Blinatumomab (Blincyto) nearly doubled median overall survival in high-risk patients with B-cell precursor acute lymphoblastic leukemia (ALL) compared to patients who underwent chemotherapy, according to results from the phase 3 TOWER trial.1

This randomized, open-label trial compared blinatumomab to standard-of-care chemotherapy in high-risk adults with Philadelphia chromosome-negative (Ph-) relapsed or refractory-cell precursor ALL. This subtype of ALL is one of the most aggressive B-cell malignancies.

In total, 405 patients were randomly assigned to receive blinatumomab (n = 271) or chemotherapy (n = 134), of which 376 patients received at least one dose.

Median overall survival (OS) was 7.7 months (95% CI, 5.6-9.6) in the blinatumomab arm and 4.0 months (95% CI, 2.9-5.3) in the chemotherapy arm (hazard ratio [HR] for death = 0.71; P =.012).

The TOWER trial was the confirmatory trial from a phase 2 study and supported the US FDA’s accelerated approval designation for blinatumomab in 2014.

Blinatumomab, a bispecific CD19-directed CD3 T cell engager, helps the body’s immune system attack cancer cells.

“Historically, patients with relapsed or refractory ALL have a poor prognosis, with an overall survival of just 4 months on standard-of-care chemotherapy,” said Max S. Topp, MD, professor and head of Hematology, University Hospital of Wuerzburg, Germany.

“Findings from this head-to-head study showed that Blincyto almost doubled the median overall survival from 4.0 to 7.7 months, offering these high-risk patients a much needed alternative to chemotherapy that is both innovative and effective.”

Blinatumomab’s survival benefit occurred independent of allogenic stem cell transplant. Additionally, improved OS was overall consistent regardless of age, previous salvage therapy, or previous allogenic stem cell transplantation.

Grade 3 or higher neutropenia and infection were more common adverse effects in the chemotherapy arm compared to blinatumomab. Neurologic adverse effects were at similar rates between the 2 arms.

“Results from the TOWER study reinforce the potential of this single agent bispecific T cell engager immunotherapy, which helped a higher percentage of patients achieve minimal residual disease response vs standard of care chemotherapy, highlighting the depth and quality of remissions achieved,” reported the investigators.

Reference

  1. Kantarjian H, Stein A, Gökbuget N, et al. Blinatumomab versus chemotherapy for advanced acute lymphoblastic leukemia. N Engl J Med. 2017 Mar 2. doi: 10.1056/NEJMoa1609783 [Epub ahead of print]