NovoNordisk's Victoza and Sanofi's insulin drug Lantus.

WSJ: New Strategies for Treating Diabetes

One reason why Sanofi has bid so eagerly for Aventis--despite the latter's reticence to be bought--is that two of its biggest investors soon will be able to sell their shares, perhaps causing Sanofi's value to drop.

FORBES: If Novartis Steps In, Will Pfizer Follow?

But there is reason to doubt that Sanofi's success with Acomplia will come from obesity alone.

FORBES: French drug giant Sanofi prepares for fat city.