unresectable iCCA harboring FGFR2 rearrangements (assessed at screening by a central laboratory). Pts must have an ECOG performance status of 0 or 1 and should not have received previous systemic anticancer therapy for adv disease (adjuvant/neoadjuvant therapy ≥6 mo prior to randomization is permissible). Pts with clinically-significant alterations in calcium-phosphorus homeostasis or ectopic mineralization/calcification will be excluded. Approximately 216 pts will be randomized (1:1 ratio) to receive 20 mg futibatinib once daily until disease progression or other discontinuation criteria are met or gem-cis (on days 1 and 8 of a 21-day cycle) for 8 cycles or until disease progression, whichever occurs first. Pts will be stratified by prior surgical excision (yes vs no), geographic region, and locally adv vs metastatic disease. The primary endpoint is progression-free survival (PFS) assessed by independent central review (ICR). Secondary endpoints include objective response rate and disease control rate based on ICR, OS, PFS per investigator assessment, and safety. The anticipated start date is in April, 2020.

Phase III, randomised trial of avelumab versus physician's choice of chemotherapy as third-line treatment of patients with advanced gastric or gastro-oesophageal junction cancer: primary analysis of JAVELIN Gastric 300

Background

There currently are no internationally recognised treatment guidelines for patients with advanced gastric cancer/gastro-oesophageal junction cancer (GC/GEJC) in whom two prior lines of therapy have failed. The randomised, phase III JAVELIN Gastric 300 trial compared avelumab versus physician’s choice of chemotherapy as third-line therapy in patients with advanced GC/GEJC.

Patients and methods

Patients with unresectable, recurrent, locally advanced, or metastatic GC/GEJC were recruited at 147 sites globally. All patients were randomised to receive either avelumab 10 mg/kg by intravenous infusion every 2 weeks or physician’s choice of chemotherapy (paclitaxel 80 mg/m² on days 1, 8, and 15 or irinotecan 150 mg/m² on days 1 and 15, each of a 4-week treatment cycle); patients ineligible for chemotherapy received best supportive care. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety.

Results

A total of 371 patients were randomised. The trial did not meet its primary end point of improving OS {median, 4.6 versus 5.0 months; hazard ratio (HR)=1.1 [95% confidence interval (CI) 0.9–1.4]; P = 0.81} or the secondary end points of PFS [median, 1.4 versus 2.7 months; HR=1.73 (95% CI 1.4–2.2); P > 0.99] or ORR (2.2% versus 4.3%) in the avelumab versus chemotherapy arms, respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 90 patients (48.9%) and 131 patients (74.0%) in the avelumab and chemotherapy arms, respectively. Grade ≥3 TRAEs occurred in 17 patients (9.2%) in the avelumab arm and in 56 patients (31.6%) in the chemotherapy arm.

Conclusions

Treatment of patients with GC/GEJC with single-agent avelumab in the third-line setting did not result in an improvement in OS or PFS compared with chemotherapy. Avelumab showed a more manageable safety profile than chemotherapy.

Trial registration

ClinicalTrials.gov: NCT02625623.

Multidisciplinary management of stage II-III gastric and gastro-oesophageal junction cancer

The aim of this manuscript is to discuss the viewpoint of the European Organisation for Research and Treatment of Cancer (EORTC) Gastric Cancer Taskforce and Japan Clinical Oncology Group (JCOG) Gastric Cancer Study Group on the current challenges in the multidisciplinary management of stage II-III gastric and gastro-oesophageal junction (GEJ) cancer. We seek to outline how these challenges are addressed in current trials of both groups. Key elements of future trials of EORTC and JCOG in this indication are described, and a joint vision on how multidisciplinary research of gastric and GEJ cancer patients should be organised is outlined.

