Pfizer and Valneva are delaying the regulatory filing of their Lyme disease vaccine by a year after they had to remove half of the participants from a Phase 3 trial in February due to Good Clinical Practice (GCP) violations discovered at some of the trial sites run by third-party operator Care Access.
The companies dropped participants from the late-stage trial called VALOR and aimed to enroll 6,000 people for a primary efficacy readout this quarter. Pfizer will absorb the additional enrollment expenses, and participants already enrolled will receive their booster shot in Q2 2024.
The trial will start enrolling participants for initial vaccinations this quarter for the 2023 season, and data from the year 2025 will be incorporated into the study. Valneva reports that Pfizer intends to submit a biologics license application for approval of VLA15 in 2026, representing a one-year shift.
Lyme disease is an infectious ailment caused by bacteria that is spread through the bite of ticks that have been infected. The symptoms associated with the condition may include skin rashes, headaches, dizziness, and inflammation of the brain and spinal cord, as well as other symptoms. Antibiotics are the typical treatment, but there is no vaccine available. VLA15, Pfizer and Valneva’s candidate is a multivalent protein subunit vaccine designed to target six serotypes of the bacteria Borrelia burgdorferi that causes the disease.
The objective of the Phase 3 study was to enroll 18,000 individuals who are in good health, reside in regions where Lyme disease is prevalent, and have lifestyles that increase their susceptibility to tick bites.
The larger study was set to administer either a placebo or three doses of the experimental vaccine. The trial site operator Care Access disagreed with Pfizer’s decision to discontinue the participants, and the sites run by Care Access are listed as withdrawn or active, not recruiting, on the trial record for the VALOR study.
Those who are currently participating in the study will be able to receive their scheduled booster shot in the second quarter of 2024. 2023 season enrollment for primary vaccinations will begin before end of June, and data from the 2025 season will be included in the trial. There is no vaccine for Lyme disease available as of now and the disease is common in Europe and the States.
Following the encouraging results from a prior Phase 2 trial in both adults and children, the companies went ahead with their Phase 3 study. While the delay is disappointing, it is hoped that the trial will ultimately lead to the availability of a vaccine to help combat the spread of Lyme disease.
Valneva and Pfizer’s VLA15 is a promising candidate for a much-needed Lyme disease vaccine. The Phase 3 study aimed to enroll 6,000 participants aged five and older, but was set back when good clinical practice violations were discovered at certain clinical trial sites run by third-party operator Care Access.
Despite the setback, Valneva and Pfizer are committed to pursuing regulatory approval for their vaccine, with Pfizer enrolling additional participants to make up for those removed from the trial. The companies have now pushed back their regulatory filing by a year and plan to submit it for approval in 2026.