Zanubrutinib Granted Accelerated Approval for Second-Line Treatment of Mantle Cell Lymphoma

Officials with the FDA today granted accelerated approval to zanubrutinib (Brukinsa, BeiGene) for the treatment of mantle cell lymphoma (MCL) in adults who have received at least 1 prior therapy, according to a press release.

MCL, an aggressive form of non-Hodgkin lymphoma, occurs from B-cells originating in the “mantle zone.” The disease, which typically has a median survival of 3 to 4 years, is estimated to affect approximately 74,200 individuals in the United States in 2019.

Zanubrutinib, a Bruton’s tyrosine kinase (BTK) inhibitor, previously received Breakthrough Therapy designation in this indication from the FDA. The accelerated approval is based on efficacy results from 2 single-arm clinical trials and continued approval may be contingent upon verification and description of clinical benefit in a confirmatory trial, according to BeiGene.

In the multicenter phase 2 clinical trial, zanubrutinib was evaluated in 118 patients with relapsed or refractory (R/R) MCL BGB-3111-206. According to the data, the overall response rate (ORR) was 84% (95% CI: 74%, 91%), including 59% complete response and 24% partial response. The study also showed a median duration of response of 19.5 months (95% CI: 16.6, NE) and median follow-up time on study was 18.4 months.

According to BeiGene, zanubrutinib is the only FDA-approved BTK inhibitor shown to deliver 100% median occupancy in peripheral blood cells and the only BTK inhibitor with the flexibility to be taken once or twice daily.

The most common adverse reactions observed in the study were decreased neutrophil count, decreased platelet count, upper respiratory tract infection, decreased white blood cell count, decreased hemoglobin, rash, bruising, diarrhea, cough, musculoskeletal pain, pneumonia, urinary tract infection, hematuria, fatigue, constipation, and hemorrhage. The most frequent serious adverse reactions were pneumonia and hemorrhage.

Of the patients treated with zanubrutinib, 7% discontinued treatment due to adverse reactions.

The recommended dose of zanubrutinib is 320 mg, taken orally 160 mg twice daily or 320 mg once daily with or without food, according to BeiGene. The dose may be adjusted for adverse reactions and reduced for patients with severe hepatic impairment and certain drug interactions.

“BTK inhibition is an established mode of treatment for patients with MCL, but many patients treated with previously approved BTK inhibitors do not fully respond to BTK therapy or are forced to discontinue treatment early due to side affects,” Luhua (Micheal) Wang, MD, clinical trial investigator and professor at the Department of Lymphoma and Myeloma, Division of Cancer Medicine at The University of Texas MD Anderson Cancer Center, said in a statement. “Today we have a new option for our adult patients who have received 1 prior systemic or targeted therapy and are living with MCL, an aggressive blood cancer that’s often diagnosed at a more advanced stage.”

BeiGene expects zanubrutinib to be available to patients in the United States in the coming weeks.

Reference

US FDA Grants BeiGene’s Brukinsa (zanubrutinib) Accelerated Approval to Treat Adult Patients with Mantle Cell Lymphoma Who Received at Least One Prior Therapy [news release]. BeiGene’s website. http://ir.beigene.com/news-releases/news-release-details/us-fda-grants-beigenes-brukinsatm-zanubrutinib-accelerated. Accessed November 14, 2019.