A jury in New York on Friday awarded $8 million in damages in a product-liability case over Merck & Co.’s (MRK) osteoporosis drug Fosamax.

The verdict is the first loss for the Whitehouse Station, N.J., drug maker as it faces hundreds of lawsuits in state and federal court over allegations Fosamax can cause a jaw-destroying condition known as osteonecrosis.

The lawsuit, brought by 72-year-old Shirley Boles, resulted in a mistrial last September. The retrial lasted about three weeks.

Hers was one of three so-called “bellwether” cases being heard in federal court in Manhattan. One was thrown out last year and a jury found in favor of Merck in another  last month.

After nearly four hours of deliberations, the jury on Friday awarded Boles $8 million in compensatory damages and found Fosamax was a “defectively designed” product, said Timothy O’Brien, her lawyer.

“She felt very vindicated,” O’Brien said. “She felt like she’s done something very important.”

In a statement, Merck said Friday that it plans to challenge the jury’s decision and believes the awarding of compensatory damages was unjustified and excessive.

“We disagree with the jury’s verdict. We believe the jury verdict was a result of plaintiff’s counsel’s inflammatory and prejudicial remarks,” said Paul Strain of Venable LLP, outside counsel for Merck. “The plaintiff was at increased risk for dental and jaw problems even if she was not taking Fosamax.”

The drugmaker is facing more than 900 cases in state and federal courts, generally alleging that use of Fosamax can cause osteonecrosis, and that Merck failed to properly warn of this risk.

Osteonecrosis is a condition where the bone dies and can eventually fracture. It can lead to exposed bone in the jaw.

Fosamax was once one of Merck’s best-selling drugs, generating more than $3 billion in annual sales. However, the drug lost its U.S. patent protection in 2008, exposing it to competition from cheaper generic versions of the drug.