* Dainippon to buy 10% stake in Roivant and interests in 5units
* Schizophrenia treatment Latuda to lose US exclusivity in2023
* Japan pharma firms grapple with declining population athome(Adds Dainippon CEO comment, context and stock price)
By Rocky Swift
TOKYO, Sept 6 (Reuters) - Japan's Sumitomo Dainippon PharmaCo will pay $3 billion for a 10% stake in Swissdrugmaker Roivant Sciences Ltd and interests in five of itsbiopharmaceutical businesses, the two companies said on Friday.
The deal, which will open up new drug lines for SumitomoDainippon, will also give it the option to acquire interests inan additional six businesses, as well as access to Roivant'stechnology platforms, they said in a statement.
It comes as Sumitomo Dainippon's schizophrenia treatmentLatuda is due to lose its U.S. market exclusivity in 2023. TheJapanese company will take ownership of Roivant units thatdevelop treatments for prostate cancer, urinary diseases,pediatric illnesses and respiratory diseases, they said.
"We look forward to deepening our relationship with Roivant,which has a rich development pipeline, technology platforms, anddistinctive talents," Sumitomo Dainippon CEO Hiroshi Nomura saidin the statement.
Like its rivals, Japan's seventh-largest pharma company byrevenue, is grappling with a declining population at home and aneed to go abroad to find growth.
While the bulk of Japanese drug firms have been largelycautious about overseas acquisitions, there are signs of change.Takeda Pharmaceutical this year completed a $59 billionpurchase of Shire Plc, catapulting it into the list of theworld's top 10 drugmakers by sales - a rarity for a Japanesepharma company.
A fifth Roivant business unit will also be transferredbefore the deal's conclusion, the two companies said.
The 11 businesses include more than 25 clinical programswith multiple product launches expected between 2020 and 2022,they said.
Shares of Sumitomo Dainippon finished up 1.7% at 1,800 yenon Friday.(Reporting by Rocky Swift; Editing by David Dolan andMuralikumar Anantharaman)