Primary cutaneous large B-cell lymphoma, leg type: Report of two cases and review of literature

While the combination of rituximab and polychemotherapy has improved prognosis of primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT), advanced age of patients limits therapeutic options in relapsing/refractory cases. A multicenter single-arm phase II trial was conducted to assess benefit and safety of lenalidomide in refractory/relapsing PCDLBCL, LT. Primary endpoint was the 6-month overall response rate (ORR). Secondary endpoints were 12-month ORR, overall and specific survival, duration of response, progression-free survival (PFS), safety and identification of prognostic factors. Among the 19 patients included, the 6-month ORR was 26.3% (90%CI, 11-47.6%), including 4 complete responses (CR) and 1 partial response (PR). At 12 months, there were still 2 CR and 1 PR. Median PFS was 4 months. Median overall and specific survivals were 19.4 and 23.8 months. Reduced doses tended to be associated with higher 6-month ORR and PFS. Absence of the MYD88L265Pmutation was associated with a higher overall response under treatment (80.0% vs 33.3%; p=0.05). The most common grade 3 adverse events (AEs) were hematologic. Two grade-5 AEs occurred (sepsis and pulmonary embolism). Lenalidomide at reduced doses may allow prolonged responses in few patients and represents a therapeutic option in relapsing/refractory PCDLBCL, LT.