Wednesday's Health Winners & Losers

Updated from 12:49 p.m. EDT

Health stocks were hit hard Wednesday, as negative analyst calls on recent favorites Dendreon (DNDN Quote) and Nuvelo (NUVO Quote) combined to weigh on the sector.

JMP Securities downgraded Dendreon to market perform from strong buy, while Banc of America Securities reduced Nuvelo to sell from neutral. Dendreon, which has tripled in price since late March, lost $3.92, or 17.7%, to $18.23. Nuvelo was off 97 cents, or 18%, to $4.43.

Fellow biotherapy company Cell Genesys (CEGE Quote) dropped 12.3% to $5.33. All three names are part of the Nasdaq Biotechnology Index, which fell nearly 1%.

On the other hand, Maxim Group upgraded Renovis (RNVS Quote) all the way to buy from sell. Renovis was higher by 18 cents, or 4.4%, to $4.30.

Cell Therapeutics (CTIC Quote) was also among the day's winners after receiving "fast track" designation from the Food and Drug Administration for the company's Xyotax drug, a treatment of certain types of non-small cell lung cancer in certain women. The stock climbed 21 cents, or 13%, to $1.83.

Amgen (AMGN Quote) was also making headlines after the company's CFO Richard Nanula resigned. Additionally, the company said it would postpone reporting first-quarter results by 4 days to April 23 in order to include trial results for the anemia drug Aranesp. Amgen was down 78 cents, or 1.4%, to $56.34.

Other healthcare winners included Adolor (ADLR Quote), which gained 2.5% to $3.69. MedImmune (MEDI Quote) was up 2.1% to $37.84, and Boston Scientific (BSX Quote) tacked on 2.2% to $15.33.

Among other decliners, AtheroGenics (AGIX Quote) slumped 3.5% to $3.08. Amylin Pharmaceuticals (AMLN Quote) slid 2.9% to $38.09. MedcoHealth (MHS Quote) lost 2.3% to $72.14.