Efficacy of ruxolitinib in the treatment of relapsed/refractory large granular lymphocytic leukaemia

Abstract

SummaryLarge granular lymphocytic (LGL) leukaemia is a rare chronic lymphoproliferative disorder characterized by an expansion of cytotoxic T or NK cells. Despite a usually indolent evolution, most patients will require a treatment over the course of the disease because of cytopenia or symptomatic associated autoimmune disorders. First‐line treatment is based on immunosuppressive agents, namely cyclophosphamide, methotrexate and ciclosporin. However, relapses are frequent, and there is no consensus on the management of relapsed/refractory patients. The implication of the JAK/STAT pathway in the pathogenesis of this disease has prompted our group to propose treatment with ruxolitinib. A series of 21 patients who received this regimen is reported here. Ten patients (47.6%) were refractory to the three main immunosuppressive drugs at the time of ruxolitinib initiation. Ruxolitinib yielded an overall response rate of 86% (n = 18/21), including 3 complete responses and 15 partial responses. With a median follow‐up of 9 months, the median response duration was 4 months. One‐year event‐free survival and 1‐year overall survival were 57% and 83% respectively. Mild side effects were observed. Biological parameters, notably neutropenia and anaemia, improved significantly, and complete molecular responses were evidenced. This study supports ruxolitinib as a valid option for the treatment of relapsed/refractory LGL leukaemia.