The finish line is in sight for Valneva’s chikungunya virus (CHIKV) vaccine candidate. With antibody levels holding steady out to six months in the phase 3 clinical trial, Valneva is set to start the pre-submission process with the FDA in the second quarter.
Valneva posted top-line results from the phase 3 clinical trial last summer. The primary endpoint result is largely unchanged from that data drop, with the removal of two subjects from the analysis increasing the proportion of participants with protective neutralizing antibody titers from 98.5% to 98.9% 28 days after receiving a single shot of VLA1553. But Valneva now also has longer-term immunogenicity data.
After six months, 96.3% of the analyzed subjects had protective levels of CHIKV neutralizing antibodies. The slight decline between the first and sixth months of the trial still leaves Valneva well above the 70% level of seroprotection it expects the FDA to use as a surrogate of protection under its accelerated approval pathway.
Valneva plans to monitor the durability of the antibody response in a subset of participants for at least five years as part of a dedicated persistence trial. But, with top-line lot-to-lot manufacturing consistency results for VLA1553 due in the second quarter, the French biotech is now close to gathering the evidence it will need to file for approval in the U.S.
The plan is to start the pre-submission process with the FDA in the second quarter. If Valneva hits that target and avoids any regulatory setbacks, it should receive a priority review voucher, valued at around $100 million, for becoming the first company to win approval for a chikungunya vaccine in the U.S.
At one point, Valneva was trailing Themis Bioscience, now part of Merck, and Emergent BioSolutions in the race to market. But Themis’ program stalled in phase 2, and Emergent only began a phase 3 clinical trial of its challenger in October.