CStone Pharmaceuticals has achieved a significant milestone with the approval of sugemalimab (Cejemly®) by the National Medical Products Administration (NMPA) of China, marking it as the world's first PD-L1 monoclonal antibody authorized for the treatment of unresectable locally advanced or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma with PD-L1 expression (Combined Positive Score [CPS] ≥5). This approval is based on the impressive outcomes of the GEMSTONE-303 study, which met its co-primary endpoints for both progression-free survival (PFS) and overall survival (OS), along with key secondary endpoints. Sugemalimab, in combination with fluoropyrimidine- and platinum-containing chemotherapy, has shown statistically significant and clinically meaningful improvements in PFS and OS for patients as a first-line treatment.

This marks the 13th New Drug Application (NDA) approval for CStone and the fifth approved indication for sugemalimab in China, following its success in treating stage III and IV non-small cell lung cancer (NSCLC), relapsed or refractory extranodal NK/T-cell lymphoma, and esophageal squamous cell carcinoma (ESCC). The approval underlines sugemalimab's potential and clinical value in oncology, extending its reach to a broader patient population in need of effective treatment options.

Dr. Jason Yang, CEO of CStone, expressed excitement about this approval and its significance in the field of gastric cancer treatment, emphasizing the company's commitment to exploring registration pathways in other territories, including the U.S. and Europe, aiming to benefit more cancer patients worldwide.

Professor Lin Shen of Peking University Cancer Hospital, the leading principal investigator of the GEMSTONE-303 study, highlighted the high burden of gastric cancer in China and the poor prognosis for patients with late-stage or unresectable disease. The approval of sugemalimab offers a new, much-needed treatment option for this patient group, promising new hope for better outcomes.

The GEMSTONE-303 trial, a multi-center, randomized, double-blinded, placebo-controlled Phase 3 study, was designed to evaluate the efficacy and safety of sugemalimab in combination with capecitabine and oxaliplatin (CAPOX) against PD-L1 expression ≥5% in unresectable locally advanced or metastatic G/GEJ adenocarcinoma. The study successfully met its co-primary endpoints of investigator-assessed PFS and OS, demonstrating sugemalimab's ability to significantly improve survival outcomes for patients in combination with chemotherapy. The treatment was also found to be safe and tolerable, with no new safety signals identified.

The approval of sugemalimab represents a landmark achievement in the treatment of gastric cancer, providing a new hope and clinical option for patients suffering from this challenging disease.