Oral Abstract Session A: Cancers of the Esophagus and Stomach

Robert Shen, MD—Chair, Mayo Clinic & Daniela Molena, MD—Chair, Memorial Sloan Kettering Cancer Center

Abstract 62: First-line pembrolizumab (P), trastuzumab (T), capecitabine (C) and oxaliplatin (O) in HER2-positive metastatic esophagogastric adenocarcinoma (mEGA).
First Author: Yelena Yuriy Janjigian, MD

CONCLUSION: Updated survival, correlative studies and 89Zr-trastuzumab PET imaging will be presented. These promising preliminary safety and efficacy results led to initiation of a definitive phase III Keynote 811 trial. Clinical trial information: NCT02954536


Abstract 2: Pembrolizumab versus chemotherapy as second-line therapy for advanced esophageal cancer: Phase III KEYNOTE-181 study.
First Author: Takashi Kojima, MD

CONCLUSION:

Pembrolizumab significantly improved OS in patients with metastatic esophageal cancer and PD-L 1 CPS ≥10 that progressed after 1 prior therapy versus chemotherapy
- Superior OS in patients with PD-L 1 CPS ≥10 metastatic esophageal cancer who had progressed after 1 prior therapy (HR 0.69, 95% Cl 0.52-0.93)
- Clinically meaningful increase in OS in patients with sec (HR 0.78, 95% Cl 0.63-0.96)
- Similar OS in ITT (HR 0.89 95% Cl 0.75-1.05)
ORR higher with pembrolizumab versus chemotherapy
- 21.5%vs 6.1% (CPS ≥10); 16.7%vs 7.4% (SCC ); 13.1%vs 6.7% (ITT)
More favorable safety profile with pembrolizumab compared with chemotherapy
- Lower frequency of grade 3-5 treatment -related adverse events with pembrolizumab versus chemotherapy (18.2% vs 40.9%)
- No new safety signals were observed
Data suggest that pembrolizumab should be considered a new standard-of-care in the second-line for patients with metastatic esophageal cancer and PD-L 1 CPS ≥10

 Clinical trial information: NCT02564263

Abstract 3: Efficacy and safety of trifluridine/tipiracil (FTD/TPI) in patients (pts) with metastatic gastric cancer (mGC) with or without prior gastrectomy: Results from a phase III study (TAGS).
First Author: David H. Ilson, MD, PhD

CONCLUSION:• FTD/TPI prolonged survival versus placebo regardless of gastrectomy • HematologicAEs such as neutropenia/leukopenia may have been somewhat more frequent among FTD/TPl-treated patients with gastrectomy than in the overall population - This did not result in more treatment discontinuations • Exposure to FTD/TPI was similar between patients with gastrectomy and those in the overall population • FTD/TPI is an effective treatment option with a manageable safety profile for patients with mGC regardless of prior gastrectomy.

Clinical trial information: NCT02500043


Abstract 4: A phase 3, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of andecaliximab combined with mFOLFOX6 as first-line treatment in patients with advanced gastric or gastroesophageal junction adenocarcinoma (GAMMA-1).
First Author: Manish A. Shah, MD, FASCO

CONCLUSION:• Addition of ADX to mFOLFOX6 did not improve OS in patients with untreated HER2- gastric or GEJ adenocarcinoma • There were no meaningful differences in the safety profile of the ADX vs placebo groups • The apparent increased activity of the combination of mFOLFOX6 + ADX in patients aged >65 needs further study and correlative work • ADX + immunotherapy has been examined and is presented at this meeting (see Posters 75, 118, and 148) Clinical trial information: NCT02545504