The hedge fund, which is now Depomed’s third-largest shareholder, said it considered the company’s shares undervalued, making them an attractive investment opportunity.

Depomed’s stock rose 9% in extended trading.

“Depomed notes that Starboard has not communicated with the company prior to filing the 13D and has not attempted to hold any discussions with the company,” a spokesman for Depomed said in an emailed statement.

Starboard raised concerns over what it said were “serious corporate governance deficiencies, questionable capital allocation decisions, and egregious actions” taken by the company to suppress shareholder rights.

The hedge fund indicated that Depomed (DEPO) took a “series of shareholder-unfriendly steps,” referring to the company’s decision to reject the takeover offers made by drugmaker Horizon Pharma (HZNP) last year.

“Depomed welcomes open communications with its shareholders and values constructive input toward the goal of enhancing shareholder value,” the company said.

Depomed, in August, rejected Horizon’s cash-and-stock offer of $32.50 per share. Depomed’s stock has more than halved in value since then.

Starboard said it intends to nominate its chief executive, Jeffrey Smith, to Depomed’s board along with five other nominees.

Starboard has taken aggressive actions at other companies in which it has invested. It successfully engineered the ouster of the board of Darden Restaurants (DRI), where Smith was named chairman in October 2014. Smith resigned from Darden earlier this month.

More recently the hedge fund has focused on Yahoo (YHOO), where it is looking to overthrow the board, including Chief Executive Marissa Mayer.

Starboard holds about 4.1 million of Depomed shares. The company had about 61 million outstanding shares as of Feb. 23.