Medarex Inc announced that the MDX-1100 phase-2 proof-of-concept trial in patients with active rheumatoid arthritis (RA) receiving methotrexate successfully met its primary endpoint. The top-line results from the recently completed 70-patient multi-centre, randomised, double-blind, placebo-controlled phase-2 trial indicated that when compared to placebo, three times the number of patients treated with 10 mg/kg of MDX-1100 every two weeks achieved at least a 20 per cent improvement in RA signs and symptoms at 12 weeks, the primary endpoint of the study, as measured by the American College of Rheumatology (ACR) 20 measurement of response.

These results were statistically significant when compared with placebo (p=0.0024). The antibody combination with methotrexate was generally safe and well-tolerated. Full results from this phase-2 trial are planned to be presented at a future scientific meeting.

"We are greatly encouraged by this demonstration of efficacy from a well-designed and well-executed study," said Howard H Pien, chairman and CEO of Medarex. "These results show that by targeting the chemokine IP-10 with our MDX-1100 antibody, we may be able to offer a potentially important and novel treatment option for rheumatoid arthritis and potentially other inflammatory indications."

"Based on these positive results with a novel pro-inflammatory target, we are actively preparing for the next stage of clinical development for MDX-1100 in RA, including the potential for subcutaneous dosing," said Geoffrey M Nichol, senior vice president of Product Development at Medarex. "We also look forward to exploring the broader potential of MDX-1100 in a range of inflammatory diseases, including ulcerative colitis in an ongoing companion phase-2 study."

MDX-1100 is a fully human antibody that targets IP-10 (also known as CXCL-10), a chemokine expressed in association with multiple inflammatory disease indications.

Medarex is a biopharmaceutical company focused on the discovery, development and potential commercialization of fully human antibody-based therapeutics to treat life-threatening and debilitating diseases, including cancer, inflammation, autoimmune disorders and infectious diseases.