China-based CStone Pharmaceuticals (HKG: 2616) has announced the achievement of the primary endpoint in the regulatory GEMSTONE-304 study for its sugemalimab in first-line unresectable, locally advanced, recurrent or metastatic esophageal squamous cell carcinoma (ESCC). This makes sugemalimab the first PD-1 inhibitor to generate positive data in this indication globally.
Study Design and Results
The GEMSTONE-304 study is a randomized, double-blind, multi-center, placebo-controlled Phase III trial designed to assess the efficacy and safety of sugemalimab in combination with chemotherapy in first-line ESCC. The primary endpoints are progression-free survival (PFS) and overall survival (OS) assessed by an independent committee. Secondary endpoints include investigator-assessed PFS, BICR, objective response rate (ORR), and duration of response (DoR). The sugemalimab regimen demonstrated a clinically significant improvement in both PFS and OS, with a safety profile consistent with previous studies and no new safety signals identified.
Regulatory Approvals and Future Prospects
Sugemalimab, a fully human, full-length anti-PD-L1 immunoglobulin G4 (IgG4) antibody, has received approvals from China’s National Medical Products Administration (NMPA) for unresectable Stage III non-small cell lung cancer (NSCLC) and in combination with chemotherapy for first-line treatment of metastatic squamous and non-squamous NSCLC. Additionally, the NMPA has accepted and granted priority review status to a supplemental new drug application (sNDA) for sugemalimab in recurrent extranodal NK/T cell lymphoma (ENKTL). A marketing authorization application (MAA) for the drug in combination with chemotherapy as a first-line treatment for metastatic NSCLC has been accepted for review by the Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom.-Fineline Info & Tech
