By Fineline Cube CStone Pharmaceuticals (HKG: 2616), a China-based biopharmaceutical company, announced that the Journal of Clinical Oncology (JCO) has published the results of the registrational clinical study GEMSTONE-201 for the PD-L1 antibody sugemalimab in the treatment of relapsed or refractory extranodal NK/T-cell lymphoma (R/R ENKTL). This study represents the largest registrational clinical trial for an anti-PD-(L)1 antibody in patients with R/R ENKTL to date.
GEMSTONE-201 Study Design and Findings
The GEMSTONE-201 was a single-arm, multicenter, Phase II pivotal trial that aimed to assess the efficacy and safety of sugemalimab in 80 patients with R/R ENKTL, with a median follow-up of 18.7 months. The primary analysis showed that sugemalimab significantly improved the objective response rate (ORR) compared to historical controls, with an ORR of 44.9% as assessed by the Independent Radiology Review Committee (IRRC) and a complete response (CR) rate of 35.9%. Durable efficacy was observed in patients who achieved objective responses, with a median duration of response (DoR) not yet reached and DoR rates at 6, 12, and 18 months at 91.3%, 82.5%, and 82.5%, respectively. The overall survival (OS) data suggested a potential survival benefit with sugemalimab monotherapy, with OS rates at 6, 12, and 18 months at 79.2%, 67.5%, and 57.9%, respectively. Sugemalimab was well-tolerated, and no new safety signals were observed.
Sugemalimab’s Breakthrough Therapy Designations and Priority Review Status
The anti-PD-L1 monoclonal antibody sugemalimab has received Breakthrough Therapy Designations (BTDs) in the US and China for the treatment of R/R ENKTL, based on preliminary efficacy data from the GEMSTONE-201 study. It has also been awarded priority review status for the treatment of R/R ENKTL in China.
Understanding Extranodal NK/T-Cell Lymphoma (ENKTL)
ENKTL is a subtype of mature T cell and NK cell lymphoma. A 2012 multicenter pathological classification survey of 10,002 lymphoma patients from China indicated that ENKTL accounted for approximately 6% of all lymphomas and 28% of mature T-cell and NK-cell lymphomas. Research indicates that there is broad similarity in the clinical presentation and treatment outcomes for ENKTL between Western and Asian populations.-Fineline Info & Tech