Sanofi-Aventis wants to make its interest in Genzyme official, reports the Wall Street Journal's Health Blog. Last week, the Journal reported that "the two sides have begun sounding out each other's interest in a deal before entering into formal talks and a completed transaction is far away." This week, the New York Times says that "Sanofi-Aventis is likely to make an unsolicited offer of up to $70 a share for Genzyme," which would then total $18.6 billion and "could become one of the year's biggest deals."