LONDON The first data from clinical trials of a fully human monoclonal antibody developed by Cambridge Antibody Technology Group plc (CAT) showed the drug was safe and effective in the treatment of rheumatoid arthritis. The data on D2E7, which neutralizes the inflammatory cytokine TNF alpha, were presented to the American College of Rheumatology in San Diego.

John Aston, finance director of CAT, based in Royston, U.K., told BioWorld International the results are the ¿first results CAT has had in man, and they look very encouraging.¿

The Phase I/II trials, conducted by CAT partner BASF Pharma, the pharmaceutical division of Ludwigshafen, Germany-based BASF AG, showed that D2E7 was safe and effective in reducing disease activity. Up to 80 percent of the 140 patients achieved a clinically significant response during treatment of up to six months for intravenous administration and three months for subcutaneous administration. The clinical response was maintained during chronic administration.

The first drug to treat rheumatoid arthritis by neutralizing TNF alpha, developed by Immunex Corp., of Seattle, received FDA marketing approval last week. Aston said this added to the significance of the D2E7 data for CAT. ¿Although the Immunex drug has a different mode of action, it has set the precedent for treating rheumatoid arthritis by neutralizing TNF alpha,¿ he said. Human monoclonal antibodies are expected to be safer and more effective than other types of monoclonal antibodies, such as those derived from mice or sheep, but Aston said that, while D2E7 has a good safety profile, the data so far do not substantiate this expectation.

The Phase I/II trials were begun in April 1997 and are still ongoing. Aston said it was not yet clear when BASF would start Phase III studies, triggering a milestone payment to CAT, but he expects it to be sometime next year.