Evaluating the Toxicity Profile of Parsaclisib in Mantle Cell Lymphoma

Amitkumar Mehta, MD, an associate professor at the University of Alabama at Birmingham Comprehensive Cancer Center, discusses the toxicity profile of the first-in-class PI3Kδ inhibitor parsaclisib, according to findings from this agent in the phase 2 CITADEL-205 clinical trial (NCT03235544) of relapsed/refractory mantle cell lymphoma (MCL).

Parsaclisib is a highly specific PI3Kδ inhibitor compared with the other PI3Kδ inhibitors, and it was designed to reduce transaminitis as a side effect, says Mehta. This study aimed to explore the efficacy and safety of this therapy.

Overall, the occurrence of transaminitis was very low, especially in terms of grade 3/4 toxicity, which occurred in about 3% to 4%. Diarrhea was observed, which is a known class side effect, according to Mehta. Grade 3 or higher diarrhea occurred in about 13% of patients in the study, and for about half of the patients, this was reason for discontinuation.

Mehta says physicians have learned to be proactive about this side effect. If a patient has diarrhea, physicians should act quickly to manage it.