ICAgen's

(ICGN)

shares sank 71% to $1.22 after the company said it would discontinue studies of a drug intended to treat sickle-cell disease in certain patients. The decision followed an analysis of one of its clinical trials by an independent data-monitoring committee. The company will immediately enter an eight-week follow-up period.

Shares of

Cell Genesys

(CEGE)

lost 8.3% following its earnings report after the close of trading on Thursday. The company reported quarterly revenue of $1.05 million compared with $2.78 million a year ago. Cell Genesys lost $27.9 million, or 60 cents a share, in the second quarter, compared with a loss of $27.4 million, or 60 cents a share, a year earlier. Analysts were expecting the company to lose 62 cents a share. The stock was recently trading at $4.54.

Amgen

(AMGN) - Get Report

fell a day after the company said a federal appeals court reversed a decision on two patent disputes with

Transkaryotic Therapies

. The federal court did affirm a lower court's decision that Transkaryotic and Aventis Pharmaceuticals infringed Amgen's patent on its anemia drug Epogen. Shares were down 3.1% to $68.73.

Shares of

Osteotech

(OSTE)

rose after the company said it swung to a profit for the second quarter. Osteotech earned $800,000, or 4 cents a share, compared with a loss of $1.9 million, or 11 cents a share, a year earlier. Revenue remained flat at $25.3 million. Shares were up 10.1% to $4.15.

Adeza Biomedical

(ADZA)

, a maker of women's health products, gained 11.3% to $16.64 following its earnings report after the close of trading Thursday. For the second quarter, the company reported record sales of $13 million, up 23% from a year ago. Net income in the quarter reached $537,000, or 3 cents a share, including stock-based compensation expenses.

Other health stocks on the move included

Acorda Therapeutics

(ACOR) - Get Report

, up 8.8% to $3.34;

Immtech Pharmaceuticals

(IMM)

, gaining 7.4% to $5.78;

Genentech

(DNA)

, rising 1.1% to $81.26;

ViaCell

(VIAC)

, up 3.5% to $3.84;

CuraGen

(CRGN)

, adding 3.9% to $3.17; and

Oscient Pharmaceuticals

(OSCI)

, up 16.8% to $1.25.

Meanwhile,

Novacea

(NOVC)

, shares took a 10.2% hit to $7.35;

Orthologic's

(OLGC)

, shares fell 6.1% to $1.54; and

CoTherix

(CTRX)

, was down 2.6% to $7.22.