Novel drug fights leukemia leukemia.

An experimental drug helps a small but significant fraction of people with acute myeloid leukemia and causes minimal side effects, research suggests.

The modest success of the drug tipifarnib is encouraging because the blood cancer is difficult to treat, especially in older patients, says Judith Karp of the Johns Hopkins Medical Institutions in Baltimore. Side effects, including weakened immunity, can kill more than 30 percent of elderly patients who receive standard chemotherapy.

Karl, Jeffrey Lancet of the University of Rochester in New York, and their colleagues gave tipifarnib to 103 people with acute myeloid leukemia and an average age of 70. The drug acts against a leukemia-associated enzyme.

Volunteers took a daily oral dose of tipifarnib that early tests suggested would cause minimal toxic side effects. Each of up to six treatment cycles lasted 3 weeks or until problems such as reduced immunity or a rash appeared.

In 21 percent of volunteers, the cancer stopped getting worse during treatment, and these people lived for an average of 18 months after the beginning of the trial. Those for whom the drug had no positive effect lived only 11 weeks on average. Seven percent of volunteers died from complications related to taking the drug.--B.H.