A lesser-known vaccine program in Pfizer's massive pipeline was thrust into the spotlight on Wednesday, after the Food and Drug Administration awarded it what's known as Breakthrough Therapy Designation.
The vaccine from Pfizer (ticker: PFE) is designed to prevent Group B Streptococcus disease in infants by immunizing their mothers. Breakthrough Therapy Designation helps new drugs to move more quickly through the regulatory process.
The vaccine, known as GBS6, is the subject of an ongoing Phase 2 study. Pfizer has yet to publish data on the trial, but the FDA awarded the new designation based on interim data.
Pfizer did not characterize that data in its press release. But the FDA awards Breakthrough Therapy Designation to drugs that have shown they offer an advantage over available alternatives, and is generally a good sign for the drug.
Pfizer stock is down 0.1% in Wednesday morning trading, while the S&P 500 is 0.3% lower. Pfizer stock is down 22.5% so far this year.
Group B Strep is caused by a common bacteria, but can causes serious disease in infants. Women in the U.S. and other countries are generally screened for Group B Strep in the late stages of pregnancy; if they are positive, certain precautions are taken during labor to prevent transmitting the disease to their babies, including administering intravenous antibiotics. Still, the bacteria remains a significant public health problem. A 2017 study estimated that Group B Strep causes 150,000 stillbirths and infant deaths per year, mostly in Africa.
"With an estimated 410,000 [Group B Streptococcus] cases worldwide—the largest burden in low- and middle-income countries—we are pursuing a global clinical development strategy with the intent to make a successfully developed vaccine available worldwide as quickly as possible," Pfizer CEO Albert Bourla wrote in a Tweet on Wednesday.
The FDA's Breakthrough Therapy Designation allows for faster development of new drugs that treat serious conditions. The program is selective: The FDA division that oversees vaccine approvals received 10 requests for Breakthrough Therapy Designation in 2021 and granted four. In 2020, it received 15, and granted only 3.
Pfizer, which before the Covid-19 pandemic sold a blockbuster pneumococcal disease vaccine known as Prevnar 13, has now firmly established itself as a world-leading vaccine marker, on the strength of its Covid-19 vaccine, known as Comirnaty.
The company is seeking to follow up the success of Comirnaty with a respiratory syncytial virus vaccine, RSVpreF, which is currently in Phase 3 trials . Pfizer is battling with a range of other big pharma firms to bring the first RSV vaccine to market; racing other contenders including GSK (GSK), Moderna (MRNA), and others.
The Group B Strep vaccine, GBS6, is farther down the pipeline. It has drawn little notice from investors, and received only scant mention in Pfizer's investor calls. The Breakthrough Therapy Designation announced Wednesday should raise the program's profile, and focus attention on Pfizer's vaccine plans.
GBS6 is a polysaccharide vaccine, a similar approach to Pfizer's blockbuster pneumococcal disease vaccine. It is designed to protect against six separate strains of Group B Strep, and would be administered to expectant mothers in the second or early in the third trimester of their pregnancies.
According to ClinicalTrials.gov , a government registry of human studies, the Phase 2 trial is recruiting patients in the U.S., U.K., and South Africa, and is expected to be completed in early 2024.