Phase 1 unblinded results up to month 7 showed an 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
o Well-tolerated in the low and medium dose. (Superior safety profile, including viremia, compared to the high dose group)
o Excellent local tolerability
Excellent immunogenicity profile in all dose groups after a single vaccination
o 100% Seroconversion1 achieved at Day 14 after a single vaccination in all dose groups
o Sustained at 100% after six months
Valneva SE (“Valneva” or “the Company”), a biotech company developing and commercializing vaccines for infectious diseases with major unmet medical needs, has announced further positive Phase I results for its chikungunya vaccine candidate, VLA1553.
The objectives of VLA1553-101 Phase I study were to assess the overall safety and immunogenicity profile after a single vaccination across three dose levels. This analysis (Part B) of the ongoing study includes the overall safety and immunogenicity
results up to Month 7, unblinded on a group level and including first results from the “intrinsic human viral challenge”.
VLA1553 was generally safe in all dose groups. The low and medium dose groups were well tolerated and showed a superior safety profile, including viremia, compared to the high dose. No adverse events of special interest (e.g. chikungunya infection related) were reported up to month 7 and the product candidate´s local tolerability profile was excellent.
The results showed an excellent immunogenicity profile in all vaccinated dose groups after a single vaccination with a 100% Seroconversion achieved at Day 14 after a single vaccination in all dose groups and fully sustained at 100% at Month 6.
A subset of study subjects were re-vaccinated after 6 months. For those subjects there was no anamnestic response observed which demonstrates that a single vaccination of VLA1553 is sufficient to induce sustaining, high titer, neutralizing antibodies. Vaccinees were protected from vaccine induced viremia serving as “intrinsic human viral challenge“.
Wolfgang Bender, M.D., Ph.D., Chief Medical Officer of Valneva commented, “We are thrilled about these exciting results confirming that we have identified a highly immunogenic and safe final product candidate which we now aim to progress into pivotal trials as quickly as possible. In addition and as hoped, the data indicate that vaccinated subjects are protected from chikungunya viremia. This marks a very important milestone getting us a step closer to a highly competitively differentiated vaccine addressing a serious threat to public health.”
Valneva is committed to advancing its chikungunya vaccine candidate as quickly as possible and expects to be in a position to announce a plan, agreed with regulators, to licensure for its FDA fast tracked candidate VLA1553 at its planned R&D investor day, July 9th in New York (details to be announced at a later point in time)
About The Phase I Clinical Study VLA1553-101
This study is a randomized, observer-blinded, multicenter, dose-escalation Phase I clinical study investigating three dose levels of VLA1553 after a single immunization. The study enrolled 120 healthy volunteers, 18 to 45 years of age, in the United States. Subjects were randomized in three different study groups to receive one of three dose levels (30 subjects in the low and medium and 60 subjects in the high dose group). The protocol includes a re-vaccination 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 Chikungunya viremia (intrinsic viral challenge). Study participants will be followed up until 13 months after initial vaccination.
An independent Drug Safety Monitoring Board (DSMB) continuously oversees the study and reviews data.
Additional information, including a detailed description of the study design, eligibility criteria and investigator sites, is available at ClinicalTrials.gov (NCT03382964).
Chikungunya is a mosquito-borne viral disease caused by the Chikungunya virus (CHIKV), a Togaviridae virus, transmitted by Aedes mosquitoes. Clinical symptoms include acute onset of fever, debilitating joint and muscle pain, headache, nausea and rash, potentially developing into long-term, serious health impairments. Chikungunya virus causes clinical illness in 72-92% 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. Chikungunya outbreaks have been reported in Asia, Africa, the Americas and
recently (2017) in Europe. As of 2017, there have been more than one million reported cases in the Americas and the economic impact is considered to be significant (e.g. Colombia outbreak 2014: $73.6m). The medical and economic burden is expected to grow as the CHIKV primary mosquito vectors continue to further spread geographically. There are no preventive vaccines or effective treatments available and, as such, Chikungunya is considered to be a major public health threat.
VLA1553 is a monovalent, single dose, live-attenuated vaccine candidate for protection against Chikungunya and was granted Fast Track designation by the U.S. Food and Drug Administration (FDA) in December 2018. The vaccine candidate is designed for prophylactic, active, single-dose immunization against Chikungunya in humans over one 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 target population segments are travelers, military personnel and individuals at risk living in endemic regions. The global market
for vaccines against Chikungunya is estimated at up to €500 million annually. 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. In pre-clinical development, a single-vaccine shot was shown to be highly immunogenic in vaccinated Non-Human Primates (NHP) (cynomolgus macaques) and showed no signs of viremia after challenge. In NHPs, VLA1553 induced a strong, long lasting (more than 300 days) neutralizing antibody response comparable to wild-type CHIKV infections, combined with a good safety profile.