[Sustained complete remission achieved with tofacitinib in a refractory T-cell large granular lymphocytic leukemia].

Introduction: Treatment of large granular lymphocytic leukemia, particularly T-cell leukemia (LGL-T), remains challenging. JAK inhibitors, although still scarcely evaluated, appear promising.

Case report: An 85-year-old woman was treated for a refractory LGL-T associated with neutropenia, unclassified polyarthritis and vitiligo. During the 7-year course of the disease, she received alternatively cyclosporine, cyclophosphamide and methotrexate, associated with prednisone and/or filgrastim. During a severe relapse with agranulocytosis complicated by infectious pneumonia, no response was observed after 14 days of filgrastim. Ten days after initiation of tofacitinib, a marked increase of the neutrophil count (98G/L) occurred, associated with Sweet syndrome. Both resolved rapidly with filgrastim discontinuation. Tofacitinib allowed a rapid and complete remission of both hematological and clinical manifestations, which was maintained throughout 37 months of follow-up.

Conclusion: This report adds to the limited evidence supporting tofacitinib in LGL-T and further highlights the potential of JAK-inhibition, particularly in refractory and systemic forms.