HOUSTON (AP) — A leukemia drug that patients say has fewer side effects than aspirin has shown surprising success in early trials, researchers at the University of Texas M.D. Anderson Cancer Center say.

The drug, STI571, a new treatment for chronic myelogenous leukemia, was a central topic at a weekend medical conference in San Francisco.

M.D. Anderson researchers reported that in all 31 CML patients given the drug at the center last year, the cancer went into complete remission. Lead investigator Dr. Moshe Talpaz called the pill "the holy grail we are looking for in our business," the Houston Chronicle reported Sunday.

This year, 550 patients with chronic CML resistant to conventional treatment have been given the drug, and in more than 90 percent of the cases, their blood was normal after six months of treatment, according to research reported Saturday at the meeting of the American Society of Hematology.