After taking a hit last week on news of an anticipated delay with cancer drug satraplatin, shares of Pharmion Corp. gained back ground - and then some - after reporting Phase III data showing that Vidaza, its myelodysplastic syndromes drug, extended overall survival by 74 percent in higher-risk MDS patients.

The company's shares (NASDAQ:PHRM) shot up 58.4 percent, or $14.39, Thursday to close at $39.03.

Data from the Phase III study, which was designed to test Vidaza (azacitidine for injection) plus best supportive care vs. conventional care regimens (CCR) plus best supportive care in 358 higher-risk patients, showed that those treated with Pharmion's drug had a median survival of 24.4 months vs. 15 months in the CCR arm, an improvement of 9.4 months. The two-year survival rate for the Vidaza group was 50.8 months, compared to 26.2 percent in the CCR group. So, not only did Vidaza increase survival time for patients, "but it did so at a magnitude that is highly surprising," said Patrick Mahaffy, president and CEO of Boulder, Colo.-based Pharmion. At the two-year point, Vidaza had "effectively doubled survival, and in oncology, that's exceptionally rare."

Vidaza was approved in 2004 for treating all subtypes of MDS, a group of hematologic diseases that are characterized by the production of poorly functioning and immature blood cells; however, "a significant percentage, maybe even the majority of high-risk MDS patients still are treated only with best supportive care," he told BioWorld Today. So those Phase III data could lead to more physicians prescribing Vidaza treatment in that patient population, leading to sales growth "over time."

Analyst Matthew Osborne, of New York-based Lazard Capital Markets, wrote in a research note that early polls of U.S. hematologists "indicate a 10 to 20 percent increase in Vidaza use over the next six to 12 months based on a survival benefit."

Whether Vidaza, which became the first drug approved to treat MDS, is able to hang on to that growth remains to be seen. Survival data from competing product Dacogen (decitabine), from MGI Pharma Inc. and SuperGen Inc., are expected in mid-2008. Dacogen, approved in May 2006, hasn't seriously dented U.S. Vidaza sales, which totaled $32.5 million in the second quarter, down only slightly from the $33.7 million recorded for the same quarter in 2006, but that could change as Dacogen becomes more entrenched in the MDS space.

Being the first to market and the first to report survival data might give Pharmion "a slight marketing edge," at least until Dacogen's survival data are released, wrote analyst Christopher Raymond, of Chicago-based Robert Baird & Co. But, he added, it's likely physicians will "view Dacogen as the more potent agent, and the [Vidaza] trial may ultimately benefit the entire class."

Both Vidaza and Dacogen are demethylation agents, though they involve different chemical entities.

Nevertheless, shares of Minneapolis-based MGI Pharma (NASDAQ:MOGN) lost 60 cents Thursday to close at $24.64, while shares of Dublin, Calif.-based SuperGen's stock (NASDAQ:SUPG) fell 86 cents, or 15 percent, to close at $4.89.

The Vidaza data are unlikely to have any immediate impact on a third MDS product, Revlimid (lenalidomide) from Summit, N.J.-based Celgene Corp, since that product, which gained FDA approval in late 2005, is indicated in a subset of low- or intermediate-1 risk MDS patients. But, with "such profound results in the high-risk [population], we really want to explore Vidaza in low-risk patients," Mahaffy said.

Pharmion also continues work on an oral version of Vidaza for MDS, as well as for other cancers where demethylation has shown to produce antitumor effects. That product is in Phase I development.

In the meantime, the company intends to use the Phase III survival results in its regulatory filing in Europe - Vidaza already is prescribed there on a compassionate-use basis - before the end of this year. At the same time, the company intends to file in the U.S. to update Vidaza's label to include the survival data. Pharmion owns rights to Vidaza worldwide, except for Japan.

Pending approval in Europe, the company intends to use the same hematologic sales force it plans to put in place for thalidomide, a multiple myeloma drug under review by European regulators. Mahaffy said approval could come late this year or early in 2008.

But it looks like the company won't have to expand that sales force right away to cover solid tumor cancers. Last week, the FDA's Oncologic Drugs Advisory Committee recommended that reviewers wait to approve satraplatin in second-line, hormone-refractory prostate cancer until survival data are in hand. Pharmion, partner GPC Biotech Inc., of Martinsried, Germany, along with licensee Spectrum Pharmaceuticals Inc., of Irvine, Calif., had hoped the FDA would approve satraplatin based solely on progression-free data.

The companies later withdrew the new drug application for satraplatin to await survival results. Pharmion has rights to satraplatin in Europe. (See BioWorld Today, July 25, 2007.)