Valneva, Pfizer's Phase 2 Data Suggests Booster Strategy For Lyme Disease Vaccine Candidate

Valneva SE VALN and Pfizer Inc PFE have announced more positive Phase 2 results, including the booster response, for their Lyme disease vaccine candidate VLA15.
The 246-subject study is evaluating the immunogenicity and safety of VLA15 in a Month 0-2-6 vaccination schedule.
The study met its primary endpoint of demonstrating that VLA15 was immunogenic across all dose groups tested.
Continued evaluation at Month 18 showed that antibody titers declined, remaining above baseline but confirming the need for a booster strategy.
VLA15 was safe and well-tolerated. No related Serious Adverse Events were observed in any treatment group.
Participants who received a complete primary vaccination series with 180 µg doses of VLA15 had an option to continue the study in a booster extension phase to receive an additional 180 µg dose of VLA15 (N=39) or placebo (N=19).
Booster dose elicited a strong anamnestic response yielding a 2.9-fold (ST3) to 4.2-fold (ST1, ST4) increase in anti-OspA IgG antibody titers compared with titers observed after primary immunization.
All participants seroconverted to anti-OspA IgG after the booster dose, meaning Seroconversion Rates were 100% for all OspA serotypes.
The companies are planning for a Phase 3 trial in 2022.
Price Action: PFE stock is down 0.69% at $43.27, and VALN stock is down 2.17% at $29.76 during the premarket session on the last check Tuesday.