Association of MAPK signaling subtypes with prognostic benefit for bevacizumab in left-sided metastatic colorectal cancer (mCRC) patients treated with FOLFIRI + cetuximab / bevacizumab (FIRE-3 trial)

3584

Background: We investigated the role of the MAPK pathway by mRNA expression profiles in microarrays of the FIRE-3 trial as it was formerly associated with prognosis. Methods: 451 patients provided eligible mRNA material for subsequent analyses of the MAPK pathway (295 genes). Non-negative matrix factorized (NMF) clustering for normalized mRNA microarray data (Almac Inc, Xcel Array) was performed for 2 to 6 ranks against randomized controls. Linear models with adjustment for multiple testing showed differential gene expression between groups. Single sample gene set enrichment analysis (ssGSEA) was used to compare differentially enriched hallmarks of cancer gene sets. Kaplan Meier method, log rank test and Cox regression analyses were performed to estimate overall (OS) and progression free survival (PFS) between MAPK subtypes. Results: NMF clustering built two groups of MAPK mRNA expression (coph: 0.91, silh: 1.00) without cohort-based bias in principal component analysis. Group MAPK1 (n = 238) was significantly associated with CMS2 (66.4 %), group MAPK2 (n = 213) with CMS4 (67.6 %, p < 0.0001). 5.551 of 23.561 genes were significantly differentially expressed between MAPK subtypes. 49 cancer hallmark gene sets were significantly differentially enriched in ssGSEA ( MAPK1: myc targets, DNA repair, cell cycle, PI3K- AKT- mTOR pathway upregulation; MAPK2: EMT-related signatures, TGFß pathway, angiogenesis upregulation among others). In overall analysis, MAPK1 showed slightly better outcome than MAPK2 (OS: HR: 0.80, 95% CI: 0.65 – 0.99, p = 0.049; PFS: HR: 0.81, 95% CI: 0.66 – 1.00, p = 0.05). However, MAPK1 was significantly more favourable for bevacizumab treatment in OS ( MAPK1: 30.8 m, MAPK2: 19.4 m, HR: 0.56, 95% CI: 0.39 – 0.81, p = 0.002) and PFS ( MAPK1: 11.7 m, MAPK2: 9.8 m, HR: 0.68, 95% CI: 0.48 – 0.98, p = 0.038) in left sided tumors, while no difference was seen for cetuximab treatment, RAS and BRAF status. Conclusions: mCRC subtypes by MAPK mRNA expression might contain prognostic information for the treatment with bevacizumab beyond mutational status in patients with left sided tumors of the FIRE-3 trial.

Association of microRNA-21 with efficacy of cetuximab in RAS wild-type patients in the FIRE-3 study (AIO KRK-0306) and microRNA-21’s influence on gene expression in the EGFR signaling pathway

3593

Background: FIRE-3 compared first-line therapy with FOLFIRI plus cetuximab (cet) or bevacizumab (bev) in KRAS exon 2 wild-type (wt) patients with metastatic colorectal cancer. Recent analyses showed mircoRNA-21 (miR-21) expression level may be a predictive biomarker for anti-EGFR-therapy raising the question whether miR-21 influences gene expression in the EGFR signaling pathway. Methods: Reverse-transcription quantitative polymerase chain reaction assay identified quantitative miR-21 expression. Median expression was defined as a threshold value to discriminate FIRE-3 population into miR-21 low and high groups. Differential gene expression based on additional mRNA microarray data (Almac Inc, Xcel Array) was calculated by linear models adjusted for multiple testing followed by single sample gene set enrichment analysis (ssGSEA) to compare differentially enriched hallmarks of cancer gene sets. Overall response rate (ORR) was compared using Fisher´s exact test. Median progression-free (PFS) and overall survival (OS) were analyzed using Kaplan-Meier estimation and log-rank test. Results: 333 RAS wt patients provided material for miR-21 expression analysis. In these patients, low miR-21 expression was associated with higher ORR (80.0% vs. 57.9%; p = 0.005) and longer OS (35.8 months (mo) vs. 25.9 mo; p = 0.005) when cet vs bev was added to FOLFIRI. High miR-21 expression was associated with comparable ORR (74.6% vs. 64.0%; p = 0.21) and OS (24.5 mo vs. 23.8 mo; p = 0.4). There was no significant difference in PFS in either group. By comparing miR-21 low and high groups using normalized mRNA microarray data, 538 genes were found to be significantly differentially expressed in RAS wt patients after adjustment for multiple testing. Including data from the two groups into ssGSEA yielded 23 hallmark of cancer gene sets that were significantly differentially enriched; among them, KRAS-signaling showed higher enrichment in the miR-21 high group (adjusted p = 2.09 E-13). Conclusions: MiR-21 expression level might be a predictive biomarker for anti-EGFR-therapy by modulating KRAS signaling in FIRE-3 patients.

