BeiGene‘s immunotherapy candidate tislelizumab was shown to eliminate tumors in 50% of patients with classical Hodgkin’s lymphoma who had failed to respond to their most recent treatment, according to preliminary results of a Phase 2 trial.
In all, 73% of patients experienced some tumor reduction.
Tislelizumab (BGB-A317) is an experimental antibody designed to bind to PD-1, a protein that guards against autoimmunity, thereby blocking signals that allow cancer cells to evade immune surveillance. Therapies targeting this pathway aim to boost anti-cancer response.
Medications targeting the PD-1 or PD-L1 proteins are already approved for many types of tumors. These include Opdivo (nivolumab), Keytruda (pembrolizumab), Tecentriq (atezolizumab), and Bavencio (avelumab).
Because these therapies unleash the immune system, immune cells other than the cancer-fighting ones might also become overly active, resulting in potentially life-threatening complications.
Tislelizumab, however, includes a specific modification that may minimize potentially negative interactions with other immune cells, compared with approved PD-1-based therapies.
The multi-center Phase 2 trial (NCT03209973) included 70 patients with classical Hodgkin’s lymphoma who either failed to respond or were not eligible for a stem cell transplant, and whose illness worsened following prior treatment regimens.
The trial’s main goal was to determine the overall response rate (ORR) — the portion of patients with a predefined tumor size reduction over a certain time period. Secondary measures included how long a patient lives without cancer progression, time to response, and duration of response. Safety and tolerability were also assessed.
As of the analysis cutoff date, patients had been in the trial for a median of six months. At this point, 73% had partial tumor reduction, including 50% who no longer had traces of tumor cells on imaging scans.
The therapy’s safety profile was consistent with results of a previous Phase 1 study or with prior reports of other PD-1 antibodies for the treatment of classical Hodgkin’s lymphoma.
“We are excited to announce the preliminary topline results from our first pivotal trial for tislelizumab,” Jane Huang, MD, BeiGene’s chief medical officer for hematology, said in a press release.
“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,” Huang said.
Based on the findings, as well as additional follow-up results from the clinical trial, BeiGene is preparing a Biologics License Application (BLA) in China for tislelizumab, estimated for later this year, Huang said.
The company is developing tislelizumab both as a stand-alone therapy and in combination with other medications for treatment of various cancers, including non-small cell lung cancer (NSCLC) and esophageal squamous cell carcinoma. BeiGene and Celgene currently collaborate in tislelizumab’s development outside Asia (except Japan).