BioWorld International Correspondent

LONDON - Alizyme plc announced positive Phase IIb results for renzapride in irritable bowel syndrome, claiming the first demonstration of safety and efficacy in the mixed-symptom form of the disease.

Alizyme CEO Richard Palmer told BioWorld International: "We are very pleased with these results and also with the way in which the trial has improved our understanding of the nature of the disease. The data are good enough to move into Phase III."

The news boosted Alizyme's share price 15 percent to £1.32. That is on top of a 40 percent increase five days earlier when Cambridge-based Alizyme released positive Phase IIb data for its lipase inhibitor, ATL-962, in obesity.

In the renzapride trial involving 168 patients with mixed-symptom irritable bowel syndrome (m-IBS), up to 14 percent more patients were classified as responders, compared to placebo, at the optimum dose of 2 mg per day. A positive response is classified as satisfactory relief of m-IBS on more than 50 percent of days during the eight-week trial. Overall, the daily responder rate in the 2-mg treatment group was up to 57 percent, compared to 43 percent in placebo. The number of responders increased to 18 percent when only the female population was analyzed.

Renzapride, a 5-HT₄ receptor agonist and 5-HT₃ receptor antagonist originally discovered by GlaxoSmithKline plc, of London, was well tolerated at all doses and there were no safety concerns. The 5-HT receptors are thought to be involved in the control of gastrointestinal motility and sensitivity.

Palmer was pleased with the positive results in a disease that is difficult to characterize and where there is such a high placebo effect. Also, the symptoms of IBS come and go, so that even without treatment sufferers can be symptom free.

Alizyme released additional results from its Phase IIb trial of renzapride in the treatment of constipation-predominant IBS, showing a response rate up from 7.7 percent to 12.3 percent over placebo, when the data from female patients only was analyzed.

"Where renzapride will fit ultimately in the IBS treatment algorithm, I can't say at present," Palmer said. "We would hope to get mixed-symptom labeling and get the constipation labeling." At present there is no treatment for m-IBS.

As a result of further work on the production of renzapride, Alizyme has filed a new patent covering several aspects of the manufacturing process and said that, if granted, it would extend the patent protection from 2012 to 2023.

Alizyme is now talking to potential licensees, but Palmer does not expect to reach agreement with a suitable partner until next year. At present the company has enough cash to last until the end of 2004.