Inotuzumab ozogamicin receives U.S. FDA approval for pediatric patients aged ≥1 year with CD22+ R/R B-ALL

On March 6, 2024, it was announced that the U.S. Food and Drug Administration (FDA) had approved inotuzumab ozogamicin for the treatment of pediatric patients aged 1 year and older with relapsed/refractory (R/R) CD22-positive B-cell precursor acute lymphoblastic leukemia (B-ALL). This approval is based on results from a multicenter, single-arm, open-label study.

The study included a total of 53 patients who were evaluated at two dose levels: (1) initial dose of 1.4 mg/m²/cycle (n = 12); and (2) 1.8 mg/m²/cycle (n = 41).

The key outcomes were as follows:

• A complete remission (CR) rate of 42% was achieved in all patients.
• A median duration of CR of 8.2 months was demonstrated.
• An MRD negativity rate of 95.5% was reported based on flow cytometry and 86.4% based on real-time quantitative polymerase chain reaction for patients who achieved a CR.
• The most commonly reported adverse reactions were: thrombocytopenia, pyrexia, anemia, vomiting, infection, hemorrhage, neutropenia, nausea, leukopenia, febrile neutropenia, increased transaminases, abdominal pain, and headache.

For the first cycle, the U.S. FDA has recommended an inotuzumab ozogamicin dose of 1.8 mg/m² per cycle given as 3 fractionated doses on Day 1 (0.8 mg/m²), Day 8 (0.5 mg/m²), and Day 15 (0.5 mg/m²).