Pfizer Receives FDA Breakthrough Therapy Designation for its RSV Vaccine

This morning, Pfizer announced that its respiratory syncytial virus (RSV) vaccine candidate, PF-06928316 or RSVpreF, received Breakthrough Therapy Designation from the Food and Drug Administration (FDA) for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years of age or older.

“Today’s decision is a significant step forward in our efforts to help protect vulnerable populations, particularly older adults, against certain potentially serious respiratory illnesses, including RSV,” Kathrin U. Jansen, PhD, senior vice president and head of Vaccine Research & Development at Pfizer, said in a statement.

Last September, Pfizer announced it had begun its phase 3 clinical trial, RENOIR (RSV vaccine Efficacy study iNOlder adults Immunized against RSV disease), which was designed to evaluate the efficacy, immunogenicity, and safety of a single dose of its RSVpreF vaccine, which is a RSV bivalent prefusion F subunit investigational vaccine candidate.

The vaccine is being studied in a global, randomized, double-blind, placebo-controlled study that is expected to enroll approximately 30,000 adults 60 years and older. The study is assessing safety and efficacy for the prevention of moderate to severe lower respiratory tract illness (msLRTI-RSV) during the first RSV season.

The federal agency’s decision for the Breakthrough Therapy Designation was primarily based from Pfizer’s phase 2a data, which demonstrated positive results of a proof-of-concept, evaluating the safety, immunogenicity, and efficacy of a single dose of 120µg RSVpreF in a human viral challenge model in healthy adults 18 to 50 years of age.

The Breakthrough Therapy Designation expedites the development and review of therapies and vaccines that are intended to treat or prevent serious conditions and preliminary clinical evidence indicates that the drug or vaccine may demonstrate substantial improvement over available therapy on a clinically significant endpoint.

“The clinical and economic burden of RSV represents a critical need, and we look forward to our ongoing dialogue with the FDA to accelerate the development of our RSV vaccine candidate,” Jansen said.

The Scope of the Problem

The Centers for Disease Control and Prevention (CDC) states that an estimated 177,000 older adults are hospitalized and 14,000 of them die in the United States annually due to RSV.

Those 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.