On 14 January 2019, zanubrutinib (BGB-3111), an investigational Bruton’s tyrosine kinase (BTK) inhibitor, was granted Breakthrough Therapy Designation by the U.S. Food and Drug Administration (FDA) for the treatment of adult patients with mantle cell lymphoma (MCL) who have received at least one prior line of therapy. Additionally, zanubrutinib has been granted Fast Track designation for the treatment of patients with Waldenström macroglobulinemia.
The Breakthrough Therapy Designation granted by the FDA was based on the positive results obtained from the single-arm, open-label, multi-center phase II trial (NCT03206970) assessing the efficacy and safety of BGB-3111, in patients with MCL who had received one to four previous lines of therapy.
The phase II study demonstrated an overall response rate in relapsed/refractory patients following treatment with BGB-3111 was 88.9%, according to investigator assessment, which suggests responses to therapy were durable. Furthermore, the median duration of response was 16.2 months and median progression-free survival for relapsed/refractory patients was 18.0 months.
According to the drug manufacturers, the third Breakthrough Therapy Designation granted for BGB-3111, “underscores the potential of zanubrutinib as a meaningful treatment for patients with MCL who have received at least one prior therapy.”