US STOCKS-Biotech shares drop, Amarin plunges 20 pct

By Ryan Vlastelica

NEW YORK, Sept 12 (Reuters) - Biotech stocks were among the weakest sectors on Friday, falling as investors continued to take profit in the high-flying sector.

The Nasdaq Biotech index is down 0.9 percent, falling for a seventh session out of the past nine. Biotechs are a frequent target for profit-taking, as many investors view the group - which largely trades on future growth prospects and such volatile elements as drug pipeline progress - as overvalued.

Vertex Pharmaceuticals lost 1.2 percent to $93.10 while Amgen (HKSE: 4332.HK - news) was off 0.9 percent to $137.64 and Regeneron Pharma lost 1 percent to $346.82.

Amarin Corp fell 20 percent on the Nasdaq, dropping to $1.44 after the company said the Food and Drug Administration had rejected a preset testing process for the second time. The stock was the biggest decliner in the Nasdaq Biotech index and was suffering its biggest one-day decline since Jan. 21. It is down almost 30 percent year-to-date.

Index snapshot at 12:43 EDT (1643 GMT):

* S&P 500 down 10.75 points, or 0.54 percent.

* Nasdaq Comp down 22.10 points, or 0.48 percent.

* Dow industrials down 67.24 points, or 0.39 percent.

* Russell 2000 down 13.07 points, or 1.11 percent.

* S&P MidCap down 12.17 points, or 0.85 percent.

* S&P SmallCap down 8.13 points, or 1.21 percent. (Editing by Bernadette Baum and Nick Zieminski)