** Shares of biopharma Clinuvel Pharmaceuticals CUV.AX
ends down 12.33% at A$35.56, their lowest since Aug. 31
** Brokerage Jefferies downgrades stock to "hold" from "buy"
on competition threat to co's Erythropoietic Protoporphyria
(EPP) drug Scenesse from Japan-based Mitsubishi Tanabe
** Mitsubishi Tanabe is conducting a Phase-3 trial for its
oral treatment for EPP, a rare inherited skin disorder, and is
due to complete in Q1 2022
** Trial for CUV's Scenesse has taken place only for adults,
while Mitsubishi is undertaking its trial in paediatric and
adult patients - Jefferies
** Says Tanabe's drug may become a major longer-term threat
to Scenesse if its trial is successful and approved in the
paediatric population
** Jefferies, however, keeps CUV's PT unchanged at A$36.8 as
it watches for the Phase-3 trial result
** Stock posts biggest intraday pct fall since Oct. 10, 2019
** CUV up 59.3% this year, as of last close
(Reporting by Navya Mittal)
((Navya.Mittal@thomsonreuters.com;))