Robert Clarke, the chief executive who led Pulmatrix to the public markets via a reverse merger in 2015, has stepped down from the company and its board of directors. The Lexington, MA-based company gave no reason for the departure of Clarke, who was promoted from chief scientific officer to CEO in 2012. But Pulmatrix (NASDAQ: PULM) said he will continue as an advisor to the company through Aug. 14. To take his place, the company appointed its chief business officer, Ted Raad, to serve as CEO and board member. Pulmatrix develops inhaled therapies to treat lung disorders.