• Tislelizumab is a monoclonal antibody PD-1 checkpoint inhibitor
• BeiGene and Celgene have a global collaboration agreement for the development of  tislelizumab outside of Asia (except Japan)

BeiGene, Ltd. (NASDAQ:BGNE) announced on 7/25/18 that the first patient was dosed in a Phase 3 clinical trial of tislelizumab, an investigational anti-PD-1 antibody, combined with chemotherapy, as a potential first-line treatment in Chinese patients with Stage IIIB or IV non-squamous non-small cell lung cancer (NSCLC). Tislelizumab is also being studied in global Phase 3 trials in solid tumors, including second-line non-small cell lung cancer, first-line hepatocellular carcinoma, and second-line esophageal squamous cell carcinoma; two global Phase 2 trials in previously treated advanced hepatocellular carcinoma and relapsed/refractory mature T- and natural killer-cell lymphomas; and two pivotal Phase 2 trials in China in relapsed/refractory classical Hodgkin’s lymphoma and second-line urothelial cancer.

“As shown by the most recent data from other checkpoint inhibitors, combining immunotherapy and chemotherapy can improve anti-tumor activity and significantly improve outcomes for patients. Our Phase 3 study will assess whether the addition of tislelizumab to standard-of-care chemotherapy will improve outcomes in Chinese patients with advanced lung cancer, a disease known for its poor prognoses even with chemotherapy treatment,” said Lai Wang, Ph.D., Senior Vice President and Head of China Development at BeiGene.

The Phase 3, open-label, multi-center trial is expected to enroll approximately 320 chemotherapy naïve patients who have Stage IIIB or IV non-squamous NSCLC in mainland China. The trial is designed to compare progression-free survival (PFS) as assessed by the Independent Review Committee (IRC) per RECIST v1.1. Key secondary endpoints include overall survival, overall response rate, PFS by investigator, and safety and tolerability.

Tislelizumab (BGB-A317) is an investigational humanized monoclonal antibody that belongs to a class of immuno-oncology agents known as immune checkpoint inhibitors. Discovered by BeiGene scientists in Beijing, tislelizumab is designed to bind to PD-1, a cell surface receptor that plays an important role in downregulating the immune system by preventing the activation of T-cells. Tislelizumab has demonstrated high affinity and specificity for PD-1. It is potentially differentiated from the currently approved PD-1 antibodies in an engineered Fc region, which is believed to minimize potentially negative interactions with other immune cells, based on preclinical data. Tislelizumab is being developed as a monotherapy and in combination with other therapies for the treatment of a broad array of both solid tumor and hematologic cancers. BeiGene and Celgene Corporation have a global strategic collaboration for the development of tislelizumab in solid tumor cancers outside of Asia (except Japan).

On July 22 of 2018 BeiGene announced top-line results of a Ph II study of  tislelizumab. The company reported an overall response rate of 73% and a 50% complete response rate. There are a growing number of PD-1 and PD-L1 checkpoint inhibitors in the market. It remains to be seen how tislelizumab will perform compared to other drugs on the market and in company pipelines. Keytruda and Opdivo are PD-1 checkpoint inhibitors already on the market.