11th Dec 2020 08:41
(Alliance News) - GlaxoSmithKline PLC and Sanofi SA on Friday said their Covid-19 vaccine has been delayed to the end of 2021 after interim study result found an insufficient response in older patients.
The phase 1/2 study's interim results showed an immune response that was comparable to patients who had recovered from Covid-19 in adults aged 18 to 49, but a low immune response in older adults.
The companies said that this lower immune response in older patients was likely the result of "an insufficient concentration of the antigen". An antigen is a substance that causes the immune system to make antibodies that would fight the virus.
Brentford, England-based Glaxo and Paris-based Sanofi pointed out that a recent challenge study in non-human primates using an improved antigen formulation showed that the vaccine candidate was able to "protect against lung pathology and lead to rapid viral clearance from the nasal passages and lungs, within 2 to 4 days".
This result boosts both drug makers' confidence in the ability of its adjuvanted recombinant platform to deliver an efficient vaccine for all adults.
"Sanofi's recombinant technology and GSK's pandemic adjuvant are established vaccine platforms that have proven successful against influenza. The recombinant technology offers the advantages of stability at temperatures used for routine vaccines, the ability to generate high and sustained immune responses, and the potential to prevent virus transmission," the two companies said.
The two firms plan to begin a phase 2b study in February 2021 with an improved antigen formulation, which will include a proposed comparison with an already authorised Covid-19 vaccine.
With positive data, a global phase 3 study could begin in the second 2021 quarter, and positive results from that would lead to regulatory submissions in the second half of 2021.
Overall, this means the vaccine potential availability has moved to the fourth 2021 quarter from the mid-2021 initial target.
Sanofi and Glaxo said they have updated governments and the European Commission, where a contraction commitment to buy the vaccine has been made.
Roger Connor, President of GSK Vaccines added: "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."
Shares in Glaxo were up 0.1% at 1,415.60 pence in London on Friday morning. Shares in Sanofi were down 1.9% at EUR80.24 in Paris.
By Anna Farley; [email protected]
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