In a significant development in pharmaceutical antitrust litigation, AstraZeneca Pharmaceuticals LP and Handa Pharmaceuticals LLC have agreed to pay a combined $51.4 million to resolve allegations they engaged in a pay-for-delay scheme to block generic competition to AstraZeneca’s antipsychotic drug, Seroquel XR.

This resolution marks the culmination of nearly six years of litigation and applies to claims brought by a certified class of direct purchasers of Seroquel XR. The purchasers allege that AstraZeneca unlawfully paid Handa and other generic-drug manufacturers to delay the launch of lower-cost generic alternatives.

Under the settlement, AstraZeneca will pay $50.9 million, while Handa has already contributed $494,000. Plaintiffs described the agreement as “an outstanding result” for the class and noted that it avoids the uncertainty and risk of trial, which had been scheduled to begin just days after the final agreement was reached in principle on May 1.

According to court filings, Handa Pharmaceuticals claimed financial limitations prevented it from paying more but pledged to offer substantial cooperation, including sworn statements and testimony from its CEO, as part of the agreement.

The case centers on allegations that AstraZeneca entered into deals with Handa and other generic manufacturers, including Par Pharmaceutical Inc. and Accord Pharmaceuticals Inc., to delay the release of generics for up to five years. In return, AstraZeneca is said to have agreed to delay its own generic launch, maintaining market exclusivity for Seroquel XR during that period. The prescription medication is used to treat schizophrenia, bipolar disorder, and depression.

A separate settlement involving retailer plaintiffs is expected to be submitted for preliminary approval in June.

The class certified by the court includes all direct purchasers of brand or generic Seroquel XR (50mg, 150mg, 200mg, 300mg) between August 2015 and April 2017.

This case is formally known as In re: Seroquel XR (Extended Release Quetiapine Fumarate) Antitrust Litigation, case number 1:20-cv-01076, filed in the U.S. District Court for the District of Delaware.