Protocol for a randomized controlled trial of perioperative S-1 plus oxaliplatin combined with apatinib and camrelizumab in patients with resectable, locally advanced gastric or gastroesophageal junction adenocarcinoma

Background: Perioperative therapy can improve the low survival benefit of surgery alone for locally advanced gastric cancer. The introduction of immunotherapy and its combination with chemotherapy and/or targeted therapy has created more opportunities for optimal treatment. The aim of the present study was to compare the efficacy and safety of S-1 plus oxaliplatin (SOX) combined with apatinib (SOXA) or SOX combined with apatinib and camrelizumab (SOXAP) versus SOX as the perioperative therapy for resectable, locally advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma.

Methods: The study was a multicenter, randomized, open-label, parallel-controlled trial conducted in China. Eligible participants were randomized to the SOX, SOXA, and SOXAP groups. Patients received three pre-operative and three postoperative 3-week cycles of SOX or SOXA or SOXAP, followed by apatinib (SOXA group) or apatinib combined with camrelizumab (SOXAP group) for 3 cycles, which could be continued at the investigator's choice. Overall treatment is up to 1 year of apatinib and up to 17 cycles of camrelizumab. SOX is 130 mg/m² oxaliplatin on day 1 plus S-1 orally twice daily on days 1 to 14. Apatinib is orally administered at a dose of 500 mg (SOXA group) or 250 mg (SOXAP group) on days 1 to 21, and camrelizumab 200 mg is given intravenously once every 3 weeks. The primary endpoint was major pathological response assessed by blinded independent review committee. The secondary endpoints included pathological complete response, lymph node status after neoadjuvant therapy, margin-free resection rate, progression-free survival (PFS), disease-free survival (DFS), overall survival (OS), and safety.

Discussion: The trial provides important data regarding the use of perioperative SOXAP and SOXA for patients with resectable, locally advanced gastric or GEJ adenocarcinoma. The results will contribute to optimal perioperative disease treatment.

Trial registration: ClinicalTrials.gov (no. NCT04208347). First posted on December 23, 2019.