Report of an international expanded access program of imatinib in adults with Philadelphia chromosome positive leukemias

Background: Imatinib is a selective inhibitor of the BCR/ABL tyrosine kinase. The remarkable initial results of the first phase I clinical trial published in 1999 prompted the rapid initiation of large phase II trials. They also generated intense media coverage and significant interest from patients and clinicians and demand for access to imatinib before marketing approval. In response, a worldwide expanded access program (EAP) for imatinib was implemented in May 2000. Patients: In total, 7380 patients with chronic myeloid leukemia (CML) and acute lymphoblastic leukemia failing prior therapies were enrolled in 106 centers in 34 countries. Results: Time to progression and overall survival, as well as the safety profile, were similar to those observed in published phase II studies. At the end of the program, patients benefiting from treatment were continued on imatinib therapy by transferring to national health care systems or patient assistance programs. Conclusion: The imatinib EAP successfully provided therapy to patients with CML before marketing approval. The program provides an efficient framework for the development of global EAPs for innovative investigational anticancer agents in patients without a satisfactory therapeutic alternative.