Fresh off its long and involved bidding quest to acquire Allergan Inc., which ultimately was unsuccessful, Canada's Valeant Pharmaceuticals International Inc. looks like it has another fight on its hands with a new suitor swooping in with a substantially higher bid to acquire gastrointestinal specialist Salix Pharmaceuticals Ltd.

Like Actavis plc, its previous rival, Endo International plc is also Dublin-based. The company confirmed on Wednesday that it had submitted an acquisition proposal to the board of directors of Salix that included both cash and stock. Based on the closing stock price of Endo Tuesday, the transaction is valued at $175 per Salix share, representing an acquisition price of about $11 billion.

Valeant's February offer is an all-cash deal valued at about $10.1 billion, or $14.5 billion in enterprise value, a measure including Salix's debt and cash on hand. At the time, both Valeant and Salix's boards said they had approved the all-cash $158-per-share offer. (See BioWorld Today, Feb.24, 2015.)

In a statement about the bid, Endo said it believes that its cash and stock proposal would provide Salix shareholders with a substantial premium and immediate cash value, as well as the opportunity to participate in the "significant upside potential of a global leader in specialty pharmaceuticals with a highly diversified platform for future growth, through a material equity component."

In heavy afternoon trading following the announcement of Endo's unsolicited bid, shares of Salix (NASDAQ:SLXP) jumped over $11 on volume of 15 million.

They closed the day at $168.61, up $10.96. There was also heavy volume trading in Valeant's shares (NYSE:VRX), which closed the day down $7.77, at $193.71.

Salix's leading products include the hepatic encephalopathy and traveler's diarrhea antibiotic Xifaxan (rifaximin) and the glucocorticosteroid Uceris (budesonide). The company has a supplemental new drug application (sNDA) for Xifaxan 550-mg tablets for the proposed indication of the treatment of irritable bowel syndrome with diarrhea and the FDA has set a PDUFA date of May 27.

In their 2014 year-end financial results, the Raleigh, N.C.-based company reported total net product revenues were $1.134 billion, compared to $914 million for 2013 and it had about $500 in cash.

The company confirmed that it had received Endo's offer to acquire all of the outstanding shares of common stock of the company for a combination of 1.4607 shares of Endo common stock and $45 in cash per share of common stock.

According to Leerink Swann analyst Jason Gerberry, the current bid from Endo will unlikely trump Valeant's bid since the Canadian company is offering all cash.

If a negotiated transaction were to be agreed to with Salix, Endo said it anticipates that the transaction could close in the second quarter and it is confident that it would obtain any regulatory and shareholder approvals. Endo International (NASDAQ:ENDP) closed Wednesday at $87.76, down $1.24.