Pfizer RSV vaccine candidate Phase 3 trial will focus on older adults

Pfizer has announced the third phase of its RSV vaccine candidate clinical trial for older adults. The company is calling the trial's third phase 'RENOIR,' noting that it involves giving its RSVpreF vaccine candidate to adults ages 60 and older. The company anticipates enrolling around 30,000 participants for Phase 3 RENOIR in order to study the vaccine's efficacy and safety.

Respiratory Syncytial Virus (RSV) is a common, highly contagious virus that can cause severe, potentially deadly, infections in older adults, as well as infants and anyone who has a compromised immune system. At this point in time, there aren't any vaccines available to help prevent the virus or reduce its severity; around 14,000 older adults die from the virus every year.

Pfizer's vaccine candidate has been in the works for a long while. The FDA granted the company Fast Track status for the vaccine candidate in late 2018. The company reported "positive top-line results" from the Phase 2b proof-of-concept study back in April 2020, followed most recently by details on Phase 2a in July 2021.

The Phase 2a study looked into the efficacy, safety, and immunogenicity of the RSVpreF vaccine candidate in healthy adults who were ages 18 through 50. Pfizer plans to share the results from this phase in the future. Phase 3 RENOIR, meanwhile, will focus on older adults who are among the most vulnerable to RSV.

RENOIR will, according to Pfizer, focus on whether its vaccine candidate can help prevent moderate and severe RSV infections in older adults. The trial will be randomized, placebo-controlled, and double-blind, taking place with participants across the world. The trial comes just ahead of the start of the next RSV season, which kicks off in early autumn.