Osteoporosis drugs linked to esophageal cancer

By Gene Emery

    BOSTON, Dec 31 (Reuters) - Merck's <MRK.N> popular

    osteoporosis drug Fosamax and other similar drugs may carry a

    risk for esophageal cancer, a U.S. Food and Drug Administration

    official said on Wednesday.

    Diane Wysowski of the FDA's division of drug risk

    assessment said researchers should check into potential links

    between so-called bisphosphonate drugs and cancer.

    In a letter in Thursday's New England Journal of Medicine,

    Wysowski said since the initial marketing of Fosamax, known

    generically as alendronate, in 1995, the FDA has received 23

    reports in which patients developed esophageal tumors.

    Typically, two years lapsed between the start of the drug

    and the development of esophageal cancer. Eight patients died,

    she reported.

    In Europe and Japan, 21 cases involving Fosamax have been

    logged, as well as six instances where Procter & Gamble's

    <PG.N> Actonel or risedronate and Didronel or etidronate, and

    Roche's <ROG.VX> Boniva or ibandronate may have been involved.

    Six of those people died.

    Esophagitis, which is an inflammation of the lining of the

    tube carrying food to the stomach, is already know to be a side

    effect of the drugs, which is why patients are instructed to

    remain upright for at least a half hour after taking them.

    In addition, Wysowski said, doctors should avoid

    prescribing the drugs to people with Barrett's esophagus, which

    is a change in the lining that leads to the stomach. It is

    often found in people with acid reflux disease and itself

    increases the risk of cancer.

    In November the FDA said clinical trial data showed no

    overall risk of heart rhythm problems in patients taking

    bisphosphonates.

    However, the FDA also said it was aware of conflicting

    findings in other studies and was considering whether

    conducting further studies to investigate the risk were

    feasible.

    The drugs aim to treat bone-weakening osteoporosis by

    increasing bone mass. An estimated 10 million Americans, mostly

    women, have osteoporosis.