Dr. Kaplan on the Use of PI3K Inhibitors in Follicular Lymphoma

Lawrence D. Kaplan, MD, clinical professor of medicine, director, Adult Lymphoma Program, Division of Hematology-Oncology, University of California, San Francisco (UCSF) Helen Diller Family Comprehensive Cancer Center, discusses the use of PI3K inhibitors in follicular lymphoma.

Three PI3K inhibitors—idelalisib (Zydelig), duvelisib (Copiktra), and copanlisib (Aliqopa)—are approved for use in patients who have received ≥2 prior lines of therapy; all have shown response rates in the 50% range, says Kaplan. However, PI3K inhibitors, as a class, are associated with significant toxicities.

Idelalisib and duvelisib are oral drugs; however, they both have black box warnings on the FDA prescribing information for autoimmune toxicities, such as hepatotoxicity, noninfectious pneumonitis, diarrhea, and colitis. A significant number of patients will experience these toxicities. For example, at least 25% of patients will experience grade ≥3 autoimmune toxicities, says Kaplan. As such, one has to be prepared to intervene, if necessary, to control those toxicities.