MannKind Corporation has secured United States Food and Drug Administration approval for Furoscix ReadyFlow, a self-administered furosemide autoinjector for treating edema in adults with heart failure or chronic kidney disease. The product delivers an 80 mg dose beneath the skin in under 10 seconds, potentially allowing appropriate patients to address worsening fluid overload at home rather than waiting to receive intravenous diuretic treatment in a hospital or clinic.
The approval expands the Furoscix franchise beyond the existing on-body infusor, which administers subcutaneous furosemide over approximately five hours. MannKind Corporation expects Furoscix ReadyFlow to become commercially available in the United States by the end of August 2026, although the company has not yet demonstrated that using the faster device directly reduces emergency department visits, hospital admissions or readmissions.
How Furoscix ReadyFlow could change at-home treatment of worsening fluid overload
Edema occurs when excess fluid accumulates in the body, contributing to swelling, rapid weight gain, shortness of breath and difficulty sleeping. Fluid overload is a recurring complication of heart failure and chronic kidney disease, and worsening congestion can require urgent treatment when a patient no longer responds adequately to an oral diuretic.
Intravenous furosemide is commonly used when stronger or more predictable diuresis is needed, but receiving an intravenous dose generally requires access to a hospital, emergency department, infusion clinic or another supervised setting. Furoscix was developed to provide systemic furosemide exposure through subcutaneous administration, creating an option that clinicians may prescribe for use outside the hospital in selected patients.
The existing Furoscix on-body infusor was approved for adults with heart failure-related edema in 2022 and expanded to adults with chronic kidney disease in 2025. That device delivers its dose gradually over about five hours. Furoscix ReadyFlow administers a concentrated 80 mg/mL formulation through a single-use autoinjector in 10 seconds or less, substantially reducing the amount of time a patient must wear or operate the delivery system.
The shorter administration period may make the treatment easier to incorporate into home care, post-discharge planning and outpatient heart failure or nephrology programs. A clinician could potentially prescribe the autoinjector for an appropriate patient to use when specified signs of worsening fluid overload emerge, although treatment decisions and instructions must remain individualized.
Furoscix ReadyFlow is not intended to replace routine oral diuretic therapy indefinitely. MannKind Corporation’s prescribing information states that Furoscix should be replaced with oral diuretics as directed by the patient’s healthcare provider, reinforcing that the product is designed as an episodic intervention rather than a new daily maintenance medicine.
What the FDA evidence shows about IV-equivalent exposure and rapid administration
The Food and Drug Administration approval was supported by a pharmacokinetic and pharmacodynamic comparison between Furoscix ReadyFlow and intravenous furosemide. MannKind Corporation reported that the autoinjector met the study’s primary pharmacokinetic endpoint and produced equivalent urine output, sodium excretion and potassium excretion at six, eight and 12 hours compared with intravenous administration.
The company describes Furoscix ReadyFlow as providing intravenous-equivalent exposure based on comparisons of drug exposure and pharmacodynamic endpoints. That wording does not mean the subcutaneous injection is identical to intravenous treatment in every clinical circumstance, nor does it establish that patients using the device experience fewer cardiovascular or renal events.
The available evidence primarily establishes that the autoinjector can deliver furosemide into the bloodstream and produce diuretic effects comparable with intravenous furosemide across the measured endpoints. MannKind Corporation said symptom relief may begin in an hour or less, but the timing and magnitude of an individual patient’s response may vary according to disease severity, kidney function, existing medication use and the cause of fluid accumulation.
The regulatory submission did not depend on proving that the active ingredient was new. Furosemide is a long-established loop diuretic used to remove excess fluid by increasing the excretion of water and electrolytes through the kidneys. Furoscix ReadyFlow’s innovation lies in the concentrated formulation and autoinjector delivery system intended to provide reliable subcutaneous exposure outside traditional intravenous settings.
