Blinatumomab in pediatric relapsed/refractory B-cell acute lymphoblastic leukemia: RIALTO expanded access study final...

Area of Science:

• Pediatric Oncology
• Immunotherapy
• Hematologic Malignancies

Background:

• Relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R B-ALL) in children has limited treatment options.
• Blinatumomab, a CD3/CD19-directed bispecific antibody, offers a targeted immunotherapy approach.

Purpose of the Study:

• To evaluate the safety and efficacy of blinatumomab in pediatric patients with R/R B-ALL.
• To assess complete response (CR), measurable residual disease (MRD) response, overall survival (OS), and relapse-free survival (RFS).

Main Methods:

• An open-label, single-arm, expanded access study (RIALTO) enrolled 110 pediatric patients (>28 days to <18 years).
• Patients received up to 5 cycles of blinatumomab via continuous infusion.
• Primary endpoint was adverse event incidence; secondary endpoints included response rates and survival outcomes.

Main Results:

• Low rates of grade 3/4 cytokine release syndrome (1.8%) and neurologic events (3.6%) were observed, with no fatal adverse events.
• Median OS was 14.6 months, significantly higher for MRD responders (not estimable) vs nonresponders (9.3 months).
• 73.5% of CR patients proceeded to allogeneic hematopoietic stem cell transplant (alloHSCT), with higher 1-year OS for those receiving alloHSCT (87% vs 29%).

Conclusions:

• Blinatumomab is a safe and effective treatment for pediatric R/R B-ALL.
• MRD response is a critical predictor of improved survival outcomes.
• Blinatumomab can serve as a bridge to alloHSCT, enhancing long-term survival in pediatric B-ALL.