The index date for patients in the 3L cohort was defined as the date of initiation of 3L therapy. The index date for the T315I cohort was defined as the date of treatment initiation with TKI or allogeneic stem cell transplantation (allo-SCT) after identification of T315I mutation status. The baseline (i.e., pre-index) period was defined as the 6 months prior to the index date, and the post-index period was defined as the time from the index date to the date of last patient contact or patient death. Patients who were alive at the end of the follow-up period were censored at the date of last contact.
A retrospective multi-center cohort study design was used to address the study objectives, using medical records obtained from three clinical centers in France.