CStone Pharmaceuticals Announces China's NMPA has Accepted its New Drug Application for anti-PD-L1 Monoclonal Antibody Sugemalimab in First-Line Advanced NSCLC

Currently,there is no anti-PD-L1 monoclonal antibody approved for stage IV NSCLC in China

An oral presentation of specific clinical trial data of CS1001-302 study will be given at ESMO Asia Congress on November 21st

SUZHOU,China,Nov. 12,2020 --CStone Pharmaceuticals ("CStone",HKEX: 2616),a leading biopharmaceutical company focused on developing and commercializing innovative immuno-oncology (IO) therapies and precision medicines,today announced that China's National Medical Products Administration (NMPA) has accepted the New Drug Application (NDA) for sugemalimab (CS1001,an anti-PD-L1 monoclonal antibody) combined with chemotherapy for the first-line treatment of advanced squamous and non-squamous non-small cell lung cancer (NSCLC) patients. This is the first NDA for sugemalimab submitted by CStone worldwide and also the sixth NDA worldwide and the third in Mainland China submitted by CStone this year.

The acceptance of NDA was based on the results of CS1001-302,a Phase III trial of sugemalimab combined with chemotherapy for the first-line treatment of squamous and non-squamous NSCLC patients. This study enrolled both squamous and non-squamous NSCLC in the same study,which saved time and cost of development significantly. As reported in August,in the planned interim analysis of this clinical trial,the pre-specified primary endpoint was reached as assessed by independent Data Monitoring Committee (iDMC). Compared with placebo in combination with chemotherapy,sugemalimab in combination with chemotherapy significantly improved progression-free survival (PFS) and reduced the risk of disease progression or death by 50%. Subgroup analysis showed that sugemalimab has demonstrated its clinical benefits in squamous or non-squamous NSCLC patients with PD-L1 expression >=1% or PD-L1 expression <1%. Sugemalimab in combination with chemotherapy showed a favorable safety profile and no new safety signals have been found. An oral presentation of specific clinical trial data will be given in Proffered Paper session (Late-Breaking Abstract) of ESMO Asia Congress on November 21st.

Professor Caicun Zhou,Principal Investigator of CS1001-302 Study and Director of the Department of Oncology,Shanghai Pulmonary Hospital,said,"We are very excited to see that NMPA has accepted the NDA of sugemalimab. In Phase III clinical trial with the inclusion of squamous and non-squamous NSCLC patients,sugemalimab showed potent antitumor activity and a favorable safety profile. Advanced squamous and non-squamous NSCLC still faced a significant unmet medical need in China. We are looking forward to the launch of sugemalimab and its clinical benefits for patients."

Dr. Frank Jiang,Chairman and CEO of CStone,said,"The NDA acceptance of sugemalimab marks another important milestone for CStone Pharmaceuticals,demonstrating our commitment to bring innovative oncology therapies to cancer patients worldwide. We expect sugemalimab can be launched as soon as possible and benefit more cancer patients in China and potentially abroad."

Dr. Jason Yang,Chief Medical Officer of CStone,"With the unique mechanism of action and best-in-class clinical data in multiple tumors,sugemalimab has the potential to become the best-in-class PD-L1 monoclonal antibody. We appreciate the dedication of our CStone team and the strong support from clinical investigators and patients,which made it possible to accomplish this phase III study from first patient enrollment to NDA acceptance in less than 2 years. Currently,registrational studies of sugemalimab for hematological malignancy,stage III NSCLC,advanced gastric cancer and esophageal cancer are progressing smoothly."

About NSCLC

In recent years,the incidence of lung cancer has been continuously increasing in China. As reported,in 2018,there were approximately 770,000 new cases of lung cancer in China and 690,000 death cases caused by lung cancer. Lung cancer is the leading cause of cancer-related death in both men and women,and non-small cell lung cancer comprises the most common form of lung cancer in China.

CS1001-302 Study

CS1001-302 is a multicenter,randomized,double-blind Phase III clinical trial (CS1001-302; clinicaltrials.gov registration number: NCT03789604; drug clinical trial registration number: CTR20181452),designed to evaluate the efficacy and safety of CS1001 in combination with chemotherapy versus placebo in combination with chemotherapy in first-line naïve patients with stage IV NSCLC. The primary endpoint of the trial was PFS as assessed by the investigators; the secondary endpoints include overall survival,PFS and the safety profile as assessed by BICR committee.

About Sugemalimab

Sugemalimab is an investigational anti-PD-L1 monoclonal antibody discovered by CStone. Authorized by the U.S.-based Ligand Corporation,sugemalimab is developed by the OmniRat® transgenic animal platform,which can generate fully human antibodies in one stop. As a fully human,full-length anti-PD-L1 monoclonal antibody,CS1001 mirrors the natural G-type immunoglobulin 4 (IgG4) human antibody,which can reduce the risk of immunogenicity and potential toxicities in patients,a unique advantage over similar drugs.

Sugemalimab has completed a Phase I dose-escalation study in China. During Phase 1a and Phase 1b of the study,sugemalimab showed good antitumor activity and tolerability in multiple tumor types.

Currently,sugemalimab is being investigated in a number of ongoing clinical trials. In addition to a Phase 1 bridging study in the U.S.,the clinical program in China includes one multi-arm Phase 1b study for several tumor types,one Phase 2 registrational studies for lymphoma,and four Phase III registrational studies,respectively,for stage III/IV NSCLC,gastric cancer,and esophageal cancer. The phase III clinical trial of sugemalimab in the treatment of stage IV non-small cell lung cancer reached the primary endpoint. China's National Medical Products Administration (NMPA) has accepted the company's New Drug Application (NDA) for sugemalimab.

About CStone

CStone is a biopharmaceutical company focused on developing and commercializing innovative immuno-oncology and precision medicines to address the unmet medical needs of cancer patients in China and worldwide. Established at the end of 2015,CStone has assembled a world-class management team with extensive experience in innovative drug development,clinical research,and commercialization. With a strategic emphasis on immuno-oncology combination therapies,the Company has built an oncology-focused pipeline of 16 drug candidates,including five late-stage candidates at pivotal trials or registration stages. With an experienced team,a rich pipeline,a robust clinical development-driven business model and substantial funding,CStone's vision is to become a world-renowned biopharmaceutical company that is leading the way to conquering cancer.

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