Inotuzumab Ozogamicin Effective in Pediatric ALL Population

Inotuzumab ozogamicin, a CD22-directed antibody conjugated to calicheamicin, was effective in a pediatric population with relapsed/refractory acute lymphocytic leukemia (ALL), according to a phase II study.

Inotuzumab ozogamicin is currently approved for adults with relapsed/refractory B-cell ALL. This study looked at patients aged 1-18 years with CD22-positive disease.

A total of 32 patients were enrolled: 28 were treated, and 27 were evaluable for response. Patients received inotuzumab ozogamicin 1.8 mg/m².

Estimated overall response rate was 81.5%. The majority of responders (81.8%) were minimal residual disease-negative. With a median follow-up of 16 months, the 1-year event-free survival was 36.7% and overall survival was 55.1%. No clinical characteristics were found to be related to survival outcomes.

All patients had at least one adverse event, the most common of which was fever (57.1%). Seven patients (25%) experienced sinusoidal obstructive syndrome.

Inotuzumab ozogamicin is currently being assessed as a front-line treatment by the Children’s Oncology Group in a phase III, randomized trial for high-risk CD22-positive B-cell ALL.

Pennesi E, Michels N, Brivio E, et al. Inotuzumab ozogamicin as single agent in pediatric patients with relapsed and refractory acute lymphoblastic leukemia: results from a phase II trial. Leukemia. 2022. doi:10.1038/s41375-022-01576-3