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  • CStone Presents Results from Phase 3 Study of Sugemalimab in First-Line Esophageal Squamous Cell Carcinoma at ESMO GI 2023

    Times:2023.06.30   Author:CStone

    • The GEMSTONE-304 study has met its pre-specified dual primary endpoints. Sugemalimab in combination with chemotherapy demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) assessed by Blinded Independent Central Review (BICR) and overall survival (OS).
    • Sugemalimab would be the first anti-PD-L1 monoclonal antibody worldwide as the first-line treatment for unresectable locally advanced, recurrent, or metastatic esophageal squamous cell carcinoma (ESCC), if approved.

     

    Suzhou, China, June 30th, 2023, CStone Pharmaceuticals (“CStone”, HKEX: 2616), a leading biopharmaceutical company focused on the research, development, and commercialization of innovative immuno-oncology therapies and precision medicines, today announced that the data from a Phase 3 clinical trial (GEMSTONE-304), evaluating sugemalimab in combination with chemotherapy as the first-line treatment for unresectable locally advanced, recurrent, or metastatic esophageal squamous cell carcinoma (ESCC), has been presented in an oral session at the ESMO World Congress on Gastrointestinal Cancer 2023 (ESMO GI 2023).

    The GEMSTONE-304 study is a randomized, double-blind, multi-center, placebo-controlled Phase 3 registrational clinical trial, designed to evaluate the efficacy and safety of sugemalimab in combination with 5-fluorouracil plus cisplatin as the first-line treatment in patients with unresectable locally advanced, recurrent, or metastatic ESCC. The dual primary endpoints are PFS assessed by BICR and OS. Secondary endpoints include investigator-assessed PFS, BICR- and investigator-assessed objective response rate (ORR) and duration of response (DoR), etc.

    Dr. Jason Yang, CEO of CStone, said, “We are pleased to present the sugemalimab data in first-line ESCC at ESMO GI 2023. The findings from the GEMSTONE-304 study have demonstrated the effectiveness of sugemalimab in improving the survival benefits for patients. There are currently no anti-PD-L1 antibodies approved worldwide in the first-line setting for ESCC. The supplemental biologics license application based on these results is under review by the National Medical Products Administration of China. This is yet another important achievement in the development of sugemalimab, following its success in stage III and stage IV NSCLC, gastric cancer, and ENKTL. We look forward to continued communications with the health authority and bring this innovative treatment to ESCC patients soon.”

    Professor Li Jin, Principal Investigator of the GEMSTONE-304 study and Director of the Department of Oncology, East Hospital, Tongji University, said, “Esophageal cancer is a prevalent malignancy in China, and many patients have already progressed to locally advanced or advanced stages at the time of initial diagnosis. Given the GEMSTONE-304 data presented at ESMO GI 2023, sugemalimab in combination with chemotherapy provides more robust clinical efficacy, compared with chemotherapy alone, to treatment-naïve patients with ESCC by prolonging both PFS and OS. The safety profile of this regimen was also manageable. We are confident that this innovative therapy will benefit a larger population of ESCC patients once it is approved in the near future.”

    The data presented at ESMO GI 2023 is based on the final analysis of PFS and the interim analysis of OS with a cutoff date of October 7, 2022. The results demonstrate that the GEMSTONE-304 study has met its predefined dual endpoints. Sugemalimab in combination with chemotherapy demonstrated a statistically significant and clinically meaningful improvement in the BICR-assessed PFS and OS. Key findings include:

    • The BICR-assessed median PFS in the sugemalimab treatment group is 6.2 months compared with 5.4 months in the placebo group, with a hazard ratio (HR) of 0.67 (95% CI, 0.54-0.82), and a p-value of 0.0002.
    • The median OS in the sugemalimab treatment group is 15.3 months compared with 11.5 months in the placebo group, with an HR of 0.70 (95% CI, 0.55-0.90), and a p-value of 0.0076.
    • Subgroup analysis demonstrates consistent clinical benefits were observed across almost all predefined subgroups, including PD-L1 expression status.
    • The BICR- assessed ORR is 60.1% vs 45.2%, with a difference of 14.9% (95% CI, 5.9%-23.8%), and a p-value of 0.0011. The DoR is 6.0 months vs 4.5 months.
    • Sugemalimab in combination with chemotherapy shows good tolerability and safety, with no new safety signal observed.

     

    About esophageal cancer

    Esophageal cancer is one of the most common cancers globally. According to the GLOBOCAN 2020 data, there were more than 600,000 new cases of esophageal cancer in the world in 2020 (ESCC accounts for about 85%), and 544,000 deaths, with the incidence and mortality ranking 8th and 6th, respectively, among cancers globally. The incidence of esophageal cancer in China accounts for more than half of the world, about 90% of which are ESCC, and most of the patients with ESCC have been diagnosed in the advanced stage and missed the opportunities of curative treatments.

     

    About Sugemalimab

    The anti-PD-L1 monoclonal antibody sugemalimab was discovered by CStone using the OmniRat® transgenic animal platform, which allows creation of fully human antibodies in one step. Sugemalimab is a fully human, full-length anti-PD-L1 immunoglobulin G4 (IgG4) monoclonal antibody, which may reduce the risk of immunogenicity and toxicity for patients, a unique advantage over similar drugs.

    Sugemalimab is approved by the NMPA of China for the treatment of patients with unresectable Stage III non-small cell lung cancer (NSCLC) whose disease has not progressed following concurrent or sequential platinum-based chemoradiotherapy and in combination with chemotherapy for the first-line treatment of patients with metastatic squamous and non-squamous NSCLC. The marketing authorization applications (MAAs) with the European Medicines Agency (EMA) and the Medicines and Healthcare products Regulatory Agency (MHRA) in the United Kingdom for sugemalimab as a first-line treatment for metastatic NSCLC are under review.

    The supplemental biologics license applications for sugemalimab for the treatment of patients with relapsed/refractory extranodal NK/T-cell lymphoma, as well as in combination with chemotherapy for first-line treatment of locally advanced or metastatic gastric/gastroesophageal junction adenocarcinoma, and in combination with chemotherapy for first-line treatment of unresectable locally advanced, recurrent, or metastatic ESCC have been accepted by the NMPA of China and are currently under review.

     

    About CStone

    CStone (HKEX: 2616) is a biopharmaceutical company focused on research, development, and commercialization of innovative immuno-oncology and precision medicines to address the unmet medical needs of cancer patients in China and worldwide. Established in 2015, CStone has assembled a management team with extensive experience in innovative drug development, clinical research, and commercialization. The company has built an oncology-focused pipeline of 15 drug candidates with a strategic emphasis on immuno-oncology combination therapies. Currently, CStone has received eleven NDA approvals for its four drugs. Multiple late-stage drug candidates are now under pivotal clinical trials or registration. CStone’s vision is to bring innovative oncology therapies to cancer patients worldwide.

    For more information about CStone, please visit www.cstonepharma.com.

     

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