Nilotinib

Nilotinib is an orally administered BCR-ABL tyrosine kinase inhibitor that has shown good clinical efficacy in imatinib-resistant or -intolerant, Philadelphia chromosome-positive, chronic myeloid leukaemia (CML) in a phase I/II trial. The phase I component of the trial established the dosage regimen used in the phase II part of the trial, which included several arms. Three of these arms, or phase II trials, evaluated nilotinib in each of the three phases of CML (chronic, accelerated or blast crisis).I n the phase II trial in patients with chronic-phase CML, major cytogenetic response (primary endpoint) was achieved in 48% of the 280 patients who received nilotinib and had a follow-up period of > or = 6 months. Major cytogenetic response rates did not differ between imatinib-resistant and -intolerant patients, and nilotinib was effective in patients with BCR-ABL mutations (except T315I). Haematologic response rate (primary endpoint) was 47% in the phase II trial with nilotinib in patients with accelerated-phase CML (n = 119). Complete haematologic response was achieved in 26% of patients and 21% had no evidence of leukaemia or returned to chronic-phase CML. Major cytogenetic response, an important secondary endpoint in the trial, occurred in 29% of patients. Data from the phase II trial in patients with CML in blast crisis (n = 135) also showed promising results, with 39% of patients achieving haematologic response with nilotinib. Adverse events reported with nilotinib have generally been of mild to moderate severity. Grade 3 or 4 neutropenia and thrombocytopenia were reported in 29% of patients each.