Helen F. Giles-Gee, the first African American and first female president of the University of the Sciences, has resigned after 21/2 years, the university announced Tuesday.

Her resignation, which came as the 2,800-student campus was preparing to close for winter break, is effective next Wednesday, the university said.

Giles-Gee was not available for comment, said university spokesman Brian Kirschner, who described the president's departure as a "personal decision."

"At this time, and after serious reflection, I have decided to leave University of the Sciences. I am honored to have served as president and will hold this university dear in my heart," Giles-Gee said in a statement.

Board Chairman Marvin Samson, CEO of Samson Medical Technologies in Cherry Hill, will be interim president, the university said.

Giles-Gee, who has degrees from the University of Pennsylvania and Rutgers University, came to the 192-year-old University of the Sciences as its 22d president from Keene State College in New Hampshire, where she had been president from 2005 through 2012.

She has spent 30-plus years in higher education at a variety of institutions and in many roles, including serving as provost of Rowan University and an administrator at Cheyney University. She also was associate vice chancellor for academic affairs at the University of Maryland, where she handled issues ranging from articulation agreements with community colleges to space planning.

The school hired Heidi M. Anderson, who is also African American, as provost a short time after Giles-Gee, ending almost two centuries of leadership almost exclusively by white males. The college focuses on pharmacy, science, and health-care careers.