GSK statement on first phase 1 trial results of a candidate Ebola vaccine

First results from a small phase 1 trial published today in the New England Journal of Medicine show that a GSK/NIH Ebola candidate vaccine was well-tolerated and produced an immunological response in each of the 20 healthy adult volunteers in the USA who received it.

The candidate vaccine used in the trial conducted by the National Institutes of Health (NIH) was co-developed by the NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and Okairos, a biotechnology company acquired by GSK in 2013. It uses a type of chimpanzee cold virus, known as chimpanzee adenovirus type 3 (ChAd3), as a carrier to deliver genetic material from two strains of the Ebola virus – the Sudan strain and the Zaire strain, which is responsible for the current Ebola outbreak in west Africa. GSK has been working with the NIH to accelerate development of both this bivalent version of the candidate vaccine and a monovalent version targeting only the Zaire strain in response to the current Ebola epidemic.

Commenting on the results, Dr Moncef Slaoui, Chairman of Global Vaccines at GSK said: “We are very encouraged by these positive first trial results showing this type of vaccine has an acceptable safety profile and can produce an immune response against Ebola in humans. 

“Working with partners including the NIH, we’re doing all we can to advance development of a candidate vaccine in response to the Ebola crisis in west Africa.

“It’s important to remember that these data are the first piece in the jigsaw and we’re continuing to gather other important information. Over the coming weeks, we will see results from further phase 1 trials which will tell us more about the profile of the monovalent vaccine; most significantly results from a trial in Mali which is assessing its safety and immune response in west African populations.

“If the combined data from these trials are positive, the next phases of the clinical trial programme will begin in early 2015 to see whether the immune response we are seeing in phase 1 actually translates into providing people in affected countries with meaningful protection against Ebola.

“These phase 3 trials will involve the vaccination of thousands of volunteers, including frontline healthcare workers in affected countries, including Liberia and Sierra Leone, and possibly Guinea. If the candidate vaccine is able to protect these healthcare workers as we hope it will, it could significantly contribute to efforts to bring this epidemic under control.”

Next steps

  • Development of the vaccine candidate is progressing at an unprecedented rate, with further data from ongoing phase 1 trials in the USA, UK, Mali and Switzerland expected by the end of the year.
  • If trials are successful, the next phases of the clinical trial programme will begin in early 2015 which will involve the vaccination of thousands of frontline healthcare workers in the two of the affected countries – Sierra Leone and Liberia. Further safety studies will also be conducted in west African countries not affected by the current outbreak in adults and children.
  • GSK continues to work with the WHO, regulators and other stakeholders to determine possible solutions to accelerate the development of the Ebola candidate vaccine with the goal of trying to limit the further spread of the epidemic.
  • Its potential future use in mass vaccination campaigns will depend on whether WHO, regulators and other stakeholders are satisfied that the vaccine candidate provides protection against Ebola without causing significant side effects and how quickly large quantities of vaccine can be made.
  • GSK continue to actively explore with relevant organisations and partners all opportunities to accelerate the development of manufacturing at an industrial scale. Additionally, the company is looking at whether use of a booster vaccine may help provide longer-lasting protection.

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Cautionary statement regarding forward-looking statements
GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Such factors include, but are not limited to, those described under Item 3.D 'Risk factors' in the company's Annual Report on Form 20-F for 2013.