FDA Expands Blinatumomab Approval in Early-Stage CD19+ B-ALL

Blood cancer cells under the microscope: © stock_acc - stock.adobe.com

• Blinatumomab (Blincyto) is a monoclonal antibody for the treatment of patients with CD19-positive, B-cell precursor acute lymphoblastic leukemia (B-ALL).
• This approval marks the third indication for blinatumomab in ALL.
• The approval is supported by findings from the phase 3 E1910 study (NCT02003222). 

The FDA has granted approval to blinatumomab for the treatment of patients with CD19-positive B-ALL.¹

Blinatumomab has been approved for patients with Philadelphia chromosome-negative relapsed or refractory B-ALL and B-ALL in first or second complete remission with positive minimal residual disease (MRD).

The approval is supported by data from the phase 3 E1910 study, which was sponsored by the National Cancer Institute and ECOG-ACRIN Cancer Research Group. Adding blinatumomab to consolidation chemotherapy showed a significant improvement in overall survival (OS) in the intent-to-treat population, according to findings presented at the 2022 American Society of Hematology Annual Meeting.² 

After a median follow-up of 43 months, the median OS was not reached in the chemotherapy plus blinatumomab arm compared with 6 years in the control arm(HR, 0.42; 95% CI, 0.24-0.75; P =.003). The rate of morphologic complete remission following induction chemotherapy was 81%, and no new safety concerns were identified.³

About the Phase 3 E1910 Study of Blinatumomab in B-ALL

E1910 is a phase 3 randomized study evaluating combination chemotherapy with blinatumomab compared with induction chemotherapy in patients with B-ALL.⁴ The study’s primary end point is OS, and secondary end points include relapse-free survival, MRD status, and incidence of adverse events. Another exploratory end point is identification and characterization of the BCR/ABL1-like phenotype.

Patients across 77 clinical sites in the United States, Canada, and Israel were randomized to receive chemotherapy with or without blinatumomab. As of December 2023, 488 patients were enrolled in the trial. Patients were eligible for participation if they were between 30 and 70 years old, negative for Philadelphia chromosome, had no history of myocardial infarction, and had an ECOG performance status of 0 to 2.

Exclusion criteria included mature B-ALL diagnosis, concurrent active malignancy, antecedent hematologic disorder, or clinically relevant central nervous system pathology.

All patients received 2.5 months of combination chemotherapy induction, and patients who were positive for B-lymphocyte antigen CD20 were also treated with rituximab (Rituxan).³ Following this step, 333 of 488 patients moved onto the next step of treatment, while the rest discontinued.

Next, patients received therapy to stop leukemia from developing in the central nervous system. Patients were then tested for MRD, and 224 were MRD-negative. A total of 224 MRD-negative and 62 MRD-positive patients were randomized to receive 4 cycles of consolidation chemotherapy with or without blinatumomab. 

Patients then proceeded to a maintenance phase where they received mercaptopurine, vincristine, methotrexate, and prednisone, a common regimen for keeping ALL in remission, for about 2 years.

REFERENCES:

1. FDA approves blinatumomab as consolidation for CD19-positive Philadelphia chromosome-negative B-cell precursor acute lymphoblastic leukemia. News release. FDA. June 14, 2024. Accessed June 14, 2024. https://tinyurl.com/3px58wm4

2. Litzow M, Sun Z, Paietta E, et al. Consolidation therapy with blinatumomab improves overall survival in newly diagnosed with B-lineage acute lymphoblastic leukemia in measureable residual disease negative remission: results from the ECOG-ACRIN E1910 randomized phase III National Cooperative Clinical Trials Network trial. Blood (2022) 140 (Supplement 2): LBA-1. doi: 10.1182/blood-2022-171751

3. Practice-changing trial results for acute lymphoblastic leukemia (ALL). News release. ECOG-ACRIN Cancer Research Group. December 13, 2022. Accessed March 15, 2024. https://tinyurl.com/847tt7pc 

4. Combination chemotherapy with or without blinatumomab in treating patients with newly diagnosed BCR-ABL-negative B lineage acute lymphoblastic leukemia. ClinicalTrials.gov. Updated December 15, 2023. Accessed March 15, 2024. https://clinicaltrials.gov/study/NCT02003222