ChemoCentryx, Inc (MOUNTAIN VIEW, California) is a privately-held, clinical-stage biopharmaceutical company focused on discovering and developing orally-administered therapeutics that target the chemokine and chemoattractant systems in order to treat autoimmune diseases, inflammatory disorders, and cancer. The company announced completed enrollment of 436 patients in PROTECT-1 (the Prospective Randomized Oral Therapy Evaluation in Crohn's disease Trial), a global phase II/III clinical trial of Traficet-EN™ (CCX282-B) in patients with moderate-to-severe Crohn's disease. The trial comprises three discrete phases to evaluate the efficacy and safety of Traficet-EN in inducing a clinical response or remission, as well as maintaining response/remission in Crohn's disease over 12 months.

PROTECT-1 is a randomized, placebo-controlled, double-blind study that includes a 12-week induction period, during which patients will receive either Traficet-EN or placebo, followed by a 4-week, open-label, active period, during which all subjects receive the drug. Patients who achieve a prespecified reduction in disease severity are re-randomized to active drug or placebo for a 36-week maintenance period, thereby permitting an evaluation of the drug's ability to maintain treatment response. The primary efficacy endpoint in the induction phase of the study is clinical response defined as a decrease from baseline in the Crohn's Disease Activity Index score of at least 70 points.

Traficet-EN is an orally-active inhibitor of the chemokine receptor CCR9, which is selectively expressed by inflammatory T-cells to migrate to the digestive tract in a process that ultimately results in the persistent inflammation underlying the disease. Targeting the CCR9 chemokine receptor represents a novel approach for the treatment of Crohn's disease and other inflammatory disorders of the gastrointestinal system. The company is on track to report data from the induction phase of the trial in the forth quarter of 2008.

ChemoCentryx is also advancing a second-generation, orally-active CCR9 antagonist, which is structurally diverse from Traficet-EN, through preclinical development and anticipates a regulatory filing to enable first-in-human studies later in 2008.

The CCR9 program is a part of a strategic alliance that ChemoCentryx signed in 2006 with GlaxoSmithKline's Center of Excellence for External Drug Discovery for the discovery and development of small molecule antagonists targeting four defined chemokine and chemoattractant receptors. Under the terms of the agreement, ChemoCentryx is responsible for advancing product candidates through clinical proof-of-concept, at which point Glaxo will have options to license certain product candidates.

In adults, CCR9 is a highly specific receptor expressed by T-cells that migrate selectively to the digestive tract. The trafficking of T-cells to the small and large intestine causes persistent inflammation that may result in Crohn's disease or ulcerative colitis. In preclinical studies, Traficet-EN worked both therapeutically and prophylactically in models of Crohn's and ulcerative colitis. In addition to the PROTECT-1 clinical trial in Crohn's disease and an ongoing phase II trial in celiac disease, ChemoCentryx has completed five phase I clinical trials and one 4-week phase II Crohn's disease trial of Traficet-EN, demonstrating that the product candidate is well-tolerated and appropriate for once- or twice-daily oral dosing. Traficet-EN may offer advantages over existing therapeutic approaches for Crohn's disease by potentially offering patients reduced side effects and convenient oral dosing. A CCR1 antagonist in phase I clinical study, CCX354, is being developed by Rigel for inflammatory diseases such as rheumatoid arthritis.