Immunex Corp. on Sunday presented positive data from a Phase III trial of its Enbrel soluble tumor necrosis factor receptor in patients with rheumatoid arthritis, providing another round of evidence that TNF-alpha inhibition is an attractive strategy for treating RA.

IMNX plans to file a BLA for FDA approval in 1998, based on the results of this and other clinical studies. It's likely competition will be Centocor Inc.'s Avakine, another TNF inhibitor which is nearing the end of enrollment in its Phase III trial, with a BLA filing planned by year-end in Crohn's disease.

With both products nearing their regulatory filings, it's now possible to project the impact of TNF approaches to RA, as well as to make some comparisons between the agents.

As discussed at the meeting of the American College of Rheumatology, the primary end point of the IMNX trial was a 20 percent improvement in the American College of Rheumatology composite of RA symptoms, ACR20, at three months. A total of 62 percent of the patients in the 25 mg group reached 20 percent improvement by the ACR criteria, versus 23 percent of the placebo group (p£0.003).