PaxVax Chikungunya Vaccine Granted Fast Track Designation by FDA

The US Food and Drug Administration (FDA) recently granted Fast Track designation to PaxVax’s vaccine for the prevention of chikungunya virus. Currently, there are no licensed vaccines available to protect against the disease.

Transmitted to individuals via infected mosquitoes, chikungunya remains a significant public health threat. This threat was underscored in a recent report released by the Centers for Disease Control and Prevention (CDC) which informed the public that the number of vector-borne cases has tripled in the United States since 2004.

Chikungunya was among the new vector-borne pathogens listed in the report as it was found for the first time in the Americas on the islands in the Caribbean and first introduced to Puerto Rico in 2014. Since it was first reported, the disease was identified in 45 countries in the Americas alone, and with 1.7 million suspected cases having been reported to the Pan American Health Organization, the risk posed to travelers continues to increase and the need for a vaccine becomes exceedingly more apparent.

“As there are currently no therapies or vaccines available for treatment or prevention of chikungunya, we are in desperate need of a medical and public health intervention,” Eva Harris, PhD, professor, Division of Infectious Diseases and Vaccinology and director of the Center for Global Public Health at the University of California, Berkeley, stressed in a recent statement.

To fill this unmet need, PaxVax has been working on a vaccine candidate in partnership with the National Institutes of Health (NIH) as well as the US Department of Defense for the prevention of chikungunya. The virus-like particle (VLP) vaccine technology for chikungunya was licensed from the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) is currently being tested in phase 2 trials.

The company recently announced that they have enrolled the first patient in their phase 2b dose-finding trial for the vaccine, which will build on the phase 2a study. Investigators are currently enrolling 400 subjects for the trial to assess multiple dosing regimens for the vaccine, and results are expected in early 2019.

“This Fast Track Designation is another positive step for the development of our chikungunya vaccine, in addition to our recent Phase 2b initial patient enrollment and is a clear recognition of the serious unmet need,” Lisa Danzig, MD, PaxVax’s chief medical officer said in a recent statement. “This is another example of the capabilities of our technology platform and our steadfast commitment to developing specialty vaccines that protect against overlooked infectious diseases as mosquito-borne diseases continue to increase due to air travel and warmer weather.”

In a recent media briefing, Lyle Peterson, MD, MPH, director of the division of Vector-borne Diseases at the CDC stressed that many vector-borne diseases are very complicated in nature and sensitive to temperatures. It is known that mosquito-borne diseases such as chikungunya tend to get worse during heatwaves, and, as such, many outbreaks tend to spring up in warmer months.

As there is no vaccine yet available, the only way for individuals to prevent chikungunya infection is to try to prevent mosquito bites, and the mosquitoes that transmit chikungunya are known to bite during the day as well as at night. The CDC recommends that individuals use Environmental Protection Agency (EPA)-registered insect repellants with ingredients such as DEET, Picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol, or 2-undecanone. These ingredients have proven to be safe and effective, even for women who are pregnant or breastfeeding.

However, if clinical development progresses, the PaxVax vaccine could potentially become the first vaccine approved by the FDA for the prevention of chikungunya.