Data from a phase I/II interim study showing an insufficient response in patients age 50 and over has caused Sanofi SA and Glaxosmithkline plc to delay their COVID-19 vaccine program, pushing its expected availability to sometime in the second half of the coming year.
The delay is pegged to data showing older patients in the study demonstrating a low immune response when treated with the vaccine. The companies said the problem could be an insufficient concentration of the neutralizing antigen titers, so they have set to work refining it and are readying a phase IIb study to begin in February for measuring the reformulation. If that study is a success, a phase III could begin sometime in the second quarter of 2021, followed by regulatory submissions in the second half of the year.
Management from both companies took the big picture view and said they would continue pursuing the vaccine program. Thomas Triomphe, Sanofi Pasteur’s executive vice president, said the delay is disappointing “but all our decisions are and will always be driven by science and data.”
Those younger than age 50, however, did well in the phase I/II study as the interim data showed their immune response to the vaccine was comparable to those who have recovered from COVID-19.
The phase I/II, which began in September, is evaluating 441 healthy adults receiving one or two doses of the vaccine or a placebo 21 days apart at 10 sites across the U.S.
Sanofi and Glaxosmithkline were awarded about $2.1 billion in July from the U.S. Operation Warp Speed to support development and large-scale manufacturing of their adjuvanted recombinant protein subunit vaccine, providing the federal government with 100 million doses. The companies also have supply deals with the U.K., Canada and Gavi, an international vaccine alliance.
Meanwhile, the Russian Direct Investment Fund said Astrazeneca plc will incorporate one of two human adenoviral vectors from the Sputnik V vaccine in its clinical trials of AZD-122 by the end of 2020.
Russia’s Sputnik V, a two-shot human adenovirus-based vaccine, hit 92% efficacy. The vaccine, which was developed by the Gamaleya National Center of Epidemiology and Microbiology and funded by the Russian Direct Investment Fund, gained emergency use authorization in Russia on Aug. 11, and 1.2 billion doses-plus are on order from more than 50 countries. Sputnik V comes in a freeze-dried formulation. The vaccine demonstrated 91.4% efficacy in the second interim analysis.
A phase III interim analysis of Astrazeneca plc’s AZD-1222, a chimpanzee adenovirus vectored vaccine, demonstrated that the vaccine is safe and effective at preventing symptomatic COVID-19.