Cancer Research Lab

Nexavar (sorafenib), used to treat kidney cancer, has shown promise in treating a small number of people with acute myeloid leukemia (AML), U.S. researchers said on Tuesday.

Nexavar (Bayer AG and Onyx Pharmaceuticals) dramatically reduced the percentage of circulating leukemia cells in 16 subjects with a mutation in the FLT3 gene, which occurs in about one third of AML patients.

“AML patients with this mutation have a particularly poor prognosis, so this highly targeted drug appears to be a significant step forward in leukemia therapy,” said Dr. Michael Andreeff of the M.D. Anderson Cancer Center at the University of Texas.

Circulating cancer cells in study patients dropped to 7.5%, from 81%. In two patients, leukemia cells circulating in the blood dropped to zero, the researchers reported in the Journal of the National Cancer Institute.

The study patients had failed all other treatments.

Dr. Andreeff said in a statement that Nexavar would need to be combined with other treatments. So far, there have been no major side effects.

Andreeff said the drug has little effect on AML patients who do not have the genetic defect.

A study last week in the journal Lancet Oncology, however, found the drug significantly raises the risk of hypertension, and researchers said patients should be monitored for this risk.

Nexavar was recently approved to treat liver cancer in the United States and Europe. It is currently being tested for use against several other types of cancer, including non-small cell lung cancer and breast cancer.