Efficacy of nilotinib in a patient relapse after 9 years of imatinib treatment and in stable complete cytogenetic response

Abstract

We report a case of a patient with chronic myeloid leukemia in chronic phase who was treated with interferon-alpha plus low dose of cytarabine for 5 years, achieving a partial cytogenetic response. In 2000, he started imatinib at 400 mg/day obtaining rapidly a complete cytogenetic response (CCyR) (after 6 months of treatment) and a “near” major molecular response (MMolR) with BCR-ABL transcript level waving from 0.13 to 0.15% (BCR-ABL/ABL%) during molecular follow-up performed in the subsequent 6 years. To further improve his molecular response, we associated to TKI an immune target therapy with a BCR-ABL derived peptide vaccine developed by us, obtaining a MMolR, confirmed during the following 12 months from the beginning of the vaccinations. Surprisingly, at 9 years from starting imatinib, we documented the loss of MMolR and CCyR. Clonal evolution, kinase domain mutations and reduced drug intake were excluded, thus the patient switched to nilotinb at 400 mg/BID: after 3 months of treatment he achieved CCyR and MMolR and after 6 months we documented also a complete molecular response (CMolR).