A phase II study of TAS-102 (FTD/TPI) in combination with ramucirumab (RAM) in advanced, refractory gastric (GC) or gastroesophageal junction (GEJ) adenocarcinomas (GEAs).

Abstract

302 Background: The RAINBOW trial established the standard of care for treatment of metastatic GEAs with ramucirumab and paclitaxel after failure of fluoropyrimidine and platinum-based chemotherapy. While the combination achieved an objective response rate (ORR) of 28%, the incidence of any grade neuropathy was 46%. Therefore, there is an unmet need for novel treatment combinations that minimize the long-term toxicity of neuropathy. In a recently published Asian study, the combination of RAM+TAS-102 showed good disease control and acceptable toxicity profile. Methods: This was a single arm, single institution phase II trial using the combination of TAS-102 plus RAM in refractory GEAs. Patients (pts) received RAM 8mg/kg intravenously on day 1 and 15, and TAS-102 35mg/m2 orally twice daily on days 1-5 and days 8-12 every 28-day cycle. The primary endpoint was 6-months overall survival (OS) rate and secondary endpoints were progression free survival (PFS), ORR and safety profile. The trial was registered at www.clinicaltrials.gov (NCT03686488). Results: At data cut-off of August 15, 2021, 23 pts were enrolled. Baseline demographics are as follows: median age of 62 years (range: 23-74), median lines of prior therapy of 1 (1: 14 pts vs ≥2: 9 pts) and location of primary tumor (GEJ:19 vs GC: 4). 6-month OS rate was 56.2%. Median OS was 6.2 month (95% CI: 5.4-7.0) and median PFS was 4.9 months with median observation of 2.3 months. Of 17 evaluable pts defined as more than one baseline imaging, 1 (6%) had partial response (PR) and 15 (88%) had stable disease (RECIST v1.1). Eleven pts came off the study due to progression of disease, 8 for toxicities and 4 for consent withdrawal. Most common treatment-emergent adverse events (TEAEs) were diarrhea (39%), fatigue (39%) and hypertension (39%). Total 11 pts (48%) experienced grade 3 and 4 TEAEs, and most common Gr3 and 4 TEAEs were neutropenia (17%) and anemia (13%). Conclusions: The combination of RAM and TAS-102 showed very similar disease control rate as the study in Asia. The combination has now shown modest activity in advanced GEAs and should be investigated further now in the context of patients receiving immunotherapy-based treatment as first-line treatment. A randomized phase II study is currently enrolling patients with ramucirumab and TAS-102 or paclitaxel. Clinical trial information: NCT03686488.