** Shares of drug developer Monopar Therapeutics Inc
MNPR.O down ~53% at $1.40 after market
** Says its experimental drug, clonidine HCl MBT, did not
meet pre-defined threshold for efficacy in a trial to prevent a
cancer treatment-related side effect called severe oral
mucositis (SOM)
** Says it will discontinue the drug's trial along with its
active development, based on interim analysis of data from
mid-to late-stage study
** SOM is the most frequent major radiation-induced side
effect observed in patients with head and neck cancer and is
caused by chemoradiation treatment - company
** MNPR shares have gained ~26% YTD, as of last close
(Reporting by Raghav Mahobe)
((Raghav.Mahobe@thomsonreuters.com;))