The U.S. Food and Drug Administration (FDA) has approved Imbruvica (ibrutinib) for the treatment of previously treated patients with Waldenström’s macroglobulinemia, a rare form of cancer of the B lymphocytes that is associated with overproduction of IgM antibodies.
The FDA’s approval is based on a clinical study that included 63 previously untreated patients with Waldenström’s macroglobulinemia. All patients received Imbruvica 420mg orally daily until disease progression or unacceptable toxicity.
Results showed an overall response rate with a duration of response ranging from 2.8 months to about 18.8 months.“Today’s approval highlights the importance of development of drugs for supplemental indications,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Continued research has discovered new uses of Imbruvica.”
In regard to toxicity, the most common adverse events observed were anemia, bruising, diarrhea, fatigue, musculoskeletal pain, nausea, neutropenia, rash, thrombocytopenia, and upper respiratory tract infections.
When prescribing Imbruvica for patients with Waldenström’s macroglobulinemia, healthcare professionals should inform patients of the risk of atrial fibrillation, embryo-fetal toxicity, hemorrhage, infection, second primary malignancies, and tumor lysis syndrome.
Imbruvica is already approved by the FDA for the treatment of patients with mantle cell lymphoma and chronic lymphocytic leukemia who have received at least one prior therapy.