Duvelisib was administered twice daily in combination with nivolumab and was evaluated across 2 dosing schedules. Patients initially received duvelisib continuously on days 1 to 28 at dose levels of 25 mg, 50 mg, and 75 mg twice daily; after DLTs emerged, an intermittent schedule of duvelisib on days 1 to 14 was evaluated at the same dose levels.
The primary end points were to determine the recommended phase 2 dose or maximum tolerated dose and the ORR at 4 months.
Among 19 patients enrolled, the median age was 66 years (range, 38-75), and 53% were male. The most common disease stage was IVA (53%), followed by IIB (26%). Patients had received a median of 5 prior therapies (range, 1-22), and the median time from diagnosis to study treatment was 30 months (range, 6-256).
Duvelisib Plus Nivolumab in Pretreated CTCL: Key Findings
- The combination elicited an ORR of 26% (n = 19), with all responses occurring in patients with MF (36%) and none in patients with SS.
- Grade 3 or higher transaminitis occurred in 58% of patients, and 43% developed rash.
- Investigators did not recommend the combination of duvelisib and nivolumab in patients with CTCL.
What else did the safety analysis show?
Recurrent toxicities included grade 3 or higher transaminitis in 58% of patients (11/19) and rash in 43% (8/19); no patient experienced grade 3 or higher diarrhea.
Reported grade 3 AEs included transaminitis (28%), rash/erythroderma (11%), and fatigue (6%), and grade 4 AEs included transaminitis (17%) and Stevens-Johnson syndrome (6%). Grade 3 infections occurred in 22% of patients, including sepsis (11%), skin infection (6%), CMV reactivation (6%), and osteomyelitis (6%).
Eleven patients discontinued therapy because of an AE, with the most common being transaminitis (n = 6). One patient each discontinued treatment due to pneumonitis, sepsis, Stevens-Johnson syndrome, Pseudomonas infection, and pancreatitis. An additional 4 patients discontinued because of disease progression, and 3 discontinued because of patient withdrawal. Among patients who discontinued for toxicity, the median time to next treatment was 8 weeks (range, 0-125).
References
- Mehta-Shah N, Payton J, Fischer A, et al. A phase 1 study of duvelisib in combination with nivolumab in relapsed/refractory cutaneous T-cell lymphoma. Presented at: 6th World Congress on Cutaneous Lymphomas; June 25-27, 2026; Montreal, Quebec, Canada.
- Duvelisib and nivolumab for the treatment of stage IIB-IVB mycosis fungoides and Sezary syndrome. ClinicalTrials.gov. Updated June 23, 2026. Accessed June 27, 2026. https://clinicaltrials.gov/study/NCT04652960