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Acambis plc announces that it has initiated pre-clinical trials with a herpes vaccine, licensed from Harvard University through its Office of Technology Development
CAMBRIDGE, UK and CAMBRIDGE, MA, USA | February 25, 2008 | Acambis plc (Acambis) (LSE: ACM) announces that it has initiated pre-clinical trials with a herpes vaccine, licensed from Harvard University through its Office of Technology Development, with a view to submitting an Investigational New Drug (IND) application in 2009.
Herpes is caused by the herpes simplex virus (HSV), which is found in two forms, HSV-1 and HSV-2, that cause oral and genital ulcers, respectively. HSV infections are life-long as the virus becomes latent and causes recurrent disease. Genital herpes is one of the most widespread sexually transmitted infections (STIs) in the world(1). The World Health Organization (WHO) estimates that 40 to 60 million Americans are infected already,(2) making the disease one of the most common STIs in the US.
The dl5-29 HSV-2 vaccine was developed by a Harvard Medical School team led by Dr David M. Knipe, Higgins Professor of Microbiology and Molecular Genetics and Chair, Harvard Virology Program. The vaccine is an HSV-2 strain from which two genes have been deleted, making the virus incapable of replication or of establishing latent infection. Acambis holds an exclusive worldwide licence under Harvard's patent rights to manufacture and sell the vaccine.
Pre-clinical studies with dl5-29 conducted by Dr Knipe's team at Harvard Medical School have previously shown that the replication defective vaccine:
-- induces strong HSV-2-specific antibody and T-cell responses;
-- can protect against challenge with a wild-type HSV-2 virus;
-- greatly reduces the severity of recurrent disease;
-- provides cross-protection against HSV-1; and
-- is unable to revert to a virulent state or to become latent.
To date, there are no licensed HSV vaccines. Infections are treated currently with anti-viral medication, which suppresses herpes symptoms without curing the infection. The cost of herpes infections to the US healthcare system was an estimated $1.8bn in 2000, which is projected to rise to $2.5bn by 2015(3).
Ian Garland, CEO of Acambis, said:
“This is an exciting addition to Acambis' increasingly broad pipeline and is part of our strategy to deliver one IND submission a year. This is a very attractive programme for a major vaccine market with limited competition and we are delighted to have licensed this Harvard Medical School technology.'
Michael Watson, Acambis' Executive Vice President, Research & Development, added:
“The dl5-29 approach offers many potential improvements on approaches to herpes vaccination that are currently being explored. The existing pre-clinical data are very encouraging and we look forward to progressing this vaccine candidate into the clinic.'
About dl5-29
In January 2005, the results of a study comparing dl5-29 with other HSV vaccine candidates were published by researchers at Harvard Medical School and the National Institute of Allergy and Infectious Diseases(4). The study included a head-to-head comparison of dl5-29 with recombinant HSV-2 glycoprotein D (gD2), which is the basis of the only vaccine to have undergone late-stage clinical testing, and showed that dl5-29 induced significantly higher neutralising antibody and cellular immune responses.
References
(1) JAMA, August 23/30, 2006 – Vol 296, No. 8, Xu F. et al. Trends in Herpes Simplex Virus Type 1 and Type 2 Seroprevalence in the United States
(2) WHO
(3) Fisman DN, Lipsitch M, Hook EW 3rd, and Goldie SJ. 2002. Projection of the future dimensions and costs of the genital herpes simplex type 2 epidemic in the United States. Sex Transm Dis. 29:608-22
(4) Hoshino et al., Journal of Virology, 79.1.410-418, 2005
About Acambis
Acambis is a leading vaccine company developing novel vaccines that address significant unmet medical needs or substantially improve standards of care. ChimeriVax™-JE, Acambis' most advanced product in its development-stage pipeline, has to date shown an excellent safety and efficacy profile following pivotal Phase 3 trials. It is currently undergoing paediatric trials in India and is partnered with Sanofi Pasteur and Bharat Biotech. Acambis' proprietary ChimeriVax™ technology, developed in association with St Louis University, has also been used to develop ChimeriVax™-West Nile, which is undergoing Phase 2 clinical testing, making it the most advanced investigational vaccine against the West Nile virus. Acambis has established a global collaboration with Sanofi Pasteur for further development and commercialisation of the vaccine. ChimeriVax™ has also been applied to development of Sanofi Pasteur's tetravalent dengue vaccine, which has successfully demonstrated proof-of-concept in a Phase 2 trial by generating 100% seroconversion to all four dengue virus serotypes.
Acambis also has the only vaccine in development against Clostridium difficile bacteria, a leading cause of hospital-acquired infections. C. difficile is estimated to cause at least 360,000 cases of C. difficile-associated disease in the US alone with annual costs to the healthcare system of $3.2bn. Acambis' influenza programme aims to develop a universal vaccine against influenza, for which a universal ‘A' strain vaccine, ACAM-FLU-A™, has recently been successfully tested in a Phase 1 trial and H5N1 (bird flu) pre-clinical challenge model. Acambis' pre-clinical pipeline includes a herpes vaccine developed at Harvard Medical School, which is currently undergoing further pre-clinical trials in preparation for submission of an Investigational New Drug application in 2009.
Acambis is recognised internationally as the leading producer of smallpox vaccines for emergency-use stockpiles held by the US Government and several other governments around the world. Acambis developed its ACAM2000™ smallpox vaccine under contracts with the US Government.
Acambis is based in Cambridge, UK and Cambridge, Massachusetts, US, and is listed on the London Stock Exchange (ACM). More information is available at www.acambis.com.
SOURCE: ACAMBIS |
