New technology being used to make first hep E vaccine

The UK biopharma firm has just announced the positive results of a preclinical study demonstrating the effectiveness of its new hepatitis E vaccine, made using its novel ImuXen liposomal formulation technology. ImuXen is a method that uses liposomal entrapment to envelope recombinant protein from a virus together with DNA from the virus to express the protein, effectively creating a synthetically reconstructed vaccine that is as powerful as a live attenuated vaccine but intrinsically safe, company spokesperson Peter Laing told In-PharmaTechnologist.com. Live attenuated vaccines achieve strong immunological responses, however, on rare occasions the use of a live vaccine in patients can actually cause infection with the virus. "The vaccine contains no aluminium, unlike the currently used alum-adjuvanted vaccines, which is very desirable as there is a limit to the amount of aluminium that the body should be exposed to each year,"​ said Laing. Clinical trials on the new hepatitis E vaccine are planned for the first half of 2007. There is currently there is no vaccine for hepatitis E, which is one of the more recently discovered strains of hepatitis and is the most common form of acute hepatitis in developing countries, transmitted via contaminated water. Although less serious than the chronic B and C forms, hepatitis E is more serious than hepatitis A and can be potentially fatal. It is also particularly dangerous in pregnant women. The company is also simultaneously working on using its ImuXen technology to improve upon some of the largest selling vaccines currently on the market, including Wyeth's pneumococcal vaccine Prevnar, which has a market in excess of $1bn (€0.8bn). "Pneumococcal vaccines are complex because they require multiple strains of the virus to be accounted for, however, using our liposomal technology we can entrap multiple proteins in the same envelope and achieve this,"​ said Laing. "The advantage of this is that we have the ability to develop a greater number of strains than the current pneumococcal vaccines which only cover seven strains."​ In addition, this method gives Lipoxen the ability to easily vary the strain of the vaccine in order to keep ahead of mutating forms of the virus. "All we would have to do is change a formulation step,"​ said Laing. "This is a real advantage because in order to vary the strain of current vaccines, the whole manufacturing method would have to be changed."​ Lipoxen has licensed the intellectual property for ImuXen to its development partner, Serum Institute of India, who is now manufacturing clinical trial supplies of the candidate vaccines. "As the candidate vaccines reach Phase III trials we may consider licensing them out to a big pharma firm, in which case they would decide who will manufacture the product from that point on,"​ said Laing. "It is likely, however, that they would choose to keep Serum Institute as the manufacturer as they are one of the world's leading vaccine companies."​