CheckMate 649: A randomized, multicenter, open-label, phase III study of nivolumab (NIVO) + ipilimumab (IPI) or nivo + chemotherapy (CTX) versus CTX alone in patients with previously untreated advanced (Adv) gastric (G) or gastroesophageal junction (GEJ) cancer

TPS192

Background: Pts with adv G/GEJ cancer have an OS of ≈ 1 y, indicating an unmet medical need for new first-line treatments. Expression of PD-L1 is observed in up to 40% of pts with G/GEJ cancer and is associated with poor prognosis. In the randomized phase 3 ATTRACTION-2 study, NIVO demonstrated superior overall survival vs placebo with a 38% reduction of the risk of death (median OS, 5.3 vs 4.1 mo; HR, 0.62 P< 0.0001) and increased the OS rate at 12 mo (27% vs 12%; Boku N et al ESMO 2017) in pts with adv CTX-R (≥ 2 lines) G/GEJ cancer. In the phase 1/2 CheckMate-032 study in pts with CTX-R G/GEJ/esophageal cancer (79% ≥ 2 prior Tx lines), NIVO 1 mg/kg + IPI 3 mg/kg had a manageable safety profile and resulted in 24% ORR (40% ORR in pts with PD-L1+ tumors), a median OS of 6.9 mo, and a 35% OS rate at 12 mo (Janjigian Y et al ASCO 2017). In the phase 1 CheckMate-012 trial, NIVO + CTX had clinical activity and manageable safety in pts with NSCLC (Rizvi NA et al J Clin Oncol 2016). These positive results support investigation of NIVO, NIVO + IPI, and NIVO + CTX in earlier lines of treatment for G/GEJ cancer. The open-label, phase 3 CheckMate 649 trial will evaluate NIVO + IPI and NIVO + CTX vs CTX alone as first-line treatment for pts with adv G/GEJ cancer (NCT02872116). Methods: 1266 pts aged ≥ 18 y with untreated, inoperable adv/metastatic G/GEJ cancer (histologically confirmed adenocarcinoma) regardless of PD-L1 status will be randomized to receive either NIVO + IPI, NIVO + CTX (capecitabine/oxaliplatin [XELOX] or fluorouracil/leucovorin/oxaliplatin [FOLFOX]), or investigator choice of XELOX or FOLFOX. Tumor tissue for determination of PD-L1 status (Dako assay) must be provided from ≤ 6 mo before study treatment. No prior systemic treatment, including HER2 inhibitors, are allowed. Pts with known HER2+ status, suspected autoimmune disease, grade > 1 peripheral neuropathy, or active infection are excluded. Primary endpoint is OS in pts with PD-L1+ (≥ 1%) tumors. Other endpoints include OS in all pts; PFS and time to symptom deterioration in all pts and in pts with PD-L1+ tumors; and safety. Clinical trial information: NCT02872116.

JAVELIN Gastric 100: Phase 3 trial of avelumab (anti-PD-L1) maintenance therapy versus continuation of first-line chemotherapy in patients with advanced gastric or gastroesophageal junction cancer (GC/GEJC)

