(CNN)Purdue Pharma has agreed to settle a historic lawsuit brought by the Oklahoma attorney general who accused the OxyContin maker of aggressively marketing the opioid painkiller and fueling a drug epidemic that left thousands dead in the state, a source familiar with the case tells CNN.

The settlement which was first reported by Reuters, comes after Purdue fought the attorney general in court, seeking to delay the start of the trial, which is scheduled for May 28.

The source would not say whether other drugmakers named in the suit would follow Purdue's lead.

A spokesman for Oklahoma Attorney General Mike Hunter declined to comment. The attorney general has planned a news conference for Tuesday afternoon in Tulsa.