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 one year after a single vaccination, through the accelerated approval.
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.
Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus (CHIKV), a Togaviridae virus, transmitted by Aedes mosquitoes, says the US Centers for Disease Control and Prevention (CDC). 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.
VLA1553 is administered intramuscularly. The dosing is being evaluated in clinical trials.
January 7th, 2020 – An End Of Phase 2 (EOP2) meeting has been scheduled with the U.S. Food and Drug Administration (FDA) 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.
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.
- VLA1553 was generally safe in all dose groups
- Well-tolerated in the low and medium dose. (Superior safety profile, including viremia, compared to the high dose group)
- Excellent local tolerability
- Excellent immunogenicity profile in all dose groups after a single vaccination
- 100% Seroconversion1 achieved at Day 14 after a single vaccination in all dose groups
- Sustained at 100% after six months
May 2, 2019: Valneva reported positive Phase 1 interim results for, VLA1553, its chikungunya vaccine candidate.
- The interim results showed an excellent immunogenicity profile after a single vaccination with a 100% seroconversion rate achieved at Day 28 in a pooled analysis of all vaccinated groups.
- Results also showed that 96.5% of subjects achieved at least a 16-fold increase in antibody titres and a high geometric mean titre, fully supporting VLA1553′s differentiated target product profile.
- The pooled safety profile of all groups was considered acceptable, supporting further development.
- No serious adverse events nor adverse events of special interest were reported up to Day 28 and the local tolerability was considered excellent.
December 21, 2018: VLA1553 was granted Fast Track designation by the US Food and Drug Administration (FDA).
Clinical Trial NCT03382964: A Phase 1 Study to Assess the Safety and Immunogenicity of a Chikungunya Virus Vaccine Candidate (VLA1553) in Healthy Volunteers
- Randomized, observer-blinded, multicenter, dose-escalation Phase 1 clinical study investigating three dose levels of VLA1553 after a single immunization.
- 120 study participants will be enrolled in the study to receive three different doses (30 subjects in the low and medium and 60 subjects in the high dose group). Vaccination will be given intramuscularly on Day 0.
- As a safety precaution, the study will begin with the enrolment of 20 sentinel subjects in an open-label fashion.
- Thereafter, subjects will be enrolled in a blinded, randomized manner in the three study arms.
- A re-vaccination will be given at Month 6 or Month 12 to confirm that a single vaccination will be sufficient to induce high titer neutralizing antibodies and protect subjects from CHIKV viremia.
- Study participants will be followed up until 13 months after initial vaccination.