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Biotech Stock Mailbag: Amicus, Amarin, Oncothyreon

Tickers in this article: AMRN FOLD ONTY

BOSTON ( TheStreet) -- This is the last Biotech Stock Mailbag for 2012. I've been writing this column for six years, but without your emails and tweets, the Mailbag wouldn't be possible. Thank you for all your comments, questions and criticism. Merry Christmas and Happy New Year. The Mailbag will return, rested and re-energized, in 2013.

@biotechmoney18 writes, "Hey, AF! Nice call on bullish $FOLD on 11/30. Maybe you should do some real DD instead of listening to your bleep boss."

I got Amicus Therapeutics (FOLD) wrong. I regret the bad call .

I expected Amicus' Fabry disease drug Amigal to demonstrate a statistically significant kidney response compared to placebo at six months -- the primary endpoint of the pivotal phase III study. Kidney response was defined as 50% reduction or more in kidney GL3 level at six months.

As reported Wednesday night , the 41% kidney response rate for Amigal patients surpassed the 28% response seen in placebo patients, but the difference was not statistically significant. The study failed. Amicus shares fell by nearly half Thursday.

The outcome is absolutely discouraging, and I'm not surprised to see the sharp selloff in Amicus. It's deserved. But I'm also unwilling to write off Amicus because the results of the study are just as frustrating and confusing as they are negative. There seems to be a signal of activity with Amigal that needs more detailed explanation. Unfortunately, Amicus chose not to hold a conference call to discuss the study results. I'll blame its partner GlaxoSmithKline (GSK) for that idiotic decision -- typical Big Pharma bull---t.

A full presentation of the Amigal study results is scheduled for the Lysosomal Disease Network World Symposium from Feb. 12 to 15.

The 28% response rate in placebo patients is much higher than expected. Why? Female Fabry patients have a lot more variability in GL3 levels, so this may have contributed to the miss. Two-thirds of the enrolled patients in the study were female, but we don't know the breakdown of female responders in each arm.

Lower-than-expected baseline GL3 levels (skewed toward the placebo patients) may also have played a role in boosting the placebo response rate higher than normal. Or, variability in the kidney biopsy samples, from which response is determined. Again, we don't know the answer but should get more clarity at the medical conference in February.

The study also measured, as a pre-defined secondary endpoint, the absolute percent change in kidney GL3 from baseline to six months. The result: Amigal 41% reduction compared to placebo 6% reduction. Again, the difference was not statistically significant but it sure seems like Amigal is doing what's it's designed to do. We'll leave the debate about the magnitude of GL3-lowering effect for another time.