Study screening flowchart for cohort selection. All adult (age ≥18) patients with confirmed Ph⁺ ALL and available clinical records at participating centers were screened for inclusion. Patients were identified via pathology reports and, where available, querying institutional leukemia- and transplant-specific databases. As described in the “Methods,” patients were excluded if they died or were lost to follow-up before day 90, had a prior diagnosis of CML, failed to achieve CR or complete molecular remission (CMR) prior to day 90 or, having achieved CR or CMR, experienced molecular or morphologic relapse prior to day 90. Patients without sufficient testing to establish CMR were also excluded. Furthermore, to improve cohort homogeneity, patients who achieved CR1/CMR prior to day 90 and underwent allo-HCT in remission after day 210 were excluded. Created with BioRender.com.