New way to make viruses patented

Medigene is developing products based on Herpes simplex virus (HSV) as treatments for tumours that have spread to the liver, although a follow-up HSV program in brain tumours is on temporary hold as the firm reins in its research spending.

The patent (No 6,642,207​) covers the use of genetically-engineered artificial chromosome, carrying the viral DNA, that can be introduced into a cell. The cell is then transformed into a production unit for the virus.

Artificial chromosomes are large, DNA-based vectors that have been used extensively in the construction of DNA libraries for complex genome mapping and analysis. The size of these vectors means that they can include all the elements derived from chromosomes that are responsible for replication and maintenance, and are capable of stably maintaining large genomic DNA fragments.

Medigene's patent describes a process in which the artificial chromosome codes for a virus that kills the host cell, which could have applications, for example, in the treatment of cancer. However, it also covers the use of the chromosomes for manufacturing viruses, as well as to deliver viral sequences that can manufacture recombinant proteins, when it is important not to kill the host cell.

"This is a basic patent for virus production frequently applied in research and medical development of therapeutic viruses,"​ said Medigene in a statement. It noted that the method is especially suited for the modification and production of complex viruses, such as HSV types 1 and 2, Epstein-Barr virus, cytomegalovirus or poxvirus (vaccinia).

Peter Heinrich, chief executive of Medigene, said that the patent not only gives the company a new way to manufacture its experimental HSV-based therapeutics but also gives it a potential revenue stream from licensing opportunities in the pharmaceutical and biotech industries.