and the outlook for next week's FDA advisory panel meeting kicks off this week's Biotech Stock Mailbag.
Calvin C. writes,
"I really appreciate your work. I have one request from you as an avid fan of your blogs: Could you blog about the upcoming FDA panel meeting regarding Affymax's peginesatide on Dec. 7th? The data look great so I and many other investors would be very interested in such a blog! Thanks!"
Yes, I'll be live-blogging the Affymax FDA advisory panel meeting on Dec. 7. Before the panel, be aware (especially if you're trading the stock) that FDA will release its review of the peginesatide data on the morning of Monday, Dec. 5. You'll be able to find the FDA's peginesatide briefing documents
"Great" isn't the adjective I'd use to characterize the peginesatide data. "Adequate" is pretty much as far as I'd go -- and that might be too optimistic. Don't be surprised if the FDA's peginesatide review Monday reads negative (briefing documents are almost always critical.) The outcome of Wednesday's expert panel is a tossup; Wall Street's biotech buy-side sentiment leans negative.
Peginesatide is an erythropoiesis-stimulating agent (ESA), which like other ESAs (
Epogen and Aranesp and
Johnson & Johnson's
Procrit) treat anemia by stimulating the body to produce red blood cells. Peginesatide is dosed once a month, which makes it more convenient that other ESAs.
Affymax and its partner
are seeking FDA approval of peginesatide for the treatment of anemia in patients with chronic kidney disease. Four phase III clinical studies were conducted: The "Emerald" studies in patients with end-stage kidney disease who are on dialysis; and the "Pearl" studies in less-sick kidney disease patients who are not on dialysis.
Overall, the four phase III studies met their primary efficacy endpoints, which was to measure the mean change in hemoglobin levels from baseline to the end of the study.
Peginesatide was non-inferior compared to currently marketed ESAs, which is the statistical way of saying peginesatide was functionally equivalent to the other ESAs.
Across all four studies combined, peginesatide was also statistically non-inferior to the other ESAs for safety, measured by a cardiovascular composite safety endpoint (CSE), which included death, heart attack, stroke and other heart-related safety problems.
That's the good news. The following is where the peginesatide data get a bit hairy:
Problems arose when Affymax analyzed the two sets of phase III studies separately. In the non-dialysis "Pearl" studies, patients treated with peginesatide reported a higher rate of cardiovascular safety events (21.6%) compared to patients treated with other ESAs (17.1%). From a statistical perspective, the relative risk of having a heart-related safety problem was actually quite high for peginesatide compared to the other ESAs.