Blinatumomab Is Safe, Effective in Pediatric, Young Adult B-ALL

Blinatumomab Is Safe, Effective in Pediatric, Young Adult B-ALL

Blinatumomab (Blincyto) proved to be efficacious in the frontline treatment setting of children and young adults with chemotherapy-intolerant B-cell acute lymphoblastic leukemia (B-ALL), according to findings published in the Journal of Clinical Oncology.

The researchers analyzed data from children and young persons (CYP) between the ages of 1 and 24 years (n=105) with Philadelphia chromosome-positive or Philadelphia chromosome-negative B-ALL. Disease outcomes of this patient population were then compared to 192 controls that were enrolled in the UKALL 2003 trial.

A total of 85 patients underwent treatment with blinatumomab then further chemotherapy. Among these patients, 50 (59%) received blinatumomab after induction therapy, while 35 (41%) received blinatumomab mid- or post-consolidation.

The majority of patients who responded to blinatumomab and received further chemotherapy underwent blinatumomab for chemotherapy intolerance (n=70; 82%). Notably, this group also had a higher risk profile.

Twenty patients underwent blinatumomab and then hematopoietic stem cell transplantation (HSCT).

“While 90% of children and young persons (CYP) with ALL are cured with contemporary risk-stratified intensive chemotherapy schedules, there is growing recognition of the associated acute and long-term toxicities and their impact on mortality and health-related quality of life (HRQOL),” the authors wrote. “Importantly, the efficacy of therapy is compromised in a substantial minority who cannot continue protocol-mandated schedules because of toxicity, while patients with pre-existing comorbidities, such as Down or Li-Fraumeni syndrome, have inferior outcomes due in part to toxicity.”

Study findings showed that blinatumomab was overall well tolerated, with only 1 patient experiencing grade 3/4 neurotoxicity, and no patients experiencing grade 4 cytokine release syndrome.

Additionally, 60 patients had minimal residual disease (MRD) positivity before treatment with blinatumomab, and within this group, 58 (97%) responded to therapy. At a median follow-up for 22 months, 2-year outcomes were similar among the 80 patients who had blinatumomab and then chemotherapy and the 192 patients in the control. Specifically, event-free survival was 95% (95% CI, 85%-98%) in the blinatumomab arm and 90% (95% CI, 65%-93%) in the control arm. In addition, overall survival was 97% (95% CI, 86%-99%) and 94% (95% CI, 89%-96%), respectively.

“Given their chemotherapy intolerance, this group would be expected to have a higher relapse risk because of delays and omissions of post-remission therapy,” the researchers wrote. “The results are even more remarkable considering that our study was enriched in patients at higher risk of relapse because of high-risk cytogenetics and persistent MRD at the end of induction or consolidation.”

In the blinotumumab-chemotherapy arm, two patients experienced disease relapse after initially responding to the drug; both had CD19-positive isolated bone marrow relapses.

Among patients who underwent HSCT, 3 died due to transplant complications, while 2 experienced disease relapse.

“The small HSCT group was effectively bridged to transplant but has suffered transplant-related deaths, highlighting the need to reduce toxicity in this group, especially as there have been no events in the 10 patients with (end-of-consolidation) MRD > 0.05% who could not be transplanted because of poor performance status or lack of donor availability,” the researchers said.

Reference

Hodder A, Mishra AK, Enshaei A, et al. Blinatumomab for First-Line Treatment of Children and Young Persons with B-ALL. Published: November 15, 2023. J Clin Oncol. doi:10.1200/JCO.23.01392