BioWorld International Correspondent

LONDON - Cambridge Antibody Technology Group plc has begun to wind down expenditure on Trabio, the first antibody it has developed in-house, after the product failed to meet its primary endpoint in a European Phase II/III pivotal trial.

That's despite the fact that an international Phase III study of Trabio, in preventing scarring following glaucoma surgery, is ongoing with results expected early in 2005.

Peter Chambre, CAT's CEO, told BioWorld International, "This trial is double-blind, but given that it was designed on the same basis [as the failed Phase II/III trial] it is deemed unlikely it will produce different results."

As a result, the Cambridge-based company is ending the program. "We are being very cautious and working on the basis [the Phase III] won't be positive," he said.

Shares in CAT fell by 80 pence to £6.05 when the news was released last week.

Next up for CAT is its court case with Abbott Laboratories, of Abbott Park Ill., in which CAT is looking to increase the royalty rate it receives for the rheumatoid arthritis drug Humira. Abbott said in March 2003 that it was invoking a clause in the agreement with CAT allowing it to offset royalties due to third parties against royalties due to CAT. CAT is arguing the offset provisions do not apply. The case is due to start in London on Nov. 22 and last for three weeks.

"Shareholders knew the fourth quarter of this year was very important for CAT because of Trabio and the trial with Abbott," Chambre said. "Trabio was important, but, in financial terms, the shareholders believe the opportunity of receiving the full royalty [on Humira] that we originally believed we were entitled to, is financially more important." Humira has been approved in 51 countries.

However, Chambre conceded that while Trabio represented a niche market, it would have been an important endorsement of CAT's development skills to see the antibody from discovery to market. "We had two encouraging early trials that were statistically significant," he said. "To go and do another trial and find it does not play out is very disappointing."

Trabio neutralizes transforming growth factor beta 2, a protein that is expressed in response to injury in the eye and believed to be responsible for the formation of excessive scar tissue following surgery for glaucoma. Chambre said CAT will continue to look at the opportunity to use Trabio in other indications. "We've really got to digest the full set of results. We only got the preliminary data [last] week."

The endpoint in the failed 344-patient trial was the proportion of patients with intra-ocular pressure in the range of 6-16 mm Hg, without other glaucoma medication, at six months and 12 months post-surgery.

The failure of Trabio leaves CAT with nine products in its portfolio, with the two next most advanced both licensed out.