Pfizer Receives Conditional Approval for Tislelizumab in the Treatment of Relapsed or Refractory Extranodal NK/T-cell Lymphoma (ENKTL)

Shanghai, China - October 30, 2023 - Pfizer Inc. announced today that its novel immuno-oncology drug, Tislelizumab, has received conditional approval from the National Medical Products Administration (NMPA) of China for the treatment of relapsed or refractory extranodal NK/T-cell lymphoma (ENKTL) in adult patients. This approval marks a significant milestone as Tislelizumab becomes the first PD-L1 monoclonal antibody to be approved for this indication globally. The approval is based on the positive results from the GEMSTONE-201 study, which evaluated the efficacy and safety of Tislelizumab as a monotherapy in adult patients with relapsed or refractory ENKTL. With the lack of standard treatment options for relapsed or refractory ENKTL, Tislelizumab's approval is expected to change the treatment landscape and bring new hope to patients in need.

ENKTL is a subtype of mature T- and NK-cell lymphomas, and it has a higher incidence rate in Asian populations compared to Europe and North America. In China, ENKTL accounts for approximately 6% of all lymphoma subtypes and 28% of mature T-cell and NK-cell lymphomas. Despite recent advancements in treatment, such as chemotherapy regimens based on L-asparaginase, approximately 50% of patients with relapsed or refractory ENKTL will experience disease progression within 5 years. The median survival for these patients is only around 6 months, with a one-year survival rate of less than 20%. Currently, there are no standard treatment options available for this patient population.

The GEMSTONE-201 study, the largest registration clinical trial to date evaluating a PD-L1 monoclonal antibody for the treatment of relapsed or refractory ENKTL, demonstrated that Tislelizumab has the potential to change the treatment paradigm for patients in this setting. Professor Huang Huiqiang, the primary investigator of the GEMSTONE-201 study and from Sun Yat-sen University Cancer Center, commented, "The results of the GEMSTONE-201 study show that Tislelizumab will change the treatment landscape for patients with relapsed or refractory ENKTL, providing them with a standard treatment option. We hope that this drug can be made available to patients as soon as possible, offering them a new therapeutic choice."

Tislelizumab, developed by BeiGene, Ltd., is an anti-PD-L1 monoclonal antibody developed based on Ligand's OmniRat® transgenic animal platform. As a fully human IgG4 monoclonal antibody, Tislelizumab closely resembles the natural human immune system, with lower immunogenicity and associated risks compared to other similar drugs. Furthermore, its preserved antibody-dependent cell-mediated cytotoxicity (ADCC) allows Tislelizumab to act on both the innate and adaptive immune systems, providing unique dual mechanism advantages. Tislelizumab has demonstrated promising anti-tumor activity and tolerability in Phase I and Phase Ib studies across multiple cancer types. Based on the early clinical data, Tislelizumab is being actively investigated in clinical trials both in China and internationally.

In December 2021, Tislelizumab received approval from the NMPA for use in combination with chemotherapy as a first-line treatment for patients with metastatic stage IV non-small cell lung cancer (NSCLC) without driver gene mutations. In May 2022, Tislelizumab was approved for the treatment of unresectable stage III NSCLC patients who did not experience disease progression after receiving platinum-based concurrent or sequential chemoradiotherapy. In 2022, Tislelizumab's indications for stage III and stage IV NSCLC were included in the "Chinese Society of Clinical Oncology (CSCO) Guidelines for the Diagnosis and Treatment of Advanced Non-Small Cell Lung Cancer." In October 2023, Tislelizumab received conditional approval as a monotherapy for the treatment of relapsed or refractory ENKTL in adult patients. This approval was based on objective response rate and duration of response results from a single-arm clinical trial and further confirmation is pending post-marketing.

Pfizer remains committed to advancing oncology research and providing innovative treatment options to patients in need. The approval of Tislelizumab for the treatment of relapsed or refractory ENKTL represents a significant step forward in addressing the unmet medical needs of these patients. By continuing to focus on scientific excellence and collaboration, Pfizer aims to improve overall survival and quality of life for patients, contributing to the realization of the "Healthy China 2030" goals.