Positive Phase II/III clinical data from ChemoCentryx' PROTECT-1 Traficet-EN trial

ChemoCentryx, Inc., announced today that Phase II/III clinical data from the Company's PROTECT-1 (the Prospective Randomized Oral Therapy Evaluation in Crohn's disease Trial) of Traficet-EN(TM) (CCX282-B) in patients with moderate-to-severe Crohn's disease demonstrated clinical efficacy with a favorable safety and tolerability profile. The study demonstrated evidence of clinical efficacy in the reduction of disease severity as defined as a 70-point decrease in the Crohn's Disease Activity Index (CDAI) in patients treated with Traficet-EN over the course of 12 weeks; the more stringent measure of at least a 100-point decrease in the CDAI score was also met by week 12. In addition, Traficet-EN treatment benefited patients who had previously not responded to anti-TNF treatment. These results reported from the Induction phase of the PROTECT-1 trial, were presented today in a poster titled "PROTECT-1 Study of Intestine-Specific Chemokine Receptor Antagonist CCX282-B (TRAFICET-EN) in Crohn's Disease" by Satish Keshav, M.D., Department of Gastroenterology, John Radcliffe Hospital, Oxford University at the GASTRO 2009 United European Gastroenterology Federation and World Gastroenterology Organization (UEGW/WCOG) conference in London.

Traficet-EN is an orally-active inhibitor of the chemokine receptor known as '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.

Study Results

Results showed that the CDAIs disease treated with 500 mg once-daily dose (QD) of Traficet-EN for 12 weeks was 61% versus 47% for placebo>

"By blocking the CCR9 chemokine receptor, we believe that Traficet-EN has the potential to offer a dramatically new treatment paradigm with significantly fewer side effects than currently available therapies for Crohn's disease," said Pirow Bekker, M.D., Ph.D., Senior Vice President, Medical and Clinical Affairs of ChemoCentryx. "Additionally, an effective oral capsule given once daily would represent a significant improvement in patient convenience and compliance as compared to existing infusion or injection regimens - an important milestone considering the lifestyle disruption already experienced by these patients as a result of Crohn's debilitating effects."

"Targeting the CCR9 chemokine receptor is therapeutically unprecedented," said Thomas J. Schall, Ph.D., President and Chief Executive Officer of ChemoCentryx. "These results solidify our leadership position in CCR9-based therapies and position Traficet-EN as a first-in-class anti-inflammatory agent for the treatment of Crohn's disease. More importantly, this study demonstrates that Traficet-EN has the potential to offer patients a novel, meaningful treatment option."