New Zika Vaccine for adults granted fast track designation by FDA

The U.S. Food and Drug Administration (FDA) has granted Fast Track designation to an investigational Zika vaccine (mRNA-1893) currently being evaluated in Phase 1 clinical trial for the prevention of Zika virus infection in healthy adults.

Zika virus has rapidly emerged in recent years as a pandemic with potential long-term public health implications. Zika is primarily transmitted by mosquitos, but can also be transmitted sexually. Children born to mothers infected with Zika can develop microcephaly, a severe disease characterized by small, not fully developed heads and severe disabilities. In adults, outbreaks in Latin American and Caribbean countries have been associated with Guillain-Barre syndrome, a rare but serious autoimmune disorder in which the immune system attacks part of the nervous system. There is no approved vaccine for Zika.

The vaccine contains a messenger RNA (mRNA) sequence encoding for the structural proteins of Zika virus and is designed to cause cells to secrete virus-like particles, mimicking the response of the cell after natural infection. The Preclinical data of the vaccine was published in The Journal of Infectious Diseases which showed that vaccination with mRNA-1893 can provide protection against transmission of Zika virus during pregnancy in mice. mRNA-1893 is currently in a Phase 1 study evaluating safety, pharmacokinetics, and pharmacodynamics in healthy volunteers.

The phase 1 trial is a randomized, observer-blind, placebo-controlled, dose-ranging study designed to evaluate the safety, tolerability and immunogenicity of mRNA-1893 in healthy flavivirus seropositive and seronegative adults ages 18 to 49 years. Primary outcome measures include frequency and grade of adverse events. Secondary outcome measures include geometric mean titers of neutralizing antibodies against Zika virus.

Fast Track is designed to facilitate the development and expedite the review of therapies and vaccines for serious conditions and fill an unmet medical need. Programs with Fast Track designation may benefit from early and frequent communication with the Food and Drug Administration, in addition to a rolling submission of the marketing application. Moderna previously received Fast Track designation for its methylmalonic acidemia (MMA) program (mRNA-3704), which is now recruiting patients for a Phase 1/2 clinical study.

“Protecting against Zika virus transmission, particularly in women during pregnancy, continues to be an area of high unmet need. Fast Track designation supports our belief in the clinical potential of mRNA-1893 and the importance of developing an effective vaccine that can be rapidly developed and deployed,” said Tal Zaks, M.D., Ph.D., chief medical officer at Moderna. “Our Zika program is part of Moderna’s broader commitment to improving global public health through developing mRNA vaccines to prevent the spread of infectious diseases.”