Alfapump® DSR Feasibility Study in Subjects With Persistent Congestion Due to Heart Failure, Resistant to Loop Diuretic Treatment

The feasibility trial will consist of a 24-subject randomized study in volume overloaded heart failure subjects receiving high dose of loop diuretics. Subjects providing consent for participating in the clinical trial will be screened for eligibility. Once eligibility is confirmed they will be implanted with the alfapump® and a standard peritoneal infusion port. After the implant, the subject will undergo a 40 mg IV furosemide (or 1 mg IV bumetanide) diuretic challenge with timed biospecimen collection. At the start of the study treatment period, the loop diuretics treatment will be stopped. Subjects will be randomized in an unblinded fashion into one of two groups:

• Group 1 (N= 12) - treatment with a standard dose of SGLT2-inhibitor, combined with DSR treatment (PRN use of loop diuretics)
• Group 2 (N= 12) - treatment with DSR treatment (PRN use of loop diuretics) Enrolled subjects in both groups will undergo at least two weeks of intensive alfapump® DSR treatment (Phase 1) followed by a maintenance and follow-up period of 16 weeks (Phase 2).

During Phase 1 (this can be an in-patient or an out-patient setting, depending on the local standard of care practices), DSR treatment will be performed in the hospital for each subject with the baseline treatment regimen being 1L 10% dextrose (DSR infusate) with a two-hour dwell time. During this phase 1 period, there will be 2 subsequent treatment intensities: Phase 1a) Active weight reduction and Phase 1b) Weight stabilization. The active weight reduction phase (phase 1a) will start with 3 consecutive daily DSR treatment visits in all subjects. Three consecutive daily visits are required to determine the subsequent DSR treatment frequency and dose. Prior to each planned DSR treatment, the subject is evaluated (weight, vital signs, and physical exam) and blood analysis is performed. Pending this evaluation, the next DSR treatment may be held, reduced (down-titrated) or escalated (up-titration) based on the proposed titration guidelines and at the discretion of the study physician. These titration guidelines differ depending on the (sub)treatment phase(s).

Before the end of the 2 intensive weeks (phase 1), many subjects may become already euvolemic and may transition from the active weight loss phase (1a) to the weight stabilization dosing phase (1b). The transition to phase 1b is based on either the resolution of signs and symptoms of volume overload and physician opinion of euvolemia or on the worsening of creatinine by 0.5mg/dL or 1.5x the subject's baseline serum creatinine. The dosing of DSR will employ identical steps as before, but the titration guidelines are adapted in order to stabilize the weight in phase 1b (rather than continue to lose weight).

After 2 weeks of DSR (end of phase 1), the subject's condition will be evaluated via a diuretic challenge before entering the Phase 2 maintenance phase of the study. Transition to Phase 2 is recommended if all of the following criteria are met