MOUNTAIN VIEW, Calif. (AP) -- The CEO put in place two months ago to resolve a dispute over control of Vivus Inc. is stepped down due to unidentified medical issues.
Anthony Zook is also leaving the biopharmaceutical company's board of directors, Vivus said Tuesday.
The Mountain View, Calif., company named Seth H.Z. Fischer as its new chief executive. Fischer is a former senior executive at Johnson & Johnson. He will also join the board.
Vivus specializes in treatments for obesity, sleep apnea, diabetes and sexual health.
Earlier this year First Manhattan Co., Vivus' biggest shareholder, staged a public proxy fight to replace the company's board of directors. In July, the two sides settled their dispute and Zook, a former executive with AstraZeneca and MedImmune, was named CEO as part of that settlement.
The company said Tuesday that Zook was dealing with recurring issues associated with a previously-diagnosed medical condition. After consultations with his physician, Zook determined that he must focus attention on resolution of this condition.
"Vivus is keeping Tony in its thoughts and we wish him a rapid recovery," Michael Astrue, chairman of the company, said in a statement.
Zook will work with Fischer through mid-September to help with a transition.
Astrue said the company will remain focused on expansion of its Qsymia obesity drug and eliminating expenses not related to this effort.
Vivus shares gained 22 cents, about 2 percent, to $12.75 in midday trading, outpacing broader market gains.