The Food and Drug Administration’s recent approval of the drug ibrutinib offers a major new option for patients with chronic lymphocytic leukemia (CLL) who tried at least one prior therapy, physicians say.
The drug, sold under the name Imbruvica, is the latest targeted therapy to be approved. It blocks a signaling protein receptor near the surface of immune system B cells, interfering with an enzyme that lymphoma cells need to multiply and spread.
Although it was approved for CLL patients who have already been treated at least once for the disease, the drug is the product of research that may eventually benefit everyone with the disease, according to Jennifer R. Brown, MD, PhD, director of the Center for Chronic Lymphocytic Leukemia at Dana-Farber. “This is the first of what will likely, ultimately be multiple targeted drugs for CLL,” she said. “So stay tuned. This is the start of what promises to be great developments in CLL over the next several years.”
The FDA’s approval of ibrutinib for CLL is based on a clinical trial that involved 48 patients previously treated for the disease. The patients took a 420 mg oral dose of ibrutinib daily until the disease began to worsen or until the side effects became severe. Overall, 88 percent of the patients had a positive response to the drug, with durable benefits such that 75 percent had not progressed at approximately two years of follow-up.