A federal judge in Newark has denied a motion to certify a Fair Labor Standards Act collective action for unpaid overtime by employees of Express Scripts Holding Co.

The suit sought to recover six years of unpaid overtime on behalf of 170 former employees of Medco Health Solutions Inc., who began working for Express Scripts when the two companies merged in April 2012. But the plaintiff failed to make the “modest factual showing” that those workers were victims of a common policy or plan that violated the law, U.S. District Judge Stanley Chesler of the District of New Jersey said in denying the motion.