Washington Editor

Pharmion Corp. filed a new drug application seeking approval to market Vidaza, an orphan-designated product, as a treatment for myelodysplastic syndromes.

The company expects notification in 60 days as to whether it will receive priority review for Vidaza (azacitidine for injectable suspension), a fast-track product.

Vidaza belongs to a class of drugs in development, known as hypomethylating or demethylating agents. Boulder, Colo.-based Pharmion acquired worldwide rights to Vidaza in an agreement with Pharmacia Corp., now part of Pfizer Inc., of New York. If Vidaza enters the market, Pharmion would owe Pfizer royalties on sales, Patrick Mahaffy, Pharmion's president and CEO, told BioWorld Today.

As for completing the NDA this year, Mahaffy referred to it as a quite an accomplishment. "This is a very significant achievement for us. Of course, it will be truly significant if it yields us an approval at some point over the next 12 months, but to have gotten this far, to do all the work required to prepare the NDA, is a real accomplishment of the regulatory team," he said.

The NDA is based on two Phase II studies and a Phase III 191-patient study comparing the effects of Vidaza plus best supportive care vs. supportive care alone, as a treatment of myelodysplastic syndromes (MDS). The studies were sponsored by the National Cancer Institute and conducted by the Cancer and Leukemia Group B.

Mahaffy said the Phase III trial showed statistically significant improvements in the treatment arm.

Meanwhile, the company is conducting a 354-patient confirmatory trial designed to compare the effect of Vidaza to conventional care on survival. Mahaffy expects accrual to be complete by the end of 2005.

Pharmion submitted the application under Subpart H (accelerated approval), under which a drug can be approved based on either evidence from adequate and well-controlled studies of the drug's effects on a surrogate endpoint that reasonably suggests clinical benefits or of the drug's effect on a clinical endpoint other than survival, provided the company agrees to a confirmatory study.

MDS, a bone marrow disorder characterized by the production of abnormally functioning, immature blood cells, can result in death from bleeding and infection in the majority of patients. It transforms into acute myelogenous leukemia in up to 40 percent of high-risk patients.

Patient population tends to vary because hematologists believe MDS is often under-diagnosed, Mahaffy said, adding that the American Cancer Society estimates that there are 10,000 to 20,000 new cases each year and between 30,000 to 40,000 total cases in the U.S.

SuperGen Inc., of Dublin, Calif., is developing an MDS candidate called Dacogen (decitabine), and Celgene Corp., of Warren, N.J., is developing a candidate called Revimid.

Mahaffy doesn't expect either product to threaten Vidaza's status as an orphan drug. The SuperGen candidate is chemically similar, but delivered differently, and the Celgene candidate likely would be used in a subset of MDS patients, he said.

Mahaffy expects to file Vidaza's application in Europe sometime in 2004.

In other business this year, Pharmion's initial public offering grossed $84 million. Also, the company filed for European approval of thalidomide as a treatment for relapsed and refractory multiple myeloma. The product currently is being sold in Europe on a compassionate-use basis. Thalidomide is approved in New Zealand and Australia. Pharmion shares certain rights to the product with Celgene.

Pharmion's stock (NASDAQ:PHRM) closed Monday at $14.50, up 40 cents.

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