ZymoGenetics and Serono have announced favorable results from a Phase Ib clinical trial with TACI-Ig in 73 patients with rheumatoid arthritis (RA). TACI-Ig is a soluble fusion protein that neutralizes molecules implicated in the pathogenesis of several autoimmune diseases.
TACI-Ig appeared to be well tolerated across the full range of dose levels and schedules tested. Clear biologic effect was observed as patients showed schedule and dose dependent decreases in the levels of immunoglobulin (Ig) and serum rheumatoid factor levels. Although this study was not specifically designed to evaluate efficacy, encouraging trends were observed in ACR and DAS 28 scores, commonly used measurements of clinical benefit. Based on these promising results, ZymoGenetics and Serono expect to begin the Phase II clinical program of TACI-Ig in patients with RA in the second half of 2006.