Update On Imatinib-Resistant Chronic Myeloid Leukemia Patients in Chronic Phase (CML-CP) On Nilotinib Therapy at 24 Months: Clinical Response, Safety, and Long-Term Outcomes.

Abstract

Abstract 1129 Poster Board I-151 Background Nilotinib is a selective and potent BCR-ABL inhibitor, developed through structure-based drug design, indicated for the treatment of Philadelphia chromosome positive (Ph+) CML patients in CP or accelerated phase (AP) resistant or intolerant to prior therapy including imatinib. Recently, 24-month follow-up data from the pivotal nilotinib 2101 study demonstrated achievement of rapid and durable cytogenetic responses in the majority of patients and an excellent overall survival (OS) rate of 87%. The current update focuses on the major molecular response (BCR-ABL transcript levels ≤ 0.1% according to the international scale; MMR) of patients treated with nilotinib. Methods Imatinib-resistant and -intolerant CML-CP patients (n=321) were treated with nilotinib 400 mg twice daily and followed for at least 24 months. In this report, the efficacy parameters studied were: rate of MMR, rate of major and complete cytogenetic response (MCyR, CCyR), time to and duration of response, time to progression (TTP), and OS. Efficacy parameters were also analyzed based on the presence or absence of a CHR at study entry. Results The median duration of exposure to nilotinib was 18.7 months ( Conclusions Nilotinib therapy led to the achievement of MMR in a majority of patients with CCyR, and in 38% of patients with CHR at study entry. Furthermore, the response and outcomes of patients treated with nilotinib was higher in patients with CHR at baseline suggesting that patients with imatinib resistance and intolerance who lost cytogenetic response but not hematologic response have a more favorable response compared to those patients who have lost hematologic response when switched to nilotinib. Overall, the safety profile of nilotinib remains well-tolerated with long-term follow-up. At 24 months, nilotinib therapy remains an effective and tolerable therapy for patients with imatinib-resistant or -intolerant CML. Disclosures Kantarjian:Novartis: Research Funding. Giles:Novartis: Consultancy, Research Funding; BMS: Research Funding; Merck: Research Funding; Clavis: Research Funding. Bhalla:Novartis: Honoraria, Research Funding; Merck: Honoraria. Pinilla-Ibarz:Novartis: Membership on an entity9s Board of Directors or advisory committees, Research Funding, Speakers Bureau. Larson:Novartis: Consultancy, Honoraria, Research Funding. Gattermann:Novartis, Celgene: Honoraria, Participation in Advisory Boards on deferasirox clinical trials, Research Funding. Ottmann:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding. Hochhaus:Novartis: Research Funding. Radich:Novartis: Consultancy, Honoraria, Research Funding. Saglio:Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau. Hughes:Bristol-Myers Squibb: Advisor, Honoraria, Research Funding; Novartis: Advisor, Honoraria, Research Funding. Martinelli:Novartis: Research Funding. Kim:Novartis: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity9s Board of Directors or advisory committees, Research Funding; Wyeth: Research Funding. Shou:Novartis: Employment. Gallagher:Novartis: Employment, Equity Ownership. Wang:Novartis: Employment. Cortes-Franco:Novartis: Honoraria, Research Funding, Speakers Bureau; Wyeth: Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria, Research Funding, Speakers Bureau. Baccarani:Novartis Pharma: Consultancy, Honoraria, Research Funding, Speakers Bureau; Bristol-Mayer Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau. le Coutre:Novartis: Honoraria, Research Funding; BMS: Honoraria.