ALL-151 Impact of Blinatumomab on Survival Outcomes in Adolescents and Young Adults with Philadelphia Chromosome-Negative B-Cell ALL Following the Initial Phase of Pediatric-Inspired Chemotherapy: A Comparative Study

• Published in: Clinical lymphoma, myeloma and leukemia myeloma and leukemia, 2024-09, Vol.24, p.S260-S261
• Main Authors: Abdrabou, Ahmed Kotb, Saleh, Mostafa Mohammed, Nassani, Momen, Benlamine, Chokri, Salman, Ahmed Bin, Samarkandi, Sara, Alkahmous, Baraah, Alshammari, Fatimah, Hussain, Taimoor, Alfadhil, Haroon, Bajuaifer, Yazeed S., Sharif, Mohamed Isam, Nassar, Marwa, Madien, Heba, Hejab, Amal, Alsugair, Ali, Ahmed, Shihab, Alfaqaawi, Samar, Alkhaldi, Hanan, Alfayez, Mansour, Alotaibi, Ahmad, Alahmari, Ali, Ahmed, Syed Osman, Saad, Ayman, Hanbali, Amr Suleiman
• Format: Article
• Language: English
• Subjects: adolescents and young adults; ALL; blinatumomab; minimal residual disease; stem cell transplantation
• ISSN: 2152-2650
• DOI: 10.1016/S2152-2650(24)01091-7

Pediatric-inspired chemotherapy protocols have markedly improved outcomes in adolescents and young adults (AYAs) with Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia (B-ALL) compared to adult-based chemotherapy protocols, with an improvement in 5-year overall survival from 40% to 75%. However, minimal residual disease (MRD) positivity post-consolidation remains a significant challenge, often leading to a poor prognosis. Blinatumomab, a bispecific T-cell engager, has emerged as a potential treatment for ALL patients with persistent MRD. This study evaluates the efficacy of blinatumomab incorporation into a pediatric-inspired treatment regimen on survival outcomes for AYAs with post-consolidation MRD-positive Philadelphia chromosome-negative B-ALL or those unable to tolerate intensive chemotherapy. We retrospectively analyzed 92 AYAs with Philadelphia chromosome-negative ALL. Patients were divided into 2 groups: those who received a pediatric-inspired chemotherapy regimen without blinatumomab (n=71) and those treated with blinatumomab for MRD positivity post-consolidation or due to intolerance to intensive chemotherapy (n=21). Outcomes measured included MRD status post-consolidation, allogeneic stem cell transplantation (allo-SCT) rates, relapse, survival, and other clinical parameters. Baseline characteristics were comparable between groups. Adding blinatumomab significantly improved post-consolidation MRD positivity (from 57% to only 5% after blinatumomab usage). In the blinatumomab group, 47.6% of patients underwent allo-SCT, indicative of its role in enabling more patients to reach a transplant in an MRD-negative state, which allows better outcomes. While not statistically significant, a trend towards improved 4-year EFS was noted in the blinatumomab group (95% vs 72.4%, P=.089), indicating a potential benefit in delaying relapse or disease progression in such high-risk disease, with comparable 4-year OS between the two cohorts (95% vs 80%, P=.311). Although blinatumomab administration post-consolidation phase in MRD-positive B-ALL or for those intolerant to intensive chemotherapy did not significantly extend overall survival, there is an indication of enhanced EFS. Blinatumomab treatment may not only overcome the poor prognosis of post-consolidation MRD-positivity but also support a trend towards better EFS. We recommend larger, prospective trials with longer follow-up periods to validate these findings and determine the full clinic