With the FDA’s approval of zanubrutinib, CLL / SLL patients have another very strong choice to manage their disease.
Zanubrutinib is the third Bruton’s Tyrosine Kinase inhibitor (BTKi) to be approved by the FDA, following ibrutinib and acalabrutinib. BTK has been found to regulate cell survival and replication in various B-cell malignancies. They all work similarly by irreversibly binding to BTK and blocking the B-cell receptor (BCR) in the cancer cells. Since CLL / SLL cells are addicted to this pathway, blocking BCR stops the cancer in its tracks.
BTK inhibitors have revolutionized the care of CLL / SLL, prolonging life with simple effective oral medications.
However, not all BTK inhibitors are the same, and “off target” effects can lead to side effects that may lead to intolerance of the medication requiring discontinuation of the drug. Medications don’t work if you can’t take them.
Data presented on Zanubrutinib at the 64th Annual American Society for Hematology (ASH) Meeting and published in the New England Journal of Medicine (NEJM) showed that it was associated with a more favorable cardiac profile, specifically fewer cases of atrial fibrillation than ibrutinib, and no cardiac deaths. Moreover, and this is the big news, it is the first BTK inhibitor that showed a higher response rate (RR) and a longer time to disease progression in a head-to-head comparison with ibrutinib.
Keep it mind that if someone has progressed on one of the irreversible BTK inhibitors, it’s a safe assumption that one will not respond to any another ones in the same drug class, but fewer patients progressed while taking zanubrutinib compared to ibrutinib.
And if more people with CLL / SLL can stay on zanubrutinib because of fewer side effects, then more will benefit from the drug in the long-run.
Those with CLL / SLL now have three great BTK inhibitor options to choose from when they need treatment.
Here is the official FDA statement.
Here is the official BeiGene Press Release, featuring comments from CLL Society’s Dr. Brian Koffman.
There is much to be grateful for.