FDA approves inotuzumab ozogamicin for pediatric patients with acute lymphoblastic leukemia
Regulatory approval: On March 6, 2024, the FDA approved inotuzumab ozogamicin (Besponsa; Pfizer) for pediatric patients aged ≥1 year with relapsed or refractory CD22-positive B-cell precursor acute lymphoblastic leukemia. Approval was based on a multicenter, single-arm, open-label study (n=53) reporting a complete remission (CR) rate of 42% with a median CR duration of 8.2 months; most CRs were MRD-negative by flow cytometry and/or PCR.
FDA approval: inotuzumab ozogamicin for pediatric r/r CD22+ B-cell precursor ALL
Type: Regulatory approval
Agency/date: US FDA, 2024-03-06
Product: Inotuzumab ozogamicin (Besponsa; Pfizer)
Indication: Pediatric patients ≥1 year with relapsed or refractory CD22-positive B-cell precursor acute lymphoblastic leukemia (ALL).
Key efficacy evidence
Efficacy was evaluated in a multicenter, single-arm, open-label study of 53 pediatric patients (≥1 year) with relapsed/refractory CD22+ B-cell precursor ALL. Two starting dose levels were studied (1.4 mg/m²/cycle in 12 patients; 1.8 mg/m²/cycle in 41 patients). Median treatment was 2 cycles (range 1–4).
Primary outcomes included complete remission (CR), duration of CR, and MRD-negative CR. Across all patients, 22/53 achieved CR (42%; 95% CI 28.1–55.9); median CR duration was 8.2 months (95% CI 2.6–NE). Among patients with CR, MRD negativity was 21/22 (95.5%) by flow cytometry and 19/22 (86.4%) by RQ-PCR.
Safety and dosing highlights
Common adverse reactions (≥20%), including laboratory abnormalities, included thrombocytopenia, pyrexia, anemia, vomiting, infection, hemorrhage, neutropenia, nausea, leukopenia, febrile neutropenia, increased transaminases, abdominal pain, and headache.
For cycle 1, recommended dosing is 1.8 mg/m² per cycle in 3 divided doses (Day 1: 0.8; Day 8: 0.5; Day 15: 0.5 mg/m²). The application received priority review and orphan drug designation.