Pfizer-Valneva Lyme Vaccine Misses Key Trial Target Despite Positive Signals

Pfizer and Valneva have reported that their Lyme disease vaccine candidate, PF-07307405, did not meet the primary endpoint in its Phase III VALOR trial, largely due to a lower-than-expected number of infection cases during the study period.

The trial, involving around 9,400 participants aged five and above, showed the six-valent OspA-based vaccine achieved 73.2% efficacy 28 days after the fourth dose compared to placebo. However, insufficient case numbers meant the results did not reach statistical significance.

Despite this, the companies highlighted clinically meaningful outcomes, noting supportive secondary analyses. They remain optimistic and plan to proceed with regulatory submissions.

Currently, no approved Lyme disease vaccine exists globally. The collaboration between Pfizer and Valneva, established in 2020, continues to focus on addressing this unmet need, even as competing early-stage candidates and treatments remain under development.

30-03-2026