TPS195

Background: Outcomes with first-line (1L) chemotherapy for GC/GEJC are limited and new strategies to increase efficacy without added toxicity are needed. Avelumab, a human anti-PD-L1 IgG1 monoclonal antibody, is approved for metastatic Merkel cell carcinoma (US and EU) and advanced urothelial carcinoma after progression on platinum therapy (US). In phase 1 studies in advanced GC/GEJC, avelumab showed antitumor activity and a manageable safety profile, including in a subgroup of patients (pts) without progression on 1L chemotherapy who received avelumab as maintenance therapy. JAVELIN Gastric 100 (NCT02625610) is a global, randomized, open-label, phase 3 trial comparing maintenance therapy with avelumab vs continuation of 1L chemotherapy in pts with advanced GC/GEJC who have not progressed after 12 weeks of 1L oxaliplatin/fluoropyrimidine chemotherapy. Methods: Eligible pts have histologically confirmed, unresectable, measurable, locally advanced or metastatic GC/GEJC adenocarcinoma, no prior chemotherapy for advanced disease, no prior therapy targeting T-cell coregulatory proteins, and ECOG PS of 0–1. Pts are not preselected based on PD-L1 expression and pts with HER2+ tumors are excluded. Approximately 466 pts who achieve at least stable disease following 12 weeks of 1L oxaliplatin/fluoropyrimidine chemotherapy will be randomized 1:1 to receive maintenance therapy with either avelumab 10 mg/kg by IV infusion Q2W or continuation of 1L chemotherapy. Maintenance therapy is given until disease progression, unacceptable toxicity, or withdrawal. Primary endpoints are overall survival and progression-free survival. Secondary endpoints include best overall response, quality of life measures, safety (NCI-CTCAE v4.03), and tumor biomarkers. Responses are evaluated per RECIST 1.1 and adjudicated by independent review committee. Enrollment is ongoing at sites in North/South America, Asia-Pacific, and Europe. Clinical trial information: NCT02625610.

Consensus molecular subgroups (CMS) of colorectal cancer (CRC) and first-line efficacy of FOLFIRI plus cetuximab or bevacizumab in the FIRE3 (AIO KRK-0306) trial

3510

Background: FIRE-3 compared 1st-line therapy with FOLFIRI plus either cetuximab or bevacizumab in 592 KRAS exon 2 wt mCRC patients. CMS is grouping CRCs according to their gene-signature in 4 different types. Relevance of CMS for the treatment of mCRC remains unclear. Methods: Patients were grouped according to tumor CRC-CMSs. Using ALMAC’s Xcel tissue array, gene signatures of FIRE-3 tumor samples were analyzed. Survival was compared using Kaplan-Meier estimation and log-rank tests. Hazard ratios (HR) were estimated according to the Cox proportional hazard method. Results: CMS classification could be determined in 385 specimens available from the ITT population (n = 592). In this KRAS exon 2 wt population (n = 385), frequencies were: CMS1 (10.4%), CMS2 (36.6%), CMS3 (11.7%), CMS4 (29.1%), non-consensus (12.2%). In RAS wt (n = 315), frequencies were: CMS1 (11.1%), CMS2 (38.1%), CMS3 (9.5%), CMS4 (29.5%), non-consensus (11.7%). Independent of the treatment, CMS was a strong prognosticator for ORR (p = 0.023), PFS (p < 0.001) and OS (p < 0.001). For data on CMS and treatment efficacy in the RAS wt population see the following table. Conclusions: CMS classification is prognostic for mCRC. The survival benefit in RAS wt previously observed for FOLFIRI cetuximab vs. FOLFIRI bevacizumab is not significantly different across CMS groups, although there are trends when comparing OS HR between categories with CMS4 showing the best HR. [Table: see text]

Cisplatin/5-FU (CF) +/- panitumumab (P) for patients (pts) with non-resectable, advanced, or metastatic esophageal squamous cell cancer (ESCC): An open-label, randomized AIO/TTD/BDGO/EORTC phase III trial (POWER)

