Pfizer, Valneva push back Lyme disease vaccine filing to 2026 after cutting half of participants

Pfizer and Valneva are pushing back a regulatory filing for their Lyme disease vaccine by a year after the companies were forced to pull half of the participants from a phase 3 study in February.

The study took a sideways turn earlier this year when good clinical practice violations were discovered at some sites in the U.S. that were run by third-party trial operator Care Access. The companies had to drop participants from the late-stage trial of VLA15 called VALOR.

Other sites not run by that specific trial operator kept going and Pfizer has been enrolling to make up for the lost participants at the existing sites and new ones in the U.S. and Canada. The companies had aimed to enroll 6,000 people for a primary efficacy readout this quarter.

Now, Pfizer intends to submit a biologics license application to the FDA and EU regulators for approval of VLA15 in 2026, Valneva reported in a first-quarter earnings report Thursday. This represents a one-year shift. Pfizer will bear the additional enrollment costs.

Participants that have already been enrolled will receive their booster shot in the second quarter of 2024 to prepare for the 2024 tick season. Enrollment for primary vaccinations will occur this quarter for the 2023 season. The trial will also include data from the 2025 season, Valneva explained in the report.

The trial originally got underway in August 2022 with an overall enrollment goal of 18,000 healthy people who live in areas with endemic Lyme disease and lead lifestyles that put them at increased risk of being bitten by ticks. Participants are receiving either VLA15 or placebo to assess the ability of the multivalent protein subunit vaccine to reduce the risk of catching Lyme disease.

The trial site operator Care Access disagreed with Pfizer’s decision to discontinue the participants, according to a February statement. The dozens of sites run by Care Access are listed as withdrawn or active, not recruiting, on the trial record for the VALOR study.