Cornerstone Therapeutics has appointed a “special committee” to review a buyout offer from Chiesi Farmaceutici.

The Cary-based drug firm said Monday it had appointed five independent directors to serve on the committee and to work on a response letter to Chiesi.

Chiesi already owns 60 percent of Cornerstone’s (Nasdaq: CRTX) outstanding shares.

The company has a market cap of some $170 million based on Monday’s closing share price of $6.44.

Chiesi made an offer of between $6.40 and $6.70 per share last week. The news sent Cornerstone shares up from $5.50 on Tuesday to as high as $6.88 on Wednesday. Shares closed Friday at $6.73.

“The Company cautions its stockholders and others considering trading in its common stock that no decisions have been made by the Board of Directors or the Special Committee with respect to Chiesi’s proposal,” Cornerstone said in a statement. “There can be no assurance that any agreement will result from the proposal submitted by Chiesi or that any transaction based on Chiesi’s proposal will be consummated.”