A trial of a promising cancer pill being developed by Pfizer has been stopped earlier than expected because the drug proved effective against a type of stomach tumor, according to a letter on a patient Web site posted by the scientist conducting the study.

Follow-up analysis of the drug continues.

Robert Hazlett, an analyst at SunTrust Robinson Humphrey, said in a note to investors this morning that the news could mean that the drug, SU-11248, could be submitted to the U.S. Food and Drug Administration in the first quarter of this year, and that it could be approved by the end of 2005. That means it would be available to patients a year earlier than expected.

The trial was testing the pill, SU-11248, as a treatment for gastrointestinal stromal tumors (GIST). These tumors were once incredibly difficult to treat, but now they are vulnerable to Gleevec, a Novartis (nyse: NVS – news – people ) drug that was one of the first targeted cancer drugs. However, in patients who fail Gleevec, there is no fallback option. The current trial by George Demetri, a GIST expert at the Dana-Farber Cancer Institute, tested SU-11248 in patients who had failed Gleevec.

In a letter e-mailed to patients and posted on the Web site GIST Support International, Demetri wrote that an independent committee had stopped the trial early because SU-11248 proved effective: “We will be working very hard to get more information to investigators and to the global community at large as soon as possible. At this point, though, I can say that this should be a very positive step towards establishing beyond any doubt another therapeutic option for patients with GIST using a novel molecularly-targeted agent if Gleevec proves inadequate to control the disease.”

More here.