The potential deal, which could be announced as soon as Monday, would value Bioverativ at about $105 a share, the Journal reported. Sanofi SA is close to a deal to take over US drug maker Bioverativ Inc for more than $11.5 billion, the Wall Street Journal reported, citing people familiar with the matter.
The price represents a 64 percent premium to Bioverativ stock's close on Friday on the Nasdaq.
Bioverativ, a hemophilia drug maker, was separated from Biogen Inc early last year.
Sanofi has failed to land major deals after losing California-based cancer specialist Medivation to Pfizer Inc in 2016 and Swiss biotech company Actelion to Johnson & Johnson last year.
Earlier this month, Sanofi said it obtained the right to develop and sell a new hemophilia drug in a restructuring of its partnership with Alnylam Pharmaceuticals.
Sanofi and Bioverativ were not immediately available for comment outside regular business hours.