Suptavumab (REGN 2222) fails Phase III trial to prevent medically-attended RSV infections in infants.- Regeneron.

Regeneron Pharmaceuticals, Inc.announced that a Phase III study evaluating suptavumab (REGN 2222), an antibody to respiratory syncytial virus (RSV), did not meet its primary endpoint of preventing medically-attended RSV infections in infants. Suptavumab did show signs of efficacy in a subgroup of patients.

Adverse events were generally balanced between suptavumab and placebo. Regeneron plans to discontinue further clinical development of this antibody. The double-blind, placebo-controlled global Phase III NURSERY Pre-term study enrolled 1,149 healthy pre-term infants. Patients were randomized in a 1:1:1 ratio to one of three study groups: suptavumab 30 mg/kg as a single dose; suptavumab 30 mg/kg administered as two doses 8 weeks apart; or placebo. Assessment of the primary endpoint occurred through Day 150 of treatment. Patients were considered 'medically-attended' if they required hospitalization and/or sought medical care for a centrally-adjudicated RSV infection. Pre-term infants in the study had a gestational age of less than 36 weeks and were 6 months old or younger at the beginning of the study. Data from the study will be presented at a future medical congress.