Yesterday there was an announcement that Acorda (NASDAQ: ACOR) has amended their NDA application for fampridine. After after taking a closer look at their Phase III study (MS-F203), here is a reason why come February 23, 2010 the FDA will provide a verdict of NOT APPROVED or at best APPROVABLE. Either case, it will have a detrimental effect on the stock's price.
Here is my analysis of the pivotal study (MS-F203):
The primary endpoint of this study was to measure the percent of patients who improve their walking ability from baseline. Again, the primary endpoint does not quantify the significance of improvement from baseline and how that relates to clinical benefit. So, to use an analogy, say I have a miracle drug that will lower ALL patients' blood pressure, but I don't say by how many mmHg. Is this clinically meaningful? Suppose I say that it was by 1mmHg, but that ALL patients' blood pressure will be lowered. Would you approve this drug? The same goes for this endpoint. Furthermore, the the results from this study showed that only 35% of patients taking fampridine demonstrated a response compared to 8% placebo. And what exactly is this response? A.51ft/sec (6 inches/sec) improvement in walking speed.
So what about the 65% of patients who didn't respond? A 16ft/sec (2 in/sec) improvement in walking speed, no better than a sugar pill (placebo) .10ft/sec improvement.
The FDA will not approve a drug that only helps 35% of the patients walk 4 inches/sec faster than the placebo while having a side effect profile causing seizures, anxieties, and loss of balance. The benefits are just not there over the risks the drug pose.
Interestingly, also look at the patient characteristics in the study. It is skewed in favor of the Fampiridine group.
Look at the male/female ratio:
- Placebo 40%/60%
- Fampridine 29%/71%
- Non-responders 31%/69%
- Responders 24%/76%
As you can clearly see, it looks like males have poorer outcome with this endpoint than females, as demonstrated by more males not responding to the drug vs. responders. Furthermore, there is a skew towards more males in the placebo group who are more less likely to have positive outcome.
In conclusion, I question the validity of the primary endpoint. Simply stating that a higher percent were able to walk faster is not a valid endpoint.
Finally a telltale sign is the insiders' transactions.