How did Celgene (NASDAQ:CELG) turn an earnings release that met analysts' expectations while lowering revenue guidance on one of its drugs into an 18.6% increase in share price yesterday? It juiced up the announcement with a little clinical trial data, that's how.

First the ho-hum news: Revenue was up 10% year over year, which is impressive except for the fact that Celgene isn't Pfizer (NYSE:PFE) or Merck (NYSE:MRK); over the last five years, revenue has grown 51% annually, so 10% doesn't look that extraordinary. Earnings per share came in a little more impressive -- 19% higher than the year-ago quarter.

The good news came in the form of a trial dubbed MM-015. Results from the phase 3 trial weren't expected quite so soon, but the data at the interim analysis was good enough to show that Revlamid in combination with two older drugs delayed the progression of newly diagnosed multiple myeloma, a type of blood cancer.

Revlamid is already used off-label by U.S. doctors to treat newly diagnosed multiple myeloma patients, but there's still benefit to getting a broader approval because the company'll be able to market the drug for that indication, once approved. Celgene should also benefit from increased sales in Europe, where it's currently not used to treat early patients.

Expanding the patient population is a pretty standard procedure to increase sales. For instance, on Wednesday Onyx Pharmaceuticals (NASDAQ:ONXX) said its kidney and liver cancer drug, Nexavar, worked in breast cancer patients, and earlier this month Eli Lilly (NYSE:LLY) got Alimta approved to be used longer in lung cancer patients.

With very few late-stage compounds in its pipeline, Celgene will need to continue this tactic of increasing sales by expanding its already-approved drugs into different cancers until its pipeline can catch up. So far, the juice is working.

Expand into this Foolishness:

Start investing today -- just $7 per trade with Scottrade. Or find the broker that’s right for you.

Motley Fool Rule Breakers is always on the hunt for hot drug stocks and other cutting-edge picks. Click here to see all of our latest discoveries with a free 30-day trial subscription.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Pfizer is a recommendation of the Inside Value newsletter. The Fool has a disclosure policy.