CStone Pharmaceuticals, a biopharmaceutical company dedicated to developing innovative cancer therapies, announced the submission of a Type II variation application to the European Medicines Agency (EMA) for sugemalimab. The application seeks approval for the treatment of patients with unresectable stage III non-small cell lung cancer (NSCLC) who have not progressed following concurrent or sequential platinum-based chemoradiotherapy (CRT). This marks CStone's second regulatory submission for sugemalimab to the EMA, following its initial approval in Europe for metastatic squamous and non-squamous NSCLC in 2024. If this new indication is approved, sugemalimab would address a critical unmet need in stage III NSCLC, where only one PD-L1 antibody is currently approved in Europe. The drug's dual utility in stage III and IV NSCLC could solidify its role as a cornerstone immunotherapy in lung cancer.

The submission is supported by data from the GEMSTONE-301 Phase III trial, a multicenter, randomized, double-blind study evaluating sugemalimab as consolidation therapy in patients with unresectable stage III NSCLC post-CRT. Results published in The Lancet Oncology demonstrated:

• 36% reduction in risk of disease progression or death, significantly improved progression-free survival (PFS).
• 56% reduction in risk of death, with a strong positive trend toward overall survival (OS) benefit.
• Consistent clinical benefits across subgroups, regardless of prior CRT modality (concurrent or sequential).
• Favorable safety profile, no new safety signals identified.

Dr. Jason Yang, CEO, President of R&D, and Executive Director at CStone, commented: "Following sugemalimab's approval in Europe for stage IV NSCLC, we are working closely with EMA to expand its indications in earlier stage lung cancer and other malignancies. With its demonstrated outstanding efficacy and safety profile, sugemalimab is poised to address critical unmet needs for stage III NSCLC patients. We remain steadfast in expanding global access through strategic partnerships and collaborations with regulatory authorities, ensuring this innovative therapy reaches patients worldwide."