Medarex Announces Primary Endpoint Achieved in MDX-1100 Anti-IP-10 Antibody Phase 2 Trial for Rheumatoid Arthritis

Medarex Announces Primary Endpoint Achieved in MDX-1100 Anti-IP-10 Antibody Phase 2 Trial for Rheumatoid Arthritis
 
  
Top-line data indicate statistically significant improvement in ACR20 responses over placebo


PRINCETON, N.J., May 14 -- Medarex, Inc. (Nasdaq: MEDX) today 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-center, randomized, 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% 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, M.B.Ch.B., 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."


About MDX-1100 in Rheumatoid Arthritis

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. The MDX-1100 Phase 2 study in RA enrolled 70 patients with active disease while on methotrexate. Patients in the study were randomized to receive either placebo or MDX-1100 (10 mg/kg) every two weeks for a total of six doses. The primary endpoint of the study was ACR20 response at 12 weeks. Secondary endpoints included other clinical response assessments, pharmacokinetics of MDX-1100, and potential biomarkers of activity.


According to the American College of Rheumatology, 1.3 million adult Americans have been diagnosed with rheumatoid arthritis, a chronic autoimmune disease that develops when certain cells of the immune system inappropriately attack healthy joint tissue, thereby causing swelling, inflammation and damage of joints, as well as systemic inflammation and damage of other tissues.


About MDX-1100 in Other Indications

MDX-1100 is also being explored as a treatment for ulcerative colitis (UC). A Phase 2 randomized, double-blind, placebo-controlled study in patients with active UC while continuing standard UC therapy is ongoing. The Phase 2 trial is expected to enroll up to 106 patients at multiple centers internationally. Patients in the study are randomized to receive either placebo or MDX-1100 (10 mg/kg) every two weeks for a total of four doses. The primary endpoint of the study is response rate at 8 weeks. Clinical response is based on the Mayo score, a composite endpoint that assesses stool frequency and the amount of bloody stool per day as recorded in a patient diary, physician global assessment and the assessment of colon mucosal inflammation ascertained by endoscopy.


Ulcerative colitis is a chronic inflammatory bowel disease characterized by inflammation and ulceration of the lining of the colon. Symptoms typically include bloody diarrhea and abdominal pain and in severe cases may require colectomy. According to the Crohn's & Colitis Foundation of America, it is estimated that there are up to approximately 500,000 Americans with ulcerative colitis.


About Medarex

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. Medarex applies its UltiMAb(R) technology and product development and clinical manufacturing experience to generate, support and potentially commercialize a broad range of fully human antibody product candidates for itself and its partners. Over forty of these therapeutic product candidates derived from Medarex technology are in human clinical testing or have had INDs submitted for such trials, with the most advanced product candidates currently in Phase 3 clinical trials, the subject of regulatory applications for marketing authorization or approved for commercial sale. Medarex is committed to building value by developing a diverse pipeline of antibody products to address the world's unmet healthcare needs. For more information about Medarex, visit its website at www.medarex.com.


Medarex Statement on Cautionary Factors

Except for the historical information presented herein, the statements relating to MDX-1100 in this press release may constitute forward-looking statements, as defined in the Private Securities Litigation Reform Act of 1995, that are subject to certain risks and uncertainties that could cause actual results to differ materially from any future results, performance or achievements expressed or implied by such statements. Medarex disclaims, however, any intent or obligation to update these forward-looking statements. Risks and uncertainties include risks associated with product discovery and development of MDX-1100, uncertainties related to the outcome of clinical trials, slower than expected rates of patient recruitment, unforeseen safety issues resulting from the administration of antibody products in patients, uncertainties related to product manufacturing, as well as risks detailed from time to time in Medarex's public disclosure filings with the U.S. Securities and Exchange Commission (SEC), including its Annual Report on Form 10-K for the fiscal year ended December 31, 2008 its quarterly reports on Form 10-Q. There can be no assurance that such development efforts will succeed or that developed products will receive required regulatory clearance or that, even if such regulatory clearance were received, such products would ultimately achieve commercial success. Copies of Medarex's public disclosure filings are available from its investor relations department.