Recently, the US Food and Drug Administration (FDA) has granted respiratory syncytial virus (RSV) bivalent pre-fused F subunit vaccine (RSVpreF) breakthrough therapy recognition (BTD), which is an active immunization for the pregnant to prevent RSV-related lower respiratory disease (LRTI) in babies from birth to 6 months of age. In November 2018, FDA awarded RSVpreF fast-track qualification.
BTD is a new drug review channel for FDA to accelerate the development and review of new drugs against serious and life-threatening diseases, and there should be preliminary clinical evidence that these drugs can substantially improve the condition compared to existing treatments. Drugs with access to BTD are developed with closer guidance, including senior FDA officials, and are eligible for rolling and potential priority reviews to ensure that new treatment options are provided to patients in the shortest possible time.
The award by FDA to RSVpreF BTD is based on the results of the 2B proof of concept study (NCT04032093), a global, double-blind, and placebo-controlled study on healthy pregnant women aged 18-49 who were vaccinated with RSVpreF during 28-36 weeks of gestation. This study assessed the safety and immunogenicity of RSVpreF in these healthy pregnant women and their infants, with the aim of enabling infants to gain protection against RSV-associated lower respiratory tract infection (LRTI) through maternal immunization. Pfizer will release the results of the clinical study in the future.
Dr. Kathrin U. Jansen, Senior Vice President and Head of Vaccine Research and Development at Pfizer said “The FDA’s decision today is a critical step in the regulatory path of our maternal RSV vaccine candidate and an important milestone in our efforts to help address the harmful effects of RSV disease on infants. If approved later, this maternal-to-infant immunization has the potential to be the first vaccine to protect vulnerable babies from the disease caused by the highly contagious virus in the first few months of life. We look forward to continuing our dialogue with the FDA to accelerate the development process. “
Respiratory syncytial virus (RSV) is a common cause of acute respiratory diseases, which is highly contagious and affects the lungs and respiratory tract. RSV infection occurs in people of all ages with symptoms like the common cold to most young people, but it can be life-threatening for infants, immunocompromised people, and the elderly.
At present, there is no vaccine to prevent RSV, and only supportive care is provided for patients. RSVpreF is a candidate vaccine for RSV under development by Pfizer, which is based on basic scientific discoveries including those of the National Institutes of Health (NIH), which detail the crystal structure of a key form of viral protein that RSV uses to attack human cells.
NIH’s research shows that antibodies that protect humans from RSV infection target one form of the viral protein. Based on this, Pfizer developed and tested a number of candidate vaccines and identified ones that could stimulate a strong antiviral immune response in preclinical evaluation, thus obtaining the RSVpreF that is currently evaluating in human trials, which consists of two preF proteins designed to optimize the protection of type A and type B of RSV