Antares Pharma Inc.'s fourth-quarter loss swelled as the drug developer spent heavily to prepare its potential rheumatoid arthritis treatment Otrexup for regulatory review.

The Ewing, N.J., company said Wednesday it lost $5 million, or 4 cents per share, in the three months that ended Dec. 31. That compares to a loss of $154,000, or less than 1 cent per share, in the final quarter of 2011, when it had fewer shares outstanding. Revenue climbed about 1 percent to $5.5 million.

Analysts expected, on average, a loss of 3 cents per share on $5.3 million in revenue, according to FactSet.

Antares makes self-injectable drugs. Otrexup combines the company's Medi-Jet drug delivery system, which allows patients to inject a drug, and methotrexate, a commonly prescribed treatment for rheumatoid arthritis.

The company's operating expenses more than doubled to $8.8 million in the quarter. That included a $2 million filing fee the company paid in connection with the new drug application it submitted to the Food and Drug Administration.

Antares has said the FDA intends to complete its review and make a decision on whether to approve the treatment by Oct. 14.

For the full year, Antares lost $11.4 million, or 10 cents per share, on $22.6 million in revenue.

The company said it ended the year with $85.2 million in cash and investments and no debt.

Shares of Antares fell 12 cents to $3.48 Wednesday afternoon, while broader trading indexes edged higher.