Amylin Rises on Byetta Sales Data

Because Amylin's long-acting product is taken once a week, it's still likely to take the majority of the market even if it follows Novo Nordisk's product, liraglutide, by six months or a year, says Cowen's Nadeau. But it's important that Byetta LAR not be delayed by more than a year, because fellow competitor Roche is also bringing a product to market, "and then it starts to get close," he says.

Goldman Sachs analyst Meg Malloy, who has a buy rating for the stock, has estimated that the Byetta/Byetta LAR franchise could address a commercial opportunity of more than $2 billion to $3 billion after several years on the market.

But some stakeholders are running out of patience. Eastbourne Capital, which owned a nearly 13% stake in Amylin as of late August, said earlier in the month that it intended to hold discussions with management, other shareholders and third parties, regarding actions that could enhance shareholder value, including a possible sale of the company.