Amgen (NASDAQ:AMGN) loves Cytokinetics (NASDAQ:CYTK) -- or at least its heart drug. Yesterday, the large biotech company exercised its right to license Cytokinetic's cardiac contractility program, including heart failure drug CK-1827452.

The companies' 2006 partnership allowed Amgen to license the program for $50 million. There's potential for Cytokinetics to get milestone payments of up to $600 million for the program and royalties on the drug, should it get approved.

For Cytokinetics, the deal has to be a sigh of relief. The company only had $64 million in cash and short-term investments at the end of last quarter. An extra $50 million -- plus not having to fund costly phase 3 trials -- must be a load off its shoulders.

The move looks like a good one for Amgen as well, since further diversifying may be just what the doctor ordered. Like Johnson & Johnson (NYSE:JNJ), Amgen has had trouble with its anemia drug franchise. Its rheumatoid arthritis treatment Enbrel, which is sold in partnership with Wyeth (NYSE:WYE), also saw lackluster sales last quarter.

Expansion into heart drugs and osteoporosis, if denosumab is approved later this year, should help Amgen diversify for any future downturns. The only concern that investors should have is that Amgen doesn't have any experience in marketing heart drugs. Gilead Sciences (NASDAQ:GILD), which is also taking the diversification route, solved that problem by buying CV Therapeutics -- sales forces and all. We'll have to see if Amgen takes that route or goes it alone, but it has some time to make a decision, since CK-1827452 hasn't entered phase 3 trials yet.

Diversify with some additional Foolishness:

Motley Fool Rule Breakers is always on the hunt for hot drug stocks and other cutting-edge picks. Click here to see all of our latest discoveries with a free 30-day trial subscription.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Johnson & Johnson is a selection of the Income Investor newsletter. Read The Fool's disclosure policy backwards, just for a little diversity.