The French pharmaceutical company said, on Friday, that an experimental Covid-19 virus vaccine developed by Sanofi and the British company GlaxoSmithKline showed an insufficient immune response in the results of clinical trials, which represents a blow to efforts to combat the epidemic.
GSK Lab, London.
Ole Scarf | Getty Images
The two companies said they intend to launch another study next year, hoping to find a more effective vaccine by the end of 2021.
The news comes as a disappointment for a batch of vaccines in development that rely on more traditional proven designs as the shot developed by Pfizer and BioNTech using advanced technology is being rolled out across Britain.
Sanofi said Friday’s results showed “a similar immune response in patients who have recovered from COVID-19 in adults between the ages of 18 and 49, but the lowered immune response in the elderly is likely due to insufficient concentration of the antigen.”
Phase III studies are expected to begin this month.
Sanofi said it will launch the Phase 2B study in February next year instead after a recent challenge study in non-human primates conducted with an improved antigen formulation showed better effects.
“The study will include a proposed comparison with a licensed COVID-19 vaccine,” the company said.
“If the data are positive, the global phase III study could begin in the second quarter of 2021. Positive results from this study will lead to regulatory introductions in the second half of 2021, thus delaying potential availability of the vaccine from mid-2021 to the fourth quarter of 2021.
The two companies said that they had “modernized governments and the European Commission as it was contractually obligated to purchase the vaccine.”
The Sanofi-GSK vaccine uses the same recombinant protein-based technology as the seasonal flu vaccines from Sanofi. It will be combined with an adjuvant, a substance that acts as a vaccine booster, made by GSK.
The companies would be the 14th player to initiate phase-three studies on potential vaccines as governments struggle to tame an epidemic that has killed more than 1.5 million people, according to WHO records.
The Phase 1/2 study tested the safety, tolerability, and immune response to the vaccine in 440 healthy adults across 11 investigation sites in the United States.
The partners are not the first in the race, but they believe their vaccine experience is an advantage.
Britain this week began deploying a vaccine using advanced mRNA technology developed by Pfizer and BioNTech, outperforming the rest of the world in the race. Canada gave the green light to shoot, too.
The data comes as the US regulator is considering the Pfizer-BioNTech vaccine for approval. Competitor developers AstraZeneca Plc and Moderna have also reported late-stage data showing that their shots are effective in preventing the virus.
The French group is also working on another candidate vaccine for the prevention of COVID-19 with the US company Translate Bio that will rely on a different technology called mRNA, similar to that developed by Pfizer and Moderna.
Trials of the first phase of this vaccine are expected to begin this month.
Sanofi and GlaxoSmithKline have scaled up manufacturing in order to prepare to produce up to 1 billion doses of their vaccine in 2021, and have entered into a few contracts including deals with the European Union, the United States, Canada and Britain.
GSK is contributing adjuvants to two other COVID-19 vaccine projects, one with Medicago of Canada and the other with Clover Biopharm Pharmaceuticals in China.
