Forty-two years after approving the potent diuretic Bumex (bumetanide) as both an oral and infused treatment for edema, the FDA has endorsed a new version of the drug to be delivered as a nasal spray.
The U.S. regulator has signed off on Corstasis Therapeutics’ Enbumyst to relieve the edema associated with congestive heart failure (CHF), chronic kidney disease (CKD) and liver disease. Edema is the accumulation of fluid in the body’s tissues that causes swelling.
It is the first FDA nod for Nevada-based Corstasis, which develops outpatient therapies for the treatment of fluid overload in patients with cardiorenal and hepatic diseases. Edema is the leading cause of hospitalization and readmission for patients with CHF, CKD and cirrhosis of the liver, accounting for more than 1 million visits annually, Corstasis explained.
Enbumyst provides a new option to water pills, which aren’t absorbed into the system as efficiently, and to intravenous therapy, which is less convenient and often more expensive. Over time, the reliance on the loop diuretics also can blunt effectiveness.
“Enbumyst was designed in direct collaboration with cardiologists to address practical challenges in the outpatient care setting,” Brian Kolski, M.D., chief medical director of Corstasis and director of the noninvasive vascular lab at the Orange County Heart Institute in California, said in a Sept. 15 release.
The approval was backed by clinical studies in which patients received all three forms of bumetanide, with Enbumyst demonstrating rapid absorption and comparable diuretic response and potassium excretion. It also was well tolerated, with less absorption variability and fewer treatment-related adverse events than pills.
The seven-year-old company expects to launch Enbumyst in the fourth quarter, targeting cardiologists, nephrologists, hepatologists, outpatient heart failure clinics and integrated delivery networks. Corstasis said that the nasal spray “represents a multi-billion-dollar opportunity annually,” given the increasing rate of CHF and CKD.
“Enbumyst offers the potential to change the standard of care by enabling earlier, outpatient intervention,” Anuradha Lala-Trindade, M.D., director of heart failure research at the Mount Sinai Fuster Heart Hospital in New York City, added in the release. “This innovation may meaningfully improve outcomes while potentially easing the economic burden on the healthcare system.”
Earlier this month, Corstasis announced that it had acquired patents in the U.S. for its subcutaneous formulations of bumetanide. The programs RSQ-786 and RSQ-789 are “multidose delivery systems with potential remote monitoring integration for outpatient fluid overload treatment,” the company said, adding that it expects to submit those products for approval in the second half of next year.
Corstasis' top rival as an innovator is Massachusetts-based scPharmaceuticals, which was bought out just three weeks ago by MannKind, a U.S. biopharma looking to cash in on the expanding market for cardiometabolic treatments. In 2022, scPharmaceuticals won an FDA approval for its on-body infuser for CHF.