U.S. Bioscience Inc. said late Tuesday that it has received aletter from the FDA stating that its new drug application forEthyol is not approvable based on data submitted so far, butthat additional data could provide the basis for an approvableindication.

In January, an agency advisory committee failed to recommendapproval of the compound as a treatment to protect healthycells from the effects of chemotherapy.

The West Conshohocken, Pa., company told the FDA that itintends to submit an amendment to its NDA when new data areavailable.

Issues raised by the FDA include the need for additional datashowing that Ethyol (amifostine) prevents or decreases any ofthe toxicities caused by chemotherapeutic agents, and thatEthyol doesn't decrease the anti-tumor effect ofchemotherapeutics.

UBS plans to accrue additional patients in its ongoing ovariancancer trial. The company has 160 patients so far and intendsto reach 200 patients by year-end. UBS also needs to generateadditional survival data, said Robert Kriebel, senior vicepresident of finance and administration.

The FDA letter, which the company received last week, saidthat based on interim results of the ovarian study, the FDA isinclined to believe that Ethyol decreases the hematologicaltoxicity of the combination of cyclophosphamide and cisplatin(CP) in the treatment of Stage III or Stage IV ovarian cancer.The letter further stated that favorable results from the trialcould provide a basis for approving the drug for decreasing thehematological toxicity of the CP regimen.

Kriebel declined to repeat the company's earlier projectionsthat UBS is back to its original timetable for Ethyol approval in1993. "We're letting people draw their own conclusions," hesaid.

Richard Vietor, a drug analyst at Merrill Lynch, wasunconcerned about the announcement. "I consider this to be oldnews," he said. "All the FDA was doing was formally taking careof old business. This places the burden squarely on U.S.Bioscience to get the statistical significance up. No one knowshow long that will take."

Vietor also said he wasn't worried about the prospect of thedrug receiving a narrow label. "The way cancer drugs work isto get a narrow indication and let the doctors establish forthemselves where it's useful," he said.

The FDA also requested additional information aboutmanufacturing and other issues, which the company said itbelieves it will be able to address.

UBS shares (AMEX:UBS) closed off 38 cents at $12.13 prior tothe announcement.

-- Karen Bernstein BioWorld Staff

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