CSTONE PHARMA-B (02616) announces that the research data of Sintilimab (Junshi) GEMSTONE-303 has been published in JAMA.

CSTONE PHARMA-B (02616) announced that the results of the GEMSTONE-303 study on the anti-PD-L1 antibody (toripalimab) have been officially published in the leading international medical journal JAMA. GEMSTONE-303 is a randomized, double-blind, placebo-controlled Phase III registration clinical trial designed to evaluate the efficacy and safety of toripalimab in combination with the CAPOX chemotherapy regimen (oxaliplatin+capecitabine) compared to placebo in combination with the CAPOX regimen as first-line treatment for locally advanced or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma with PD-L1CPS5 that is unresectable. The primary endpoints of the study are overall survival (OS) and investigator-assessed progression-free survival (PFS), with secondary endpoints including progression-free survival assessed by a blinded independent central review committee (BICR), objective response rate (ORR), and duration of response (DoR). Dr. Frank Jiang, CEO, Chief R&D Officer, and Executive Director of CStone Pharmaceuticals, stated, "We are honored that the data from the toripalimab GEMSTONE-303 study has been published in the top international journal JAMA. This study lays an important foundation for toripalimab in combination with chemotherapy to become the standard first-line treatment for patients with PD-L1CPS5 gastric/GEJ adenocarcinoma. Toripalimab has already been approved for 5 indications in China. Meanwhile, we have expanded its registration and commercialization overseas and have reached cooperation agreements for its commercialization in multiple international markets. The excellent clinical data from the GEMSTONE-303 study once again gives us strong confidence, and we will actively promote the global registration and commercialization of toripalimab, believing that it will gradually unlock more clinical applications and bring greater survival benefits to patients." Professor Lin Shen, the lead investigator of the toripalimab GEMSTONE-303 study at Peking University Cancer Hospital, said, "Before the application of PD-1 inhibitors in clinical practice, chemotherapy for patients with unresectable locally advanced or metastatic gastric/GEJ adenocarcinoma, the median OS did not exceed 1 year. PD-1 inhibitors in combination with chemotherapy as a new first-line standard treatment has been shown to significantly prolong the survival of these patients, and the GEMSTONE-303 study further builds on this. Toripalimab, as the world's first approved PD-L1 antibody in this patient population, decisively selected the PD-L1 expression population in the key study design, demonstrating excellent efficacy and manageable safety. The acceptance and publication of the study results by JAMA is a full affirmation and recognition of the innovation and high-quality contributions of all researchers and participants involved in GEMSTONE-303."