Vivus says activist investor criticisms are off base

Obesity drugmaker Vivus Inc on Tuesday said its biggest investor, First Manhattan Co, has been offering only "uncertainty and delay" in its efforts to shake up the company's board of directors.

"FMC's 'plan' - to the extent they have one - appears to revolve solely around doing things that the Vivus board and management team are already doing, 'fixing' things that aren't broken," Vivus said in a release.

First Manhattan, an activist investor that owns 9.9 percent of Vivus shares and which has nominated a slate of new company directors, has argued that sales of Vivus obesity drug Qsymia have been foundering and that Vivus should partner with a bigger drug company to bolster sales.

Vivus on Tuesday said the company's management is already doing what needs to be done to "unlock" the full sales potential of the pill.

(Reporting by Ransdell Pierson; Editing by Maureen Bavdek)