SEATTLE (AP) -- Dendreon Corp., which is developing the prostate cancer drug Provenge, said Wednesday its third-quarter loss widened on a boost in operating expenses and costs to cover the value of warrants to buy its shares.

The company lost $45.6 million, or 40 cents per share, compared with a loss of $26.8 million, or 29 cents per share, during the same period a year prior. Revenue fell slightly to $25,000 from $26,000.

Excluding charges for the warrants, the company said it lost 23 cents per share.

Analysts polled by Thomson Reuters expected a loss of 19 cents per share.

Operating expenses rose 49 percent to $25.8 million. Meanwhile, the company recorded $19.4 million in losses to cover the value of warrants, up from $9.1 million a year prior.

In April 2008, Dendreon raised money by selling 8 million shares of stock and warrants to buy 8 million more shares. The warrants can be exercised any time before April 8, 2015. During the second quarter of 2009, Dendreon's stock surged to $25 from $4.20, following positive study data on Provenge. The increase prompted the company to set aside funds to cover the value of the warrants.

The company is waiting for a regulatory decision on Provenge by the Food and Drug Administration.

Shares of Dendreon fell 13 cents to $29.50 in after-hours trading after rising 26 cents to close at $29.63 during the regular trading session.