GlaxoSmithKline (GSK) said today it was preparing an experimental Ebola vaccine to test on healthy volunteers in the U.K., The Gambia, and Mali starting as early as mid-September, with more than $4.6 million in funding from an international consortium.
The vaccine candidate—among platforms GSK inherited when it acquired Okairos last year for €250 million ($329 million)—will be tested in Phase I safety trials being co-developed by the pharma giant and the NIH. The trials will be launched alongside similar studies in the U.S. by the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) once ethical and regulatory approvals are obtained.
The approvals are being considered on an expedited basis given the seriousness of Ebola, which has killed more than 1,500 people in West Africa and been declared a public health emergency of international concern by the World Health Organization (WHO).
“Developing a new vaccine is complex with no guarantees of success and it’s still early days for our Ebola vaccine candidate. But we are encouraged by progress so far and will do the best we can, along with WHO and our partners, to speed up development and explore ways in which the vaccine could contribute to the control of this or future Ebola outbreaks,” Moncef Slaoui, Ph.D., GSK’s chairman of Global R&D and Vaccines, said in a statement.
The investigational vaccine was designed by Nancy J. Sullivan, Ph.D., chief of the Biodefense Research Section in NIAID’s Vaccine Research Center (VRC). She worked in collaboration with researchers at the VRC, the U.S. Army Medical Research Institute of Infectious Diseases, and Okairos.
The NIAID/GSK Ebola vaccine candidate is based on an attenuated strain of chimpanzee cold virus, called chimp adenovirus type 3 (ChAd3). The adenovirus is used as a vector to deliver benign genetic material derived from the Ebola virus Zaire species, which has caused the current Ebola outbreak in West Africa.
The candidate vaccine delivers a single Ebola virus protein to human cells and does not replicate further, but allows the vaccine recipient’s cells to express a protein, prompting an immune response in the individual. Because the experimental vaccine does not contain infectious virus material, it cannot cause a person who is vaccinated to become infected with Ebola, GSK said.
Professor Adrian Hill, D.Phil., director of The Jenner Institute, a partnership between the University of Oxford and The Pirbright Institute, will lead a team of researchers in carrying out the human trials, which are being funded by a £2.8 million ($4.64 million) grant from the Wellcome Trust, and the U.K.’s Medical Research Council (MRC) and Department for International Development (DFID).
GSK said the funding will also enable it to begin manufacturing up to about 10,000 additional doses of the vaccine at the same time as the initial clinical trials. If the trials prove successful, stocks of the vaccine could then be made available immediately by GSK to the WHO toward an emergency immunization program in high-risk communities, the company added.
Preclinical research by the NIH and Okairos showed promising protection from Ebola in nonhuman primates exposed to the virus, without producing significant adverse effects.
Those results prompted the consortium to move ahead with the Phase I safety trials in small groups of healthy volunteers, the company said. The Oxford study will involve 60 healthy volunteers, while studies in The Gambia and Mali will each involve 40. Each set of volunteers will be split into groups of 20 that will receive different doses of the vaccine.
If the first volunteers vaccinated in the Oxford study show a good response with no adverse reactions, the trial will be extended to volunteers at the MRC Unit in The Gambia, subject to approval from authorities. A second West African arm of the study is set to begin in Bamako, Mali. The multiple trials are designed to help ensure the fastest possible progress toward determining the best candidate vaccine approach and delivery, GSK said.
By adding trial arms in West Africa, researchers aim to ensure that their studies account for differences between European and West African populations that might affect safety or immune response.
The study in Mali is to be led by Myron M. Levine, M.D., D.T.P.H., director of the Center for Vaccine Development at the University of Maryland School of Medicine, and Samba Sow, M.D., director general of the Center for Vaccine Development in Mali—a joint initiative between the University of Maryland School of Medicine and Mali’s Ministry of Health.
Researchers hope to conclude the Phase I trials by the end of this year, with deployment of the vaccine to be fast-tracked should it prove to be safe and immunogenic, GSK said.
NIAID said the U.S. Centers for Disease Control and Prevention has begun discussions with Ministry of Health officials in Nigeria about the prospects for conducting a Phase I safety study of the vaccine among healthy adults in that country.
The NIAID trials are designed to study the same vaccine’s effects on Ebola Sudan in addition to Ebola Zaire. NIAID’s trials are set to take place at the NIH Clinical Center in Bethesda, MD, and will assess the GSK vaccine as well as an experimental Ebola vaccine developed by the Public Health Agency of Canada and licensed to NewLink Genetics.
NewLink said August 5 that its BioProtection Systems subsidiary signed a $1 million contract with the U.S. Defense Threat Reduction Agency to fund research designed to advance the Public Health Agency vaccine into human trials.
“There is an urgent need for a protective Ebola vaccine, and it is important to establish that a vaccine is safe and spurs the immune system to react in a way necessary to protect against infection,” NIAID Director Anthony S. Fauci, M.D., said in a statement released by his agency.