PaxVax has announced positive results from a Phase 3 safety and lot-to-lot consistency trial of its single-dose oral cholera vaccine candidate, PXVX0200, which utilizes the same attenuated vaccine strain (CVD 103-HgR) previously approved and marketed in several countries under the brand name Orochol®. PaxVax intends to submit a Biologics License Application (BLA) for this product, under the brand name Vaxchora®, to the U.S. Food and Drug Administration (FDA) in mid-2015.
The Phase 3 trial evaluated the immunogenicity and safety of three consecutive production lots of the PXVX0200 vaccine candidate. The three production lots induced immunological responses across the clinical trial subjects that met the pre-specified immunological endpoint for consistency of manufacture. The lots of vaccine used for the trial were formulated by PaxVax in its San Diego Good Manufacturing Practice (GMP)-certified facility. The results of this trial are the last major clinical milestone prior to submission of market applications in the U.S., the European Union, Canada, and Australia.
A vaccine for cholera is not currently available in the U.S. for residents who travel abroad to areas where cholera poses a risk, such as Haiti or Central Africa. A cholera vaccine is available in Europe and elsewhere for travelers, but it requires a two-dose regimen. If licensed, oral PXVX0200 would be the first single-dose vaccine against cholera making it more convenient for all travelers, particularly for those traveling on short notice.
“U.S. travelers currently have limited options to protect themselves against cholera, and we are pleased with the progress we are making in bringing an effective single-dose cholera vaccine to travelers and potentially those suffering endemic disease in developing countries in the future,” said Kenneth Kelley, Chief Executive Officer of PaxVax. “These favorable lot-to-lot consistency results validate our manufacturing capabilities and provide us with the last critical data required to support our BLA submission for Vaxchora.”
The results from the lot-to-lot consistency trial complement previously reported results from 10-day and 90-day cholera challenge, safety and immunogenicity trials. Approximately 3,000 participants were enrolled in the PXVX0200 vaccine phase 3 trial at sites in Australia and the U.S.
Cholera is an acute intestinal diarrheal infection caused by toxigenic Vibrio cholerae bacteria generally acquired by ingesting contaminated water or food. According to the World Health Organization, the global disease burden is estimated to be three to five million cases and 100,000 to 120,000 deaths per year. 1 Cholera often manifests as explosive epidemics that rapidly move through populations, such as the outbreaks that occurred in Peru and Haiti in 1991 and 2010, respectively.