Valneva’s single-shot chikungunya vaccine candidate, VLA1553, has seen positive topline results from its Phase III pivotal trial. VLA1553 was recently awarded breakthrough designation status by the Food and Drug Administration (FDA).

The trial, involving 4,115 adults, aged 18 years and above, across 44 sites in the US, met its primary endpoint of inducing protective CHIKV neutralising antibody titers in 98.5% of participants 28 days after receiving a single dose.

The seroprotection rate result of 98.5% exceeded the 70% threshold (for non-acceptance) agreed with the FDA, to serve as a surrogate of protection that can be utilised in a potential FDA submission of VLA1553 under the accelerated approval pathway.

The vaccine candidate was also highly immunogenic with a GMT of approximately 3,270, confirming the immunogenicity profile seen in a previous Phase I trial of the jab.

On top of that, VLA1553 was highly immunogenic in elderly study participants, who achieved equally high seroprotection rates and neutralising antibody titers as younger adults, as well as an 'equally good safety profile'.

“We are delighted with these Phase III results confirming the compelling profile of our vaccine candidate across all age groups,” said Juan Carlos Jaramillo, chief medical officer of Valneva.

“These first-ever Phase III trial results for a chikungunya vaccine mean that we are a step closer to addressing this major, growing and unmet public health threat. I would like to thank everyone who participated in the trial and who continued to advance the trial during the pandemic. We will continue to work with regulators to bring VLA1553 to market as soon as possible,” he added.

Final trial results are expected within the next six months, Valneva said in a statement.