MannKind (NASDAQ:MNKD) said the U.S. Food and Drug Administration approved Furoscix ReadyFlow, an auto-injector designed to deliver an 80-milligram dose of subcutaneous furosemide in five to 10 seconds for the management of fluid overload.
Chief Executive Officer Michael Castagna said the approval was the company’s third FDA action in 2026, following an Afrezza conversion-dose update in the first quarter and a pediatric approval in the second quarter. MannKind expects to launch Furoscix ReadyFlow during the third quarter.
ReadyFlow Study Results
Chief Medical Officer Dr. Ajay Ahuja said the FDA approval was supported by a prospective, randomized crossover pharmacokinetic and pharmacodynamic study involving 21 healthy adult volunteers. Each participant received both ReadyFlow and intravenous furosemide, with a three-day washout period between treatments.
In the ReadyFlow arm, participants received 80 milligrams of furosemide subcutaneously through the auto-injector. The IV comparator consisted of two 40-milligram furosemide boluses administered two hours apart, according to the FDA label.
Ahuja said ReadyFlow achieved 107% bioavailability relative to IV furosemide, within the 80% to 125% range used to establish bioequivalence. While the subcutaneous injection produced a lower and more gradual concentration peak than IV administration, overall drug exposure measured by area under the curve was equivalent, he said.
The study also found that ReadyFlow generated urine output comparable with IV furosemide at six, eight and 12 hours, with similar urinary sodium and potassium excretion. Ahuja said injection-site adverse events were generally mild and local, while systemic adverse events were consistent with the known safety profile of oral and IV furosemide. No participants discontinued treatment because of an adverse event.
Commercial Focus on Outpatient and Hospital Settings
Castagna said MannKind views ReadyFlow as a potential tool for addressing fluid overload before hospitalization, supporting earlier discharge for appropriate patients and managing patients after discharge. He said the company estimates roughly 1 million addressable fluid-overload events occur annually in the U.S.
Furosemide has historically been administered orally or intravenously in a hospital setting, according to Castagna. The prior Furoscix on-body infuser delivers treatment over five hours, while ReadyFlow is intended to provide a full dose through an auto-injector in seconds. MannKind refers to the emerging category as non-oral diuretics, or NODs.
The company plans to train and deploy its sales force over the coming weeks and launch an integrated marketing campaign aimed at healthcare professionals and patients. Castagna said MannKind is engaging more than 60 prioritized integrated delivery networks, or IDNs, with another 20 to 40 planned as the year progresses.
- Establish: Build awareness and clinical confidence among health systems.
- Embed: Incorporate Furoscix into early-discharge, post-discharge and outpatient heart-failure care pathways.
- Expand: Scale use across providers, patients and sites of care.
Castagna said the company’s IDN business, launched around January 2025, accounted for approximately 10% of sales. He identified organizations including Cleveland Clinic, NYU, Emory and Kaiser among MannKind’s priority systems, while noting that health-system contracting and implementation can take eight to 12 months.
Pricing, Conversion and Future Plans
MannKind expects ReadyFlow pricing to be comparable with the on-body infuser. Castagna said the company had previously indicated that ReadyFlow could reduce cost of goods sold by about 70%, adding that the auto-injector is made entirely in the U.S. while the on-body infuser includes international components.
For new patients, Castagna said MannKind expects more than 85%—and potentially nearly all—to begin on the auto-injector. Existing users of the on-body infuser may transition as systems and physician offices select which product to train on and use. MannKind will continue to offer the on-body infuser for physicians who prefer continuous five-hour administration.
The company expects to offer ReadyFlow samples at launch after reducing sampling activity for the on-body infuser because of its cost. Castagna said approximately 40% of current Furoscix prescriptions do not require prior authorization and that the company expects coverage comparable with the on-body device.
MannKind did not update its 2026 Furoscix revenue outlook of $110 million to $120 million during the call, saying it would revisit assumptions at its upcoming earnings call. The company also said it is assessing international opportunities and plans to pursue a 40-milligram auto-injector that could support a future pediatric filing.
About MannKind (NASDAQ:MNKD)
MannKind Corporation, a biopharmaceutical company, focuses on the development and commercialization of inhaled therapeutic products for endocrine and orphan lung diseases in the United States. It offers Afrezza, an inhaled insulin used to improve glycemic control in adults with diabetes, and the V-Go wearable insulin delivery device, which provides continuous subcutaneous infusion of insulin in adults. The company's product pipeline also includes Tyvaso DPI (Treprostinil), an inhalation powder for the treatment of pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease; MNKD-101, a nebulized formulation of clofazimine, for the treatment of severe chronic and recurrent pulmonary infections, including nontuberculous mycobacterial lung disease; MNKD-201, a dry-powder formulation of nintedanib, for the treatment of idiopathic pulmonary fibrosis (IPF).
