Salix Pharmaceuticals, Ltd. (NASDAQ:SLXP) and Progenics Pharmaceuticals, Inc. (NASDAQ:PGNX) today announced the successful outcome of the Phase 3 trial to evaluate the efficacy and safety of oral methylnaltrexone for the treatment of opioid-induced constipation (OIC) in subjects with chronic, non-cancer pain. This trial, evaluating three once-daily oral methylnaltrexone dosing regimens (150, 300 and 450mg), demonstrated highly statistically significant results for the primary endpoint in two of the three treatment arms when compared to the placebo treatment arm. Both the 300 and 450 mg treatment arms demonstrated highly statistically significant improvements in rescue-free bowel movement (RFBM) within 4 hours of administration over 28 days of dosing when compared to placebo treatment. In addition, the 300 and 450 mg treatment arms demonstrated highly statistically significant improvements in RFBM within 4 hours of administration following the first dose when compared to placebo treatment. Statistically significant efficacy was also seen in both the 300 and 450 mg treatment groups for the two key secondary efficacy endpoints including one assessing response (responder/non-responder) to study drug during Weeks 1 to 4 where “responder” is defined as having 3 or more RFBMs per week, with an increase of at least one RFBM per week over baseline, for at least 3 out of the first 4 weeks. Overall, efficacy of oral methylnaltrexone in this study was comparable to that reported in clinical studies of subcutaneous methylnaltrexone in subjects with chronic, non-cancer pain. The overall observed safety profile seen in patients treated with oral methylnaltrexone was comparable to placebo in this study.
“We are extremely pleased with the outcome of this 804-subject Phase 3 trial of oral methylnaltrexone in the treatment of opioid-induced constipation in subjects with chronic, non-cancer pain,” stated Bill Forbes, Pharm.D., Executive Vice President, Medical and R&D, and Chief Development Officer, Salix. “The results of this Phase 3 study show a clear dose response for oral methylnaltrexone. We look forward to presenting detailed data from this study at a medical conference in 2012, as well as submitting the New Drug Application (NDA) for this oral formulation mid-year 2012.”