A New Treatment for Marginal Zone Lymphoma  


The U.S. Food and Drug Administration (FDA) granted accelerated approval to zanubrutinib (Brukinsa) for certain adult patients with marginal zone lymphoma (MZL), a slow-growing form of non-Hodgkin lymphoma that originates from B cells at the edges of the lymph nodes or other lymphoid tissues. 

Zanubrutinib is a kinase inhibitor. It works by blocking a protein called BTK that plays a role in cell signaling and is critical for proliferation and survival of leukemic B cells. Blocking this protein and its signaling pathways helps prevent cancer cells from growing.  

The FDA approval is for certain adult patients with relapsed or refractory MZL who have received at least one prior anti-CD20-based therapy, which aims to deplete B cells.  

marginal zone lymphoma
Marginal zone lymphoma. Image by Librepath via Wikimedia.

The approval was based on data from two open-label, multicenter, single-arm trials. The first trial involved 66 patients with MZL who had undergone at least one prior anti-CD20-based therapy. In this study, the objective rate of response was 56 percent, with 20 percent of patients achieving complete responses. The second involved 20 patients with previously treated B-cell malignancies. In this study, the objective rate of response was 80 percent, with a complete response rate of 20 percent. The estimated one-year rate of duration of response was 85 percent and 72 percent for the first and second trial, respectively. 

Serious adverse events occurred in 40 percent of patients, most often resulting from fever or pneumonia. The prescribing information includes precautions and warnings about bleeding, infections, low blood cell count, secondary cancers, and irregular heart rhythms. 

There are five different types of MZL, characterized by where they originate. MZL represents about 5 to 10 percent of all lymphomas.  

The FDA decision was rendered on September 14, 2021. Accelerated approval means continued approval may be contingent upon a confirmatory trial.