In commenting on the results of the phase II PRIMO trial of the PI3K inhibitor duvelisib by Pro et al, Deepa Jagadeesh, MD, MPH, Assistant Professor, Cleveland Clinic Lerner College of Medicine, Lymphoma and Bone Marrow Transplant Program, and Taussig Cancer Institute, observed that while response rates were higher with the 75-mg dose in the dose-optimization phase, preliminary data from the modified treatment schedule in the expansion phase showed comparable efficacy: an overall response rate of 52% and a complete response rate of 36%. However, 80% of patients discontinued treatment, primarily due to disease progression.

Deepa Jagadeesh, MD, MPH

“The clinical efficacy with duvelisib is intriguing, since the response rate with currently approved agents in relapsed/refractory T-cell lymphoma is around 30%. As with most PI3K inhibitors, the key challenge remains in identifying an optimal dose schedule with manageable toxicity, without compromising efficacy and duration of response,” she concluded. 

DISCLOSURE: Dr. Jagadeesh has served in a consulting or advisory role for Atara Biotherapeutics, Kyowa Hakko Kirin, Seattle Genetics, and Verastem; has participated in a speakers bureau for Verastem; and has received institutional research funding from Seattle Genetics, Regeneron Pharmaceuticals, Debiopharm, Trillium, ADC Therapeutics, Rhizen Pharmaceuticals, AstraZeneca, and MEI Pharma.