Ixchiq was approved through the FDA Accelerated Approval pathway.
The FDA has announced the approval of Ixchiq, the first licensed vaccine for chikungunya virus, for use in adults aged 18 years and older who are at increased risk of exposure.1,2
“Infection with chikungunya virus can lead to severe disease and prolonged health problems, particularly for older adults and individuals with underlying medical conditions,” said Peter Marks, MD, PhD, director of the Center for Biologics Evaluation and Research. “Today’s approval addresses an unmet medical need and is an important advancement in the prevention of a potentially debilitating disease with limited treatment options.”
Ixchiq, a live attenuated vaccine, is administered via a single dose injected intramuscularly. The vaccine may cause symptoms “similar to those experienced by people who have chikungunya disease.”1
Vaccine manufacturer Valneva initially reported final data from a pivotal phase 3 randomized, placebo-controlled, double-blind, multicenter clinical trial (NCT04546724) in March 2022.3 Results of that trial, which were later published in The Lancet,4 showed that the vaccine met all primary and secondary endpoints: proportion of participants with seropositive chikungunya virus antibody level and immune response measured by chikungunya virus-specific neutralizing antibody titers at 7, 28, and 84 days.
A total of 4115 enrolled participants were randomly assigned 3:1 to receive the vaccine (VLA1553) or placebo. Data from the final analysis “confirmed the very high level of seroprotection,”3 with 98.9% of participants reaching a protective level of virus neutralizing antibodies 1 month after receiving a single vaccination. Immunogenicity was maintained over time, with 96.3% of participants demonstrating protective titers at 6 months postvaccine. The vaccine was also demonstrated to be “highly immunogenic” in adults aged 65 years of age or older.
“The first-ever licensed chikungunya vaccine will play a crucial role in preventing the suffering caused by this debilitating disease,” said Richard Hatchett, CEO of the Coalition for Epidemic Preparedness Innovations (CEPI).2 “Climate change is intensifying the threat posed by chikungunya, which means safe and effective vaccines are needed now more than ever before.”
It is estimated that more than 75% of the world’s population lives in an area at risk for chikungunya virus transmission due to global warming and climate change, said Juan Carlos Jaramillo, MD, chief medical officer at Valneva. “Chikungunya has already spread to over 110 countries and is currently regarded as one of the most likely viral infections to emerge in new geographic areas.”2
The most commonly reported adverse effects included headache, fatigue, muscle pain, joint pain, fever, nausea, and tenderness at the injection site. A total of 1.6% of participants who received the vaccine experienced severe chikungunya-like adverse reactions that either prevented daily activity and/or required medical intervention. Prescribing information includes a warning for this adverse reaction. Additionally, the FDA is requiring Valneva to conduct a postmarketing study evaluating the serious risk of severe chikungunya-like adverse reactions following vaccine administration.1
Ixchiq was approved through the FDA’s Accelerated Approval pathway, using evidence of effectiveness based on immune response data in trial participants; it was also granted Fast Track and Breakthrough Therapy designations, and the application was granted Priority Review. As a condition for approval, confirmatory studies verifying the clinical benefit are also being required by the FDA. A clinical study of adolescents aged 12 to 17 years is ongoing in Brazil, in an effort to make the vaccine more accessible in low- and middle-income countries.
Chikungunya is a mosquito-borne viral disease transmitted by Aedes mosquitoes. Up to 97% of individuals infected experience symptomatic disease within 4 to 7 days of being bitten. Although mortality is low, morbidity is high; symptoms include acute onset of fever, debilitating joint and muscle pain, headache, nausea, rash, and chronic arthralgia. The virus frequently causes large and sudden outbreaks with high attack rates—affecting between one-third and three-quarters of the population in areas with viral circulation.
Ixchiq is anticipated to be available in the United States early next year, “while continuing to support the work towards an anticipated vote from the Advisory Committee on Immunization Practices (ACIP) at the end of February 2024.”