BeiGene Shows Off Strong Results from Checkpoint Inhibitor While Eying Potential Approval for BTK Inhibitor
China-based BeiGene is starting off the week with a bang. Late Sunday the company announced positive preliminary topline results from its Phase II trial of tislelizumab, the company’s investigational checkpoint inhibitor for relapsed/refractory classical Hodgkin’s lymphoma (R/R cHL).
In its Phase II trial, BeiGene said patients on tislelizumab have shown an overall response rate of 73 percent and a complete response rate of 50 percent. BeiGene said the duration of response rate in the trial, a six-month average follow-up, has not yet been observed in the preliminary examination. The positive results from the trial are certainly pleasing to BeiGene and its developmental partner Celgene. Last year the two companies struck a developmental deal for tislelizumab that has a potential value of $1.4 billion.
Checkpoint inhibitors have proven to be a valuable tool in combating various cancers, with Merck’s Keytruda and Bristol-Myers Squibb’s Opdivo leading the pack. Tislelizumab (BGB-A317) 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. It is being developed as both a monotherapy and as part of a combination treatment for both solid and hematologic tumors.
“We are excited to announce the preliminary topline results from our first pivotal trial for tislelizumab. Despite short follow-up, we believe there was a demonstration of robust activity, with high overall and complete response rates in addition to a safety profile that is consistent with other PD-1 inhibitors. We believe these strong results will support our first regulatory filing in China for tislelizumab, which is planned for later this year,” Jane Huang BeiGene’s chief medical officer for hematology said in a statement.
The Phase II trial’s primary endpoint was overall response rate and the secondary endpoints included progression-free survival, duration of response, complete response rate, time to response and safety and tolerability. BeiGene said it intends to file a Biologics License Application with the China Drug Administration later this year. The company said it anticipates sharing full results of the Phase II trial later this year at a medical conference.
In addition to the classic Hodgkin’s Lymphoma trial, tislelizumab is also being studied in global Phase III trials in a number of cancers, including non-small cell lung cancer, hepatocellular carcinoma, and esophageal squamous cell carcinoma. BeiGene said the checkpoint inhibitor is also being studied in two Phase II trials in patients with previously treated hepatocellular carcinoma or with R/R mature T-and NK-cell lymphomas, and an additional pivotal Phase II trial in China in urothelial cancer.
Not only did the company announce the positive results for its anti-PD-1 antibody, BeiGene said its investigational Bruton’s tyrosine kinase (BTK) inhibitor zanubrutinib has been granted Fast Track designation by the U.S. Food and Drug Administration (FDA) for the treatment of patients with Waldenström macroglobulinemia (WM). Based on its discussions with the FDA, BeiGene said it plans to submit a New Drug Application in the first half of 2019 in an attempt to pursue accelerated approval for the WM treatment based on the results from the Phase I study. The company said a final determination about the possible filing of an NDA for zanubrutinib will be made following the pre-NDA meeting with the FDA. That meeting will happen after the company collects additional data from the Phase I trial this fall, BeiGene said.
John Oyler, BeiGene’s chief executive officer, said the company believes zanubrutinib is a differentiated BTK inhibitor based on the “depth and durability of responses” that have been seen in the ongoing Phase I trial.