Alkermes Inc., which is waiting for regulators to make a decision on two key drug candidates, said Thursday that its first-quarter loss grew as its revenue decreased.

In October, the Food and Drug Administration is scheduled to make decisions on the company's Vivitrol as a treatment for opioid addiction, and on Bydureon, a long-lasting diabetes drug Alkermes developed with Eli Lilly & Co. and Amylin Pharmaceuticals Inc.

Vivitrol is already on the market, but Alkermes gets most of its revenue from manufacturing drugs for other companies.

In the quarter that ended June 30, Alkermes said it lost $13.4 million, or 14 cents per share. Excluding stock-based compensation costs, the company said it lost 9 cents per share. A year ago it reported a smaller loss of $10.2 million, or 11 cents per share. Revenue fell 11 percent, to $42.3 million from $47.5 million.

Analysts surveyed by Thomson Reuters on average expected a loss of 14 cents per share on $42.7 million in revenue.

Alkermes makes the schizophrenia drug Risperdal Consta for Johnson & Johnson, and it gets royalties on those sales. It said manufacturing revenue slipped 7 percent to $26.9 million, and royalty revenues edged up to $8.9 million from $8.7 million.

Alkermes said sales of Vivitrol as a treatment for alcohol addiction rose to $6.2 million from $4.2 million. Research and development revenue from collaborations fell to $268,000 from $1.5 million. A year ago the company received $4.3 million in net collaborative profit. It did not report any net collaborative profits in its most recent quarter.

Worldwide sales of Risperdal Consta grew 3 percent to $356 million, the company said.

An FDA advisory panel is scheduled to review Vivitrol Sept. 16, and the agency is to make its decision by Oct. 12. The ruling on Bydureon is due Oct. 22.

Bydureon is a once-per-week version of Eli Lilly's drug Byetta.

Alkermes shares rose 12 cents to $13.13 in aftermarket trading. The stock slid 12 cents to $13.13 during the day.