Songjiang Wang, who Cambridge, Massachusetts-based Merrimack has employed as director of statistical programming since 2011, was charged with conspiring to commit securities fraud in a criminal complaint filed in federal court in Boston. He was arrested after prosecutors brought related charges in June against Schultz Chan, who had been the director of biostatistics at another Cambridge-based company, Akebia Therapeutics Inc ( Wang, 52, of Westford, Massachusetts, was released on a $750,000 bond after a court hearing on Tuesday, a spokeswoman for Acting U.S. Attorney William Weinreb in Boston said.