Cancer pill could affect women's fertility: report

BOSTON (Reuters) - Long-term use of the cancer pill Gleevec may produce fertility problems in women, Greek doctors reported on Wednesday.

Chemotherapy and radiation have long been known to damage the fertility of patients, but little is known about more targeted drugs such as Gleevec, known generically as imatinib.

Dr. Constantinos Christopoulos of the Amalia Fleming General Hospital in Athens and colleagues reported on the case of a 30-year-old woman with chronic myeloid leukemia who stopped menstruating after two years of taking Gleevec, made by Novartis Pharmaceuticals Corp.

She had terminated a pregnancy after the cancer was discovered, initially received 400 milligrams per day, and the dose had been boosted to 600 milligrams six months before her periods started to become unusually light or irregular, Christopoulos and colleagues wrote in a letter to the New England Journal of Medicine.

After the periods stopped, ultrasound revealed that the number of eggs in her ovaries was greatly reduced, they said.

"These findings suggest that prolonged administration of imatinib may have profound effects on female fertility," the Christopoulos team wrote.

"The true incidence, possible dose dependence, and reversibility of imatinib-induced ovarian failure should be examined in future studies."

It is not the first time the drug has been linked to reproductive issues. The Journal published a report in 2004 of a man who also developed fertility problems while on an even higher dose -- 800 milligrams daily.

Gleevec is a so-called targeted drug that supposedly affects a protein active in tumors, It is not supposed to be taken during pregnancy. The drug is also approved for certain tumors of the intestinal tract.

(Editing by Maggie Fox and Eric Beech)