Thursday's Health Winners & Losers

Updated from 2:31 p.m. EDT

Mixed earnings results, expectations and announcements continued to drive an uneven response in the biotech and health care sector Thursday.

Among the winners, AtheroGenics (AGIX Quote) climbed 6 cents, or 2.2%, to $2.90 following an earnings release Thursday. The company reported a net loss that narrowed by 34.2% compared with the same quarter in 2006. The company's net loss per share was 32 cents; analysts surveyed by Thomson Financial had estimated that the company would lose 39 cents a share.

Cephalon (CEPH Quote) announced on Wednesday that it expects first-quarter earnings per share to exceed previously issued guidance by 50%, driven by lower expenses and stronger-than-expected sales. Shares jumped by $5.12, or 6.8%, to $80.42.

Losing ground Thursday was Affymetrix (AFFX Quote), which released disappointing earnings late Wednesday. The company saw a 6.9% decrease in revenue from a year ago, and shares dropped $3.59, or 11.4%, to $27.88.

Elsewhere, Zoll Medical's(ZOLL Quote) shares fell $3, or 10.5%, to $25.50 after it reported earnings beating Wall Street's estimates but showed revenue shy of targets.

Cancer-drug maker ImClone Systems'(IMCL Quote) first-quarter results included a steep decline in profit, driven by a decline in license fees and milestone revenue, but results were in line with analysts' expectations. Its share price closed up 74 cents, or 1.7%, to $43.49.

Other stocks that were down, even after reporting smaller-than-expected losses, included Celera(CRA Quote), which fell 19 cents, or 1.3%, to $14.11, and Millennium Pharma (MLNM Quote), which fell 32 cents, or 2.7%, to $11.64.