The US Centers for Medicare and Medicaid Services (CMS) announced preliminary plans today to provide full reimbursement for Seattle-based Dendreon Corp.’s expensive prostate cancer vaccine Provenge. In a proposed decision memo, the agency said the $93,000-a-year drug was “reasonable and necessary” for men with advanced, hormone-refractory prostate tumors who have minimal or no symptoms of the disease — the stage of prostate cancer for which the drug was approved last April.

“This is a very important milestone,” says Tom Kirk, President & CEO of Us TOO International Prostate Cancer Education & Support, a non-profit organization based near Chicago. “This is a very exciting and attractive option for many men who have limited options with this disease.”

Sean Tunis, director of the Center for Medical Technology Policy in Baltimore and a former CMS chief medical officer, says the decision comes as no surprise as it effectively mirrors the recommendations of a CMS advisory panel that gave Provenge a favorable vote in November 2010. In fact, Tunis argues, “what’s more interesting is what they didn’t do in this policy.” Namely, the CMS did not call for restrictions on reimbursement for off-label use, which could open the door to men with non-metastatic cancers taking the drug.

The proposal is now subject to a 30-day public comment period, and a final decision will be issued 60 days after that.