For a drug that has had so much drama during its existence, the final decision by the Centers for Medicare and Medicaid Services to pay for Dendreon's (Nasdaq: DNDN) Provenge was pretty anticlimactic.

Major health insurers -- Aetna (NYSE: AET), Humana (NYSE: HUM), and Kaiser, for example -- have agreed to pay for the treatment. But advanced prostate cancer is primarily a disease in older men who tend to be on Medicare. Dendreon needs Medicare coverage to get the prostate cancer treatment to blockbuster status.

The decision to issue a national coverage decision covering the $93,000 treatment was widely expected after the preliminary decision said the same thing. And that decision fell in line with the vote by experts back in November. If you were looking for drama, you'll need a time machine.

If the decision had been widely expected, why is Dendreon trading up 4% today? It seems to be nothing more than a recovery from worrying. There's always a possibility that something could go terribly wrong, and the stock fell almost 3% yesterday as investors pondered the company's fate prior to CMS' decision.

The national coverage requires patients to match the description on the drug's label: asymptomatic or minimally symptomatic metastatic castrate resistant (hormone refractory). The decision to cover off-label use by patients that have worse symptoms or patients that are less sick -- the cancer hasn't spread or is still responding to hormone withdraw -- will be left up to individual subcontractors.

In theory, off-label use could be a bonus for Dendreon, but I would expect few -- if any -- subcontractors to cover off-label use. Sales of Sanofi's (NYSE: SNY) Jevtana and Johnson & Johnson's (NYSE: JNJ) Zytiga, which are approved for use later in the disease progression, are likely safe.

Instead, CMS gave the rights to the subcontractors in case evidence emerges that the drug works in patients not listed on the label. Dendreon is testing the drug in patients earlier in their disease progression, for instance.

It took the agency a year to make this decision. With the off-label clause in effect, patients could get Provenge during the next round of drama that is sure to happen if Dendreon is able to prove that Provenge helps patients earlier in their disease progression.