Blinatumomab receives FDA approval for MRD+ Philadelphia negative B-ALL

Blinatumomab was initially granted accelerated approval in March 2018 for patients with B-cell precursor acute lymphoblastic leukemia (B-ALL) who had received three blocks of prior chemotherapy, were in hematologic complete remission, and had MRD ≥0.1%¹. This was based on data from the BLAST clinical trial (NCT01207388) which demonstrated an 18-month relapse-free survival (RFS) rate of 56% and an estimated median RFS of 22.3 months. Blinatumomab has now been granted full approval following support from both BLAST and ECOG-ACRIN E1910 (NCT02003222) phase III clinical trials.¹

BLAST

BLAST was an open-label single-arm trial including 86 patients with B-ALL. Undetectable MRD was achieved in 81.4% (95% confidence interval [CI], 71.6%–89.0%) with a sensitivity of 0.01% for 6 patients and ≥0.005% for 80 patients in the whole population.² The estimated hematological RFS was 24.2 months.

ECOG-ACRIN E1910

ECOG-ACRIN E1910 is a phase III randomized trial investigating 488 adult patients (aged 30–70 years) with newly diagnosed Philadelphia negative B-ALL.³ Among the MRD-negative patients (n = 224), median OS was not reached in patients treated with blinatumomab and chemotherapy versus 71.4 months with chemotherapy treatment alone (HR, 0.42; 95% CI, 0.24-0.75).

Conclusion

Additional data from these two clinical trials demonstrated the clinical benefit of blinatumomab for patients with B-ALL who had MRD ≥0.1%; this supported the conversion from accelerated approval to full approval for blinatumomab.¹