Pfizer, Valneva report positive pediatric, adolescent phase 2 booster results for Lyme disease vaccine

Depending on the primary schedule they received (month 0-2-6 or month 0-6), participants seroconverted after the booster dose, yielding seroconversion rates (SCRs) of 95.3% and 94.6% for all outer surface protein A (OspA) serotypes in all age groups, respectively. Additionally, OspA antibody titers were significantly higher one month after the booster dose compared to one month after the primary schedule with 3.3- to 3.7-fold increases (Geometric Mean Fold Rises) in adults, 2.0- to 2.7- fold increases in adolescents and 2.3- to 2.5-fold increases in children for all serotypes.

Juan Carlos Jaramillo M.D., Chief Medical Officer of Valneva, said, “We are pleased with these data which validate the use of a booster dose in all age groups. Lyme disease continues to spread, representing an important unmet medical need that impacts the lives of many people in the Northern Hemisphere. With each new set of positive data, we come one step closer to potentially bringing this vaccine to both adults and children living in areas where Lyme disease is endemic.”

The Phase 2 booster results emphasize the vaccine candidate’s potential to provide immunity against Lyme disease in pediatric and adolescent populations. Geometric Mean Titers (GMTs) one month following the booster dose were similarly high for children and adolescents.

The safety and tolerability profile of VLA15 after a booster dose was consistent with previous studies as the vaccine candidate was well-tolerated in all age groups regardless of the primary vaccination schedule. No vaccine-related serious adverse events (SAEs) and no safety concerns were observed by an independent Data Safety Monitoring Board (DSMB).

“Protection against Lyme disease is important for anyone who lives or spends time outdoors in areas where Lyme disease is endemic. This data from the VLA15-221 study is vital to improve our understanding of how vaccination may help to protect both adults and children from this potentially devastating disease,” said Annaliesa Anderson, Ph.D., Senior Vice President and Head Vaccine Research and Development at Pfizer. “We are encouraged by the positive Phase 2 results for VLA15, and, in partnership with Valneva, look forward to continuing to study the vaccine candidate in ongoing Phase 3 clinical trials.”

These results follow six-month antibody persistence data in children and adults reported for the VLA15-221 study in December 20221 and positive immunogenicity and safety data reported in April 20222.

In August 2022, Pfizer and Valneva initiated the currently ongoing Phase 3 clinical study, Vaccine Against Lyme for Outdoor Recreationists (VALOR) (NCT05477524), to investigate the efficacy, safety and immunogenicity of VLA15 in participants five years of age and older in highly endemic regions in the United States (U.S.) and Europe. A second Phase 3 study (VLA15-1012), aiming to provide further evidence on the safety profile of VLA15 in the pediatric population, is also ongoing.

"Pfizer aims to submit a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) and Marketing Authorisation Application (MAA) to the European Medicines Agency (EMA) in 2026, subject to positive Phase 3 data," the Company stated.

Read also: Majority of children getting treatment for Lyme disease improve in 6 months