March 23 (Reuters) - Pfizer and Valneva said on Monday their Lyme disease vaccine showed more than 70% efficacy in a late-stage study, even as it missed its main goal.
Despite falling short of a key statistical requirement meant to ensure reliability, Pfizer said the overall results give it confidence in the vaccine’s potential and it plans to move ahead with regulatory submissions.
U.S.-listed shares of the French drugmaker tumbled nearly 37% following the update, while Pfizer was marginally down.
The vaccine demonstrated 73.2% efficacy starting 28 days after the fourth dose in reducing confirmed Lyme disease cases, compared to the placebo.
However, the companies said the trial was designed to show that this benefit had a confidence interval of at least 20%. In the first analysis, that figure came in slightly lower at 15.8%, largely because fewer Lyme cases than expected were recorded during the study, limiting the data.
