LONDON - The protein engineering company AdProTech Ltd. has raised #5.6 million in its second round, and says first revenues from its novel adjuvant, Immudaptin, "are imminent."

Geoff Race, who has just moved up from finance director to CEO, told BioWorld International, "The money will allow us to move our first product, APT070, from late preclinical development through to Phase I and to Phase II by early 2001." APT070 is an anti-inflammatory, membrane-active complement inhibitor.

AdProTech, which spun out of SmithKline Beecham plc in 1997, also is attracting a lot of interest for Immudaptin, and Race said he expects the first licenses to be signed before the end of 2000. "We intend to license Immudaptin on an antigen by antigen basis. It will soon be under formal evaluation by potential partners."

Immudaptin is a single polypeptide derived from C3d, the naturally occurring human immune system protein. The company believes it will be applicable across a wide range of traditional, subunit, genetically modified and DNA vaccines. "Although we refer to this as an adjuvant, Immudaptin is in fact a powerful immune potentiator," said Race.

Immudaptin-modified antigens have produced an immune response two times greater than the same antigen with alum as adjuvant. AdProTech, based in Royston, Hertfordshire, has demonstrated that Immudaptin modification of a poorly immunogenic malaria protein gave unprecedented primary responses. After a single boost, antibody titres were equivalent to those seen after multiple boosting with alum, with no evidence of local or systemic adverse reaction.

The molecular mechanism of Immudaptin mimics the natural immune response in which pathogens are coated with the complement component C3b. This is subsequently processed to C3d ,which binds to receptors on B-cells, stimulating the production of antibodies. Race said he believes Immudaptin will first be applied to existing, conventional vaccines, where it could result in reduced dose or frequency. It also will enhance the efficacy of poorly immunogenic subunit vaccines. As it can be encoded within a DNA vaccine, it offers a novel mechanism for boosting humoral response to this type of vaccine.