Once an outpost of Boies, Schiller & Flexner, four-year-old Stone & Magnanini is making a name for itself as a go-to shop for health care qui tam suits under the False Claims Act. Conflicts with Boies Schiller’s pharmaceutical and health care clients led David Stone and Robert Magnanini to go out on their own in 2009, and last year they reaped the dividends.

Those included a $360 million settlement in July from McKesson Corp., the nation’s largest pharmaceutical wholesaler, in a major case joined by the U.S. Department of Justice. The suit began in 2004 after a pharmacy auditor uncovered evidence the company was manipulating a key price index used to determine the cost of prescription drugs sold to government health care programs.