FDA Approves New Targeted Treatment for CLL/SLL
Rye Brook, N.Y., February 6, 2023 – The U.S. Food and Drug Administration recently approved zanubrutinib (Brukinsa®), a next generation BTK inhibitor, for the treatment of adults with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL).
Zanubrutinib is already approved to treat mantle cell lymphoma, marginal zone lymphoma and Waldenström macroglobulinemia. The drug works by blocking the BTK enzyme, which is essential to the growth and survival of these B-cell blood cancers.
“Zanubrutinib led to longer progression-free survival times compared to other standard therapies both as first-line treatment and for treatment after relapse in clinical trials,” said Lee Greenberger, Ph.D., LLS Chief Scientific Officer. “It was also easier to tolerate than the widely used first-generation BTK inhibitor ibrutinib.”
Patients with CLL and SLL live with the expectation of periodic relapses and the knowledge that each relapse will be more difficult to treat than the last. CLL and SLL are the same disease, except that in CLL, which is the most common form of adult leukemia, the cancer cells are found mostly in the blood and bone marrow, while in SLL they are found mostly in the lymph nodes.
Discovering new treatments will be key to keeping CLL and SLL in check and improving patient outcomes. LLS is supporting research into drugs that work through different mechanisms than current drugs to inhibit the BTK enzyme and others that bind to and degrade BTK so it cannot drive cancer growth.
LLS is also supporting research into combination therapies that can provide stronger and longer lasting results. In ongoing trials, a combination of BTK inhibitors and venetoclax has led to complete responses in some patients, meaning no cancer can be detected. The duration of this effect is being studied. The long-term safety of the combination is also being evaluated.
Today’s FDA approval for first line treatment of CLL and SLL was based on results from the SEQUOIA trial and approval for relapsed or refractory disease was based on results from the ALPINE trial, which enrolled patients who had at least one prior treatment.
With a median follow-up of 26.2 months, zanubrutinib demonstrated a 42% improvement in progression-free survival time versus bendamustine plus rituximab for first line treatment of CLL. In the ALPINE trial, patients treated with zanubrutinib had a better overall response rate compared to patients treated with ibrutinib (80.4% compared with 72.9%).
Zanubritinib, like other BTK inhibitors, comes with the risk of side effects including decreased white blood cell and platelet counts, upper respiratory infections, hemorrhage and muscle and skeletal pain.