The Genetic Engineering Approval Committee (GEAC) has accorded permission to Acambis for import and conduct of phase II clinical trials on ChimeriVax- JE vaccine in children in India, through Quintiles. GEAC noted that the vaccine is urgently required for India. The committee approved the conduct of phase -II clinical trials in children of descending age in India subject to the condition that patients would be recruited in a phased manner.
Acambis, based in Cambridge, UK, aims concurrent clinical trials in India with a view to submit a product licence application for ChimeriVax-JE for populations where the disease is endemic. In 2005, a JE epidemic in northern India and Nepal caused 1,200 deaths, mostly in children. Acambis plans to initiate a Phase II paediatric trial of ChimeriVax-JE in India in the second quarter of 2006.
The company announced in April, 2006, that it has completed enrolment into two pivotal phase 3 trials of its investigational vaccine against Japanese encephalitis (JE), ChimeriVax-JE, ahead of schedule. With this milestone met, Acambis remains on track for preparing the ChimeriVax-JE licence applications for submission in India and Australia in 2007.
The Japanese encephalitis (JE) virus, the world's most significant cause of viral encephalitis, is found throughout China, Korea, the Indian sub-continent, south-east Asia and parts of Australia. Using its proprietary ChimeriVax technology, originally developed in collaboration with St. Louis University, Acambis is developing an investigational vaccine against JE. Known as ChimeriVax-JE, the investigational vaccine candidate is a live, attenuated, injectable vaccine, which is currently undergoing clinical trials to test its safety and immunogenicity.
During 2001, the company completed a phase I trial and a phase II 'challenge' trial. The phase I trial revealed positive results for this vaccine and also demonstrated proof-of-principle for it's proprietary ChimeriVax technology. In the phase II 'challenge' trial, subjects vaccinated with ChimeriVax-JE exhibited an immune response with long-term memory and a rapid rise in protective antibodies on exposure to the virus.
In 2002, Acambis completed a phase II trial comparing the safety and immunogenicity of a range of dose levels of ChimeriVax-JE and evaluating any benefit of a second dose 30 days later. The trial found that ChimeriVax-JE was well-tolerated at all doses tested and that 82-100 per cent of subjects developed JE-neutralising antibodies within one month of vaccination. A second dose of ChimeriVax-JE given 30 days later did not enhance the sero-conversion rate.
The company finds ChimeriVax-JE has potential as a single-dose vaccine for travellers to JE-endemic areas. Another phase II trial is underway in Australia to expand the safety and immunogenicity information, and to investigate the duration of immunity. Acambis is also collaborating with the WHO for paediatric trials of ChimeriVax-JE in endemic countries as part of the WHO's efforts to facilitate the development of effective paediatric vaccines against JE for developing countries.
The ChimeriVax technology is also the basis for Acambis' vaccine candidates against West Nile and Dengue, both of which are currently in phase 2 clinical trials.