4011

Background: Most ESCC pts have advanced disease at time of diagnosis. Chemotherapy (CTX) is used to improve quality of life (QoL) and overall survival (OS), but still with limited impact. Prior studies suggested increased efficacy of EGFR antibodies (AB) combined with CF (Lorenzen, Ann Oncol 2009). Methods: This open-label, randomized (1:1), multicenter, multinational phase III included pts with non-resectable, advanced or metastatic ESCC (RECIST1.1), not radiochemotherapy (RCTX) eligible and ECOG 0-1. Previous CTX in metastatic setting, concurrent RCTX and exposure to EGFR-AB were excluded. Pts received CF (C 100 mg/m² d1 + F 1000 mg/m²/d, d1-4) or CFP (9 mg/kg d1) q3 weeks until disease progression. Due to more Gr3-4 SAEs in the first 60 Pts with CFP, C was reduced to 80mg/m²d1 Tumor assessment was performed q9 weeks. Primary objective was OS: superiority of CFP (9 months [mo]) over CF (6 mo) with 300 pts (90% power). Results: Between 6.2012-5.2015, 146/155 pts were randomized. After interim analysis for futility, the trial was stopped. 60(83%) of CFP and 55(79%) of CF pts had any AE, mostly diarrhea, hypokalemia, hypomagnesaemia, rash, and hand-foot syndrome. Main Gr≥3 AEs were low neutrophils 21/ 24% and anemia 13/16 % for CFP vs CF, respectively. Gr 3-4 skin reactions and rash were higher in CFP (10%) vs CF (0%). Overall, 51/72 (71%) of CFP and 36/70 (51%) of CF had SAE. Main SAE were dysphagia, acute kidney injury, diarrhea, fevers and febrile neutropenia in 6/6%, 7/4%, 7/3%, 3/6% and 6/1% for CFP vs CF, respectively. For all CFP vs CF pts, median OS was 9.4 vs. 10.2 mo (hazard ratio (HR) 1.17, 95%CI 0.79-1.75; P=0.43). For 56 pts treated with cisplatin 100mg/m²d1, OS was 9.4 vs. 12.9 mo (HR 1.83, 95 % CI 0.98-3.42; P=0.06). After C was reduced (80mg/m²), OS (85 pts) favored CFP vs CF, with 9.8 vs. 8.3 mo (HR 0.84, 95%CI 0.49-1.43; P=0.51). Median PFS for all CFP vs CF pts, was 5.3 vs. 5.8 mo. (HR 1.21, 95%CI 0.85-1.73; P=0.29) respectively. Conclusions: Addition of Panitumumab to CF provided no additional benefit to chemotherapy alone as first-line treatment of ESCC. Biomarker program is going on for further analyses. Clinical trial information: NCT1627379.

CheckMate 577: A randomized, double-blind, phase 3 study of adjuvant nivolumab (nivo) or placebo in pts with resected esophageal (E) or gastroesophageal junction (GEJ) cancer

TPS4131

Background: Expression of the PD-1 ligands PD-L1 and PD-L2 has been reported in ≈ 40% of pts with E/GEJ cancer and is associated with a poor prognosis. In a phase 3 trial, the PD-1 inhibitor nivo demonstrated an OS benefit vs placebo (HR, 0.63; P < 0.0001), resulting in a 37% reduction in the risk of death and double the OS rate at 12 mo (27% vs 11%) in pts with advanced gastric (G)/GEJ cancer refractory to ≥ 2 lines of chemotherapy (Kang YK, et al. J Clin Oncol. 2017;35 (suppl 4S) [abstract 2]). In this study, nivo was well tolerated, with a safety profile comparable with that of the placebo arm. These results indicate that nivo could be a new standard of care (SOC) for pts with heavily pretreated advanced G/GEJ cancer and provide a strong rationale to explore nivo in earlier lines of treatment for G/E/GEJ cancer. Currently, no effective adjuvant SOC is available after chemoradiotherapy (CRT) followed by resection for pts with E/GEJ cancer. This multinational, double-blind, phase 3 trial will evaluate nivo as an adjuvant therapy for pts with resected E/GEJ cancer (CheckMate 577; NCT02743494). Methods: In this study, an estimated 760 pts aged ≥ 18 years with stage II/III E/GEJ cancer are randomized to receive nivo or placebo. Prior to randomization, pts must have completed preoperative CRT followed by surgery and been diagnosed with residual pathologic disease after being surgically rendered free of disease with negative margins following complete resection. Pts with stage 4 resectable disease, cervical esophageal cancer, or those who have not received concurrent CRT prior to surgery are not eligible for study enrollment. Primary endpoints are OS and disease-free survival. Other key endpoints include the OS rate at 1, 2, and 3 years and safety. Clinical trial information: NCT02743494.

