Blinatumomab Improves OS vs Chemo in B-Cell Precursor ALL

Among patients with relapsed or refractory B cell precursor acute lymphoblastic leukemia (ALL), treatment with blinatumomab (Blincyto) significantly prolonged overall survival compared with chemotherapy, according to a study published in The New England Journal of Medicine.¹

The multicenter, open-label, phase 3 TOWER trial (ClinicalTrials.gov Identifier: NCT02013167) randomly assigned 405 adults with heavily pretreated B-cell precursor ALL 2:1 to receive blinatumomab or investigator’s choice of 1 of 4 standard-of-care chemotherapy regimens. Nearly a quarter (24%) of patients in each arm had undergone allogeneic hematopoietic cell transplantation.

Treatment with blinatumomab reduced the risk of death by 29% compared with chemotherapy (hazard ratio [HR], 0.71; 95% CI, 0.55-0.93; P = .01). Median overall survival was 7.7 months in the blinatumomab arm vs 4.0 months in the chemotherapy group. A survival benefit in the blinatumomab group occurred irrespective of receipt of allogeneic hematopoietic cell transplantation, but this benefit appeared greatest in patients who had received fewer lines of salvage therapy.

“Historically, patients with relapsed or refractory ALL have a poor prognosis, with an overall survival of just 4 months on standard of care chemotherapy,” Max S. Topp, MD, professor and head of hematology, University Hospital of Wuerzburg, Germany, said in a press release.² “Findings from this head-to-head study showed that Blincyto almost doubled the median overall survival from 4 to 7.7 months, offering these high-risk patients a much needed alternative to chemotherapy that is both innovative and effective.”

Remission rates within 12 weeks after treatment initiation were also significantly higher in the blinatumomab group than in the chemotherapy arm. Patients who received blinatumomab were more likely to achieve complete remission with full hematologic recovery (P < .001) and achieve complete remission with full, partial, or incomplete hematologic recovery (P < .001).

Patients treated with blinatumomab were 45% less likely to relapse after achieving a complete remission with full, partial, or incomplete hematologic recovery, or death (HR, 0.55; 95% CI, 0.43-0.71; P < .001). Investigators observed grade 3 or higher adverse events in 87% of blinatumomab-treated patients compared with 92% of those who received chemotherapy.

Reference

1. Kantarjian H, Stein A, Gokbuget N, et al. Blinatumomab versus chemotherapy for advanced acute lymphoblastic leukemia. N Engl J Med. 2017; 376:836-847.
2. Blincyto (blinatumomab) significantly improved overall survival in patients with B-cell precursor acute lymphoblastic leukemia compared to chemotherapy [news release]. Thousand Oaks, CA: Amgen; March 1, 2017. http://www.amgen.com/media/news-releases/2017/03/blincyto-blinatumomab-significantly-improved-overall-survival-in-patients-with-bcell-precursor-acute-lymphoblastic-leukemia-compared-to-chemotherapy/. Accessed March 2, 2017.