Safety of Repeat Doses of IV Serelaxin in Subjects With Chronic Heart Failure

Inclusion Criteria:

- Body weight of ≤ 160 kg.

- Subjects with compensated CHF (NYHA Class II - III) at time of screening with a prior
documented history of chronic heart failure.

- NT-proBNP >300 pg/ml (according to central measurement) at visit 1.

- Subjects treated with appropriate and guideline-indicated CHF standard of care.

- Ability to comply with all requirements, including ability to receive at least a 48
hour infusion plus follow-up time required for each dosing visit.

Exclusion Criteria:

- Current acute decompensated HF

- Any major solid organ transplant recipient or planned anticipated organ transplant
within 1 year.

- Documented history of untreated ventricular arrhythmia with syncopal episodes,
ventricular tachycardia, or ventricular fibrillation without ICD (implantable
cardioverter defibrillator) with significant hemodynamic consequences within the 3
months prior to screening.

- Presence of hemodynamically significant mitral and /or aortic valve disease, except
mitral regurgitation secondary to left ventricular dilatation: including significant
left ventricular outflow obstruction (e.g., obstructive hypertrophic cardiomyopathy,
severe aortic stenosis)

- Subjects with severe renal impairment defined as pre-randomization eGFR < 30
ml/min/1.73m2 calculated using the sMDRD equation and/or those receiving current or
planned dialysis or ultrafiltration

Other protocol defined inclusion/exclusion criteria may apply.