In drug development, delays and missed timelines can be maddening for biotech investors. That's especially true for people who buy shares of drugmakers with early-stage pipelines, since the drug-development process can take years even without delays. One way to minimize the impact of such drug-development holdups is to buy shares of biotechs with multiple drug candidates in the clinic. To that end, Rule Breakers pick Exelixis (NASDAQ:EXEL) has done a great job of keeping its promise to stock its pipeline with three new drug candidates each year.

Continuing with this annual goal, Exelixis yesterday filed another investigational new drug (IND) application to bring a new compound into the clinic for further testing. This move brings Exelixis' pipeline up to eleven drug candidates that are either in clinical testing or about to begin it. That's two more compounds in development than Exelixis had by the end of 2005, even including the failed XL119 phase 3 program that was discontinued last year.

Even better, Exelixis expects to surpass its annual goal of three new IND applications and bring a fourth new compound into clinical development this year. Considering that, on average, only one out of five drugs entering the clinic crosses the finish line and gains marketing approval, Exelixis is smart to stock up its pipeline and to have made partnerships with so many of the leading pharmaceutical and biotech companies, including Genentech (NYSE:DNA), GlaxoSmithKline (NYSE:GSK), and Wyeth (NYSE:WYE).

It's refreshing to follow a development-stage biotechnology company such as Exelixis that sticks with its goals, even if the path forward is not always perfectly flat. As Rule Breakers biotech analyst Charly Travers laid out in his recommendation for the company, this magnitude of clinical development is unmatched for a biotech the size of Exelixis. Even if a few of the shots on goal go astray, as XL119 did, Exelixis is ensuring that investors are given multiple chances for success.

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GlaxoSmithKline is an Income Investor selection.

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