On Friday, biotech Introgen (NASDAQ:INGN) reported data for its potential cancer-fighting compound INGN 241 at the American Society of Gene Therapy medical conference. The data that Introgen released was from a small, 22-person phase 1/2 study of INGN 241 that tested the compound in various solid tumors. But before you get too excited, keep in mind that this drug has been in trials for many years with little hard data on its effectiveness presented to the public.

Big on hype, but not much actual data
A signature characteristic of a lower-quality biotech company is  numerous press releases that trumpet a drug's potential benefits in preclinical studies or rehash early-stage data for years on end.

Introgen is a bit too hype-happy for my tastes. Here's a small sampling of the many press releases concerning INGN 241 that the company has put out over the past three years:

"Introgen's INGN 241 Works Synergistically With Celebrex to Kill Breast Cancer Cells."

"Introgen's INGN 241 in Combination With Tarceva Inhibits Tumor Growth."

"Introgen's INGN 241 Works Synergistically With Avastin to Cut Blood Supply to Cancers."

"Introgen's INGN 241 Kills Chemotherapy-Resistant Cancer Cells."

After reading these headlines, you'd almost think that INGN 241 was the next holy grail of cancer-fighting drugs.

But imagine the market opportunity for INGN 241 if it could be used in conjunction with Pfizer's (NYSE:PFE) Celebrex (which isn't even approved as an oncology compound) or blockbuster drugs like Avastin and Tarceva (from Genentech (NYSE:DNA) and OSI Pharmaceuticals (NASDAQ:OSIP), respectively)!

Delays, delays, delays
Unfortunately, all of these press releases were only announcing preclinical studies -- that is, not tests of the drug in humans -- of INGN 241. The drug's effects in humans have been much less exciting. Even though the drug started phase 1 testing in 2000, Introgen has released very little human clinical stage data on the drug. The only real hard data on INGN 241 comes from the phase 1/2 cancer study.

Introgen originally began releasing data from the completed phase 1/2 study back in 2003. Aside from the constant rehashing of study data over the past four years, the company tends to be pretty sparse in the data that it releases on this compound except when it comes to press releases touting the drug's possible effects with proven cancer treatments in preclinical studies.

Despite this dearth of data, Introgen is testing the drug in what it calls a phase 3 study in various solid tumors. Considering that the FDA usually requires patient data from hundreds of patients for oncology compounds to gain regulatory approval, I'm not optimistic on INGN 241's chances of ever gaining marketing approval, let alone from this phase 3 trial.

The takeaway
The bottom line is that biopharmas can often be very selective in the data that they announce to investors. With the length of time that most clinical trials take, drugmakers can easily string investors along for years with little tidbits of information that make their compounds sound like the next billion-dollar blockbuster drug. This can happen while the company secretly knows that the drug has little chance of making it past the FDA and onto the market.

The length of time that biotech investors have to wait for the clinical trial development process to play out is why investing in development-stage biotechs with an honest and forthcoming management team is so important. I'm not saying Introgen hasn't been completely honest with the state of its drug development programs, but investors should take notice of how the company presents itself and how slowly the company moves its compounds through its pipeline.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has a disclosure policy. Pfizer is an Inside Value recommendation.