Suzhou, China, May 9^th 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 CStone will regain rights for the development and commercialization of sugemalimab (anti-PD-L1 monoclonal antibody) and nofazinlimab (anti-PD-1 monoclonal antibody) outside of Greater China, upon the termination of the License Agreement for sugemalimab and nofazinlimab between CStone and EQRx. Both parties are committed to ensuring a smooth transition. The termination of this License Agreement will not affect the upfront and milestone payments previously received from EQRx.

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 non-small cell lung cancer (NSCLC) are under review. Upon transition completion, CStone will lead the regulatory process for sugemalimab MAA reviews by the EMA and the U.K. MHRA.

CStone strongly believes that there are significant market opportunities for sugemalimab and nofazinlimab and is delighted to take back the development and commercialization rights outside of Greater China for the two assets. Sugemalimab has achieved success in five registrational clinical trials, covering indications of stage III NSCLC, stage IV NSCLC, lymphoma, gastric cancer, and esophageal cancer. The multi-regional, Phase 3 registrational trial of nofazinlimab in combination with lenvatinib as a first-line treatment for advanced hepatocellular carcinoma is ongoing, to support the new drug applications globally. The clinical data of sugemalimab and nofazinlimab have been presented at international academic conferences. The results from multiple studies of sugemalimab have been published in journals such as The Lancet Oncology and Journal of Clinical Oncology.

Given the promising results from multiple clinical trials of these two assets, CStone remains confident in global market for sugemalimab and nofazinlimab, and continues to engage health authorities, such as the U.S. Food and Drug Administration (FDA), the EMA and the U.K. MHRA.

In the meantime, CStone will actively explore partnership for the development and commercialization of sugemalimab and nofazinlimab outside of Greater China.

Conference Call Information

CStone will host a live conference call in Mandarin for investors at 9:00 a.m. Beijing time on May 9th, 2023. The conference call may be accessed via https://zoom.us/j/95657885602?pwd=S3VTNUZseXhDTUdGMEsxZUdTeHJNZz09.

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 reduce the risk of immunogenicity and toxicity for patients, a unique advantage over similar drugs.

Currently, sugemalimab is approved by the National Medical Products Administration (NMPA) of China for the treatment of patients with unresectable Stage III 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 China’s NMPA accepted 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 esophageal squamous cell carcinoma.

About Nofazinlimab

Nofazinlimab is a humanized recombinant IgG4 monoclonal antibody targeting human programmed cell death protein 1 (PD-1) being developed in solid tumors. Nofazinlimab shows comparable high binding affinities to the PD-1 of humans, cynomolgus monkey, and mouse, and can block the interaction of PD-1 with its ligands PD-L1 and PD-L2.

The U.S. Food and Drug Administration has granted nofazinlimab Orphan Drug Designation in July 2020 for the treatment of patients with hepatocellular carcinoma.

In March 2022, the global multi-regional phase 3 registrational trial of nofazinlimab in combination with lenvatinib as first-line treatment for patients with advanced hepatocellular carcinoma, CS1003-305, has successfully reached its prespecified enrollment target.

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 ten 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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