Alliance A041703 Cohort 1: Inotuzumab ozogamicin followed by blinatumomab in older patients with ND B-ALL

Results from Cohort 1 of the phase II Alliance A041703 study (NCT03739814), evaluating the efficacy of inotuzumab ozogamicin (InO) followed by blinatumomab in 33 older patients (≥60 years) with newly diagnosed Philadelphia chromosome (Ph)-negative B-cell acute lymphoblastic leukemia (B-ALL), were published by Wieduwilt et al. in the Journal of Clinical Oncology. The primary endpoint was 1-year event-free survival (EFS).

Key data: The composite complete remission (CRc) rate was 85% after two cycles of InO and 97% by the end of two cycles of blinatumomab. The median follow-up was 30 months. The 1-year EFS rate was 75% (95% confidence interval [CI], 61–92), and the overall survival (OS) rate was 85% (95% CI, 73–98). Lower CD22 expression and detectable measurable residual disease (MRD) were associated with shorter EFS.

Key learning: InO followed by blinatumomab showed high rates of remission and EFS, supporting its potential as a standard treatment option for older patients with newly diagnosed Ph-negative, CD22-positive B-ALL.