GlaxoSmithKline's vaccines group aims for a first as it kicks off PhIII RSV studies
One of GlaxoSmithKline’s big projects at its global vaccine R&D center in Rockville, MD is set to enter Phase III after passing early-stage tests with flying colors.
Eyeing the wide-open respiratory syncytial virus (RSV) space, GSK is pushing two different vaccine candidates: GSK3888550A is designed to confer protection to infants via maternal immunization, while GSK3844766A is meant for the elderly.
The pharma giant presented Phase I/II data for both at ID Week. Three different doses of the maternal candidate were tested among 502 healthy non-pregnant women and investigators reported “high levels” of protective neutralizing antibodies. For the older adults candidate, the 60-to-80-year-old vaccinated group had “a close to 10 times increase of protective antibodies” compared to placebo, coupled with CD4+ T cells boosted to similar levels observed in younger adults who were given the vaccine in the lead-in phase.

“We are delighted to see these positive results confirming our approach to develop dedicated vaccines building on the strategic use of our platform technologies for the populations most at risk from RSV infections – young infants and older adults,” Emmanuel Hanon, SVP and head of vaccines R&D, said in a statement.
A leading cause of respiratory infections and pneumonia for children and the elderly, RSV has been an elusive target for vaccine developers.
Before Novavax became a favorite to deliver a shot for Covid-19, RSV was a key focus in the pipeline. Despite multiple Phase III flops, the biotech insisted that they had a comeback plan for the Gates Foundation-backed program by highlighting prevention of serious consequences. And a host of biotechs, including Meissa and Codagenix, have bagged considerable venture cash to explore new ways of assembling a vaccine.
GSK’s approach involves administering a recombinant subunit pre-fusion RSV antigen to pregnant women and combining it with its adjuvant system, AS01, to boost the immune response among older adults. AS01 is also used in GSK’s new shingles vaccine, Shingrix.
Phase III studies for both candidates are on track to start in the coming months, according to the company. A third pediatric program, which targets both infants, is in Phase I/II for RSV-seronegative populations and Phase II for a RSV-seropositive group.