Amylin Pharmaceuticals has announced that it expects to begin selling a once-weekly version of its diabetes drug, Byetta, by the end of the year. The company reports that the FDA is nearing final inspections of its manufacturing plant and could give the go-ahead for U.S. sales in early March.

Byetta, the commercial name for exenatide, is an injectible drug that increases insulin sensitivity, slows glucose production, and decreases appetite. Introduced in 2005, the drug has been used by several hundred thousand people, many of whom have reported dramatic weight loss while taking it. Users typically inject Byetta twice daily, once before their morning meal and once before their evening meal. The drug is usually used in conjunction with other diabetes therapies, such as metformin or sulfonylureas, but has been available since late 2009 as an FDA-approved monotherapy.

Amylin, which developed Byetta in conjunction with Eli Lilly and Co., has been looking for a more convenient way to deliver the drug ever since introducing it. The new product, called "once-weekly exenatide," will require one injection every seven days, a far simpler and less uncomfortable routine. 

One hurdle Amylin had to overcome in developing a long-term version was ensuring that the time-release technology used to  deliver Byetta at specific intervals during the week was reliable and robust. A larger hurdle has been FDA concerns about Byetta's possible role in causing pancreatitis, a painful and debilitating inflammatory condition that in some cases ends in death. Although the FDA concerns have led to stronger warning language on the drug's label, the statistical evidence has not been strong enough to prove causation. As a result, Byetta remains on the market, with more than 900,000 U.S. users.

Still, the company is concerned that FDA worries about a possible link to pancreatitis could slow the approval of long-acting Byetta. On the other hand, the FDA's recent approval of Novo Nordisk's Victoza, an injectible drug for type 2 diabetes that is chemically very similar to Byetta, may indicate that the agency is inclined to approve once-weekly exenatide. 

San Diego-based Amylin, which took a financial hit from the pancreatitis concerns about Byetta and the introduction of rival drugs, is hoping that its long-term version will increase sales and attract patients who are tired of daily injections. The company and its partner, Eli Lilly and Co., believe that U.S. sales of the drug could reach $2 billion by 2015, compared to a projected $900 million in sales for Victoza in the same year. U.S. sales of Byetta in 2009 were an estimated $790 million.   

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Sources:

Reuters press release

IBJ.com article