Merck lawsuit over Fosamax ends in mistrial

NEW YORK (Reuters) - A lawsuit alleging that Merck & Co's osteoporosis drug Fosamax caused jaw damage ended in a mistrial on Friday.

U.S. District Judge John Keenan declared the mistrial two days giving the New York jury considering the case a "cooling off period" in light of supposed acrimony among jurors.

A Merck lawyer on Wednesday referred to an "unsubstantiated claim" of a chair being thrown in the jury room.

Merck faces lawsuits involving almost 900 cases by patients who say the use of Fosamax causes osteonecrosis of the jaw, or the death of jawbone tissue. The trial is Merck's first over the drug treatment.

In the New York case, Shirley Boles, 71, from Walton Beach, Florida, claimed she suffered dental and jaw problems because she took Fosamax from 1997 to 2006.

Keenan this week rejected Merck's effort to dismiss 24 other Fosamax cases, letting the plaintiffs introduce testimony by doctors to show the drug's use can cause jaw damage.

In afternoon trading, Merck shares were up 28 cents at $32.24 on the New York Stock Exchange.

The case is In re Fosamax Products Liability Litigation, U.S. District Court, Southern District of New York (Manhattan), No. 06-1789.

(Reporting by Christine Kearney, Grant McCool and Jonathan Stempel; Editing by Steve Orlofsky)