Another large market, another failure for Pfizer's (NYSE: PFE) Sutent.

The pharma giant announced yesterday that it was ending a trial testing Sutent in prostate cancer. The trial was supposed to continue through next year, but an interim peek at the data by the independent Data Monitoring Committee determined that Sutent wasn't going to be able to show an effect compared to placebo in prostate cancer patients that had failed sanofi-aventis' (NYSE: SNY) Taxotere.

Sutent isn't a complete failure, but the fact that it doesn't work in prostate cancer is a big loss for Pfizer. In fact, despite some successes, most of Sutent's failures have been big.

Cancer

Estimated New Cases, 2010

Status of Sutent

Stomach

21,000

Approved for a rare stomach cancer called gastrointestinal stromal cancer after Novartis' (NYSE: NVS) Gleevec.

Kidney and renal pelvis

58,240

Approved for advanced kidney cancer.

Pancreas

43,140

Positive results for a rare type called pancreatic neuroendocrine tumors.

Breast

209,060

Failed multiple trials on its own and in combination with other drugs.

Lung and bronchus

222,520

Failed to extend lung cancer survival when combined with Roche and OSI Pharmaceuticals' (Nasdaq: OSIP) Tarceva.

Liver and intrahepatic bile duct

24,120

Trial in liver cancer stopped early because it wasn't as efficient as Bayer and Onyx Pharmaceuticals' (Nasdaq: ONXX) Nexavar.

Prostate

217,730

Failed.

Source: American Cancer Society.

The incidence numbers don't translate perfectly with market size since they don't take into account cancer subtypes that might have different treatment options, but the trend is fairly obvious; Sutent hasn't performed well in the cancer types that could have boosted sales the most.

In the press release announcing the prostate cancer trial ending, Pfizer highlighted a trial testing Sutent in kidney cancer after surgery. Treating patients before they reach the advanced stage would boost sales, and the fact that Sutent already works against kidney cancer should give patients confidence that the trial might actually succeed.

Until the results are in, investors will just have to dwell on what could have been.

Alex Dumortier warns you not to buy stocks for the wrong reason.