USA Truck announced that John M. Simone has resigned from his position of chief executive officer and director to focus on treatment and recovery from lung cancer.

Simone’s successor, Thomas Glaser, was named the company’s president and CEO after having served as the interim chief operating officer since April 6, when Simone took medical leave.

Simone had sent a letter to investors on May 7th indicating that he had suffered a series of strokes which affected him physically, but said that he was expected to recover from the effects.

“Although it has been a very difficult decision, after consultation with my doctors, who continue to be optimistic about my recovery, I have concluded that I need to concentrate full time on my treatments and recovery,” said Simone. “Working with the Company and its outstanding employees has been a very rewarding experience, and I look forward to watching USA Truck’s continuing progress.”

Glaser has 30 years of management experience in the trucking industry, having served as the president of two truckload carriers as well as holding various other leadership positions. He also shortly served as the interim CEO from Jan. 2013 to June 2013.

“We fully support John’s decision to resign so he can devote his time and energy to improving his health,” said Robert A. Peiser, USA Truck chairman of the board. “All of us wish John continued success with his recovery.”