Sanofi and GlaxoSmithKline are delaying their COVID-19 vaccine program to improve their candidate's immune response in older adults, the drugmakers announced Dec. 11.
The vaccine uses Sanofi's recombinant technology and GSK's pandemic adjuvant. Phase 1/2 study interim results showed the immune response for participants aged 18 to 49 years to be comparable to patients who recovered from COVID-19. However, the immune response for older participants was lower, which the drugmaker predicts is because of an inadequate concentration of the antigen.
"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," Thomas Triomphe, executive vice president and head of Sanofi Pasteur, said in a news release. "We have identified the path forward and remain confident and committed to bringing a safe and efficacious COVID-19 vaccine."
The drugmakers plan to begin a phase 2b study in February, which will include a proposed comparison with a COVID-19 vaccine that has received emergency use authorization from the FDA.