Merck & Co shareholders can forward with a class-action suit alleging the company misrepresented the safety of its arthritis drug Vioxx and that share prices fell when the true risk was disclosed. U.S. District Judge Stanley Chesler in Newark granted certification on Wednesday for a class of plaintiffs claiming the company’s statements violated the 1934 Securities Exchange Act. Chesler rejected Merck’s argument that factual variations in the plaintiffs’ claims, in In Re Merck & Co. Securities, Derivative & ERISA Litigation, defeat the typicality and adequacy requirements for class certification.