AstraZeneca P.L.C.'s search for new drugs to boost lagging sales continued Tuesday when the company agreed to pay as much as $443 million for Princeton-based Omthera Pharmaceuticals Inc.

Omthera had only 14 employees at the end of 2012, according to a prospectus it filed with the Securities and Exchange Commission prior to its initial public stock offering April 11.

But, by industry standards, Omthera is close to being able to sell a new treatment called Epanova for dyslipidemia, a lipid disorder involving high levels of triglycerides that can contribute to heart disease.

AstraZeneca is based in the United Kingdom but has about 2,000 employees at facilities in Wilmington and Newark, Del. The company has laid off thousands of employees on both sides of the Atlantic in recent years as it tries to get its bearings.

Also Tuesday, Omthera released financial results for the first quarter of 2013, and the report offers a simple, clear example of a small drug company that came to focus on one product and is close to generating revenue when there was little or none before.

The company said it lost $6.3 million in the first quarter, but the key number in the company timeline was $400,000 for research and development expenses, compared with $8 million a year earlier. The difference was that the company completed the all-important phase 3 trials of Epanova, which is the last big step before applying to the U.S. Food and Drug Administration for approval.

AstraZeneca will pay $323 million up front for Omthera, and then perhaps as much as $120 million to shareholders, based on sales reaching certain milestones.

"This is an exciting acquisition that clearly complements our existing portfolio in cardiovascular and metabolic disease, one of our core therapy areas," AstraZeneca chief executive officer Pascal Soriot said in a statement.

AstraZeneca shares closed up 84 cents, or 1.6 percent, at $53.01 in midafternoon trading. Omthera shares doubled to $13.51.

Contact David Sell at 215-854-4506, dsell@phillynews.com, or @phillypharma. Read his blog at www.inquirer.com/phillypharma.