Keryx治疗肾病药物Zerenex二期研究结果良好

Keryx生物制药公司最近披露其治疗慢性肾脏疾病（CKD）药物Zerenex疗效显着，这一结果也助涨公司股价。Zerenex是被设计治疗高磷酸盐血症的药物，高磷酸盐血症主要常见于一些CKD患者，血液中磷酸盐浓度过高会导致生命危险。而此次而其研究Zerenex对缺铁性贫血也有很好疗效，预示着Zerenex未来可能有更广阔的应用。在此次有149名CKD患者参与的研究中，研究人员发现Zerenex有效降低了患者血液中磷酸盐的含量并提高了铁离子含量。一旦Zerenex同时获得了治疗缺铁性贫血的认证，这种药物将可能增加150万潜在患者用户。

然而，Zerenex的前景并不是像看上去那么美好，因为其主要成分和日本大冢公司的Ferriseltz相近，FDA可能不会批准其创新药物地位，这也意味着Zerenex可能很快会面临仿制药的挑战。

详细英文报道：

Keryx Biopharmaceuticals' ($KERX) shares leapt nearly 20% Tuesday morning on news that its chronic kidney disease (CKD) drug Zerenex cleared a Phase II trial on nondialysis-dependent patients, possibly setting the stage for a broader indication once the much-scrutinized drug is approved.

Zerenex is designed to treat hyperphosphatemia, a common ailment among CKD patients in which phosphorus levels reach dangerous heights, but Keryx is looking to flesh out its benefits in iron-deficiency anemia with eyes on a bigger market. In a midstage study of 149 anemic, nondialysis-dependent CKD patients, the drug charted statistically significant reductions in phosphorus and increases in iron over 12 weeks, and Keryx believes those data will help persuade the FDA to give Zerenex a labeled indication to treat a broader population.

Keryx's move to widen Zerenex's possible indications comes amid long-running concerns that the drug's launch will be blunted by soon-to-launch generics of Sanofi's ($SNY) Renvela and Shire's ($SHPG) Fosrenol, two phosphate-lowering drugs indicated for dialysis patients. As a result, Keryx is touting its drug's tertiary benefits--like a reduced need for intravenous iron and erythropoiesis-stimulating agents--in an effort to set Zerenex apart from the competition.

The drug is slated for a final FDA decision in June, based on positive Phase III results in dialysis patients with hyperphosphatemia. If Keryx can stretch that approval to include less-dire CKD patients with iron-deficiency anemia, Zerenex would become the first oral iron drug indicated for another roughly 1.5 million currently underserved patients, CEO Ron Bentsur said, adding that the treatment has the potential to lead the $2.4 billion market for phosphate binders.

But despite Wall Street's cheery reaction to the latest data, Keryx has done little to assuage fears that Zerenex's time on top would be short-lived. The drug's active ingredient bears a strong resemblance to Otsuka's long-ago-approved Ferriseltz, stoking worries that it won't get New Chemical Entity status from the FDA and thus would face generic competition sooner than expected.