New combo shows promise in shrinking stomach tumors before surgery

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age ≥ 18 years * Untreated localized gastric or GEJ adenocarcinoma considered resectable (clinical stage ≥cT2 and/or cN+ and no metastasis) * Histologically confirmed adenocarcinoma * ECOG performance status score of 0 or 1 * Tumor tissue must be provided for biomarker analyses (fresh or archival with an FFPE tissue block) * All subjects must consent to allow the acquisition of blood samples for performance of correlative studies * Screening laboratory values must meet the following criteria: * WBC ≥ 2000/ mm³ * Neutrophils ≥ 1500/ mm³ * Platelets ≥ 100 000/ mm³ * Hemoglobin ≥ 9.0 g/dL * Bilirubin ≤ 1.5 x ULN, AST and ALT ≤ 3 x ULN * Measured or calculated creatinine ≥ 50 ml/min clearance (CrCl) (using the Cockcroft-Gault formula) * Potassium ≥ LLN * Magnesium ≥ LLN * Calcium ≥ LLN * Female subject of childbearing potential must have a negative urine or serum pregnancy test within 72h before study start * Subject in reproductive age must be willing to use adequate contraception during the study and at least 9 months in men and 12 months in women after the last dose of investigational drug. In addition, given the toxicities observed on the male reproductive system, a conservation of gametes will be proposed for men, as usually in routine practice * Subject affiliated to a social security regimen * Patient has signed informed consents obtained before any trial related activities and according to local guidelines Exclusion Criteria: Subject with any distant metastasis * Subject with no recovering from the effects of major surgery or significant traumatic injury within 14 days before inclusion * Documented significant cardiovascular disease within the past 6 months before the first dose of study treatment, including: history of congestive heart failure (defined as NYHA III or IV), myocardial infarction, unstable angina, coronary angioplasty, coronary stenting, coronary artery bypass graft, cerebrovascular accident or hypertensive crisis * History of anterior organ transplant, including stem cell allograft * Pneumonitis or interstitial lung disease * History of other malignancy within the previous 3 years (except for appropriately treated in-situ cervix carcinoma and non-melanoma skin carcinoma) * Subject with active, known, or suspected autoimmune disease * Subject with a condition requiring systemic treatment with either corticosteroids (\> 10 mg daily prednisone equivalent) or other immunosuppressive medications within 14 days of start of study treatment GASPAR Protocol - EUDRACT number: 2020-004497-21 - version 1.3 / 2021-01-18 Page 8 sur 44 * Known history of HIV or HBV infection * Known active HCV infection * Known history of active tuberculosis * Vaccination with live vaccine within 30 days before the first dose of study treatment * Prior treatment with an anti-PD-1, anti-PD-L1, anti-PD-L2 or any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint pathways * Recent or concomitant treatment with brivudine (herpes virostatic) * Prior anticancer therapy for the current malignancy * Known hypersensitivity to any of the study drugs or their excipients * Chronic inflammable gastro-intestinal disease * Uracilemia ≥ 16 ng/ml * QT/QTc \> 450 msec for men and \> 470 msec for women * Peripheral neuropathy ≥ Grade II * Uncontrolled diabetes * Active infection requiring systemic therapy * Participation in another therapeutic clinical study * Patient deprived of liberty or placed under the authority of a tutor * Patient assessed by the investigator to be unable or unwilling to comply with the requirements of the protocol