Vertex Pharmaceuticals Inc, of Cambridge, Massachusetts, announced that its oral drug candidate, the p38 mitogen-activated protein (MAP) kinase inhibitor VX-702, met its primary objectives in a multicenter, randomized, double-blind, 12-week phase II clinical trial conducted in Eastern and Central Europe.

The study enrolled 315 patients with moderate to severe rheumatoid arthritis (RA) who received either 5 mg or 10 mg VX-702 once daily, or placebo. VX-702 treatment resulted in a dose-dependent, statistically significant increase in week 12 ACR 20 response rates, the primary endpoint of the study. Thirty percent of patients receiving placebo, 38% receiving 5 mg VX-702, and 40% of patients receiving 10 mg VX-702 achieved an ACR 20 response at week 12 (P = .04). VX-702 proved to be well-tolerated. Vertex is conducting a full analysis of the safety, pharmacokinetics, and efficacy data from the study and anticipates results to be presented at a medical conference later in 2006.

By mid-2006, Vertex plans to begin clinical studies to evaluate VX-702 in combination with methotrexate in RA patients, including a 3-month, dose-ranging phase II study. The company also expects to file an IND to conduct clinical studies of the drug in the US. 

Vertex holds development and commercial rights for its p38 MAP kinase inhibitors in the US and Europe. In Japan and certain Asian countries Kissei Pharmaceutical Co, Ltd, holds the development and commercial rights for VX-702. In 2005, Kissei initiated clinical development of VX-702 in Japan.

p38 MAP kinase regulates production of the inflammatory cytokines TNF-alpha, interleukin-1 (IL-1) beta, and IL-6, which have been implicated in a range of inflammatory diseases, including RA.

—A. Techman