Merck & Co. Inc.’s Ervebo has become the first FDA-approved vaccine to prevent Ebola Zaire virus in people age 18 years and older.
The FDA decision comes well before the March 14, 2020, PDUFA date. Merck expects to make doses of the live attenuated vaccine (rVSVΔG-ZEBOV-GP) available to patients in the third quarter of 2020.
Merck is in line to obtain conditional marketing authorization from the European Union for Ervebo following a positive recommendation for approval from the EMA's Committee for Human Medicinal Products at its October meeting.
Ervebo, which has been genetically engineered to contain a protein from the Zaire Ebola virus, is administered as a single-dose injection, and it has its limits. The duration of protection conferred is unknown, it doesn’t protect against other species of Ebola virus or Marburgvirus and its effectiveness when administered concurrently with antiviral medication, immune globulin and/or blood or plasma transfusions is not known.
Ervebo, a replication-competent recombinant vesicular stomatitis vector expressing Zaire Ebola virus glycoprotein, was initially engineered by the Public Health Agency of Canada’s National Microbiology Laboratory. The technology was then licensed by a subsidiary of Ames, Iowa-based Newlink Genetics Corp. In late 2014, at the peak of the 2013-16 epidemic in Guinea, Merck acquired the rights to develop the drug from Newlink in a $500 million deal.
A phase III field trial conducted during the epidemic, involving 5,837 individuals, appeared to provide 100% protection after a single shot. None of those who received the vaccine became infected, whereas 23 cases occurred in a control group who received the vaccine 21 days after randomization.
Burundi is using the vaccine under a protocol allowing expanded access and compassionate use during Ebola outbreaks related to the Zaire strain. "No cases of Ebola have been reported in Burundi, but preparation remains crucial," the WHO said.
Plenty of others are working to stop Ebola.
Regeneron Pharmaceuticals Inc., of Tarrytown, N.Y., is in a phase III study of REGN-EB3 (atoltivimab + odesivimab + maftivimab), a viral structural protein inhibitor to treat Ebola virus infection. In August, the Palm trial of 681 patients during an ongoing outbreak in the Democratic Republic of the Congo showed triple-antibody cocktail outperformed Zmapp (Mapp Biopharmaceutical Inc., Defryus Inc.) control arm across multiple measures, including primary endpoint of mortality at day 28 (33.5% vs. 51.3%, p=0.002) and secondary endpoint of reduction in days until virus was undetectable in bloodstream.
Bavarian Nordic A/S, of Copenhagen, said Johnson & Johnson, of New Brunswick, N.J., is providing up to 200,000 regimens of its investigational Ebola vaccine to the Republic of Rwanda to support a new immunization program led by the Rwanda government. The vaccine regimen, which consists of the MVA-BN Filo vaccine from Bavarian Nordic and the Ad26.ZEBOV vaccine from J&J unit Janssen Pharmaceuticals, will help protect the citizens of Rwanda from the current Ebola outbreak in the neighboring country, the Democratic Republic of Congo, the companies said. The marketing authorization application was submitted to the EMA in early November.