QVT Financial LP, the third largest shareholder of Vivus Inc backed up activist investor First Manhattan Co on its proposed change of directors in the company. On Wednesday, QVT announced that it would vote for the full slate of nominees endorsed by First Manhattan Co.

QVT owned roughly 8.3% percent stake in Vivus. This was according to the latest public filings. The investment firm came up with the decision to support the activist First Manhattan Co as it believed changes were needed at the drug manufacturer firm said source.

First Manhattan Co is the largest shareholder at Vivus. The company owned 9.9% of stake and looked to take full control of the company's board with nine nominees.

The annual meeting of the Vivus board would take place on July 15.

Representatives for Vivus and First Manhattan were not readily available to comment with the report. The source asked not to be named as he was not authorized to speak with the media. QVT also declined to give comments.