Peptech investee Domantis lands development deal

A potentially lucrative drug-development deal between UK pharma Argenta and domain-antibody pioneer Domantis limited has added a silver lining to the week for Sydney biotech Peptech (ASX:PTD), which has a 36.1 per cent stake in Domantis.

Argenta, a specialist in respiratory and inflammatory drugs, has engaged Domantis to develop an inhalable, domain-antibody treatment for the world's most common respiratory disorder, chronic obstructive pulmonary disease (COPD). Domantis will begin pre-clinical tests of candidate domain-antibody (dAb) molecules immediately, using Argenta's proprietary models of COPD.

COPD is caused by chronic inflammation of the lung -- often associated with smoking -- and results in a progressive, life-threatening decline in lung function. Argenta CEO Dr Christopher Ashton said there was a critical need for new therapeutic approaches for COPD, which is intractable -- no currently available treatment even slows the course of the disease. Patients have poor quality of life.

Rheumatoid arthritis, another chronic, inflammatory disease, is currently treated successfully with humanized monoclonal antibodies (mAbs) like Centacor's Remicade, and Abbott's Humira, which target the TNF-alpha receptor, a key mediator of the inflammation.

But full, humanised mAbs lose function when dried and administered in powdered form via an inhalant, so they cannot be used as an inhalant to treat lung inflammation, according to Peptech's investor relations manager Dr Paul Schober. Domain antibodies consist of just the antigen-binding domain from the active end of the molecule. They retain their activity even in desiccated form.

Domantis and Argenta say their deal combines Domantis' novel drug-development technologies with Argenta's two decades of experience in respiratory disease research.

In 2001, the World Health Organisation estimated the international market for COPD therapies at AUD$4.5 billion. The figure is predicted to grow to AUD$18 million by the end of the decade, when COPD will be the third leading cause of death worldwide. Chronic smokers in populous Asian nations like China are at high risk of developing COPD.