• The National Medical Products Administration approved sugemalimab for the treatment of patients with unresectable stage III non-small cell lung cancer whose disease has not progressed following concurrent or sequential platinum-based chemoradiotherapy
• Sugemalimab became the first anti-PD-1/PD-L1 monoclonal antibody approved for stage III NSCLC following concurrent or sequential chemoradiotherapy. It's also the only anti-PD-(L)1 monoclonal antibody approved for both stage III and stage IV NSCLC
• This is the eighth approved new drug application (NDA) for CStone

SUZHOU, China, June 6, 2022 /PRNewswire/ -- CStone Pharmaceuticals ("CStone", HKEX: 2616), a leading biopharmaceutical company focused on research, development, and commercialization of innovative immuno-oncology therapies and precision medicines, and Pfizer Inc. (NYSE: PFE) today announced that the National Medical Products Administration (NMPA) of China has approved sugemalimab (Cejemly^®) 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. Together with the previous approval of the treatment for first-line stage IV NSCLC patients, sugemalimab is now the only anti- PD-1/PD-L1 monoclonal antibody for both stage III and stage IV NSCLC patients.

Dr. Frank Jiang, CEO of CStone, said, "We appreciate the NMPA for granting the new approval which is an important milestone in our journey to lead the treatment of lung cancer as China steps up efforts to support innovative therapies and address unmet needs. As a leading biopharma company in fostering precision medicines and immuno-oncology therapies, CStone has been spearheading multiple medical breakthroughs. With this approval, it will provide a new treatment option for stage III NSCLC patients, while demonstrating our prowess in advancing lung cancer treatments and bringing forward transformative drugs to the market. Partnerships are crucial to meet massive clinical needs of cancer patients. We will continue to work closely with Pfizer to deliver cutting-edge oncology therapies and improve the health of cancer patients in China."

Jean-Christophe Pointeau, China President of Pfizer Biopharmaceutical Group, says, "Committed to delivering 'breakthroughs that change patients' lives', Pfizer has achieved a series of important breakthroughs in the field of immuno-oncology. After the approval of Stage IV NSCLC indication a few months ago, Cejemly^® achieved immediate commercialization across China, offering hopes to Chinese NSCLC patients with improved diagnosis and treatment solutions. We firmly believe that the approval of the new indication will allow more patients to benefit from this drug, bridge the gap and fulfill the unmet needs, especially the needs of unresectable Stage III NSCLC patients for immune consolidation therapy after sequential chemoradiotherapy. Cejemly^® is Pfizer's strategic asset in immuno-oncology, and a paradigm for innovative strategic partnership with local biotech companies, like CStone guided by the slogan of "Science Will Win, Conquer Cancer Together". Starting from here, Pfizer will continue the exploration in this field, promote the upgrades and advances in immunodiagnostics and immunotherapy, offer more tailor-made, globally innovative solutions to Chinese cancer patients, and help to achieve the grand goal of "Healthy China 2030".

Professor Yi-Long Wu of Guangdong Provincial People's Hospital, the Leading Principal Investigator on the GEMSTONE-301 study, said, "Patients with stage III NSCLC urgently need new treatment options, and the NMPA approval of sugemalimab brings them hope. The results from GEMSTONE-301 demonstrated that sugemalimab as a consolidation therapy had robust efficacy and a well-tolerated safety profile. It is now recommended by the Chinese Society of Clinical Oncology (CSCO) guidelines for this patient population. With proven clinical benefits, sugemalimab will potentially reshape the treatment landscape as a preferred immuno-oncology therapy for patients with mid- and late-stage lung cancer."

Dr. Jason Yang, Chief Medical Officer of CStone, said, "We are thrilled that sugemalimab has become the first anti- PD-1/PD-L1 monoclonal antibody approved for stage III NSCLC after concurrent or sequential chemoradiotherapy. The GEMSTONE-301 study has an innovative study design that enrolled patients with either concurrent or sequential chemoradiotherapy to better reflect real-world clinical practice and cover a broad patient population. We've also made significant progress in the registrational studies of sugemalimab in patients with esophageal squamous cell carcinoma, gastric cancer, and relapsed or refractory extranodal natural killer/T-cell lymphoma in a bid to benefit more cancer patients."

The NMPA approval is based on the GEMSTONE-301 study, a multicenter, randomized, double-blind phase 3 clinical trial, designed to evaluate the efficacy and safety of sugemalimab as a consolidation therapy in patients with unresectable stage III NSCLC without disease progression after concurrent or sequential chemoradiotherapy. Sugemalimab significantly improved patients' progression-free survival (PFS). The risk of disease progression or death was reduced by 36%, together with encouraging overall survival (OS). Subgroup analyses demonstrated clinical benefits regardless of whether patients received prior concurrent or sequential chemoradiotherapy. Sugemalimab had a well-tolerated safety profile, and no new safety signals were observed. The results of the GEMSTONE-301 study were published in The Lancet Oncology in January 2022.

About Sugemalimab

The anti-PD-L1 monoclonal antibody sugemalimab was discovered by CStone using 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 allow a reduced risk of immunogenicity and toxicity for patients, a unique advantage over similar drugs.

Currently, the NMPA of China has approved sugemalimab (Cejemly^®) in combination with pemetrexed and carboplatin as first-line treatment of patients with metastatic non-squamous NSCLC, lacking epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) genomic tumor aberrations; and in combination with paclitaxel and carboplatin as first-line treatment of patients with metastatic squamous NSCLC; for the treatment of patients with unresectable stage III NSCLC  whose disease has not progressed following concurrent or sequential platinum-based chemoradiotherapy.

With its proven therapeutic advantages, sugemalimab is set to be recommended by the 2022 CSCO clinical guidelines for the diagnosis and treatment of NSCLC, in combination with chemotherapy as the first-line treatment of patients with stage IV non-squamous/squamous NSCLC without driver alterations; or as a consolidation therapy in patients with stage III NSCLC after concurrent or sequential chemoradiotherapy.

CStone formed a strategic collaboration agreement with Pfizer that includes the development and commercialization of sugemalimab in mainland China, and a framework to bring additional Oncology medicines to the Greater China market.