Amylin's Once A Week Byetta: Good Is Not Enough

This morning Amylin Pharmaceuticals,Eli Lilly and Alkermes announced the highly anticipated test results on their once-a-week, Type 2 diabetes drug. One analyst recently called this the most important biotech data of the second half of this year. Many expect the drug to become a multi-billion dollar blockbuster.

AMLN and LLY are partners on the twice-a-day injectable diabetes drug Byetta. Over the past few weeks they started doing direct-to-consumer advertising for the first time. And in the last week I've noticed that the campaign has escalated from a very basic brand-awareness tone to a more pointed approach where they're even mentioning how much weight patients lost in clinical trials.

I'm assuming the FDA is cool with that, but it does make me wonder. Analysts have long talked about how they believe a lot of people who are not diabetic are going on Byetta just to help them shed pounds. That would be what's called "off-label use" and Amylin and Lilly are prohibited from promoting it as a diet drug. Anyway, I digress.

So, the companies say that the once-a-week Byetta resulted in a greater reduction in blood-sugar levels than was achieved in a mid-stage test and with twice-a-day Byetta. Three out of four patients got their blood-sugar level below the recommended benchmark. There was a 30% lower incidence of mild, transient nausea which is a common side-effect with twice-a-day Byetta.

However, on average patients lost about eight pounds. And because that's comparable to the weight loss seen with twice-a-day, investors seem to be disappointed and are selling shares of AMLN and ALKS as I write this, while LLY has been up and down. Alkermes makes the technology that allows the drug to last a week in the body and would receive a royalty on sales. LLY and AMLN would split the rest evenly.

Byetta Needle
Byetta Needle

The twice-a-day Byetta is injected into the belly using a stick pen with a relatively small needle. There's been some concern that the size of the once-a-week needle would be so huge that some patients might be afraid to use it. One analyst on the conference call half-jokingly said some people think "it's a sword".

Amylin execs were quick to point out that 90% of the 300 or so patients in the clinical trial finished the study. The once-a-week Byetta comes with a 23 gauge needle and Amylin officials say, "It was very well accepted."

23 Gauge Needle
23 Gauge Needle

The companies say they plan to file for FDA approval of the drug by the end of the first half of 2009, but Amylin CEO Dan Bradbury said they will try to speed things up, if possible. "This is the best glucose control ever demonstrated for any diabetes drug ever and the best weight-loss data ever demonstrated in a pivotal study of a diabetes drug ever," Bradbury said emphatically on the call. He provided no other details.

The companies are saving them for publication in a peer-reviewed medical journal which in the scientific and investor communities give drug data additional credibility. Today, though, investors don't seem to be assigning any.

Questions? Comments?