VLA-1553 Chikungunya Vaccine Description
VLA1553 is a monovalent, single dose, live-attenuated vaccine candidate. VLA1553 is based on an infectious clone (CHIKV LR2006-OPY1) attenuated by deleting a major part of the gene encoding the non-structural replicase complex protein nsP3, aiming for protection against various Chikungunya virus outbreak phylogroups and strains.
VLA1553 is currently the only chikungunya vaccine candidate in clinical development showing fully sustained titers 1-year after a single vaccination, through the accelerated approval.
Chikungunya fever, a disease caused by the chikungunya virus (CHIKV), reemerged and affected over 52,000 people in southern Thailand in 2008 and 2009. The CHIKV strain involved in this outbreak was the East Central South African (ECSA) strain with the E1-A226V mutation.
Chikungunya disease, which results in incapacitating arthralgia, has been reported worldwide. Chikungunya virus, a Togaviridae virus, is a mosquito-borne alphavirus that circulates predominantly in tropical and subtropical regions, potentially affecting over 1 billion people. Recently, an outbreak began in the western hemisphere.
VLA-1553 Chikungunya Vaccine Indication
The VLA1553 vaccine candidate is designed for prophylactic, active, single-dose immunization against Chikungunya in humans over 1-year-old. The vaccine targets long-lasting protection and an anticipated safety profile similar to licensed vaccines for active immunization in adults and children.
The Chikungunya virus causes clinical illness in 72-92 percent of infected humans around 4 to 7 days after an infected mosquito bite. Complications resulting from the disease include visual, neurological, heart, and gastrointestinal manifestations; fatalities have been reported (case fatality rates of 0.1% to 4.9% from epidemics) in elderly patients at higher risk.
VLA-1553 Chikungunya Vaccine Dosage
VLA1553 is administered intramuscularly. The dosing is being evaluated in clinical trials.
At professional clinical trial centers in Illinois and Alabama, USA, healthy volunteers aged 18–45 years were randomly assigned (1:1:2) to one of three escalating dose groups (low dose 3·2 × 10 3 per 0·1 mL; medium dose 3·2 × 10 4 per 1 mL; or high dose 3·2 × 10 5 50% tissue culture infection dose per 1 mL) and received a single-shot immunization on day 0. Individuals in all groups were revaccinated with the highest dose on either month 6 or 12, and followed up for 28 days after revaccination.
VLA-1553 Chikungunya Vaccine Updates
- June 1, 2020 - A new study published in The Lancet found the live-attenuated CHIKV vaccine was well tolerated and highly immunogenic in an adult population and could be an effective intervention for prophylaxis of chikungunya disease worldwide.
- May 7, 2020 - Valneva Reports Q1 Results and Updates 2020 Guidance. Valneva is currently advancing all activities, including its Contract Research Organization (CRO), to allow Phase 3 initiation as soon as the COVID-19 situation permits. As previously announced, the Company’s assumption is that it may start Phase 3 clinical studies in the fourth quarter of this year, which is three months later than originally planned.
- May 5, 2020 - Valneva SE and Instituto Butantan announced the signing of a binding term sheet for the development, manufacturing, and marketing of Valneva’s single-shot chikungunya vaccine, VLA1553, in Low and Middle-Income Countries (LMICs). Valneva held its End of Phase 2 meeting with the U.S. Food and Drug Administration (FDA) in February 2020 and is now preparing to initiate Phase 3 clinical studies in the U.S. later in 2020.
- March 25, 2020 – Valneva SE announced that it has successfully completed an End-of-Phase 2 meeting with the U.S. FDA and agreed on the clinical development plan towards licensure for its unique, single-shot chikungunya vaccine VLA1553.
- January 24, 2020 - The Company’s assumption is that it may start Phase 3 in the fourth quarter of 2020, representing approximately a delay of 3 to 6 months compared to its original plans.
- January 7, 2020 – An End Of Phase 2 meeting has been scheduled with the U.S. Food and Drug Administration on February 24, 2020, for the chikungunya vaccine candidate VLA1553.
- November 18, 2019 - Final Phase 1 results up to Month 13 confirm the excellent immunogenicity and safety profile for VLA1553, its single-shot vaccine candidate. The final results showed an excellent immunogenicity profile in all vaccinated dose groups after a single vaccination, with a 100 percent seroconversion achieved at Day 14 after a single vaccination, in all dose groups, and titers were sustained at 100 percent at Month 12.
- December 21, 2018: VLA1553 was granted Fast Track designation by the US Food and Drug Administration (FDA).
VLA-1553 Chikungunya Vaccine Clinical Trials
Clinical Trial NCT03382964: A Phase 1 Study to Assess the Safety and Immunogenicity of a Chikungunya Virus Vaccine Candidate (VLA1553) in Healthy Volunteers. On May 22, 2019: Phase 1 unblinded results up to month 7 showed excellent immunogenicity and safety profile confirming Valneva's unique, single-shot vaccine candidate. These results strongly support further development acceleration. Then on June 1, 2020, The Lancet published a summary of this phase 1 study.
On March 25, 2020, Valneva announced that it has successfully completed an End-of-Phase 2 meeting with the U.S. FDA.
A Phase 3 pivotal trial will be, subject to detailed protocol review, a double-blinded, placebo-controlled, multi-center study in approximately 4,000 healthy adults. Subjects will be randomized into two study groups to receive either vaccine or placebo; a subset will be tested for seroprotection. The primary endpoint of the study will be to demonstrate safety and immunogenicity after a single-shot vaccination with VLA1553 on Day 29 (one month after immunization). The final analysis will be conducted on Day 180 (six months after immunization). The total duration of the study is expected to be nine months.