WASHINGTON – In a rare boost for securities fraud class actions, the U.S. Supreme Court yesterday closed off a “statute of limitations” defense for Merck & Co. in its battle against Vioxx-related shareholder suits.

The Court unanimously ruled in Merck v. Reynolds, 08-905, that the litigation is timely and must go forward, in spite of Merck’s insistence that the suit was filed too late under the two-year statute of limitations contained in the Sarbanes-Oxley Act of 2002.