(Bloomberg) -- A fully-owned subsidiary of Sumitomo Pharma Co. offered to buy the remaining outstanding shares of pharmaceutical company Myovant Sciences Ltd., seeking to bolster the development of drugs for women’s health and prostate cancer. 

Sumitomo Chemical Co., the parent of Sumitomo Pharma, owns 52% of Myovant, according to filings compiled by Bloomberg. The Japanese company is offering $22.75 a share in cash for Myovant, 27% higher than the drugmaker’s closing price on Sept. 30, through fully owned subsidiary Sumitovant Biopharma Ltd., they said in a statement Monday. 

In response, Myovant said the proposal “significantly” undervalues the company and that it remains open to considering any “improved proposal.” Myovant is listed in the US, and has its global headquarters in Basel, Switzerland.

Myovant shares rose 26% in premarket US trading. Sumitomo Pharma fell as much as 2.6% in Tokyo on Monday.  

The proposition is a “natural step” in further building the relationship between the two companies to combine expertise, platform and resources to deliver new drugs, Sumitomo said in its statement. Since the investment in Dec. 2019, the companies “have enjoyed a collaborative and successful relationship,” and launched Orgovyx and Myfenbree, treatments for prostate cancer and women’s health. 

The proposed acquisition represents an equity value of $2.4 billion for Myovant, and an enterprise value of $2.5 billion, Sumitomo Pharma said. 


(Updates with premarket trading)

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