CheckMate 649: A randomized, multicenter, open-label, phase 3 study of nivolumab (nivo) + ipilimumab (ipi) or nivo + chemotherapy (CTX) vs CTX alone in pts with previously untreated advanced (adv) gastric (G) or gastroesophageal junction (GEJ) cancer

TPS4132

Background: Pts with adv G/GEJ cancer have an OS of ≈ 1 y, indicating an unmet medical need for new first-line treatments (Tx). Expression of the PD-1 ligands PD-L1/PD-L2 is observed in up to 40% of pts with G/GEJ cancer and is associated with poor prognosis. In a phase 3 study of the PD-1 inhibitor nivo vs placebo in pts with adv CTX-refractory (CTX-R; ≥ 2 lines) G/GEJ cancer, nivo reduced the risk of death by 37% (HR, 0.63; P < 0.0001) and increased the OS rate at 12 mo (27% vs 11%; Kang YK, et al. J Clin Oncol. 2017;35 (suppl 4S) [abstract 2]). In a phase 1/2 study in pts with CTX-R G/GEJ/esophageal cancer (79% ≥ 2 prior Tx lines), nivo 1 mg/kg + ipi 3 mg/kg had a manageable safety profile and resulted in 26% ORR (44% ORR in pts with PD-L1+ tumors), a median OS of 6.9 mo, and a 34% OS rate at 12 mo (Janjigian Y, et al. ASCO, 2016 [abstract 4010]). In the phase 1 CheckMate 012 trial, nivo + CTX had clinical activity and manageable safety in pts with NSCLC (Rizvi NA, et al. J Clin Oncol. 2016;34:2969-2979). These positive results support investigation of nivo, nivo + ipi, and nivo + CTX in earlier lines of Tx for G/GEJ cancer. The open-label, phase 3 CheckMate 649 trial will evaluate nivo + ipi and nivo + CTX vs CTX alone as first-line Tx for pts with adv G/GEJ cancer (NCT02872116). Methods: 1266 pts aged ≥ 18 y with untreated, inoperable adv/metastatic G/GEJ cancer (histologically confirmed adenocarcinoma) regardless of PD-L1 status will be randomized to receive either nivo + ipi, nivo + CTX (capecitabine/oxaliplatin [XELOX] or fluorouracil/leucovorin/oxaliplatin [FOLFOX]), or investigator choice of XELOX or FOLFOX. Tumor tissue for determination of PD-L1 status (Dako assay) must be provided from ≤ 6 mo before study Tx. No prior systemic Tx, including HER2 inhibitors, are allowed. Pts with known HER2+ status, suspected autoimmune disease, grade > 1 peripheral neuropathy, or active infection are excluded. Primary endpoint is OS in pts with PD-L1+ (≥ 1%) tumors. Other endpoints include OS in all pts; PFS and time to symptom deterioration in all pts and in pts with PD-L1+ tumors; and safety. Clinical trial information: NCT02872116.

Phase I Study of Definitive Radio-chemotherapy with Cisplatin, 5-Fluorouracil and Cetuximab for Unresectable Locally Advanced Esophageal Cancer

BACKGROUND/AIM

Prognoses of patients receiving radio-chemotherapy with 5-fluorouracil (5-FU) and cisplatin for unresectable esophageal cancer may be improved with the addition of cetuximab. This phase I study aimed to define the maximum tolerated dose of 5-FU when combined with cisplatin, cetuximab and radiotherapy.

PATIENTS AND METHODS

Treatment included 59.4 Gy of radiotherapy concurrently with two courses of cisplatin (20 mg/m², d1-4) and 5-FU (dose level 0: 500 mg/m², dose level 1: 750 mg/m², d1-4; dose level 2: 1,000 mg/m², d1-4), followed by two courses of chemotherapy. Cetuximab was given for 14 weeks (400 mg/m² loading dose followed by 250 mg/m² weekly).

RESULTS

At dose level 1 (n=3) and 2 (n=3), no patient experienced a dose-limiting toxicity. Minor treatment modifications were due to organization or request by physicians/patients. At dose level 2, only five grade 3 adverse events occurred.

CONCLUSION

Dose level 2 appears safe and is used in a subsequent randomized phase II study.

