Microscience now able to deliver DNA vaccines orally

UK biotechnology company Microscience has entered into an exclusive licence agreement with the University System of Maryland (USM) to give it access to USM's Bactofection DNA vaccine technology. The company will apply the rights acquired to the delivery of DNA from a live bacterial vector in all fields, except HIV antigens. Microscience will pay USM an upfront licence fee, plus milestones and royalties if the products based on the technology are successful.

Wokingham-based Microscience, which focuses on the discovery and development of innovative vaccines, will now be in a position to use its oral delivery system spi-VEC to facilitate delivery of many different DNA antigens.

Taken orally, spi-VEC vaccines induce a strong mucosal and systemic response. The company has five vaccines entering clinical development. These include an oral vaccine to protect against typhoid, another to prevent traveller's diarrhoea and a therapeutic vaccine for hepatitis B. Clinical trials are also planned for two injectable preventative vaccines designed to protect against meningitis B and neonatal Group B streptococcus infections.

Spi-VEC, Microscience's proprietary oral antigen delivery system, is a technological extension of its oral Salmonella vaccine programmes. These employ live bacteria from which genes have been deleted rendering them unable to cause disease. With spi-VEC it is possible to deliver a wide range of protective and therapeutic antigens using controlled gene expression. As a new generation of oral vaccines they can induce both strong mucosal and systemic immune responses.

The three key advantages in delivering DNA orally are:

• Oral delivery generates strong mucosal immunity.

• Oral administration may improve patient compliance.

• spi-VEC targets key immune cells and is believed to increase the efficiency with which the administered DNA stimulates an immune response.

Rod Richards, ceo of Microscience, said: 'This licence gives us an opportunity to expand the potential of spi-VEC, which will now be utilised to develop a range of DNA vaccines. It gives Microscience the opportunity to enter the important and commercially attractive area of cancer vaccines.'