Last year, Flamel Technologies (Nasdaq: FLML) was in the spotlight, as investors waited with bated breath to see how well its first commercial drug would sell. The launch of Coreg CR by partner GlaxoSmithKline (NYSE: GSK) went worse than expected, for reasons as diverse as bad follow-on clinical study results and distracting troubles for Glaxo's other drugs.

Trading at less than two-thirds its 52-week high, Flamel's stock has yet to recover from the sting of the underwhelming launch. Nonetheless, the company is still advancing its early stage internal drug pipeline, and it's also signed a spate of new early stage drug development deals with Wyeth (NYSE: WYE) and other large-cap pharmas.

Last week, Glaxo's first-quarter financial results revealed no material change in the sales trajectory for Coreg CR. In the first quarter, net sales of the heart-failure treatment rose to $70 million worldwide, up 4.5% from the previous quarter's $67 million.

Remember that a host of variables can affect quarter-over-quarter sales numbers, including wholesaler inventory stocking, the weather, and even the leap-year addition of an extra day in the quarter. As a result, small quarterly sales gains or losses don't reliably indicate a real change in a drug's prospects.

Coreg CR's $70 million in sales this quarter suggests a run rate of $280 million for the year. If Flamel receives an estimated royalty rate of roughly 3% on all Coreg sales, that alone will put an extra $8.4 million in Flamel's coffers this year. The extra cash should help reduce Flamel's development costs on some of its internally developed pipeline drugs, including its hepatitis C interferon-alpha 2bXL treatment.

Last week, Flamel presented additional, modestly promising phase 1 data on this compound at the European Association for the Study of the Liver (EASL) medical conference. Other second-generation interferons like Human Genome Sciences' (Nasdaq: HGSI) albuferon have earned nice partnership deals. Investors hope that Flamel can do the same with its attempt at a second-generation interferon, perhaps soothing some of the heart pain caused by Coreg CR.

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

Fool contributor Brian Lawler does not own shares of any company mentioned in this article. GlaxoSmithKline is an active Income Investor pick. The Fool has an A+ disclosure policy.