To print: Select File and then Print from your browser's menu --------------------------------------------------------------------------------------- Title: High-Dose Imatinib Followed by Maintenance Not Significantly Different Than Continuous Standard-Dose Imatinib in Patients With Previously Treated Chronic Phase Chronic Myeloid Leukaemia: Presented at EHA URL: http://www.pslgroup.com/dg/223926.htm Doctor's Guide June 15, 2008
By Emma Hitt, PhD COPENHAGEN, Denmark -- June 15, 2008 -- Induction of high-dose imatinib, followed by maintenance imatinib, produces similar outcomes to that of continuous standard-dose imatinib in previously treated patients with chronic-phase chronic myeloid leukaemia (CML), according to interim findings from the Imatinib Standard Dose Versus High Dose Induction Trial (ISTAHIT) study. Andreas L. Petzer, MD, Innsbruck and Hospital BHS Linz; Central European Leukaemia Study Group (CELSG), Innsbruck, Austria, and colleagues, reported the interim findings of this multicentre, randomised, open-label, phase 3 trial on June 15 at the 13th Congress of the European Hematology Association (EHA). Between February 2004 and December 2006, 227 pretreated Ph+/BCR-ABL+ patients with chronic-phase CML were randomised in a 1-to-1 ratio to receive continuous standard-dose imatinib 400 mg QD (SD arm) or high-dose imatinib 800 mg QD (HD arm) for 6 months followed by a maintenance dose of imatinib 400 mg QD. The researchers performed the first planned interim analysis after 50% of the patients had been treated for 12 months after randomisation. All patients were imatinib-naive, although they could have received other prior treatment for at least 12 months before study entry. Pretreatment of patients included hydroxyurea, interferon, and busulfan in about 97%, 70%, and 20% of patients in both arms. The median age of the patients was approximately 46 years, and median duration of CML was about 26 to 27 months. The median follow-up at the time of interim analysis was 12.75 months (range, 3-24 months). Rates of major cytogenetic response (MCyR) at 48 weeks, the primary endpoint, were not significantly different between arms at 58.9% (SD arm) versus 56.5% (HD arm). However, high-dose imatinib followed by maintenance imatinib resulted in a significantly higher MCyR at 12 weeks (20.6% vs 37.3%, P = .01) and 24 weeks (33.8% vs 53.8%, P = .009). Rates of complete haematologic remission at 48 weeks were also not significantly different between arms, with 82% in the SD arm versus 90% in the HD arm. Rates of complete cytogenetic response (CCyR) were significantly higher in the HD arm compared with the SD arm at week 12 (24.5% vs 6.2%, P < .001) and week 24 (43.8% vs 19.8%, P < .001), but not at week 48 (47.8% vs 37.3%, P = .29). Rates of major molecular response (MMR) were significantly higher in the high-dose arm compared to the standard-dose arm at week 24 (20.3% vs 8.2%, P = .034). However, at week 48, there was no significant difference between arms with 25% (HD arm) and 17.5% (SD arm) achieving this endpoint. Haematologic toxicity was more common in patients receiving high-dose imatinib. Anaemia was noted in 2% of the SD group versus 14% of the HD group B (P = .02), leukopenia in 24% versus 46% (P = .02) and thrombocytopenia in 15% versus 39% (P = .003). "Despite high rate of grade 3/4 leukopenias in the high-dose arm, the incidence of grade 3/4 infections was low in both arms (2% vs 3% in the standard vs high-dose arms, respectively)," Dr. Petzer said. He added that the major cytogenetic response at 12 months was not yet statistically significantly different, "but there was still a clear trend to higher rates of CCyR and MMR in the experimental high-dose arm," Dr. Petzer concluded. [Presentation title: High Doses of Imatinib Mesylate (800mg/day) Significantly Improve Rates of Major and Complete Cytogenetic Remissions (MCR, CCR) - Results From the First Planned Interim Analysis of a Multicenter, Randomised, 2-Arm - Phase III Study Comparing Imatinib Standard Dose (400 mg/day) With Imatinib High Dose Induction (800 mg/day) Followed by Imatinib Standard Dose Maintenance (400 mg/day) in Pretreated Ph+/BCR-Abl-, Abl+ CML Patients in Chronic Phase. Abstract 407.] --------------------------------------------------------------------------------------------- Copyright © 1999 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content. --------------------------------------------------------------------------------------------- This news story was printed from *Doctor's Guide to the Internet* located at http://www.docguide.com --------------------------------------------------------------------------------------- Return to News Story Page This site is maintained by webmaster@pslgroup.com Please contact us with any comments, problems or bugs. All contents Copyright (c) 1998 P\S\L Consulting Group Inc. All rights reserved.