Updated from 1:56 p.m. EST

Shares of Keryx Biopharmaceuticals ( KERX) were among the best-performing health and pharmaceutical stocks Wednesday, rising 26.3% after the company said it plans to initiate a phase III trial for its diabetic nephropathy drug.

The company said that no safety concerns were raised with either the 200-milligram or 400-milligram dosage of the drug during the company's most recent phase II trial. As a result, Keryx expects to begin studies of KRX-101 during a phase III trial within the next three months. Diabetic nephropathy is a life-threatening kidney disease that affects millions of diabetics. Shares traded up $2.95 to $14.18.

Immunomedics ( IMMU) rose 6.8% after the company said its therapy to treat severe systemic lupus erythematosus received fast-track status from the Food and Drug Administration. Immunomedics plans to initiate a phase III trial during the first half of 2005. Shares traded up 21 cents to $3.28.

Shares of Affymetrix ( AFFX) rose 5.9% after the company said its sales would exceed $100 million during the fourth quarter. Analysts polled by Thomson First Call expect the company, which makes chips used in genetic research, to post sales of $103.8 million. Affymetrix also said that sales for its next-generation products grew to over $10 million at the end of the fourth quarter. These products -- which the company expects to release and ship during the first half of fiscal 2005 -- include new genotyping arrays and automated instrument systems. Shares of Affymetrix traded up $2.01 to $35.95.

Water Pik Technologies ( PIK) rose 3.3% after the maker of personal health care products said it is exploring various strategic alternatives to enhance shareholder value. These alternatives include selling a portion or all of the company. J.P. Morgan Securities is acting as financial adviser to the company. Shares traded up 59 cents to $18.57.

Shares of Biopure ( BPUR) fell 12.9% after the biotechnology company said it would sell 22.2 million shares of stock at 51 cents a share, raising about $10.4 million in net proceeds. The price represents an 18% discount to Tuesday's closing price of 62 cents. Biopure said its cash on hand, plus proceeds from the stock offering, should be sufficient to fund operations into January 2006. Shares traded down 8 cents to 54 cents.

Other health care volume movers included StemCells ( STEM), down 36 cents to $5.61; Pfizer ( PFE), down 18 cents to $26.27; Aastrom Biosciences ( ASTM), down 7 cents to $1.56; Merck ( MRK), up 21 cents to $31.34; Schering-Plough ( SGP), down 12 cents to $20.36; Genentech ( DNA), up $1.40 to $53.15; and Bristol-Myers Squibb ( BMY), down 8 cents to $24.79.