Defense lawyers for Proskauer Rose have lodged a late-stage request for a federal appeals court to shut down a case accusing the firm and a former partner of helping R. Allen Stanford to conceal his massive Ponzi scheme from regulators.

Ahead of an upcoming Dallas trial, Proskauer, through its defense team at Davis Polk & Wardwell, filed a notice on Thursday with the U.S. Court of Appeals for the Fifth Circuit as part of an effort to escape claims from an official committee of investors in Stanford Financial Group—a collection of companies that Allen Stanford used to perpetrate a years-long, $7 billion fraud that landed him in prison on a 110-year sentence.