Multicenter phase 3 trial of denileukin diftitox-cxdl for relapsed or refractory cutaneous T-cell lymphoma

Denileukin diftitox (DD)-cxdl is a fusion protein comprising diphteria toxin fragments A and B and human interleukin-2. A multicenter, single-arm phase 3 study evaluated DD-cxdl for patients with stage IA-IIIB relapsed or refractory cutaneous T-cell lymphoma (R/R CTCL). Patients received DD-cxdl 5 days every 21 days for up to eight cycles. The objective response rate was 36.2%, including 8.7% with complete response. The median time to response was 1.4 months, and the median duration of response was 8.9 months. A total of 84.4% of patients showed decreased skin tumor burden, with 48.4% showing a ≥ 50% decrease. Most treatment-emergent adverse events were grade 1 or 2. The authors conclude that these results suggest that DD-cxdl could potentially fulfill a serious, unmet medical need for patients with R/R CTCL.