Themis’ chikungunya vaccine, furthest in development, nabs fast FDA review

Themis secured an FDA Fast Track designation for its vaccine candidate against chikungunya, a mosquito-borne disease. (auimeesri/iStock/Getty Images Plus/Getty Images)

After turning up positive phase 2 data late last year, Themis Bioscience’ chikungunya vaccine candidate has picked up an FDA “fast track” designation that comes with closer assistance from the agency.

The vaccine, MV-CHIK, is Themis’ lead candidate and is also the most advanced chikungunya vaccine program in development. The Austrian company now hopes the label “will greatly support our pivotal Phase 3 development efforts this year,” Themis’ CEO, Erich Tauber, said in a statement.

The FDA previously granted the same designation to chikungunya shots from PaxVax (now part of Emergent BioSolutions), currently in phase 2b, and from Valneva, which is close to wrapping up phase 1.

MV-CHIK, developed using Themis’ measles vector platform licensed from Institut Pasteur, showed encouraging results in phase 2. In the 263-subject study, the vaccine produced neutralizing antibodies against chikungunya virus in all treatment groups, with seroconversion rates reaching up to 95.9%. Besides, pre-existing immunity against the measles vector didn’t affect immunogenicity, the investigators reported in a study published in The Lancet.

RELATED: Themis eyes phase 3 study for chikungunya vaccine after passing midstage test

With the “fast track” designation, Themis will be able to communicate more frequently with the FDA along the development line, and it could be eligible for accelerated approval and priority review, if certain criteria are met.

Last August, the FDA added chikungunya, along with Lassa fever, rabies and cryptococcal meningitis, to a list of tropical diseases for which drug candidates may qualify for a priority review voucher. Themis also has a Lassa candidate and a MERS program, under a $37.5 million grant from international vaccine group the Coalition for Epidemic Preparedness Innovations (CEPI).

As for Themis’ competitors, Valneva recently reported phase 1 interim results for its live-attenuated candidate, VLA1553. A single vaccination achieved 100% seroconversion rate at day 28 across all three dose levels, and 96.5% of subjects achieved at least a 16-fold increase in antibody titers, according to the French company. Valneva is now looking to unveil more data by mid-2019.

PaxVax, which was recently acquired by Emergent, will soon post phase 2b readouts for its virus-like particle vaccine. That study is designed to determine the optimal dosing regimen for further tests in phase 3.