CStone Pharmaceuticals announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has issued a positive opinion recommending approval of sugemalimab in combination with chemotherapy as a first- line treatment for metastatic non-small cell lung cancer (NSCLC), which is one of the cancer indications and a leading cause of cancer death in the world. Sugemalimab is expected to become the first anti-PD-L1 monoclonal antibody (mAb) to be approved in Europe for both first-line squamous and non- squamous NSCLC, regardless of PD-L1 expression, also making CStone the very first biopharmaceutical company in China to potentially launch a domestic anti-PD-L1 mAb in international markets. CHMP's recommendation is based on the results of a Phase 3 clinical trial (GEMSTONE-302) demonstrating significant progression-free survival (PFS) and overall survival (OS) benefits of sugemalimab in combination with chemotherapy as a first-line treatment for non-small cell lung cancer (NSCLC).

Sugemalimab is expected to become the first anti-PD-L1 monoclonal antibody (mAb) in the world to be approved in Europe for both first-line squamous and non-squamous NSCLC, regardless of PD-L1 expression, potentially also the first domestic anti-PD-L1 mAb to be marketed in internaltional regions. In addition to the recent strategic commercial collaboration with Ewopharma in 18 Central Eastern Europe countries and Switzerland, multiple potential partners in other countries or regions are in deep conversations with CStone for sugemalimab. CHMP's positive opinion is primarily based on the results of GEMSTONE-302, a multi-center, randomized, double-blind, Phase 3 clinical trial.

Sugemalimab in combination with chemotherapy significantly improved PFS and OS compared to placebo in combination with chemotherapy in previously untreated stage IV NSCLC patients. The clinical trial results have been published in The Lancet Oncology and Nature Cancer and reported in oral sessions at various international academic conferences. Sugemalimab is an anti-PD-L1 monoclonal antibody developed by CStone, which has been approved in China for five indications, including stage III and IV NSCLC, extranodal NK/T-cell lymphoma, esophageal squamous cell carcinoma, and gastric cancer.

Additionally, the U.K. Medicines and Healthcare products Regulatory Agency (MHRA) is currently reviewing the marketing authorization application (MAA) for sugemalimab combined with chemotherapy as a first-line treatment for metastatic NSCLC. The Company is also in communications with regulatory authorities such as the EMA, MHRA, and U.S. Food and Drug Administration (FDA) regarding additional indications for sugemalimab and is actively seeking development and commercialization partnerships in other countries and regions worldwide.