The U.S. Food and Drug Administration (FDA) today expanded the approved use of ibrutinib (Imbruvica) to treat patients with chronic lymphocytic leukemia (CLL) who carry deletions of the short arm of chromosome 17, which are associated with poor responses to standard treatment for CLL. Ibrutinib received a Breakthrough Therapy designation for this use.
The FDA is also approving new labeling to reflect that ibrutinib’s clinical benefit in treating CLL has been verified. In February 2014, ibrutinib received accelerated approval for the treatment of patients with CLL who have received at least one prior therapy based on its effect on overall response rate. New clinical trial results examining progression-free survival and overall survival have confirmed the drug’s clinical benefit.
“We continue to see advances in the availability of therapies to treat chronic lymphocytic leukemia, especially for difficult-to-treat patient populations,” said Richard Pazdur, MD, Director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “[Ibrutinib] is the fourth drug approved to treat CLL that received a Breakthrough Therapy designation, reflecting the promise of the Breakthrough Therapy designation program and demonstrating the FDA’s commitment to working cooperatively with companies to expedite the development, review, and approval of these important new drugs.”
RESONATE Trial
Today’s approvals for ibrutinib are based on data from the phase III RESONATE trial of 391 patients with previously treated CLL or small lymphocytic lymphoma, 127 of whom had CLL with 17p deletion. Participants were randomly assigned to receive ibrutinib or ofatumumab (Arzerra) until disease progression or side effects became intolerable.
The trial was stopped early for efficacy after a preplanned interim analysis showed ibrutinib-treated participants experienced a 78% reduction in risk of disease progression or death. Results also showed a 57% reduction in risk of death in participants treated with ibrutinib. Of the 127 participants who had CLL with 17p deletion, those treated with ibrutinib experienced a 75% reduction in risk of disease progression or death.
The most common side effects associated with ibrutinib included thrombocytopenia, neutropenia, diarrhea, anemia, fatigue, musculoskeletal pain, upper respiratory tract infection, rash, nausea, and pyrexia.
Ibrutinib’s new use is being approved more than 2 months ahead of the product’s prescription drug user fee goal date of Oct. 7, 2014. The FDA reviewed ibrutinib's application for this new use under the agency’s Priority Review program, which provides for an expedited review of drugs that are intended to treat a serious disease or condition and, if approved, would offer significant improvement compared to marketed products.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.