Unfortunately, Zerenex is likely coming to market in late 2013 or early 2014 at the same time as generic phosphate binders. Both Sanofi's ( SNY) Renagel/Renvela (the market leader with $537 million in sales) and Shire's ( SHPGY) Fosrenol will be largely replaced by cheap generic versions just as Zerenex tries to compete. Phoslo, another phosphate binder, is already generic. Going up against generics is tough enough, but Keryx faces an even more impossible challenge with Zerenex because dialysis providers (the primary users of phosphate binders) only receive a single, fixed or "bundled" fee from Medicare that covers all ancillary products involved in providing dialysis to patients. Under a bundled reimbursement system, dialysis providers can only increase their profits by reducing costs. One way to reduce costs, obviously, is to spend less on phosphate binders. The likelihood that dialysis providers will eschew cheap, generic phosphate binders in favor of a premium-priced product like Zerenex is low to nil. Medicare set up bundled payments for drugs and services tied to the treatment of end-state, chronic kidney disease patients in 2011 but delayed the inclusion of oral drugs into the payment bundle until 2014. Zerenex is an iron-based phosphate binder that Keryx claims may allow dialysis clinics to reduce patients' use of iron supplements and/or costly red blood cell boosting drugs like Epogen that treat anemia. The ongoing phase III study is measuring IV irons and anemia drugs to determine whether Zerenex reduces their use compared to non iron-based phosphate binders. FDA will determine whether any "iron benefit" observed is clinically meaningful enough to make it into the Zerenex label. It will be up to the bean counters at dialysis clinics to determine whether buying Zerenex over cheaper generic phosphate binders lowers overall costs and boost profits. Color me skeptical. AMAG Pharmaceuticals ( AMAG) tried to market a better, premium-priced IV iron to dialysis clinics and failed fairly miserably. Dialysis clinics preferred lower cost IV irons. And don't for a second believe Keryx is going to convince dialysis clinics to eschew Epogen for Zerenex without Amgen ( AMGN) fighting back with its considerable expertise and marketing muscle. A fight between Amgen and Keryx is a mismatch. @amlewis4 asks, "If a delay was to occur in the $AMRN PDUFA date, what would be the typical time frame that delay could occur within." The FDA decision date (PDUFA) for Amarin's ( AMRN) AMR101 is July 26. My sense is that most investors expect full approval. While at ASCO, I did speak to an investor with a dissenting view. She believes FDA will reject AMR101 on July 26, or technically, delay approval. And this investor suspects Amarin knows bad news is coming and has even dropped some clues to investors. At this point, she has no position in Amarin but may open a position in next few weeks, she told me.