This distinction is clinically important. The approval validates the drug-device combination and its delivery performance, but broader claims about avoiding hospitalization will require real-world evidence showing that patients can recognize worsening congestion, use the product correctly and receive treatment early enough to prevent further deterioration.
Which patients may benefit from Furoscix ReadyFlow and what safety risks remain
Furoscix ReadyFlow is approved for adults with edema associated with heart failure or chronic kidney disease. It may be particularly relevant for patients who experience episodic worsening fluid overload despite oral therapy and whose physicians believe at-home subcutaneous treatment is appropriate.
MannKind Corporation said the product could be used across several intervention points, including the onset of worsening symptoms, outpatient management and the transition home after hospitalization. Cardiologists, nephrologists, heart failure clinics and integrated delivery networks are expected to be among the principal prescribers and care settings targeted during the launch.
The treatment carries the established risks of furosemide. Excessive diuresis can cause dehydration and loss of electrolytes, with possible symptoms including thirst, muscle cramps, reduced urine output, headache, nausea and vomiting. Patients may require monitoring of electrolyte levels and kidney function, particularly when they have advanced heart or renal disease or are taking other medicines that affect blood pressure and fluid balance.
Furoscix may also produce temporary low blood pressure, increased blood glucose and hearing-related effects such as ringing in the ears. The most common reported adverse effects involve the injection site and skin, including pain, bruising, redness and swelling.
Correct device use is another safety consideration. MannKind Corporation warns that patients may receive an incomplete dose if the viewing window does not turn fully yellow or if the device is removed from the skin too early. Patients experiencing an incomplete administration are instructed to contact their healthcare provider rather than immediately using a second device without medical direction.
These requirements mean the autoinjector does not remove the need for clinical oversight. Successful use will depend on patient selection, education, monitoring and clear instructions about when worsening symptoms require emergency assessment rather than another dose at home.
Why the August launch could expand MannKind Corporation’s Furoscix franchise
MannKind Corporation acquired the Furoscix business through its purchase of scPharmaceuticals Inc. in October 2025, adding a commercial cardiorenal franchise to a portfolio that already included Afrezza and royalty and manufacturing revenue associated with United Therapeutics Corporation products. The acquisition was partly built around the expectation that the ReadyFlow device could expand Furoscix adoption by reducing treatment time and simplifying administration.
The established Furoscix product generated $15.5 million in net sales during the first quarter of 2026, while doses dispensed increased 64% from the corresponding period of 2025. MannKind Corporation had already built launch infrastructure and aligned its field teams before the approval, suggesting that the company intends to move quickly once commercial supply becomes available.
The ReadyFlow launch could expand use among patients who considered the five-hour on-body infusor inconvenient or difficult to integrate into daily life. It may also provide clinicians with greater flexibility when deciding whether a patient can receive intensified diuretic therapy at home, in an outpatient clinic or immediately after discharge.
Commercial adoption will depend on reimbursement, prescribing protocols, device training and whether health systems believe the product can reduce the total cost of managing fluid overload. Heart failure hospitalizations account for a substantial share of disease-related expenditure, but MannKind Corporation will need outcomes and real-world utilization data to establish that the autoinjector meaningfully changes those costs.
MannKind Corporation shares were trading near $4.12 during the July 24 session, up approximately 5.9%, after reaching an intraday high of $4.52. The positive reaction suggests investors viewed the approval and expected August launch as meaningful additions to the company’s growth outlook, although the commercial value will ultimately depend on how rapidly Furoscix ReadyFlow prescriptions, coverage and repeat use develop.
Furoscix ReadyFlow offers a materially faster way to deliver the Furoscix dose and could move intravenous-equivalent diuretic exposure closer to the patient’s home. The approval establishes the device’s pharmacokinetic and diuretic performance, while the launch will test whether speed, simplicity and earlier intervention can translate into sustained use and fewer disruptions for adults living with recurrent fluid overload.
