A former Delaware judge has been appointed to determine whether Orexo AB violated a protective order from previous litigation in order to accuse generic drugmaker Actavis Elizabeth of infringing two patents for its opioid treatment drugs.

On Tuesday, U.S. District Judge Gregory M. Sleet of the District of Delaware said that retired Superior Court Judge Charles H. Toliver IV would act as special master in the case, tasked with addressing Actavis’ allegations that Orexo had used confidential information to build its case seeking to boot Actavis’ generic versions of Suboxone and Subutex from the market.

Actavis moved to dismiss the suit in April, arguing that Orexo’s infringement allegations drew directly from confidential documents the company obtained during an earlier dispute over two patents for Orexo’s Zubsolv drug, which is also used to combat opioid addiction.

In that case, Judge Sue L. Robinson determined that Actavis had infringed Orexo’s so-called ’996 patent but ruled a second patent, set to expire 13 years later, invalid as obvious. Actavis chose not to appeal the decision, and Orexo filed its current suit in February, asserting infringement of the ’996 patent.

Actavis said the complaint was premised on confidential information about the chemical properties of its generics that could have only been obtained through discovery, which was restricted only to the Zubsolv litigation. And it faulted Orexo for waiting on the outcome of the previous case to raise its concerns about the Suboxone and Subutex generics.

“Orexo should have laid its cards on the table when it first received Actavis’ confidential information,” its attorneys said in a redacted briefing.

“Instead, Orexo improperly sat on the information, remained silent about its intentions, and then without ever asking permission from Actavis or this court, misused Actavis’ confidential information by bringing this case only after the ’996 patent had already been litigated.”

Actavis said that it had already been selling its generics for years and that the timing of the suit was “no accident,” given the secret disclosures in the earlier litigation. It noted that 10 other manufactures selling similar products had not been sued in connection with their generics.

Orexo has rejected the allegations, saying they are “based solely on layer arguments and self-serving speculation.”

In its answering brief, Orexo said its allegations were derived from publicly available material, including expert analysis of Actavis’ generics and information printed on the drugs’ labels. Further testing of the tablets themselves revealed important details about the relationships between the generics’ ingredients, Orexo said.

“Simply put, Orexo had no need to and did not use any Actavis confidential information to make any allegation in the complaint,” the company said.

Orexo, however, did not address Actavis’ arguments regarding the timing of the lawsuit.

The dispute has raised a number of procedural issues, including whether discovery should continue and how exactly to determine whether a violation had occurred. Late last month, Sleet ordered both sides to submit additional documents, and attorneys for the companies met Sept. 25 in Wilmington to discuss their proposed plans for discovery.

Discussions, however, broke down, leading Sleet to name Toliver, now a partner with Morris James, to sort out the dispute.

In his order on Tuesday, Sleet said Toliver would be responsible for identifying any violations of the protective order and determining whether Actavis’ allegations had met the requisite burden of proof.

Orexo was also ordered to submit to Toliver additional documents regarding its testing of Actavis’ drugs and whether it had tested any other Suboxone and Subutex generics.

Attorneys for the companies were not immediately available to comment on Wednesday.

Actavis is represented by George C. Lombardi, Ivan M. Poullaos, Michael K. Nutter and Tyler G. Johannes of Winston & Strawn and David A. Bilson and John C. Phillips Jr. of Phillips, Goldman, McLaughlin & Hall.

Orexo is represented by Derek J. Fahnestock and Jack B. Blumenfeld of Morris, Nichols, Arsht & Tunnell.

The case is captioned Orexo v. Actavis Elizabeth.

Tom McParland can be contacted at 215-557-2485 or at tmcparland@alm.com. Follow him on Twitter @TMcParlandTLI.