Elan (NYSE:ELN) is Johnson & Johnson's (NYSE:JNJ) new best buddy.

First J&J bought half of Elan's Alzheimer drug pipeline, and agreed to become Elan's partner on Tysabri if Biogen Idec (NASDAQ:BIIB) were ever acquired. Now Johnson & Johnson is kicking partner Alkermes (NASDAQ:ALKS) to the curb in favor of Elan's technology.

Yesterday, Alkermes said that J&J was discontinuing the development of a once-monthly version of its antipsychotic Risperdal. The company currently markets Risperdal Consta, developed using Alkermes' long-lasting technology, which allows the drug to be taken once every two weeks.

The development halt seems purely commercial in nature. As the patent expiration on Risperdal approached, Johnson & Johnson developed a follow-on drug called Invega, and then used Elan's NanoCrystal technology to develop a long-lasting version of the drug, called Invega Sustenna, which was approved by the Food and Drug Administration a few weeks ago.

Since Invega Sustenna is dosed once a month, sorry, Alkermes -- your services are no longer needed. Welcome to the party, Elan! Sit down and have a beer! We've got the U.S. market all to ourselves, at least until Eli Lilly (NYSE:LLY) finally clears up issues with its once-monthly Zyprexa.

Ironically, Eli Lilly is now Alkermes' ticket to getting out of the doghouse with investors. Eli Lilly and Amylin Pharmaceuticals (NASDAQ:AMLN) have a once-weekly version of their diabetes drug, Byetta, under review by the FDA, developed using -- you guessed it -- Alkermes' long-lasting technology.

Keep your chin up, Alkermes. You'll get a new friend soon enough.

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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. The Fool has a disclosure policy.