Time-course evaluation of survival and treatment in FIRE-3 (AIO KRK0306, first-line therapy of KRAS wild-type metastatic colorectal cancer with FOLFIRI plus cetuximab or bevacizumab)

617

Background: FIRE-3 reported overall survival (OS) difference in favour of arm A (FOLFIRI plus cetuximab, N= 297 pts.) compared to arm B (FOLFIRI plus bevacizumab, N= 295 pts.) in the absence of significant differences in progression-free survival and response rate. Methods: We subdivided the study into six-month time intervals, starting at the time point of randomisation and evaluated OS in a time-wise fashion. Within each interval, OS was analyzed by Cox regression. Furthermore, systemic treatment and local interventions were investigated in the respective time-frames. Results: The time-course hazard ratios of OS are summarized in the Table. Pronounced differences in overall survival by time-interval analysis are observed between 24 and 30 months and between 30 and 36 months. Within the interval of 24-30 months, 24.6% (73/297) of pts in arm A and 25.1% (74/295) of pts in arm B received systemic therapy (any treatment-line). In the subsequent interval of 30-36 months, systemic anti-tumor treatment decreased to 18.9% (56/297) of pts in arm A and 16.3% (48/295) of pts in arm B. Median time on treatment was less than 2 months in the intervals of 24-30 months and 30-36 months. Updated data including RAS wild-type population will be presented at the meeting. Conclusions: The differences in OS observed in FIRE-3 are pronounced in time intervals between 24-30 months as well as 30-36 months after randomisation into the study. A small number of patients received rather short courses of anti-tumor therapy in these observation units. The significant difference in OS that manifests in time-frames between 24 and 30 months as well as between 30 and 36 months suggests that underlying effects on OS in FIRE-3 may include multiple factors and cannot be explained by the number of patients on active treatment alone. Clinical trial information: NCT00433927. [Table: see text]

Avelumab (MSB0010718C), an anti-PD-L1 antibody, as a third-line treatment in patients with advanced gastric or gastroesophageal junction cancer: A phase Ib JAVELIN Solid Tumor trial

TPS188

Background: The programmed death-1 receptor (PD-1) and its ligand (PD-L1) are key therapeutic targets in the reactivation of the immune response against cancer. Avelumab* (MSB0010718C) is a fully human anti-PD-L1 IgG1 antibody being investigated in clinical trials. The phase Ib study (NCT01772004) is an open-label, parallel-group expansion trial in patients (pts) with locally advanced or metastatic (LA/M) solid tumors that includes a heavily pretreated cohort of pts with advanced gastric or gastroesophageal junction adenocarcinoma (GC/GEJ) to evaluate safety and efficacy of avelumab in the 3rd-line setting. Prior to adding this 3rd-line cohort, this trial had enrolled a separate cohort with advanced GC/GEJ who had received prior 1st-line chemotherapy (Chung et al, ECC 2015). Methods: This trial cohort is enrolling pts with histologically confirmed unresectable LA/M GC/GEJ who have been previously treated with 1st-line combination chemotherapy and 2nd-line ramucirumab, alone or in combination, and whose disease has progressed during or after ramucirumab treatment. Pts who have received prior treatment with trastuzumab and pts with HER2+ status are allowed. Eligible pts also must have tumor archival material or fresh biopsy, an ECOG performance status of 0 or 1 at the time of trial entry, and disease with ≥ 1 measurable lesion according to RECIST 1.1. Exclusions include prior therapy with immune checkpoint drugs or history of autoimmune disease. Up to 150 eligible pts will receive avelumab at 10 mg/kg as an IV infusion Q2W. Treatment will continue until disease progression, unacceptable toxicity, or any criterion for withdrawal occurs. Primary endpoint is confirmed best overall response (RECIST 1.1) as adjudicated by an IERC. Secondary objectives include assessment of progression-free survival, overall survival, and immune-related efficacy assessments. Association between tumor PD-L1 expression and efficacy will be evaluated. Adverse events will be assessed and graded according to NCI-CTCAE v4.0. Tumor evaluation will be performed every 6 wks until progression. Enrollment in this cohort began in June 2015. *Proposed INN Clinical trial information: NCT01772004.

