Pfizer Reports Positive Data on RSV Vaccine Candidate for Seniors

The company announced results for its investigational RSV vaccine, RSVpreF, from its phase 3 RENOIR trial which demonstrated an efficacy of 85.7% in participants with more a severe disease primary endpoint of lower respiratory tract illness (LRTI-RSV).

“We are delighted that this first bivalent RSV vaccine candidate, RSVpreF, was observed to be efficacious in our clinical trial against this disease, which is associated with high levels of morbidity and mortality in older adults,” Annaliesa Anderson, PhD, senior Vice President and Chief Scientific Officer, Vaccine Research and Development, Pfizer, said in a statement.

More severe disease of LRTI-RSV was defined as three or more RSV-associated symptoms. Older adults who are most at risk for severe RSV are those who are 65 years and older; adults who have chronic heart or lung disease; and adults with weakened immune systems. RSV in adults will look like cold symptoms, but can lead to more serious symptoms including pneumonia, severe symptoms for people with asthma, chronic obstructive pulmonary disease, and congestive heart failure.

In a pre-planned, interim analysis of Pfizer’s RSVpreF vaccine’s protection against LRTI-RSV, which was defined by two or more symptoms, the shot demonstrated a 66.7% efficacy. The analysis was conducted by an independent, external Data Monitoring Committee (DMC).

The RENOIR trial is a global, randomized, double-blind, placebo-controlled study designed to assess the efficacy, immunogenicity, and safety of a single dose of RSVpreF in adults 60 years of age and older. The trial has enrolled approximately 37,000 participants, randomized to receive 120μg RSVpreF or placebo in a 1:1 ratio. Enrollment up to approximately 40,000 participants continues in the Southern Hemisphere to accumulate cases during their first season.

The company plans to file for an FDA BLA in the coming months.

“Scientists and researchers have worked to develop RSV vaccines with little success for over half a century. These findings are an important step in our effort to help protect against RSV disease, and we look forward to working with the FDA and other regulatory agencies to make this vaccine candidate available to help address the substantial burden of RSV disease in older adults," Anderson said in the same statement.