Sanofi-GSK's COVID-19 vaccine enters EMA rolling review as the companies work on phase 3 trial

Three weeks after commencing a global phase 3 trial, Sanofi and GlaxoSmithKline's COVID-19 vaccine candidate, Vidprevtyn, has entered a rolling review in Europe. 

The continent's drug regulator said Tuesday its human medicines committee has begun the real-time review based on lab studies and early clinical studies in adults. The European Medicines Agency (EMA) "will evaluate data as they become available to decide if the benefits outweigh the risks."

Once enough evidence is available, the rolling review will move onto a formal marketing authorization application, the regulator said. 

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In mid-May, the French and British Big Pharmas passed a small phase 2 study, consisting of 722 volunteers aged 18 to 95 in the U.S. and Honduras. Across all doses and after both shots, the vaccine showed 95% to 100% seroconversion, meaning the immune system responds to the virus via antibody production. 

Reuters reported that Sanofi's vaccine is "about to" undergo rolling reviews in Britain, Canada and Singapore. The World Health Organization will review it, as well.

Following that phase 2 data drop, Sanofi and GSK began enrolling patients in a global phase 3 study of more than 35,000 volunteers over age 18 across the U.S., Asia, Africa and Latin America to test the safety, efficacy and immunogenicity of the jab. The primary endpoint is prevention of symptomatic COVID-19, and secondary endpoints include the prevention of severe COVID-19 disease and prevention of asymptomatic infection. 

The two-stage study is investigating the efficacy first against the original strain of the virus. A second stage will assess another formulation targeting the Beta variant, or B.1.351, which was first identified in South Africa. The companies are hoping their adjuvanted protein-based technology—the recombinant antigen coming from Sanofi and GSK contributing the adjuvant—will be a success against variants that are causing new so-called waves of the pandemic. 

Additionally, the companies are looking at clinical studies to evaluate the adjuvanted recombinant-protein vaccine as a booster shot, "regardless of initial vaccine platform." Pfizer itself is attempting to move forward with a booster application for its own COVID-19 vaccine, of which millions of jabs have been given.

RELATED: Novavax COVID-19 vaccine hits 90% efficacy in pivotal U.S. trial

At the time of Vidprevtyn's phase 3 start, the companies also said manufacturing would start in "the coming weeks" to ensure "rapid access" to the vaccine, pending approval. A GSK spokesperson noted that the rolling review does not change any of the vaccine's timelines and Vidprevtyn could be approved in the fourth quarter of this year, pending positive phase 3 results and regulatory review. 

The EMA started a rolling review of Sinovac's COVID-19 vaccine in May and Novavax's and CureVac's in February. 

Editor's note: A spokesperson for GlaxoSmithKline responded to a request for comment, and the article has been edited to reflect the reply.