Submitted February 17, 2006
Accepted May 2, 2006
Survival Benefit with Imatinib Mesylate versus Interferon Alpha-Based Regimens in Newly Diagnosed Chronic Phase Chronic Myelogenous Leukemia
Hagop M. Kantarjian*, Moshe Talpaz, Susan O'Brien, Daniel Jones, Francis Giles, Guillermo Garcia-Manero, Stefan Faderl, Farhad Ravandi, Mary Beth Rios, Jianqin Shan, and Jorge Cortes
Departments of Leukemia,University of Texas M. D. Anderson Cancer Center
Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center
Departments of Leukemia, U.T. MD Anderson Cancer Center
Hematopatology, University of Texas M. D. Anderson Cancer Center
Departments of Leukemia, University of Texas M. D. Anderson Cancer Center
Departments of Leukemia,, University of Texas M.D. Anderson Cancer Center
Departments of Leukemia, The University of Texas M.D. Anderson Cancer Center
Departments of Leukemia,, University of Texas - M. D. Anderson Cancer Center
Departments of Leukemia,, The University of Texas M.D. Anderson Cancer Center
Departments of Leukemia,, UT MD Anderson Cancer Center
* Corresponding author; email: hkantarj{at}mdanderson.org.
A survival benefit for imatinib mesylate versus interferon-
therapy could not be demonstrated in the randomized study in newly diagnosed Philadelphia chromosome (Ph)-positive chronic phase chronic myelogenous leukemia (CML) due to the high rate of cross over (90%) from interferon- to imatinib within a year of study entry. We compared survival in 279 patients with newly diagnosed CML treated with imatinib at our institution (2000 - 2004) to 650 patients treated with interferon- (1982 - 1997). The complete cytogenetic response rates were 87% with imatinib and 28% with interferon- (p < 0.0001). The estimated 3-year survival rates were 96% with imatinib and 81% with interferon- (p < 0.01). Survival rates with imatinib were significantly better than with interferon- within each of the CML prognostic risks groups. By multivariate analysis, imatinib therapy was identified as an independent favorable prognostic factor, after accounting for the impact of pretreatment factors (hazard ratio 0.04; p < 0.01). By landmark analysis at 12 months, survival within each cytogenetic response category was similar with imatinib or interferon-, suggesting that the survival benefit of imatinib (versus interferon- in newly diagnosed CML) is through improving cytogenetic response.
