The study schedule for each patient consists of a screening period followed by an infusion day with an optional overnight in-clinic stay, and a follow up call 48h post infusion.~Screening Phase:~At screening, patient eligibility will be determined according to inclusion and exclusion criteria, with evaluation of patient's vital signs, ECG and laboratory parameters. The duration of screening can be as short as one day but should not exceed 7 days. Patients who show potassium level > 6 mmol/L at screening should have their potassium level corrected and can be re-screened afterwards.~Treatment Phase:~Eligible patients will be admitted to the in-clinic unit to be dosed with arginine/lysine solution for infusion of 1,000 mL, which is administered intravenously over a period of 4 hours. Before the infusion (at 0 h time point), a set of baseline tests will be performed. During and after the infusion, patient condition will be monitored for evaluation of any adverse events. Only patients with a potassium level of ≤ 6 mmol/L at screening will be allowed to be dosed. Potassium testing on the infusion day will be performed at 0h (before the infusion), and at 2h, 4h, 6h, 8h, 12h, and 24h after the start of infusion. Vital signs and ECGs will be taken as specified in the assessment schedule. All patients will be monitored closely for signs and symptoms of hyperkalemia, e.g. dyspnoea, weakness, numbness, chest pain and cardiac manifestations (conduction abnormalities and cardiac arrhythmias). Other common adverse reactions during arginine/lysine solution administration are nausea and vomiting. Before the start of arginine/lysine solution infusion, an intravenous bolus of an anti-emetic should be given. The choice of anti-emetic drugs is at the discretion of the physician.~Follow-up Phase:~All patients will be called for a safety follow-up in 48 hours after dosing. Patients should not be scheduled to receive repeat dosing with arginine/lysine solution as concomitant medication with Lutathera® within 7 days of the arginine/lysine solution infusion in the study.
The purpose of the study is to evaluate the effect of arginine/lysine solution administration on serum potassium levels. A systematic assessment of serum potassium levels will be performed during infusion and up to 24 hours post start of infusion compared to baseline.