Looks like the love triangle between partners Elan (NYSE:ELN) and Biogen Idec (NASDAQ:BIIB) and third-wheel Johnson & Johnson (NYSE:JNJ) is going to get settled in court.

In case you missed it, here's a rundown of their quarrel (which is only slightly less convoluted than your average episode of Desperate Housewives):

  • Biogen and Elan's partnership to sell multiple sclerosis drug Tysabri has a provision that, in the event of a change in control, the other company can buy out the rights to Tysabri.
  • Elan doesn't really have the money to buy Tysabri if Biogen is purchased, so Biogen says that Elan asked Johnson & Johnson to fund the purchase, potentially making Johnson & Johnson and Elan partners on Tysabri should Biogen be purchased.
  • Biogen is less than thrilled. Such a deal would lower the value of Biogen because a potential acquirer -- Pfizer (NYSE:PFE), Roche, or Novartis (NYSE:NVS), for instance -- would have to factor the likely loss of Tysabri into any purchase price.

Last week Biogen sent a letter to Elan claiming that Elan was in breach of their contract because the two partners cannot assign their right to acquire Tysabri to another company. Biogen apparently plans to take full control of Tysabri if Elan doesn't repair the breach, presumably by canceling its contract with Johnson & Johnson. Elan announced yesterday that it's suing Biogen to stop it from breaking up the partnership, claiming that it didn't assign the rights to Tysabri -- it just gave Johnson & Johnson the right to fund its purchase.

Ironically, this isn't the only fight over change of control provisions that Johnson & Johnson is a part of. The company recently took Merck (NYSE:MRK) and Schering-Plough (NYSE:SGP) to arbitration claiming that it can take back rights to Remicade and its follow-on, Simponi, which Schering markets outside the U.S.

The $1 billion question is how the Tysabri deal affects Johnson & Johnson's $1 billion investment in Elan and the acquisition of part of its Alzheimer's pipeline. The Tysabri deal wasn't announced at the same time, but, according to reports, was apparently part of the deal. I can't imagine Elan would give up Tysabri to keep the Johnson & Johnson deal if a judge says Elan is in violation of its partnership with Biogen.

Hopefully for Elan's, Biogen's, and Johnson & Johnson's investors, a judge puts an end to this lovers' quarrel quickly.

For Elan and Biogen, the stakes are huge. For J&J, not so much. How do you think the judge will rule and who will win and who will lose? Let us know in the comments box, below.

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Elan is a Rule Breakers selection. Pfizer is an Inside Value recommendation. Johnson & Johnson is an Income Investor recommendation. Novartis is a Global Gains pick. Whether you like your companies big or small, dividend-laden or with multibagger written all over them, we've got a newsletter for you.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool has a disclosure policy.