Proving once again how fickle the FDA can be, CV Therapeutics (Nasdaq: CVTX) announced on Friday in an SEC filing that the FDA would likely be delaying the results of its review of the company's marketing application for regadenoson for a "few weeks."

Regadenoson is CVT's diagnostic aid that helps with heart imaging tests. CVT and partner Astellas filed a New Drug Application (NDA) for the agent on May 14 last year. The FDA tries to make an approval decision within 10 months for most drugs like regadenoson.

This 10-month goal -- called a PDUFA date after the fees that help fund the "quicker" decisions -- would have put an FDA decision on regadenoson with a target date of March 14. As CVT revealed in its SEC filing (and it's refreshing to see a drugmaker be so open), it still has not heard anything from the FDA, but said it plans to get a final answer on the drug's approval "within the next few weeks."

CVT pointed out that one possible reason for the delay is a lack of FDA funding (or mismanagement of funds, as I think). As fellow Fool analyst Brian Orelli pointed out on the Rule Breakers discussion boards, it's ironic that the FDA is experiencing such delays and issues in reviewing marketing applications considering the large increase in PDUFA fees that the agency just got. For example, another unlucky Astellas partner, Cardiome (Nasdaq: CRME), has yet to report an FDA decision since its Jan. 19 PDUFA date passed. The Cardiome delay is inexplicable, because its compound won near unanimous FDA and advisory panel praise.

While the news of its NDA review delay is bad, there may be a big silver lining for CVT. The drugmaker also said Friday that it is in "final labeling discussions" with the FDA over regadenoson. What I think has happened is that rather than issue a class 1 approvable letter that could lead to even more delays, the FDA chose instead to be nice to CVT and simply delay its final review until the labeling discussions could be completed and regadenoson approved.

This same scenario happened to BioMarin (Nasdaq: BMRN) about three months ago. If CVT is experiencing the same scenario as BioMarin, then the regadenoson approval delay is not such a big deal, although the irrational markets may make investors think it is.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has an A+ disclosure policy.