Pfizer (NYSE:PFE) and Valneva (NASDAQ:VALN) today announced topline results from the Phase 3 VALOR study evaluating their 6-valent OspA-based Lyme disease vaccine candidate, PF-07307405.
The trial demonstrated a clinically meaningful efficacy rate of 73.2% in reducing confirmed Lyme disease cases starting 28 days after the fourth dose.
A second pre-specified analysis showed an efficacy of 74.8% beginning just one day after the fourth dose.
The study encountered a statistical hurdle as the primary endpoint did not meet the pre-determined criterion of a 95% confidence interval lower bound greater than 20.
Management attributed this to a lower-than-anticipated number of Lyme disease cases accrued during the study period, which impacted the statistical power of the first analysis.
However, the second pre-specified analysis did successfully clear this threshold, providing the companies with the confidence necessary to proceed with global regulatory filings.
Currently, there is no vaccine available for Lyme disease, a condition that can lead to long-term neurological and cardiac complications if left untreated.
The investigational vaccine targets the outer surface protein A (OspA) of Borrelia burgdorferi, the bacteria that causes the disease.
By neutralizing the bacteria within the tick before it can infect the human host, the vaccine offers a unique preventative mechanism.
Annaliesa Anderson, Pfizer’s Chief Vaccines Officer, noted that the efficacy exceeding 70% is highly encouraging given the debilitating nature of the illness.
Under the terms of their 2020 collaboration agreement, Pfizer holds the exclusive rights to manufacture and commercialize the vaccine, assuming it receives the green light from health authorities.
Valneva, which originally developed the candidate, remains a co-development partner.