Domantis in licence deal with Tanox

UK biotech Domantis -- in which Sydney firm Peptech (ASX:PTD) is a 36 per cent investee -- has licensed the rights to domain antibodies for a specific but undisclosed autoimmune target to US biotech Tanox, best known for its asthma biological Xolair.

Under the deal, the privately-held Domantis will receive an undisclosed up-front fee, research funding and annual fees, as well as milestones and royalties on the therapeutic products developed and commercialised by Tanox.

"What we develop will be theirs to commercialise. Our payoff out of that would be milestones and royalties, but they cover the costs of development completely," said Domantis chief executive Bob Connelly today.

The companies had met first at last year's BIO2004 conference in San Francisco. "It moved very quickly as deals go," Connelly said.

Domain antibodies have been described as the 'sensitive fingertips' of antibodies. Although they are a 13th of the size of normal humanised antibodies, they are as specific as normal antibodies in their ability to bind to proteins.

"Compared to small molecule drugs and even to IgG technologies, the technology we use for selecting domain antibodies is extremely quick," said Connelly. "Because we have libraries with billions of domain antibodies, we're able to fish out 'binders' from those libraries in a matter of days.

"The black magic of the Domantis technology is the functionality of the library. The percentage of high-affinity, excellent solubility, excellent stability, characteristics of domain antibodies is much higher than with other antibody libraries. Domain antibodies have extraordinary natural properties: you can boil them, freeze them, put in acid, and they unfold and refold, which is very unique."

Connelly said the company plans to oulicense a number of other domain antibody projects this year, as well as taking some targets into the clinic itself, then license them at Phase II.

Other antibody fragment technologies are already moving into the clinic. One of UCB and Celltech's Fab antibody fragments is currently in Phase III clinical trials. A German company, Micromet, is also working with smaller single-chain antibodies.