By Brendan Pierson

April 3 (Reuters) - Pharmacy benefit managers OptumRx and Express Scripts have asked the federal judge overseeing nationwide litigation over the opioid crisis to recuse himself from cases against them, claiming that the judge has had frequent backchannel communication with a plaintiffs' attorney.

In a motion filed in Cleveland, Ohio federal court, the PBMs cited reports that Michael Kahn, a Florida lawyer representing some of the cities and counties suing the companies, had repeatedly told potential clients that Peter Weinberger, a leading plaintiffs' attorney in the litigation, spoke to U.S. District Judge Dan Aaron Polster "every day" and got "inside information" from him.

Kahn also claimed that Polster was a "tremendous plaintiff-oriented judge" who put "enormous pressure" on defendants to settle, according to the PMBs.

A spokesperson for the plaintiffs' attorneys declined to comment. Helen Norton, an assistant to Polster, said the judge could not comment on a pending case.

Optum and Express Scripts told Polster in February about Kahn's statements, which they discovered by reviewing public records, and sought disclosure of all communications between plaintiffs' counsel and the judge outside defense counsel's presence.

Polster did not grant that request but ordered an evidentiary hearing at which Kahn was questioned last month. Kahn testified that he "misspoke" and had never been told that Weinberger engaged in frequent conversations with the judge.

Polster sanctioned Kahn with a fine of $100,000, finding that his statements were "without any factual basis" and "improperly cast aspersions upon the integrity of the court."

The PBMs, however, said that Polster's response, and refusal to disclose the communications they requested, were reason for him to recuse himself.

"There is no question that Mr. Kahn’s statements have undermined the integrity" of the litigation, the PBMs wrote. "But the response to Mr. Kahn’s statements has only further undermined the appearance of impartiality."

The opioid litigation, which includes thousands of lawsuits brought by local governments across the country, has already resulted in more than $50 billion in settlements resolving claims that drug manufacturers concealed the addictive pain drugs' risks, and that distributors and pharmacies ignored red flags that pills were being diverted into illegal channels.

Less attention has been paid so far to the claims against PBMs like UnitedHealth Group's UNH.N Optum and Cigna Group's CI.N Express Scripts. PBMs act as middlemen between drug companies, health plans and pharmacies to negotiate prescription drug prices and decide which drugs will be covered by insurance. The parent companies are also named as defendants in the case.

Plaintiffs allege that PBMs both colluded with drugmakers to promote dangerous drugs and failed to limit access to them in response to red flags. The cases against PBMs are still in early stages, with pretrial motions expected to continue into 2026.

Optum and Express Scripts have said that all the claims against them are without merit.

The PBMs in 2023 had sought, unsuccessfully, to get a special master removed from the case after being inadvertently copied on an email that they said showed he was biased.

The MDL is In Re: National Prescription Opiate Litigation, U.S. District Court for the Northern District of Ohio, No. 1:17-md-02804.

For plaintiffs: Jayne Conroy of Simmons Hanly Conroy; Joe Rice of Motley Rice; Paul Farrell of Farrell & Fuller; and Peter Weinberger of Spangenberg Shibley & Liber

For OptumRx: Brian Boone of Alston & Bird

For Express Scripts: Jonathan Cooper of Quinn Emanuel Urquhart & Sullivan

Read more:

Optum, Express Scripts want opioid special master out after reply-all email mishap

Purdue Pharma, Sacklers reach $7.4 billion national opioid settlement

(Reporting By Brendan Pierson in New York)