It's a fact of life for pharmaceutical companies without a pipeline full of drug candidates that they'll eventually go bust because of generic competition. They can either invest more in research and development or get licenses for and become partners with other companies for novel drug candidates. Thursday morning, Motley FoolStock Advisor pick BiogenIdec (NASDAQ:BIIB) chose the latter route.

In a deal worth $42.5 million (including a $5 million equity investment), Biogen bought the rights to an inhaled pulmonary arterial hypertension drug (PAH) named Aviptadil from privately held Swiss biotech mondoBIOTECH. Aviptadil is in early stage clinical trials. If the drug is eventually approved, Biogen would take over all of its testing and sales.

In the past two years, Biogen has been very active in bolstering its pipeline. It has signed partnership deals with mondoBIOTECH and Rule Breakers recommendation PDLBioPharma (NASDAQ:PDLI). It also recently acquired two privately held companies outright -- Conforma Therapeutics and Fumapharm AG.

For Rule Breakers subscribers, PAH -- a type of high blood pressure -- should sound familiar because that's the disease that another newsletter selection, EncysivePharmaceuticals (NASDAQ:ENCY), is trying to treat with its lead drug, Thelin. Without much published clinical data (Aviptadil was most recently in an eight-person trial), it's way too soon to compare Biogen's new PAH drug with Thelin, Myogen's (NASDAQ:MYOG) Ambrisentan, or United Therapeutics' (NASDAQ:UTHR) Remodulin.

Even making the huge assumption that Aviptadil could show that it's as effective as Thelin or Ambrisentan in treating PAH, the drug would serve a different patient group because it's an inhalation therapy. As I've said on the Rule Breakers discussion boards, I don't think Encysive investors should worry too much about the imagined superiority of competing drugs.

It would take Biogen many years to commercialize Aviptadil even if the drug makes it through the regulatory process. If Aviptadil can carve out a niche and compete with the other treatments for PAH, then the $42.5 million that Biogen paid for the drug would be a steal, because treating PAH could be worth well over a billion dollars to companies.

Ordinarily, I'd be a little wary of biotech companies that have run out of in-house drug candidates and are forced to scour the market for new drugs. Biogen, though, has had a long and successful history of filling out its pipeline via acquisitions of drug candidates and then successfully commercializing them.

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Fool contributor Brian Lawler owns shares of Encysive but no other company mentioned in this article. He welcomes your feedback . The Fool has a disclosure policy .