China-based CStone Pharmaceuticals (HKG: 2616) has announced that the National Medical Products Administration (NMPA) has accepted for review another market filing for its programmed death-ligand 1 (PD-L1) inhibitor sugemalimab. The filing is for the drug’s use in combination with chemotherapy as a first-line treatment of locally advanced or metastatic gastric/gastroesophageal junction adenocarcinoma (GC/GEJC).
GEMSTONE-303 Study Results
The filing is based on the positive results of the GEMSTONE-303 study, a multi-center, randomized, placebo-controlled Phase III regulatory trial. The study was designed to assess the efficacy and safety of sugemalimab combined with oxaliplatin and capecitabine for the treatment of GC/GEJC. Primary endpoints included investigator-assessed progression-free survival (PFS) and overall survival (OS), alongside secondary endpoints such as PFS assessed by Blind Independent Central Review (BICR), objective response rate (ORR), and duration of response (DoR) assessed by the investigator. Preliminary results showed that sugemalimab combined with chemotherapy significantly improved PFS (7.6 months vs 6.1 months) and OS (14.6 months vs 12.5 months) compared to the placebo-combined chemotherapy control group, with no new safety signals identified.
Sugemalimab’s Regulatory Journey
Sugemalimab, an in-house developed PD-L1 inhibitor, was first approved in China in December 2021. Since then, it has received approvals for use in the first-line treatment of epidermal growth factor receptor (EGFR) gene mutation-negative and anaplastic lymphoma kinase (ALK) negative metastatic non-squamous non-small cell lung cancer (NSCLC) combined with pemetrexed and carboplatin; in combination with pemetrexed and carboplatin in the first-line treatment of metastatic squamous NSCLC; and for unresectable stage III NSCLC without disease progression after platinum-based synchronous or sequential chemotherapy and radiotherapy. The drug is currently awaiting regulatory decisions in China for use in extranodal NK/T-cell lymphoma (R/R ENKTL) and first-line NSCLC combined with chemotherapy in the UK.
Strategic Implications
The acceptance of the market filing for sugemalimab in GC/GEJC by the NMPA represents a significant step forward for CStone Pharmaceuticals in expanding its indications for this promising PD-L1 inhibitor. This move is expected to enhance the company’s position in the oncology market and provide new treatment options for patients with gastric and gastroesophageal junction adenocarcinoma.-Fineline Info & Tech
