近日美国Salix医药公司宣布公司开发的用于治疗罕见病遗传性血管水肿的药物Ruconest已经获得FDA批准。遗传性血管水肿是一种罕见遗传病，在美国约有6000-10000人患有这种疾病。患病者会出现脸部、肺部以及上呼吸道浮肿和疼痛。Ruconest可以通过阻断一种名为complement system esterase C1的酶类从而使患者缓解患者水肿状况。

目前市场上治疗这种疾病的药物还有Firazyr和Kalbitor两种，但是这两种药物都是直接针对导致水肿相关蛋白而不是像Ruconest这样直接对其病因进行处理。Salix公司希望Ruconest的这一特性可以使其获得一部分市场份额。

详细英文报道：

Salix Pharmaceuticals ($SLXP) picked up FDA approval for an orphan therapy, giving the company another revenue source as it plots a tax-saving move to Ireland.

The drug, Ruconest, is designed to treat acute swelling in patients with hereditary angioedema, a genetic disease that affects between 6,000 to 10,000 people and results in pain and swelling in the face, lungs and upper airway. The treatment works by blocking the complement system esterase C1, replacing a protein that helps tamp down allergic reactions in healthy patients.

Ruconest is meant to be administered at the onset of hereditary angioedema attacks, returning patients' C1 inhibitor protein levels to normal and relieving dangerous swelling, Salix said. In its pivotal trial, the drug beat out placebo in providing relief from attacks, according to the company.

Now Salix will have to contend with entrenched offerings from Shire ($SHPG) and Dyax ($DYAX), companies that have been selling treatments for hereditary angioedema attacks for years. However, unlike its competitors' Firazyr and Kalbitor, which block a protein responsible for swelling, Salix's treatment addresses the deficiency at the heart of the disease, a difference the company hopes will help it gain market share.

"Ruconest is a much-needed treatment option for patients suffering from acute attacks of hereditary angioedema," CEO Carolyn Logan said in a statement. "Until now, there hasn't been an FDA approved recombinant C1 esterase inhibitor option to treat symptoms of HAE."

Salix acquired the North American rights to Ruconest in its $2.6 billion cash acquisition of Santarus, leaving the Netherlands' Pharming with rest-of-the-world marketing permission.

Meanwhile, the North Carolina company is waiting on the close of a $2.7 billion reverse merger that'll join it with Cosmo Pharmaceuticals ($COPN) and give it an Irish domicile, lowering its effective tax rate through a process called inversion. Salix joins a growing list of U.S. outfits pursuing such deals, including Medtronic ($MDT), AbbVie ($ABBV) and Auxilium