Merck & Co drops development of PD candidate preladenant

Following review of three separate Phase III studies of preladenant, US pharma giant Merck & Co (NYSE: MRK) said that these did not provide evidence of efficacy for this investigational adenosine A2A receptor antagonist in the treatment of Parkinson’s disease (PD).

Based on these results, Merck says it is taking steps to discontinue the extension phases of these studies and no longer plans to pursue regulatory filings for preladenant. The decision to discontinue these studies is not based on any safety finding. The results of these studies will be presented at an upcoming scientific meeting and will be submitted for publication in a peer-reviewed journal.

Preladenant was never expected to be a blockbuster for the company; estimates of three analysts compiled by Bloomberg suggested the drug, if it gained marketing approval, could generate sales of $211 million in 2016 and $271 million in 2017.