- Pfizer and partner Valneva have begun a large Phase 3 trial for their Lyme disease vaccine candidate, the companies announced Monday.
- The partners entered a collaboration in 2020 to develop Valneva’s candidate, dubbed VLA15 and at the time in Phase 2 clinical testing. In February, the two companies reported positive results from an additional Phase 2 study, setting the stage for the just-started Phase 3 trial, which will test a three-dose series.
- According to Pfizer and Valneva, VLA15 is the only Lyme disease vaccine candidate in development. A previously available vaccine, called Lymerix and developed by GSK, was withdrawn in 2002 due to consumer complaints and low demand.
Lyme disease is common in the U.S. The disease is caused by a bacterium that is transferred to humans from infected ticks. Symptoms include fever, rash, fatigue and other flu-like effects.
The condition can be treated with antibiotics if caught early enough. But if left untreated or caught too late, lyme disease can cause arthritis, affect the heart and attack the nervous system.
Its prevalence in the U.S. is growing, with most cases popping up in July, when more people are outdoors, according to the Centers for Disease Control and Prevention. With Lymerix withdrawn, there is no preventive option available, although there is a Lyme disease vaccine for animals.
Pfizer and Valneva’s study — dubbed VALOR, or Vaccine Against Lyme for Outdoor Recreationists — will enroll 6,000 participants aged 5 years or older in Europe and the U.S. After the three-dose primary series, participants will receive either a booster dose of VLA15 or a saline placebo.
If the study is successful, the companies expect they could approach regulators about approval as early as 2025.
VLA15 would be the first Lyme disease vaccine since Lymerix if it reaches market. According to The New Yorker, drugmakers did not want to invest in another vaccine after lawsuits against GSK, which were fueled by consumer beliefs the company had withheld information on the vaccine’s dangers. GlaxoSmithKline denied the allegations and settled the lawsuits in 2003.
The episode was an example of how communication over vaccines and their side effects can be difficult and easily distorted, as has happened with COVID-19 shots.