Submitted February 7, 2006
Accepted April 7, 2006
Survival advantage from Imatinib compared to the
combination Interferon-
plus Cytarabine in chronic
phase CML: historical comparison between two phase III
trials
Lydia Roy, Joelle Guilhot, Tillmann Krahnke, Agnes Guerci-Bresler, Brian J Druker, Richard A Larson, Stephen G O'Brien, Charlene So, Giorgio Massimini, and Francois Guilhot*
1 Department of Oncology-Hematology and Cell Therapy, EA 3805 and Clinical Research Centre, CHU La M
Novartis Pharma AG, Basel, Switzerland
Department of Hematology, CHU Brabois, Vandoeuvre les Nancy, France
Oregon Health Science University Cancer Institute, Portland, OR, USA
University of Chicago, Chicago, IL, USA
University of Newcastle, Newcastle, United Kingdom
Centre Hospitalier Universitaire De Poitiers
* Corresponding author; email: f.guilhot{at}chu-poitiers.fr.
In the multinational IRIS study comparing imatinib to
interferon plus cytarabine (IFN/AraC) in patients with
newly diagnosed chronic-phase chronic myelogenous
leukaemia (CP CML), imatinib demonstrated significantly
higher rates of complete cytogenetic responses (CCyR)
and improved progression free survival (PFS). However,
because of a high early cross over rate to imatinib,
survival benefit was not assessable. Here we report the
result of a study comparing long term outcome of
patients included in two prospective randomized trials:
551 patients assigned to imatinib in the IRIS trial from
2000 to 2001 and 325 patients who received the
combination IFN/AraC in the CML91 trial between 1991 and
1996 before imatinib was available. With a follow-up of
42 months for both groups of patients, estimated CCyR,
survival free of transformation and overall survival
were significantly higher with imatinib compared with
IFN/AraC (P < .0001, P = .004, and P < .0001
respectively). Improved overall survival was also
confirmed within different Sokal prognostic risk groups.
Interestingly, among all patients who achieved major
cytogenetic response or CCyR at 12 months, the survival
rate was similar irrespective of their treatment. In
conclusion, within the limitation of this historical
comparison, there is a survival advantage from first
line therapy with imatinib over IFN/AraC.
