I received a lot of email about Dendreon ( DNDN) and the decision by Medicare to open a coverage assessment for Provenge, including this email from Yang O. "Hi Adam, I have been a fan of your articles for many years now. Thank you for your earnest analysis of biotech companies. You saved me from losing too much on junk science. On your take about Dendreon: "Firstly, one of the concerns is the fact that Medicare might limit the coverage of Provenge. I wonder about that, as the indication that Provenge is approved for is the last hope for prostate cancer patients that have failed all therapies. How is Medicare going to further limit the usage of Provenge? If Provenge is for first-line prostate cancer, then there might be scope of decreasing its first-line usage. "Secondly, I read that most prostate cancer doctors are hoping to prescribe Provenge at an earlier prostate cancer stage with the hope of ensuring better response. Could the enquiries to Medicare for earlier usage of Provenge be the cause of Medicare's coverage analysis?" Before I get to the meat of Yang's question, let me correct a misperception. The FDA approved Provenge for the treatment of asymptomatic or minimally symptomatic, metastatic, castration-resistant prostate cancer. That's a mouthful, but described more simply, doctors will use Provenge to treat patients with prostate cancer that no longer responds to hormone therapy -- before the use of chemotherapy drugs like Taxotere and the newly approved Jevtana. Provenge will not be used, therefore, in patients who have failed all other therapies, as Yang states. It will be used well before that, which is a big reason why estimates of Provenge's peak commercial potential are measured in billions of dollars. If Medicare decides to limit or restrict Provenge coverage, the agency will likely only do so by requiring doctors to adhere strictly to the drug's label when choosing patients for Provenge treatment. This would dampen doctors' ability to treat prostate cancer patients with earlier stages of the disease; it would also remove from treatment consideration patients with "symptomatic" disease, generally defined as patients who require narcotics to treat pain associated with the spread of prostate cancer to bone.