A federal judge Tuesday denied Johnson & Johnson's request for a preliminary injunction barring Amgen Inc. from offering discounts on certain drugs to treat side effects of chemotherapy, which J&J blames for declining sales of its anemia drug.

But J&J, of New Brunswick, N.J., Wednesday said it still plans to pursue a full trial in the case. J&J argues Amgen's discounts have hurt sales of Procrit, which treats chemotherapy-related anemia in cancer patients.

J&J has licensed Procrit from Amgen since the 1980s. Amgen sells the same drug under the brand Epogen, but under an agreement with J&J, Amgen only sells Epogen to treat anemia in kidney-dialysis patients, while J&J sells it in non-dialysis settings.

Amgen, Thousand Oaks, Calif., also sells a newer drug, Aranesp, to treat anemia in both dialysis and chemotherapy patients, thus competing directly with J&J's Procrit in chemotherapy settings.

To spur sales, Amgen offers cancer clinics discounts if they purchase certain amounts of Aranesp and two other Amgen chemotherapy-related drugs, Neupogen and Neulasta, which are designed to boost white blood cell counts and ward off infections. Partly as a result, Aranesp sales have taken off and gained market share from Procrit, rising 27 percent to $1.1 billion for the third quarter.

J&J sales of Procrit and Eprex -- the brand name it's sold under in Europe -- fell 5.3 percent to $2.4 billion for the third quarter.

J&J's Ortho Biotech unit sued Amgen in October 2005 in federal court in New Jersey alleging violations of antitrust law. J&J alleges the discounts constitute "unlawful tying" and an unlawful attempt to gain a monopoly. J&J also sought a preliminary injunction stopping Amgen from offering the discounts to oncology clinics.

Tuesday's ruling in Newark, N.J., by U.S. District Court Judge Stanley Chesler denies the preliminary injunction. He wrote that J&J's allegations, if true, can be remedied by monetary damages, so a preliminary injunction wasn't necessary.

"We believe that Amgen does not engage in anticompetitive practices in the sale of Aranesp," said David Scott, Amgen's senior vice president and general counsel.

Ortho Biotech also is seeking a permanent injunction against Amgen, which Chesler's ruling doesn't address. "The ruling does not resolve our underlying challenge to Amgen's anticompetitive contracting strategy," said Ortho Biotech.

In afternoon trading J&J shares rose 17 cents to $66.77 on the New York Stock Exchange. Amgen shares fell 37 cents to $72.61 on the Nasdaq Stock Market.