** Drugmaker BioMarin Pharmaceutical's BMRN.O shares rise ~1.8% to $68.25 premarket

** Oppenheimer upgrades BMRN to "outperform" from "perform" rating

** Brokerage says new management's focus on operational efficiencies, cost reduction and return on R&D investments will boost BMRN's revenue growth

** Twenty-three of 29 brokerages rate the stock "buy" or higher, 6 "hold"; their median PT is $95 - data compiled by LSEG

** As of last close, stock up ~3.8% YTD

(Reporting by Prakhar Srivastava in Bengaluru)

((Prakhar.srivastava2@thomsonreuters.com))