A clinical study of Amgen Inc.'s G-CSF came under fire today inthe New England Journal of Medicine, as doctors wrote tocriticize the cost of the adjunct to cancer therapy andquestioned the relatively high dose of chemotherapy used inthe study.

Amgen was licensed last February to sell its Neupogengranulocyte-colony stimulating factor for use in reducing theincidence of infection, as manifested by fever and low counts ofwhite blood cells, in cancer patients with non-myeloidmalignancies receiving myelosuppressive anti-cancer drugs.

The "escalated chemotherapeutic doses" used in the study werehigher than those routinely given for the small-cell lung cancerstudied, giving an incidence of neutropenia with fever "farabove what is routinely encountered," said Dr. John T. Hamm ofthe University of Louisville in Kentucky.

Clinical hematologist Richard S. Stein of Vanderbilt Universityin Nashville, Tenn., calculated that the study's 104 patientsreceived about $1.7 million worth of G-CSF to prevent 30infections. "Unless the cost per infection is greater than$50,000, the widespread use of G-CSF ... would ... dramaticallyincrease the cost of therapy while having no effect ontreatment-related mortality," he concluded.

The study, headed by Duke University investigator JeffreyCrawford, had shown that G-CSF reduced the incidence ofconfirmed infection by about 50 percent. The drug also cuthospitalization rates and use of intravenous antibiotics forfever and neutropenia by about 50 percent, according to theconclusions published in the July 18 issue of the Journal.

Crawford and his colleagues responded to the critique bysaying that Stein's calculations differed from their cost analysis,in which the G-CSF expense was offset by savings associatedwith its use.

Amgen (NASDAQ:AMGN) estimates that a typical patient mayreceive G-CSF for a week to 12 days following chemotherapy, ata cost of $750 to $1,300. Hospitalization for neutropenia-induced complications of chemotherapy can run severalthousand dollars, Amgen calculates, so G-CSF can reduce theeconomic burden of cancer therapy.

The doses of chemotherapy used "were in the range" of dosesused in other studies, Crawford and his associates said.Moreover, they said, the possibility that CSFs may allow higherdoses of chemotherapy is a major focus of clinical trials inprogress.

-- Roberta Friedman, Ph.D. Special to BioWorld

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