An experimental Covid-19 vaccine developed by Britain's GlaxoSmithKline and Sanofi has been found to show an 'insufficient immune response' in clinical trial results, in a blow to efforts to fight the pandemic.
The two companies said they planned to launch another study next year, hoping to come up with a more effective vaccine by the end of 2021.
The results showed an immune response comparable to patients who recovered from COVID-19 in adults aged 18 to 49 years, but a low immune response in older adults.
Thomas Triomphe, Executive Vice President and Head of Sanofi Pasteur, said: “We care greatly about public health which is why we are disappointed by the delay announced today, but all our decisions are and will always be driven by science and data.
"We have identified the path forward and remain confident and committed to bringing a safe and efficacious COVID-19 vaccine. Following these results and the latest encouraging new preclinical data, we will now work to further optimize our candidate to achieve this goal.
"No single pharma company can make it alone; the world needs more than one vaccine to fight the pandemic.”
While Phase III studies were expected to start this month, Sanofi said it will now launch another Phase 2b study in February next year instead.
The Sanofi-GSK vaccine uses the same technology as one of Sanofi’s seasonal influenza vaccines, and is coupled with a substance that acts as a booster, made by GSK.
Roger Connor, President of GSK Vaccines, said: “The results of the study are not as we hoped. Based on previous experience and other collaborations, we are confident that GSK’s pandemic adjuvant system, when coupled with a COVID-19 antigen, can elicit a robust immune response with an acceptable reactogenicity profile.
"It is also clear that multiple vaccines will be needed to contain the pandemic. Our aim now is to work closely with our partner Sanofi to develop this vaccine, with an improved antigen formulation, for it to make a meaningful contribution to preventing COVID-19.”
The companies would have been be 14th to embark on Phase III studies on potential vaccines, had the Phase II trial gone according to plan.
