Sanofi and GlaxoSmithKline have moved their adjuvanted protein-based COVID-19 vaccine into the clinic, setting them on a path they expect to lead to a filing for approval in the first half of next year.
The phase 1/2 trial will enroll 440 people across 11 U.S. clinical trial sites. If all goes to plan, Sanofi and GSK will have safety, tolerability and immunogenicity data from the study in December and move into phase 3 later that month. The partners expect to have the data to support a filing for approval of their two-dose adjuvanted vaccine regimen in the first half of 2021.
Sanofi and GSK are moving into the clinic on the strength of preclinical data they say suggests their vaccine has an acceptable tolerability profile and triggers the production of neutralizing antibodies at levels comparable to those seen in convalescent patients.
While companies such as AstraZeneca and Moderna have rapidly advanced COVID-19 vaccines based on relatively new, unproven technologies, Sanofi and GSK have chosen a more established platform. That has put Sanofi and GSK well behind the front-runners—they are entering the clinic as rivals race to finish phase 3 trials—but could make them a force to be reckoned with once they get to market.
Protein-based subunit vaccines have been used to protect against pathogens including hepatitis B and acellular pertussis for decades. Sanofi enhanced its capabilities in the area in 2017 by acquiring Protein Sciences, the developer of the only FDA-approved recombinant protein-based flu vaccine.
The use of established technology might mean Sanofi and GSK have an edge over more advanced rivals in terms of safety, tolerability and efficacy. It may also help the partners to reliably produce vast quantities of vaccines. The partners plan to make up to 1 billion doses next year.
A significant minority of those doses are already accounted for. The U.S. government has struck a deal to source up to 100 million doses, with an option to buy as many as 500 million more. Its U.K. counterpart is set to buy 60 million shots. And the European Commission is lining up a 300-million dose agreement.