Dr. Woyach Discusses Progression on Ibrutinib With the Acquisition of Resistance Mutations

Jennifer Woyach, MD, assistant professor of Internal Medicine, Division of Hematology, The Ohio State University Comprehensive Cancer Center, discusses the association of disease progression on ibrutinib therapy with the acquisition of resistance mutations.

In this study, 267 patients treated with ibrutinib on three previously-reported trials were analyzed. Among these patients, the rate of relapse was low: 29 patients relapsed after a median follow-up of 20 months. Of these, 17 patients relapsed with Richter’s transformation (RT) while 12 relapsed with chronic lymphocytic leukemia (CLL).

Ten of 10 patients who relapsed with CLL and could be analyzed had mutations that were not present at baseline but were acquired during therapy at BTK and PLCγ2. Among patients who developed RT, 2 of 8 patients had mutations at BTK and PLCγ2 in peripheral blood and had a rising white count. Woyach says these patients may have had progressive CLL as well as RT.

As the association of RT with these mutations is not clear, future trials are planned.