Dr Rijneveld on the Addition of Blinatumomab to Prephase and Consolidation Therapy in B-ALL

Anita Rijneveld, MD, internist-hematologist, Erasmus MC Cancer Institute, Rotterdam, the Netherlands, discusses outcomes with the addition of blinatumomab to prephase and consolidation therapy for patients with adult B-cell acute lymphoblastic leukemia (B-ALL), according to a comparison of data from the consecutive phase 2 HOVON-100 and HOVON-146 trials.

At the 2024 EHA Hybrid Congress, Rijneveld presented updated results from the HOVON-146 study, which evaluated the addition of blinatumomab to prephase and consolidation therapy in adults with ALL. Results were then compared with the standard arm of the preceding HOVON-100 study, which had a median follow-up of 70 months and used the same blinatumomab backbone without the agent itself.

After a median follow-up of 43 months (range, 33-62), 85% of patients in the overall population of HOVON-146 (n = 71) achieved a complete response (CR) with blinatumomab, Rijneveld reports. Administration of blinatumomab in the prephase led to an early CR rate of 63%, and 53% of patients achieved minimal residual disease (MRD) negativity. Following the first blinatumomab consolidation, 97% of patients (n = 59) achieved a CR, 91% of whom also achieved MRD negativity, meeting the study's primary end point. No cases of grade 4 or 5 cytokine release syndrome or immune effector cell–associated neurotoxicity syndrome were reported.

Four-year event free survival (EFS) rates for patients 40 years or younger vs older than 40 years of age were 64% vs 40%, respectively, Rijneveld continues. For patients up to 60 years of age, the overall survival (OS) rate after 4 years was 86%, including all patients with Philadelphia chromosome (Ph)–positive ALL. For patients above 60 years of age, the OS rate was 50%, indicating that blinatumomab can be given up front and is safe, she explains.

In elderly patients above 60 years of age, the outcomes improved with blinatumomab, especially compared with what was observed in the HOVON-100 trial where chemotherapy was given alone, Rijneveld continues. Although the incidence of toxicities in patients older than 60 years was substantial, no significant safety concerns were noted following chemotherapy dose adaptations, she notes.

The results suggest that incorporating blinatumomab early, such as in the prephase as done in HOVON-146, could be beneficial, Rijneveld says. Moving forward, it may be necessary to compare the incorporation of blinatumomab in the prephase vs consolidation to determine the most effective strategy, she states. Overall, the addition of blinatumomab to early prephase and consolidation chemotherapy suggests a favorable outcome compared with the preceding HOVON-100 study, especially in patients older than 40 years of age and who have Ph-positive disease, Rijneveld concludes.