By LINDA JOHNSON
Associated Press

TRENTON, N.J. - Drugmaker Merck & Co. said Thursday it will fund the $4.85 billion settlement expected to resolve roughly 50,000 lawsuits related to its Vioxx painkiller, with initial payments to former users of the withdrawn drug beginning late next month.

Merck said more than 97 percent of eligible claimants have enrolled in the settlement program, surpassing threshold levels the company required for the deal to proceed. Therefore, Merck said that on Aug. 4 it will waive its right to walk away from the $4.85 billion settlement deal reached with plaintiffs' attorneys last fall.

"This is an important milestone that shows the resolution program is on track," Bruce Kuhlik, Merck's general counsel, said in a statement.

According to Merck, more than 48,500 of the roughly 50,000 individuals with registered eligible injuries have enrolled in the settlement program. Nearly all have submitted papers releasing Merck from further liability and documenting their use of Vioxx and medical care received as a result.

Former Vioxx users, or their relatives, are eligible for part of the settlement if the patient suffered a heart attack, ischemic stroke or sudden cardiac death. They also must have had pending lawsuits or tolling agreements, which suspend the statute of limitations, as of Nov. 9, 2007, the date the settlement was reached.

Merck will make total payments of $4.85 billion into the settlement fund, with the first $500 million payment scheduled for Aug. 6.

Payments to claimants will begin to be made before the end of August.

Merck withdrew Vioxx from the market on Sept. 30, 2004, after its own research showed that the once-blockbuster arthritis pill doubled risk of heart attack and stroke.