The Backstory
Earlier this month, the FDA approved ibrutinib for first-line use in patients with chronic lymphocytic leukemia (CLL). This makes it the first FDA-approved non-chemotherapy option for initial CLL treatment. The approval adds an alternative to current first line standard treatments which include fludarabine, cyclophosphamide, and rituximab as well as chlorambucil and obinutuzumab.
This is the fifth approval granted to ibrutinib by the FDA and third approval related to CLL. The previous FDA-approved indications included previously treated CLL (February 2014) and patients with 17p deletion (July 2014). Other prior approvals included ibrutinib for use as a monotherapy in patients with Waldenstrom’s macroglobulinemia (July 2015) and as a treatment for mantle cell lymphoma patients who received at least one prior therapy (November 2013).
What is ibrutinib?
Ibrutinib is a first-generation oral drug that inhibits Bruton’s tyrosine kinase (BTK), an enzyme that plays a role in the development of B-cells. In CLL, malignant B-cells grow uncontrollably and prevent other blood cells from properly forming. Ibrutinib disrupts the function of BTK, slowing cell growth and promoting cell death in CLL cells.
Why was ibrutinib granted FDA approval?
Ibrutinib was approved based on the results from the RESONATE-2 trial. Ibrutinib was found to have superior results when compared to the standard chemotherapy treatment, chlorambucil, in a large study of older CLL patients who had not previously received any treatment. Overall, there was an 84% decrease in the risk of death when treated with ibrutinib compared to chlorambucil. These results were presented at the latest American Society of Hematology meeting and published in the New England Journal of Medicine. (December 2015)
Were there any side effects?
Side effects related to ibrutinib included diarrhea, fatigue, coughing, and nausea. Few patients required treatment discontinuation or dose reductions due to adverse side effects of the medication.
How can you access ibrutinib?
Ibrutinib has been approved for use in CLL, mantle cell lymphoma, and Waldenstrom’s macroglobulinemia, and researchers are attempting to optimize its use in those lymphomas while continuing to investigate its use in other forms of lymphoma. To learn more about whether this is the best treatment for you please call us at (646) 962-2064 and make an appointment with one of our physicians. A full list ibrutinib-related trials currently open at Weill Cornell Medicine can be found on our Joint Clinical Trials website, including two trials for patients with CLL.
New Developments in Lymphoma 