Allergan advised its stockholders to refrain from taking any action in response to Pershing Square Capital Management's proposal to replace a majority of the Botox maker's board.
William Ackman's Pershing Square has been pushing for a special meeting of Allergan shareholders to consider the removal of six directors and the appointment of its slate of nominees.
"We believe Pershing Square's attempt to replace a majority of the Allergan Board is a further effort to support Valeant in its bid to acquire Allergan at a grossly inadequate price," Allergan said on Friday.
Allergan is expected to unveil details of its plan to remain a stand-alone company when it releases second-quarter results this month.
The company has said it is considering acquisitions of its own, additional spending cuts or taking on debt to buy back shares.