Wyeth and partner Progenics Pharmaceuticals have been informed by US regulators that a review of methylnaltrexone, their new treatment for opioid-induced constipation in patients receiving palliative care, has been delayed.

The US Food and Drug Administration had originally set a Prescription Drug User Fee Act date of January 30 to complete its review of methylnaltrexone but that has now been pushed back three months. The reason for the delay is that the agency has requested the results of a recently-completed QT study of intravenous methylnaltrexone, which is also being developed for the management of post-operative ileus.

The companies said that the study has been submitted to the FDA and it shows that there was no evidence of an effect of the drug on QT prolongation. Nevertheless the agency says it needs the extended time to review the study fully hence the need to push the action date back to April 30.

Progenics chief executive Paul Maddon said he is confident the subcutaneous version of the drug for OIC will prove successful. He added that "we are enthusiastic about the entire methylnaltrexone programme” and plans are also afoot to submit a New Drug Application for the intravenous formulation, for POI, later this year.

Wyeth gains rights to Mochida pain drug
Meantime, Wyeth has bought the global rights to develop and market an experimental pain drug from Japan’s Mochida Pharmaceutical Co. The drug candidate, which is still at the preclinical stage, is a transient receptor potential vanilloid sub-family 1 (TRPV1) antagonist, a potential next-generation treatment for various pain conditions.

Financial terms of the deal were not disclosed but Mochida will receive a one-time fee which will not have any major effect on its earnings, and developmental milestone payments. The firm will retain the option of jointly developing and marketing the drug with Wyeth in Japan.