Morrisville-based Furiex Pharmaceuticals (Nasdaq: FURX), which had been the subject of buyout rumors, has been sold for $1.1 billion in cash to Forest Laboratories. But that’s not all.

Another $360 million could be paid if Furiex’s lead product eluxadoline is approved.

The deal, which was announced Monday, triggered a 29 percent spike in Furiex shares to $103.50, up $22.90 per share.

Furiex was launched by Fred Eshelman, the founder of Wilmington-based PPD and a philanthropist who has been extensive donations to UNC-Chapel Hill. The university’s pharmacy school is named in his honor. Eshelman serves as chairman of Furiex.

“Furiex has built a strong portfolio of life-improving therapies for patients, including development stage assets and royalty-bearing products. Forest’s acquisition of our company is a testament to the strength of the business we have built,” Eshelman said in a statement.

“I am very proud of our team for its hard work and excellent development of eluxadoline in just under four years,” he added. “There is a strong business fit between Furiex and Forest, and eluxadoline is expected to contribute to Forest’s leading GI franchise.”

Forest Labs (NYSE: FRX) is paying some $1.1 billion in cash for Furiex, or $95 per share.

Furiex shareholders must still approve the deal. 

The company lost nearly $30 million in 2012. However, that total is down more than $13 from 2012. It pulled in $45 million in drug development milestone payments from its partners.

Bloomberg news reported on Feb. 20 that Furiex was looking for a possible buyer.

Not counting milestone payments, Furiex received $26 million in royalty payments from its products. That’s up from $20.5 million the previous year.

Citing unnamed “people familiar with the matter,” Bloomberg said Furiex is looking for a buyer with help from Bank of America.

“The acquisition of Furiex builds on our growing position in gastroenterology and helps to create a leading GI company within Forest. It is a natural extension of our GI business following our $2.9 billion acquisition of Aptalis earlier this year,” said Brent Saunders, the CEO of Forest Labs.

The product that could produce more money for Furiex shareholders is called eluxadoline. It targets symptoms of irritable bowel syndrome.

“We believe eluxadoline will be very complementary to our anchor GI [gastrointestinal] product Linzess and additive to our broader GI portfolio, making us more relevant to gastroenterologists and primary care physicians,” Saunders said. “With eluxadoline, we expect to have one of the broadest product offerings for the $38 billion GI disease market.”

The drug is in clinical trials, and Furiex expects to file a New Drug Application later this year.