Leukemia Drug Side Effect: Color Returned to Gray Hair

By LAWRENCE K. ALTMAN

n a puzzling and intriguing side effect, a new antileukemia drug has darkened the gray hair of some patients, French doctors reported yesterday.

The drug, Gleevec, can damage the liver and blood, making its use as a color-restoring agent unlikely. But the finding raises the possibility that a safer drug may someday be developed to serve that purpose.

In a letter published in The New England Journal of Medicine, the French doctors said that among 133 patients treated with Gleevec, 9 had progressive return of color to their hair. The darkening effect began 2 to 14 months after the patients, five men and four women, began therapy and the hair roots had time to grow. Their ages ranged from 53 to 75 years with a median of 63.4.

The darkening occurred on the head in 8 patients and on the head and body in 1, said the doctors, Gabriel Étienne, Pascale Cony-Makhoul and François-Xavier Mahon from the Victor Segalen University in Bordeaux.

Even before Gleevec was marketed last year for the treatment of chronic myeloid leukemia, a number of other doctors reported the finding to its manufacturer, Novartis of East Hanover, N.J., said Dr. Brian Druker of the Oregon Health and Science University in Portland.

But Dr. Druker added in an interview that the drug was "not a panacea for gray hair" and did not completely return hair to its original color.

The French team did not report how many of the 133 patients had gray hair when they began therapy from December 1999 to June 2001, making it difficult for readers of the letter to determine the frequency with which darkening occurred.

The frequency was 5 percent to 10 percent among his patients, Dr. Druker said.

Because some patients may have dyed their hair, the frequency can be difficult to determine unless the observations are made as part of a study.

In addition, Dr. Druker said, lightening of dark skin has been noted among a smaller number of patients.

Scientific understanding of the drug's action on the body would have suggested that it would have the opposite effect of darkening gray hair, Dr. Druker said. The new observation, he added, "may give us some clues to the mechanism and perhaps a safer treatment" for gray hair.

A spokeswoman for Novartis said the company was not studying Gleevec or related compounds for their coloring effect. But other doctors said that researchers elsewhere would be likely to explore that potential.