French biotech company Valneva has announced positive data from the Phase I clinical trial of its chikungunya vaccine candidate, VLA1553.
VLA1553 is a single-dose, monovalent, live-attenuated vaccine developed to offer prophylactic, active immunisation against chikungunya virus in individuals aged above one year.
The randomised, multi-centre, observer-blinded, dose-escalation Phase I trial assessed the safety and immunogenicity of three dose levels of the vaccine candidate after a single vaccination.
It involved 120 healthy volunteers aged 18 to 45 in the US. Participants were followed for 13 months after the initial vaccination.
Data indicated that the vaccine candidate was generally safe in all dose groups. Valneva added that the low and medium doses were well tolerated with a superior safety profile, compared to the high dose.
Investigators did not observe any specific adverse events, such as chikungunya infection-related events, or vaccine-related serious adverse events (SAEs) up to month 13.
Results showed a favourable immunogenicity profile with all dose levels after a single vaccination. At day 14, seroconversion was 100% and titres were maintained at 100% at month 12.
The trial involved re-vaccination after either six or 12 months. Re-vaccination did not demonstrate any anamnestic response, indicating the use of a single vaccination to trigger a sustained titre of neutralising antibodies.
In addition, patients who received the second shot were protected against vaccine-induced viremia and associated clinical symptoms.
Valneva chief medical officer Wolfgang Bender said: “These fantastic results confirm that VLA1553 is a highly differentiated and promising vaccine candidate that has the potential to address a serious threat to public health.
“On the basis of all our data, we aim to work with the regulators towards an accelerated approval pathway potentially allowing us to enter directly into pivotal Phase III next year.”
VLA1553 received fast track status from the US Food and Drug Administration (FDA) in December last year.