US-based specialty vaccine company PaxVax has reported positive efficacy results from the 90-day Phase III clinical trial of its single-dose oral cholera vaccine candidate, PXVX0200.
The company said that PXVX0200 uses the same attenuated vaccine strain (CVD 103-HgR) previously approved and marketed in several countries under the brand name Orochol.
In the trial, the rate of diarrhea in patients vaccinated with PXVX0200 was compared with the rate in people who received placebo.
Efficacy was assessed by immunising volunteer participants with an oral dose of the PXVX0200 vaccine or placebo and then subsequently exposing them to the cholera-causing agent (Vibrio cholerae O1 El Tor).
The trial included two patient groups, with the first vaccinated and then challenged at ten days after vaccination. The second separate group of volunteer participants were challenged at 90 days post-vaccination to further assess duration of vaccine protection.
University of Vermont infectious disease medicine professor Beth Kirkpatrick: "If approved, PXVX0200 has the potential to provide an effective new single-dose option for people living in and travelling to areas where cholera is endemic."
In addition to the ten and 90-day cholera challenge trials, immunogenicity, safety, and lot-to-lot consistency of the PXVX0200 cholera vaccine are being assessed in a broader population at trial sites in Australia, Canada, and the US.
Approximately 3,000 participants are being enrolled in these additional pivotal Phase III clinical studies.
PaxVax chief executive officer Kenneth Kelley said: "US travellers currently have limited options to protect themselves from cholera, and we are pleased with the progress we are making in bringing an effective and logistically simple, single-dose cholera vaccine to travellers, as well as developing countries for use during fast-moving cholera outbreaks."