AstraZeneca will pay up to $443 million to buy a pharmaceutical company that is developing a treatment for dyslipidemia.

AstraZeneca said it is acquiring Omthera, a Princeton, N.J.-based firm that is developing the investigational drug Epanova. The drug has a novel omega-3 free fatty acid composition that AstraZeneca said has been shown to reduce triglyceride levels and improve other key lipid parameters.

Under the terms of the agreement, AstraZeneca will acquire Omthera for about $323 million, with an additional $120 million if specified milestones are met.  

Omthera is expected to file a new drug application (NDA) for Epanova with the FDA in mid-2013 for patients with severe hypertriglyceridemia. London-based AstraZeneca added that it also has numerous plans for the drug, including filing a supplemental NDA for Epanova for patients with mixed dyslipidemia and as a fixed-dose combination with its statin rosuvastatin (Crestor) for mixed dyslipidemia patients at high risk of a cardiovascular event.

The transaction is expected to close in the third quarter of 2013.