When you see a report of a "shortage," a government intervention is almost always somewhere nearby. Bloomberg News has an article about shortages of Dendreon's new prostate cancer medicine, Provenge. The article runs under the headline, "Prostate Cancer Patients Face Yearlong Rationing of Provenge." Reports Bloomberg:
The shortages stem from Dendreon's uncertainty about whether the U.S. Food and Drug Administration would approve the drug. The agency had previously denied approval, asking for more testing. Dendreon couldn't develop manufacturing facilities and seek clearance of the plants until the regulators reached a decision...Regulators must approve each new facility
The Dendreon-Provenge saga was discussed in a post on this site earlier here.