A federal judge pushing for a settlement in lawsuits seeking to hold drug companies responsible for their roles in the U.S. opioid epidemic on Wednesday set an aggressive schedule that would have the first trial take place in March 2019.

U.S. District Judge Dan Polster in Cleveland, Ohio picked three lawsuits by municipalities and counties in the state to be the first cases against drug manufacturers and distributors to face a jury in the sprawling litigation.

Polster, who is overseeing at least 433 lawsuits largely by cities and counties, has been pushing for a global settlement and has invited state attorneys general with state court cases or probes not before him to participate in those talks.

But roadblocks have emerged, and Polster in a ruling on Wednesday said the companies have “asserted forcefully that they cannot reach final settlement without litigating certain matters.” He said his scheduling order was intended to “address this impediment.”

The March 18, 2019 trial date will put the Ohio cases ahead of a May 2019 trial previously scheduled in a lawsuit by Oklahoma’s attorney general in state court. The four drugmakers in that case had sought a 2020 date. They will include the city of Cleveland, Cuyahoga County and Summit County. Discovery and depositions will proceed until then, and the trial date may be delayed or scuttled altogether if a settlement is reached.

“Getting the cases to trial accelerates an outcome of some sort,” said Archie Lamb, a lawyer for some of the plaintiffs.

Polster said additional trials would be scheduled in lawsuits by local governments in West Virginia, Illinois, Alabama, Michigan and Florida.

The cases were picked for so-called bellwether trials, essentially test cases used in mass litigation in the United States to help both sides gauge the range of damages and define settlement options.

To help the plaintiffs, Polster on Wednesday also ordered the U.S. Drug Enforcement Administration turn over “critical” data that would allow them to assess to what extent the companies sold or distributed drugs in the six states at issue.

The next settlement conference is scheduled for May 10.

To date no public information is available that would indicate any California workers’ compensation carrier or self insured employer is seeking a cost recovery based upon theories in these cases.