The differential effect of lenalidomide monotherapy in patients with relapsed or refractory transformed non-Hodgkin lymphoma of distinct histological origin.

Transformed lymphoma (TL) represents a heterogeneous group of lymphomas with an aggressive course and poor prognosis. We assessed the clinical benefit of single-agent lenalidomide based on histological origin, including transformed follicular lymphoma (tFL) and transformed chronic lymphocytic leukaemia/small lymphocytic lymphoma (tCLL/SLL). Our analysis included 33 patients with TL. Patients received lenalidomide at a median dose of 25 mg/d. The overall response rate (ORR) was 46%, with a median response duration of 12·8 months after a median follow-up of 5·6 months. Median progression-free survival was 5·4 months. Among patients with tFL, ORR was 57%, with a median response duration of 12·8 months. None of the patients with tCLL/SLL responded to lenalidomide monotherapy. The most common grade 3/4 adverse events were reversible myelosuppression. Our results suggest that the original lymphoma histology (i.e. FL) in TL patients may potentially be associated with response to salvage lenalidomide monotherapy.