Merck shareholders filed a class-action lawsuit alleging that Merck, Merck/Schering-Plough Pharmaceuticals, MSP Distribution Services, and MSP Singapore Company violated federal securities laws by failing to disclose material information and making false and misleading statements about the commercial prospects of the cholesterol drug Vytorin (a combination of the Merck drug Zocor and the Schering-Plough drug Zetia) between 2006 and 2008. They claimed that the defendants concealed the results of a clinical test (known as the “ENHANCE” study) that showed Vytorin was no more effective than Zocor alone. In June 2013, the lawsuit was settled for $215 million. See related Merck instances, “ENHANCE Securities Litigation” and “Vytorin Multistate Investigation”.