Aventis and Vertex Pharmaceuticals Incorporated announced that Aventis has begun enrollment into a Phase IIb clinical trial of the oral anti-cytokine therapy, pralnacasan, for rheumatoid arthritis (RA) in the U.S. and Canada. Aventis and Vertex are collaborating on the development and commercialization of pralnacasan.

Pralnacasan is an orally administered ICE (interleukin beta converting enzyme) inhibitor. ICE regulates the production of both interleukin-1 beta (IL-1 beta) and IL-18, key pro-inflammatory cytokines that initiate and sustain the progression of inflammation. Inhibiting ICE may be a useful strategy for curtailing damaging inflammatory processes common to a number of acute and chronic conditions.

"The Phase IIb RA study announced today is another important step forward in the development of pralnacasan," said Dr. Sol Rajfer, Senior Vice President and Head of Global Product Realization at Aventis. "RA is a debilitating disorder that affects millions of people worldwide. We believe that as an oral therapy, pralnacasan could be an important new treatment option to help address this significant medical need."

The Phase IIb randomized, placebo-controlled, double-blind, multi-center clinical trial will evaluate the safety and efficacy of pralnacasan in patients with RA receiving stable methotrexate treatment. The Phase IIb study will evaluate approximately 400 patients treated with pralnacasan or placebo for 12 weeks. RA is a progressive, systemic autoimmune disease characterized by the inflammation of the membrane lining in joints. This inflammation causes a loss of joint shape and alignment, resulting in pain, stiffness and swelling, ultimately leading to joint destruction and disability.

The companies also announced today that they plan to further expand development of pralnacasan in the indication of psoriasis. Psoriasis is a chronic, immunologically mediated skin disease characterized by thickening, scaling and inflammation. According to the National Psoriasis Foundation, psoriasis affects nearly seven million people in the U.S., one million of whom have moderate-to-severe plaque psoriasis.

"The biological and clinical rationale for the use of cytokine inhibitors across major inflammatory diseases is compelling, and oral agents such as pralnacasan have the potential to transform the way that diseases such as RA, OA and psoriasis are treated," stated Vicki Sato, President of Vertex Pharmaceuticals. "We look forward to continued close partnership with Aventis as this comprehensive development program advances toward the marketplace."