LONDON - Peptide Therapeutics plc dropped its tolerizing peptide for the treatment of hay fever after it failed to show a statistically significant treatment effect in a Phase II study conducted at four UK centers.

CEO John Brown told BioWorld International, "Twenty-five percent of the people who took the drug did not require any further medication at all, in what was a very bad summer for hay fever. But some did get severe symptoms. If we are going to show statistical significance, I think we need to segment the treatment groups, and we do not have the resources to do this sort of trial."

Brown said Peptide would have licensed the product had it been successful, so dropping it will not have any effect on cash burn. "We have plotted the cash burn carefully over the next few years because we don't want to have to ask for more," he said. "But we would not in any case have spent more money on this."

The company had #26 million (US$41.5 million) as of June 30.

Peptide, based in Cambridge, was founded to develop allergy vaccines. It recently dropped its lead compound, a broad-spectrum allergy vaccine, which was being developed in collaboration with SmithKline Beecham plc, of London.

The two are now collaborating to find a new allergy vaccine candidate. "We are not saying the concept of allergy vaccines does not work," Brown said. "That's why SB is still with us. The preclinical data look good, and we have now got a better understanding of the mode of action."

Apart from the SB collaboration, Peptide no longer has any allergy products, and is now focused on vaccines. Its lead compound is ArilVax, a yellow fever vaccine in Phase III. Recruitment of 1,240 subjects is due to be completed before the end of this year, with data available in the first quarter of 2000.

The company is awaiting results of a Phase I/II safety and immunogenicity trial of a C. difficile vaccine to prevent and treat antibiotic-associated diarrhea and colitis. Data are due before the end of 1999. In addition, results of a second Phase I of an oral ETEC vaccine to prevent traveler's diarrhea are expected in the first quarter of 2000.

Peptide recently announced plans to spin out its drug discovery technologies into a separate company called Mimetrix. Brown said there was interest both from trade and financial investors, and he is aiming to complete the process by the first quarter of 2000. n