Regeneron discontinues clinical development of antibody for respiratory virus

Regeneron Pharmaceuticals has announced plans to discontinue further clinical development of its antibody, suptavumab, for respiratory syncytial virus (RSV), as it has not met the primary endpoint of preventing infections in infants in the Phase III study.

“We are disappointed in these results, as we had hoped suptavumab might offer a new option for the thousands of infants impacted by serious RSV infections every year,” said Dr George D. Yancopoulos, PhD, president and chief scientific officer of Regeneron. “Regeneron has a robust pipeline across many serious diseases, and we look forward to important data readouts from other programmes in the coming weeks and months.”

The Phase III study (NURSERY) evaluating the antibody, was a double-blind, placebo-controlled global trial that enrolled 1,149 healthy pre-term infants. The study groups comprised suptavumab 30 mg/kg in a single dose, suptavumab 30 mg/kg administered as two doses, or placebo and patients were randomised to these groups in a 1:1:1 ratio.

After 150 days the researchers assessed if the primary endpoint, prevention of medically attended RSV infections in infants, was met. Medical attendance was considered to be hospitalisation and/or if medical care for infection was sought. Although subtavumab did not meet the primary endpoint it was found to show signs of efficacy in a subgroup of patients. Adverse events were found to be balanced between the antibody-treated and placebo groups.

Data from the study will be presented at a future conference.