Second-line Dasatinib Therapy Improved Compliance and Deep Molecular Responses in Imatinib-intolerant Chronic Myeloid Leukemia Patients.

Abstract

Imatinib (IM) is the standard-of-care treatment for most chronic myeloid leukemia (CML) patients in chronic phase (CP). However, some patients suffer from low-grade side-effects that, in the long run, severely affect the quality of life and require treatment discontinuation due to toxicities. Fortunately, there are several therapeutic alternatives for these patients. Among them, the second-generation tyrosine kinase inhibitor dasatinib (DAS), used as second-line treatment, has shown to be a valid option in patients with CP-CML after intolerance to prior IM. Herein, we report on seven CP-CML patients who achieved a stable major molecular response (MMR) with IM-therapy, but were shifted to DAS treatment due to recurrent low-grade IM-intolerances (grades 1-2). All patients received conventional DAS treatment with a median daily dose of 83.3 mg. Treatment was well tolerated and side-effects were mild. In addition, after a median follow-up of 25 months (range=24-43 months) a deep molecular response (DMR) (either MR4 or MR4.5) was achieved in all patients after 24 months of treatment. This finding, although limited to a small cohort of CP-CML patients, supports the view that a therapy switch from IM to DAS induces a reduction of symptom burden, improves patient compliance and shows clinical efficacy in achieving and sustaining deep molecular responses.