FDA Grants Approval to Inotuzumab Ozogamicin for Pediatric Patients With R/R CD22-Positive B-Cell Precursor ALL

On March 6, 2024, the Food and Drug Administration (FDA) approved inotuzumab ozogamicin for pediatric patients ages 1 year or older with relapsed/refractory (R/R) CD22-positive B-cell precursor acute lymphoblastic leukemia (ALL). 

This approval is based on results from a multicenter, single-arm, open-label study. In this study, a total of 53 pediatric patients ages 1 year and older with R/R CD22-positive B-cell precursor ALL were enrolled and assigned to 1 of 2 groups. The 12 patients in the first group received an initial dose of inotuzumab ozogamicin at 1.4 mg/m2  /cycle, and the 41 patients in the second group received an initial dose at 1.8 mg/m2/cycle. Patients also received premedication, including methylprednisolone at 1 mg/kg (maximum of 50 mg), an antipyretic, and an antihistamine. A median of 2 therapy cycles was administered to all patients. 

The study authors aimed to assess complete remission (CR), which was defined as less than 5% blasts in the bone marrow and the absence of peripheral blood leukemia blasts, full recovery of peripheral blood counts (platelets ≥ 100 × 109 and ANC ≥1 × 109/L), and the resolution of extramedullary disease. They also aimed to assess the duration of CR and the proportion of patients with minimal residual disease (MRD)-negative CR, with MRD defined as leukemic cells making up < 1 × 10-4 (< 0.01%) of bone marrow nucleated cells by flow cytometry or by polymerase chain reaction (PCR). 

Results indicated that 42% (n = 22) of total patients achieved CR with a median duration of 8.2 months (95% confidence interval [CI]). Among the 22 patients who achieved a CR, results showed that 21 patients achieved MRD-negativity based on flow cytometry, and 19 based on real-time quantitative reverse transcriptase polymerase chain reaction [(RQ)-PCR]. 

Regarding safety, the most prevalent adverse reactions (≥20%) to occur were thrombocytopenia, pyrexia, anemia, vomiting, infection, hemorrhage, neutropenia, nausea, leukopenia, febrile neutropenia, increased transaminases, abdominal pain, and headaches. 

Source: 

FDA approves inotuzumab ozogamicin for pediatric patients with acute lymphoblastic leukemia. Published online: March 6, 2024. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-inotuzumab-ozogamicin-pediatric-patients-acute-lymphoblastic-leukemia