First Chikungunya Vaccine Approaches Launch

Today, France-based Valneva SE's published positive topline results from the Phase 3 pivotal clinical trial of its chikungunya vaccine candidate, VLA1553. The trial, involving 4,115 adults across 44 sites in the USA, met its primary endpoint inducing protective Chikungunya neutralizing antibody titers in 98.5% of participants 28 days after receiving a single shot.

The seroprotection rate result of 98.5% exceeded the threshold agreed with the U.S. Food and Drug Administration (FDA). And the single-dose vaccine candidate was found highly immunogenic with a GMT of approximately 3,270, confirming the immunogenicity profile seen in the Phase 1 trial.

Additionally, VLA1553 was also highly immunogenic in elderly study participants.

And VLA1553 was generally well-tolerated among the trial subjects evaluated for safety.

An independent Data Safety Monitoring Board continuously monitored the study and identified no safety concerns. The safety profile is consistent with results from the Phase 1 clinical trial. The majority of solicited adverse events were mild or moderate and resolved within 3 days. However, 1.6% of study participants reported severe solicited adverse events, most commonly fever.

Approximately 50% of study participants experienced solicited systemic adverse events, most commonly headache, fatigue, and myalgia (seen in more than 20% of subjects).

The local tolerability profile showed that approximately 15% of participants experienced solicited local adverse events.

Juan Carlos Jaramillo, M.D, Chief Medical Officer of Valneva, commented in a press release, “These first-ever Phase 3 trial results for a chikungunya vaccine mean that we are a step closer to addressing this major, growing and unmet public health threat."

"We will continue to work with regulators to bring VLA1553 to market as soon as possible.”

The trial will continue towards the final analysis, including the 6-month safety data expected within the next six months. The sponsor of the first chikungunya vaccine approved in the U.S. will be eligible to receive a Priority Review Voucher.

The FDA awarded the VLA1553 program Breakthrough Therapy Designation in July 2021. This new milestone came in addition to the FDA Fast Track designation and the European Medicines Agency’s PRIME designation, which the Company received in December 2018 and in October 2020, respectively.

Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus (CHIKV), a Togaviridae virus transmitted by Aedes mosquitoes. The infection leads to symptomatic disease in 72-92% of humans after 4 to 7 days following the mosquito bite. While mortality with CHIKV is low, morbidity is high, says the U.S. CDC. The chikungunya virus has spread to more than 100 countries.

As of July 27, 2021, the CDC reported five chikungunya virus disease cases during 2021.

To make VLA1553 more accessible to Low and Middle-Income Countries, Valneva and Instituto Butantan in Brazil signed an agreement for the development, manufacturing, and marketing of VLA1553. The collaboration falls within the framework of the funding agreement between Valneva and the Coalition for Epidemic Preparedness Innovations signed in July 2019, which provides funding of up to $23.4 million with support from the European Union’s Horizon 2020 program.

Located in Saint Herblain, France, Valneva is a specialty vaccine company focused on developing and commercializing prophylactic vaccines for infectious diseases with significant unmet medical need.