Sanofi-Aventis is purchasing additional 12 million shares on biotech firm Regeneron for $400 million, upping its shares from 4% to 19%.

As part of the new deal, Sanofi and Regeneron plan to bring two to three biotech drugs into the pipeline each year, Sanofi Vice President of Research and development Jean-Claude Muller said in a conference call, according to Dow Jones.

They'll start with a drug that's in clinical trials for rheumatoid arthritis. They also plan to collaborate on a second drug (an antibody to Delta-like ligand-4 (Dll4), if you must know) that affects the body's ability to grow new blood vessels - the same function targeted by Avastin and VEGF Trap.

The two biotech companies are already co-developing Aflibercept (VEGF Trap), a cancer drug in late-stage trials for prostate and lung cancer, an equivalent of Genentech's Avastin.

Source: Wall Street Journal