FDA Grants Orphan Drug Exclusivity for Mixed Salts Oxybate for Cataplexy or Excessive Daytime Sleepiness

The Food and Drug Administration has granted 7 years of Orphan Drug Exclusivity for mixed salts oxybate  (Xywav; Jazz Pharmaceuticals, Philadelphia, PA) for the treatment of cataplexy or excessive daytime sleepiness (EDS) caused by narcolepsy in individuals age 7 years or more.

FDA Orphan Drug Designation is designed to advance the development of drugs that treat a condition affecting 200,000 or fewer US patients annually. 

Mixed salts oxybates uses a combination of cations to provide the same dose of sodium oxybate for adults with 92% less sodium—and approximate reduction of 1,000 to 1,500 mg/night less sodium. 

The FDA also published a summary of clinical superiority findings for mixed salts oxybate, stating that “the active moiety, oxybate, was previously approved as Xyrem (sodium oxybate) for the treatment of cataplexy or EDS in patients 7 years of age and older with narcolepsy. Xywav (calcium, magnesium, potassium, and sodium oxybates) is clinically superior to Xyrem by means of greater safety because Xywav provides a greatly reduced chronic sodium burden compared to Xyrem.” 

"We are pleased that FDA has recognized the greater safety of Xywav by virtue of the greatly reduced chronic sodium burden,” said Robert Iannone, MD, MSCE, executive vice president, research and development; and chief medical officer, Jazz Pharmaceuticals. “This action is consistent with FDA's long-established position on the benefits of reducing daily sodium intake. We are encouraged that FDA recognized the benefits of reducing sodium in a chronic medication for these patients.”