The Food and Drug Administration approved the use of ibrutinib (Imbruvica) for patients with chronic lymphocytic leukemia who have undergone at least one prior therapy, the agency announced Feb. 12.
The FDA’s expanded approval is based on a study of 48 CLL patients who had received previous therapy, the agency said in a statement. On average, participants were diagnosed 6.7 years before the study, and had received four therapies prior to ibrutinib. Patients received a 420-mg oral dose of the drug daily until either treatment reached unacceptable toxicity, or the disease progressed. The overall response rate was almost 58%, with duration of response ranging from 5.6 months to 24.2 months. An improvement in overall survival has not yet been demonstrated.
The drug was approved for CLL patients under the FDA’s accelerated approval process, which allows the agency to approve a medication "based on a surrogate or intermediate endpoint that is reasonably likely to predict clinical benefit," the FDA said.
In November 2013, the FDA approved ibrutinib under its accelerated process to treat patients with mantle cell lymphoma who had received previous therapy.
Drugs receiving accelerated approval are usually bound by an agreement with the company to conduct further confirmatory trials to demonstrate clinical benefit, the FDA said. Because of ibrutinib’s demonstrated potential to treat CLL, a rare disease, the drug received priority review and orphan-product designation.
The FDA reported a number of common side effects in the study, including thrombocytopenia, diarrhea, bruising, neutropenia, anemia, upper respiratory tract infection, fatigue, musculoskeletal pain, rash, fever, constipation, peripheral edema, joint pain, nausea, mouth sores, sinus infection and dizziness.
Ibrutinib is manufactured by Pharmacyclics in Sunnyvale, Calif.