Long-Term Outcome of Imatinib Treatment in Chronic Myeloid Leukemia (CML) Patients in Shanghai: An International Patient Assistance Programs (GIPAP) Analysis.

Abstract 4275

Imatinib as an oral Bcr-Abl tyrosine kinase inhibitor is approved as first-line therapy for patients with CML chronic phase (CP), accelerated phase (AP) and blast crisis (BC). As the appointed clinical center for the International Patient Assistance Programs (GIPAP) program, a total of 339 CML patients with CML-CP (n=274), AP (n=30) and BC (n=35) were registered and received imatinib treatment in our center. The starting dose of Imatinib treatment was 400mg daily and dose escalation to 600mg was allowed in patients of CML-AP or BC and in patients who failed to obtained optimal response. All patients were evaluated regularly according to the GIPAP protocol. In this study, we analysed the outcome of Imatinib treatment in these patients in terms of cytogenetic response, overall and progression-free survival and adverse events. The median age was 42 (13-81) years old. The median time from diagnosis to imatinib therapy was 4.4 (0-273) months. The median follow-up was 29 (3-103) months. The overall survival for patients received Imatinib treatment were 92.8±3.1%, 57.3+11.3% and 12.3±9.7% for CML-CP, AP and BC respectively. Among patients with CML-CP, the cumulative complete cytogenetic response (CCyR) were 71.9% at 12 months and 79.9% at the censored follow-up timepoint. In prognosis analysis, there were two major impact factors associated with progression-free survival (PFS) for the CML-CP patients: achievement of CcyR and Imatinib as initial therapy. The estimated 60 month PFS was 87.1±3.7% for patients who achieved a CCyR irrespective of time and only 46.7±1.37% for patients who failed to obtain a CCyR (P<0.0001). For those patients who received imatinib as initial therapy (95.6±1.85%) had a significantly superior PFS than those patients received imatinib as secondary treatment after initial interferon therapy either due to intolerance or failed to obtain optimal response (65.9±6.4%, P<0.0001). Overall Imatinib was well tolerated and no patient switched to other treatment due to toxicity of Imatinib treatment. Overall, Imatinib as initial treatment for CML-CP was effective and safe in the first analysis of GIPAP program in Shanghai.