Systemic therapy in elderly patients with advanced biliary tract cancer: Sub-analysis of ABC-02 and 10 other prospective studies

382

Background: Outcomes in elderly patients (pts), with advanced biliary tract cancer (ABTC) receiving palliative chemotherapy are unclear. The aim of this study was to assess the outcome of monotherapy vs combination therapy in elderly pts with ABTC in ABC-02, and 10 other prospective studies of systemic therapy. Methods: Multivariable analysis was employed to explore impact of therapy on progression-free (PFS) and overall survival (OS) in 2 age cohorts; non-elderly ( < 70 yrs) vs elderly ( ≥ 70 yrs). Results: Overall, 1163 pts were recruited from Jan 97-Dec 13. Median age of entire cohort was 63 yrs (range 23-85); 260 (22%) were ≥ 70 yrs, 18 (2%) were ≥ 80 yrs. In pts ≥ 70 yrs; 208 had ECOG PS 0-1, 129; male and 174; metastatic disease. Combination therapy was platinum-based in 9 studies. Among the 260 pts ≥ 70 yrs, 182 (70%) received combination therapy. Baseline characteristics/therapy received was balanced in both age cohorts. Median follow-up time for all pts was 42 months (95% CI 37-51). Median PFS for those < 70 yrs and ≥ 70 yrs was 6.0 (95% CI 5.5-6.4) and 5.0 months (95% CI 4.2-6.4) respectively. Median OS for pts < 70 yrs and ≥ 70 yrs was 10.2 (95% CI 9.6-11.1) and 8.8 months (95% CI 7.9-9.6) respectively. For the entire cohort, the PFS and OS were significantly better in those pts receiving combination therapy: HR 0.66, 95% CI 0.58-0.76, P < 0.0001 and HR 0.72, 95% CI 0.63-0.82, P < 0.0001 respectively, and in group ≥ 70 yrs: HR 0.54 (95% CI 0.38-0.77, P = 0.001) and HR 0.6 (95% CI 0.43-0.85, P = 0.004) respectively. In pts < 70 yrs, stage (locally advanced vs metastatic) and ECOG PS were prognostic for PFS (P < 0.001 and P = 0.04 respectively) and OS (P < 0.001 and P = 0.001 respectively) and in pts ≥ 70 yrs, they were prognostic for OS (P = 0.03 and P = 0.02 respectively). There was no evidence of interaction between age ( < 70 yrs and ≥ 70 yrs) and treatment (monotherapy and combination therapy) for PFS (P = 0.66) or OS (P = 0.75). Conclusions: In ABTC, PFS and OS in elderly pts receiving palliative chemotherapy (monotherapy or combination therapy) are comparable with that of non-elderly pts, therefore age in isolation should not influence treatment decisions. Clinical trial participation among elderly pts with ABTC is appropriate.

Parvovirus H-1-induced tumor cell death enhances human immune response in vitro via increased phagocytosis, maturation, and cross-presentation by dendritic cells

Oncotropic and oncolytic viruses have attracted high attention as antitumor agents because they preferentially kill cancer cells in vitro and reduce the incidence of spontaneous, induced, or implanted animal tumors. Some autonomous parvoviruses (H-1, minute virus of mice) and derived recombinant vectors are currently under preclinical evaluation. Still not fully understood, their antitumor properties involve more than just tumor cell killing. Because wild-type parvovirus-mediated tumor cell lysates (TCLs) may trigger antigen-presenting cells (APCs) to augment the host immune repertoire, we analyzed phagocytosis, maturation, and crosspresentation of H-1-induced TCLs by human dendritic cells (DCs). We first established H-1-mediated oncolysis in two HLA-A2(+) and A2(-) variant melanoma cell clones. Monocyte-derived immature DCs phagocytosed H- 1-infected TCLs as well as ultraviolet-induced apoptotic TCLs and better than freeze-thaw-induced necrotic TCLs. Immature DCs incubated with H-1-induced TCLs acquired specific maturation markers comparable to a standard cytokine cocktail. Furthermore, A2(+) DCs pulsed with H-1-infected A2(-) TCLs cross-presented melanoma antigens to specific cytotoxic T lymphocytes (CTLs) and released proinflammatory cytokines. This shows for the first time that tumor cell killing by a wild-type oncolytic virus directly stimulates human APCs and CTLs. Because H-1-infected tumors enhance the immune repertoire, the clinical perspectives of parvoviral vectors are even more promising.