Pfizer Lyme Disease Vaccine: 70% Efficacy & FDA Approval Bid

Pfizer will seek regulatory approval for a Lyme disease vaccine candidate despite the shot failing to meet the statistical goals of a late-stage trial, the company announced Monday. The decision, made in collaboration with Valneva, its French partner, hinges on observed efficacy exceeding 70% in preventing Lyme disease, even as the trial did not accrue as many cases of the illness as anticipated.

The Phase 3 VALOR trial, involving 9,437 participants aged five years and older across the U.S., Canada, and Europe, demonstrated 74.8% efficacy in reducing confirmed Lyme disease cases compared to a placebo, according to a joint statement from Pfizer and Valneva. A separate analysis showed 73.2% efficacy at a slightly later timepoint. However, the trial’s primary endpoint – a pre-determined confidence interval – was not met, due to a lower-than-expected incidence of Lyme disease among study participants.

“Given the clinically meaningful efficacy and the fact that the 95% confidence interval lower bound was above 20 in the second pre-specified analysis, Pfizer is confident in the vaccine’s potential and is planning submissions to regulatory authorities,” Pfizer stated. The companies are now preparing to submit data to the Food and Drug Administration (FDA) for review.

Analysts at RBC Capital Markets described the results as “mixed,” noting the missed primary endpoint, but acknowledged the potential for a favorable reception at the FDA, particularly given the current administration’s stance on vaccine scrutiny. Health and Human Services Secretary Robert F. Kennedy Jr.’s views on vaccine policy could influence the regulatory process, according to the analysis.

Valneva previously estimated peak annual sales for the Lyme disease vaccine could exceed $1 billion, though Pfizer anticipates the vaccine will not be a major revenue driver, forecasting overall revenue of approximately $60 billion this year, with its COVID-19 vaccine contributing over $5 billion. Despite not being expected to be a blockbuster, Pfizer had highlighted the Lyme vaccine results as a key catalyst for the year, representing a potential first-in-class human vaccine for the disease.

The vaccine candidate, known as PF-07307405 (LB6V), is a 6-valent OspA-based vaccine. The companies reported the vaccine was well-tolerated, with no significant safety concerns identified during the trial. Pfizer expects to move forward with regulatory submissions despite the statistical complexities of the trial results.