Sanofi, the French pharmaceutical company, announced Monday that it will move the experimental Covid-19 vaccine it is developing with GlaxoSmithKline to a late-stage study after the shot provoked strong immune responses in an interim study in volunteers.
The results are encouraging news for a vaccine that has fallen behind in development and so far has disappointed those who expect it to be vital in fighting the pandemic. If the vaccine can be available in the last three months of this year, as the developers hope, it could continue to play a pivotal role as a booster, as well as an initial vaccination, in developing countries where vaccination pace is lagging.
The vaccine suffered a major setback in December when its developers announced that it did not appear to work well in older adults and that they had plans to test it in a Phase 3 study, the pivotal test in assessing the vaccine’s effectiveness. would have to move.
However, the companies modified the vaccine and began testing it in February in a Phase 2 study that enrolled more than 700 volunteers in the US and Honduras between the ages of 18 and 95. Sanofi said the vaccine raised no safety concerns and produced a strong immune response across age groups, suggesting it was successfully optimized.
Sanofi announced the results in a statement, saying it plans to publish the results in a medical journal soon.
Sanofi and GSK have much more vaccine development experience than some of their previously approved competitors. The two companies took a more established approach than those used in other, more rapidly developed Covid vaccines. Their shot is based on viral proteins made with engineered viruses that grow in insect cells. GSK supplies the Sanofi vaccine with an adjuvant, a component used in many vaccines to boost the immune response.
The Sanofi and GSK vaccine was one of six vaccines selected for funding through Operation Warp Speed, the Trump administration’s effort to accelerate vaccine development. Last summer, the federal government agreed to give companies $ 2.1 billion to develop and manufacture the vaccine, against 100 million doses once the shot was done.
Sanofi also has delivery agreements with the European Union and Canada. It was also agreed to ship 200 million doses to Covax, the program to deliver vaccines to middle and low income countries that is grappling with a shortage of expected doses. Sanofi also announced plans to help manufacture the approved vaccines from Pfizer-BioNTech, Moderna and Johnson & Johnson.
Sanofi said the Phase 3 trial of its vaccine will begin in the coming weeks and will enroll more than 35,000 adult volunteers around the world. Two formulations of the vaccine are being tested, one to prevent the original strain of the virus and the other for variant B.1.351, which was first observed in South Africa and against which some vaccines appear to be less effective.
Su-Peing Ng, Sanofi’s global medical director for vaccines, told journalists on Monday that the company believed it would be “operationally quite difficult” to enroll unvaccinated participants in the Phase 3 study because the vaccination rate was in many countries. Still, she said, vaccine doses are still scarce in many parts of the world, pointing to Latin America and Asia as places the company may want to enroll volunteers.
The company said that shortly after the Phase 3 trial begins, it will test whether its vaccine can boost immune responses in people who had been vaccinated with approved vaccines months earlier. These booster studies are expected to enroll volunteers in well-vaccinated parts of the world, including the US and Europe.
Sanofi and GSK said last year they are preparing to produce 1 billion cans a year. Thomas Triomphe, Sanofi’s global director of vaccines, said Monday that if the vaccine turns out to work, the company’s production would depend on the needs of the world this year.
The vaccine “has the potential to be a booster of choice for many nations and many different platforms”.