Watch-and-Wait Approach With Dostarlimab in Localized dMMR/MSI-H Gastric Cancer: GERCOR Phase II Study
Trial Parameters
Brief Summary
This phase II study will evaluate dostarlimab with a watch-and-wait approach for patients with localized mismatch repair deficiency (dMMR)/microsatellite instability (MSI) gastric or oeso-gastric junction adenocarcinoma. The goal of the study is to determine whether the surgery could be avoided in patients with localized dMMR/MSI-H gastric/OGJ adenocarcinoma with complete response at endoscopy and biopsies free of tumoral cells after treatment with dostarlimab, with a watch-and-wait approaches.
Eligibility Criteria
Inclusion Criteria: 1. Capable of giving signed and dated informed consent, 2. An ECOG PS of 0-1, 3. ≥18 and ≤75 years old, The patient over 75 years of age is eligible only if all the following conditions are met: * The patient's G8 questionnaire score is above 14 AND * The patient is eligible for surgery and has no contraindications to repeated UGI endoscopy with biopsies, 4. Histologically proven non-metastatic gastric or OGJ adenocarcinoma cT2 to T4, Nx, M0 after computed tomography thorax-abdomen-pelvis (TAP-CT) and echo-endoscopy (EUS) according to the 7th Edition of the International Union Against Cancer; NB: Echo-endoscopy will be performed only if the tumor is not obstructive at UGI endoscopy ± a new UGI endoscopy with 10 biopsies, photos (if not done at the first UGI endoscopy done for diagnosis) and if possible (not mandatory) tumor tattooing/inking. If obstructive, the tumor will be classified as cT3 or cT4 (in the situation when the tumor was obstructive and prevented EUS,