Vemurafenib As First Treatment Of Hairy Cell Leukemia

44 years old lady presented with fever and pancytopenia in March 2014.CXR showed bilateral pneumonia. Hb 7.5xg/dl, plt 42x x109/l, wbc 1.2 x19neutrophils22%, lymphocytes75%.Circulating lymphocytes with hairy cytoplasmicprojections and indented nuclei were noted. Flow cytometry showed these abnormal lymphoid cells were CD19+ve, CD5-ve, CD 23-ve, FMC7+ve, CD25+ve, CD11c+ve and CD103+ve.Bone marrow biopsy revealed a hypercellular marrow with dense infiltration of lymphoid cells of the same immunophenotype. Braf V600 mutation was detected. Cladribine or pentostatin was out of stock and import of these drugs would take at least 2 months. In view of the severe pancytopenia and on -going infection, various treatment options were discussed with, the patient .Patient decided to start on vemurafenib 960mg twice daily while awaiting cladribine. After 8weeks of treatment, the peripheral blood counts were normalized. Hb 12.2g/dl, plt 153x x109/l, wbc 3.1x109/l, neutrophils 53%,lymphocytes 40%. Braf V600 mutation was no longer detected. Vemurafenib was well tolerated and the patient received treatment mainly as outpatient. Vemurafenib was discontinued after 8 weeks and the patient then received a 5-day course of cladribine. She remained in complete remission