A Phase I open-label pilot study was conducted to evaluate the safety (primary endpoint) and preliminary efficacy of escalating single doses of MDX-1100 in 11 patients with moderate to severe ulcerative colitis (UC). This study demonstrated that single doses (ranging from 0.3 to 10.0mg/kg) of MDX-1100 in patients with active UC were safe and well-tolerated. Four patients in the study had protocol-defined clinical responses, determined by the ulcerative colitis disease activity index (UCDAI) which scores the frequency and the amount of bloody stool per day that is recorded in a patient diary, physician global assessment and the assessment of colon mucosal inflammation ascertained by endoscopy.
A separate Phase I double-blind, placebo-controlled study was also conducted to determine safety and pharmacokinetics of escalating single doses (ranging from 0.01 to 10mg/kg) of MDX-1100 in 50 healthy volunteers. MDX-1100 demonstrated dose-proportional pharmacokinetics, and a potential pharmacodynamic effect that signaled a decrease in the production of CXCL10 was observed at 10mg/kg. There were no infusion reactions, and the drug was non-immunogenic.
Geoffrey Nichol, senior vice president of product development at Medarex, said: “We are excited with the Phase II program and look forward to the outcome of the proof-of-concept studies in ulcerative colitis and rheumatoid arthritis.”