An experimental arthritis therapy known as golimumab showed promising results in a late-stage clinical study for the treatment of psoriatic arthritis, Johnson & Johnson unit Centocor and Schering-Plough said Wednesday. The data signals the potential appearance of a new rival to Enbrel, the best-selling treatment developed in Seattle by Immunex and now sold by Amgen.

The compound is designed to be administered less frequently than Enbrel and Abbott Laboratories' Humira (one injection a month, instead of one a week for Enbrel and one every two weeks for Humira). The therapy constitutes an "incremental improvement" over Enbrel and other similar drugs, said Dr. Philip Mease, chief of the Swedish Medical Center's Division of Rheumathology Research in Seattle. Dr. Mease served as an investigator in the trial.