Projects

Tiacci et al. recently reported durable complete responses with the combination of vemurafenib plus rituximab in patients with relapsed and refractory hairy cell leukemia (HCL).[1] Single agent rituximab is also effective in relapsed and refractory HCL.[2] However, 55% (n = 17) of the patients in the study had not received prior rituximab therapy. Hence, independent therapeutic responses attributable to rituximab, vemurafenib, or the combination of both need to be further elucidated.

The reported incidence of the HCL variant (HCLv) in relapsed/refractory cases of HCL is 40%. HCLv has an aggressive course, and the conventional chemotherapeutic agents used in the management of HCL result in poor outcomes in cases of HCLv.[34] HCLv has a similar morphological and immunophenotypic profile to HCL but have unmutated BRAF V600E and immunoglobulin rearrangement IGHV4-34. The efficacy of vemurafenib in unmutated BRAF V600E and IGHV4-34 is unknown. With 19% (n = 6) of cases in the current study being primary refractory to standard chemotherapy with a purine analog, it would be of interest to find out the proportion of cases with HCLv in this study and their responses.