Briefs: Sanofi to up stake in Regeneron; Bayer files for riociguat approval

US biotech Regeneron Pharmaceuticals (Nasdaq: REGN) saw its shares rise 4.8% to $173.84 in early trading yesterday, after it said yesterday that French drug major Sanofi (Euronext: SAN), which already owns around 17% of the company, intends to acquire common stock of Regeneron through open market purchases and direct purchases from shareholders. Sanofi shares also gained, but that was more to do with negative US regulatory news for Novo Nordisk, a rival in the long-acting insulin market (The Pharma Letter February 11).

As a result, Sanofi intends that the value of its ownership of voting securities of Regeneron stock will be in excess of the $500 million HSR Act notification threshold. The announcement led to instant speculation of a full-blown takeover attempt from the French firm. However, under a 2007 “standstill” agreement between two firms, which collaborate on the colorectal cancer drug Zaltrap (aflibercept/ziv-aflibercept) as well as other investigational compounds, Sanofi cannot raise its holding in the US firm above 30%.