Biotechnology companies shares down at 10 a.m.

Shares of some top biotechnology companies are down at 10 a.m.:

Amgen Inc. fell $1.05 or .9 percent, to $118.37.

Biogen Idec fell $1.16 or .4 percent, to $313.61.

Celgene Corp. fell $.64 or .7 percent, to $85.82.

Gilead Sciences Inc. fell $.22 or .3 percent, to $81.58.