Mek-kinase inhibitor as a treatment option for hairy cell leukemia

Introduction. Hairy cell leukemia (HCL) is a chronic indolent B-cell lymphoproliferative disease with a good response to treatment in most cases. However, despite successful treatment, there remains a group of patients with a resistant/recurrent course of the disease, a short remission after treatment, and with contraindications to standard therapy. The use of the RASRAF-MEK-ERK pathway inhibitor in the V600E marker mutation of the BRAF gene may prove to be an effective treatment option for complicated/resistant cases of HCL. Aim - to present the results of the use MEK-kinase inhibitor trametinib in the treatment of HCL. Main findings. The MEK-kinase inhibitor trametinib was used at a dose of 1 mg/day for 3 months in three patients. In two patients trametinib was used as preliminary stage before the main course of treatment with cladribine. In one patient with a resistant/relapsing course of HCL, trametinib monotherapy made it possible to achieve a good partial remission, and the treatment continues without a decrease in the quality of life. Conclusion. Trametinib can be used as a preliminary stage before analogous purine treatment in patients with HCL without the BRAF V600E mutation, in a case of deep neutropenia or infectious complications, and as the main antitumor therapy in patients with resistant/recurrent HCL. Trametinib is effective in the absence of the MAP2K1 mutations. Trametinib monotherapy can be effective at a reduced dosage (1 mg/day or 1 mg every other day).