GSK’s market-leading Shingrix vaccine proved effective against shingles more than 10 years post-administration, creating a new hurdle for a number of potential competitors.
Shingrix was 82% effective against shingles after 11 years, according to an extension study in adults 50 years and older. In adults 70 years and older, Shingrix maintained a 73% efficacy rate between six and 11 years post-vaccination, GSK reported on Wednesday.
The data could help differentiate Shingrix from incoming rivals, including experimental mRNA-based candidates in early testing by Pfizer and Moderna. In January, a Seattle biotech called Curevo Vaccine said its adjuvanted vaccine amezosvatein triggered an immune response at least as good as Shingrix in a head-to-head Phase 2 trial.
Shingrix is one of GSK’s top sellers, generating nearly $4.3 billion in 2023.
Robyn Widenmaier“It’s actually very unique to see such long-term and persistent efficacy for this population of older adults,” Robyn Widenmaier, VP and global medical strategy lead for GSK’s shingles vaccine, told Endpoints News. “This data really reinforces the durability of Shingrix.”
Curevo previously said it hopes to create a shot that has similar efficacy to Shingrix but with fewer side effects. Shingrix was shown to be 97% effective at preventing shingles in adults 50 years and older in one study. But when it comes to safety, Curevo said its candidate “exhibited lower rates of solicited local and systemic adverse events” in Phase 2.
The FDA added a warning to Shingrix’s label in 2021 for Guillain-Barré Syndrome (GBS), a rare autoimmune disorder that can cause muscle weakness or in some cases paralysis. But the FDA specified that evidence was insufficient to establish a causal relationship between Shingrix and GBS, and determined that the benefits of the vaccine continue to outweigh the risks.
“GBS is very rare,” Widenmaier said Wednesday. “There was no additional concern noted in any of the long-term follow-up studies.”
Shingrix is currently administered in a two-dose regimen. GSK said Wednesday that it will continue to evaluate long-term data “to assess a potential need for revaccination in future.” But Widenmaier added that based on the latest results, it isn’t expected that boosters will be needed.