BTK Inhibitor Zanubrutinib Yields High ORR in R/R MZL

Eighty percent of patients with marginal zone lymphoma (MZL) experienced tumor response with zanubrutinib monotherapy, according to a recent study.

The phase I/II study examined the use of the Bruton’s tyrosine kinase inhibitor in 385 patients with B-cell malignancies. About half of the patients (n=53) had relapsed/refractory MZL (n=20) or relapsed/refractory follicular lymphoma (FL; n=33). These patients were all enrolled during a dose-expansion phase of the study.

Patients with MAZL had an overall response rate (ORR) of 80%, with 20% of patients achieving a complete response (CR). After a median follow-up of 33.8 months, the median progression-free survival (PFS) was not reached.

Among patients with FL, the ORR was 36.4%, with 18.2% of patients achieving a CR. Median PFS was 10.4 months.

The most common side effects ranged from diarrhea, bruising, and rashes to colds, fevers, and reduced levels of white blood cells.

The U.S. Food and Drug Administration has approved zanubrutinib on a contingent basis for adults with relapsed/refractory MZL.

“Treatment options with improved tolerability and better disease control were much needed for MZL and FL,” Tycel Phillips, MD, a hematologist at the Rogel Cancer Center, a clinical associate professor at the University of Michigan Medical School, and the lead author of the study, said in a press release. “While the small size of this study limits broad conclusions, the safety and efficacy results highlight the potential for zanubrutinib as an addition to available therapies for these cancers.”

Phillips T, Chan H, Tam CS, et al. Zanubrutinib monotherapy in relapsed/refractory indolent non-Hodgkin lymphoma. Blood Adv. 2022. doi:10.1182/bloodadvances.2021006083