Both low and OK'd doses of Acorda's Ampyra fall shy of key endpoint

Over the past two weeks Acorda Therapeutics' ($ACOR) shares have been languishing under a cloud cast by analysts raising doubts about a post-marketing study ordered for Ampyra, its multiple sclerosis drug designed to improve patients' ability to walk. Early this morning the biotech announced that the 5 mg dose the FDA wanted to test in order to check out a lower-risk, lower-reward approach to the disease failed to hit the primary endpoint in the study. But so did the already-approved 10 mg dose.

Acorda quickly pointed out that the follow-up study employed a new measure of efficacy: The change in walking speed for a 25 foot-walk after 4 weeks of treatment. While the 10 mg dose produced slightly better data than the 5 mg dose, neither dose was statistically significantly better than placebo. The biotech quickly added that a further analysis applying standards used in the pivotal study demonstrated a significant improvement for the 10 mg does--but not the 5 mg dose. Ampyra 10 mg hit the secondary endpoint in the new study, but the 5 mg dose fell short.

CEO Ron Cohen told analysts this morning that data show that the 10 mg twice daily is the best dose for patients. Investigators added that the placebo response was higher than what they expected compared to the historical data. "In our view we fulfilled our post-marketing commitment" to the FDA, Cohen told analysts. He added that this new study was designed to be the "most effective and efficient way to compare the 5 and 10."

That bottom line evidently reassured investors, despite the troubling failure of the approved dose to clearly beat out a placebo. Acorda's shares surged 5% in pre-market trading this morning.

Acorda gained approval to sell the 10 mg dose more than two years ago. But regulators have been eager to learn if a 5 mg dose, which would likely reduce the risk of seizures, could be used instead. Just a few weeks ago the agency raised a red flag over its seizure concerns. And the new trial raised fears at the company that a 5 mg dose--which could have significantly reduced the value of the franchise--could have been just as effective.

- here's the press release
- and the story from Reuters

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