ALSO NOTED: Merck cleared to sell Isentress in Canada; Sanofi, Astellas restructure Japanese venture;

> Merck's new, first-in-class HIV treatment Isentress won approval from Canadian regulators for patients resistant to other AIDS drugs. Report

> Sanofi-Aventis and Astellas Pharma say they're restructuring their joint venture by splitting up the rights to market various drugs. Report

> Teva Pharmaceutical Industries got the FDA's tentative nod to market a generic version of GlaxoSmithKline's Parkinson's drug Requip when its patent expires in May. Report

> Walgreen's has stopped filling prescriptions for four CVS Caremark drug plans, saying the reimbursement levels are too low. Report

> Lifecycle Pharma has tapped Hans Christian Teisen as its new chief financial officer; Teisen most recently served as CFO of the drug maker Bavarian Nordic. Report

> A Friedman Billings Ramsey analyst downgraded MGI Pharma's stock, joining market watchers skeptical that the up-for-sale biotech will attract suitors anytime soon. Report

> Questcor Pharmaceuticals upgraded its interim president Don M. Bailey to permanent president and chief executive. Report

> Canada's Axcan Pharma is being bought out for $1.3 billion by the private equity group TPG Capital. Report

> Regeneron is feeling the warm embrace of Sanofi-Aventis, France's acquisition-hungry pharma giant. Sanofi has upped its stake in Regeneron from 4 percent to 19 percent while putting up $85 million in an up-front fee to seal a development deal covering therapeutic antibodies. Report

> The latest survey from the National Venture Capital Association shows that biotechnology is still on a roll with investors. Report

And Finally... What's good for the gander isn't for the goose: A genetic variation puts women at risk of depression from chronic stress, but protects stressed-out men from the same mood disorder. Report