Wyeth announces preliminary methylnaltrexone results

Wyeth Pharmaceuticals and Progenics Pharmacueticals have announced the preliminary results of a phase I clinical study assessing a novel oral formulation of methylnaltrexone.

In the trial, the drug – being developed as a treatment for opiod-induced constipation – exhibited positive activity in patients receiving the higher of the two doses tested.

Methylnaltrexone is a peripherally acting mu-opioid receptor antagonist currently being assessed in trials as a treatment for the adverse effects related to use of opioid analgesics.

Conducted by Wyeth, the randomised pharmacodynamic study saw a “substantial majority” of patients experiencing a bowel movement following administration of the higher of the two tested doses, with the compound generally well tolerated in patients in the study.

The firms have reported that they will conduct additional clinical studies of orally-administered formulations of methylnaltrexone.

Paul J Maddon, founder, chief executive officer and chief science officer of Progenics, said: “I am pleased by the rapid development and testing of a new formulation of oral methylnaltrexone.”

He added that an orally-administered formulation of the drug could provide vital benefits as a new treatment option for patients experiencing opiod-induced constipation.

Last month, both firms reported positive results of a clinical trial assessing methylnaltrexone as a treatment for opioid-induced constipation, with subcutaneous administration of the compound for up to three months continuing to induce laxation in patients with advanced illness.