Drug development milestones pushed Furiex Pharmaceuticals (NASDAQ: FURX) to $40.5 million in revenue in 2012, according to financial results the drug developer released after the markets closed Wednesday.

Morrisville-based Furiex said fourth quarter royalty revenue was $9.2 million, up from $2.0 million in the fourth quarter of 2011. For the full year 2012, Furiex recorded royalty revenues of $20.5 million, compared to $4.5 million in the prior year. Revenue included royalties from sales of diabetes drugs Nesina and Liovel in Japan and sales of premature ejaculation drug Priligy in various countries outside the United States.

Furiex’s net loss for the fourth quarter widened to $9.1 million compared to $6.7 million for the fourth quarter of 2011. But Furiex narrowed its net loss to $42.9 million for the year, compared to a $49.0 million loss in 2011. The company attributed the performance to changes in revenues and research and development expenses.

R&D expenses for 2012 totaled $69.5 million, up from $44.2 million in 2011. Much of that expense related to phase III clinical trials of MuDelta (also referred to as eluxadoline), an experimental treatment for diarrhea-predominant irritable bowel syndrome that is now the company’s lead drug program.

“As of February, we were over 55 percent enrolled in the two pivotal studies,” CEO June Almenoff said in a statement. “The team is highly focused on execution of the clinical program and bringing this much needed treatment to the market.”

Furiex’s drug partner Takeda received Food and Drug Administration approval in Januaray for diabetes drug Nesina, triggering a $25 million milestone to Furiex. Furiex believes that the milestone payment and other royalties will give the company financial flexibility on the eluxadoline program.