Even with two products on pharmacists' shelves, diabetes drug developer Amylin Pharmaceuticals (NASDAQ:AMLN) continues to look more like a development-stage company than a full-fledged drugmaker.

Data released yesterday showed that product sales of its two drugs -- Byetta, which it markets with Eli Lilly (NYSE:LLY), and Symlin -- were up 28% year over year for the third quarter. Gross margins edged up a bit to 92%, presumably because of increased sales on fixed plant costs, but the increased revenue wasn't enough to bring the company into the black.

Research and development costs for its obesity drug pipeline and the extended-release version of Byetta, which Amylin is developing with Alkermes (NASDAQ:ALKS), wiped out earnings and resulted in a net loss of almost $40 million for the quarter. Fortunately, the company has more than $1 billion in cash and investments still on the books, so it's got quite a while to turn things completely positive.

Amylin's had a rough month thanks to the FDA. At the beginning of the month, the agency approved a pen formulation for Symlin, which the company plans to launch by the end of the year, but turned down a request to expand the label indication for use in patients using basal insulin. Then, earlier this week, the agency issued a warning letter that Byetta might be causing acute pancreatitis in a small number of patients. On the conference call, management said that there had been no cases of pancreatitis in the ongoing phase 3 trial of the extended-release version of Byetta; that's good news, since Amylin's future rests on the easier-to-take version.

In order to increase sales of Byetta, Eli Lilly and Amylin have recently initiated a "consumer education program" -- a euphemism for advertisements to tell patients to ask their doctors about Byetta. The more patients the company can get on the drug, the easier a time it will have competing against Novo Nordisk's (NYSE:NVO) liraglutide, which should go in for FDA review next year.

This quarter should bring news about how quickly Amylin can get into the black. Results from the clinical trial of the extended-release version of Byetta, as well as the Pramlintide weight-loss trial, are both expected during the quarter. Amylin's chances of gaining full-fledged drugmaker status rest on those results.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Eli Lilly is a selection of the Income Investor newsletter. The Fool has a disclosure policy.