Trial Outcomes & Findings for ZS Ph2/3 Dose-response Study in Japan (NCT NCT03127644)

Patients not receiving any therapy for hyperkalaemia and with 2 consecutive potassium values of ≥ 5.1 millimoles/litre (mmol/L) and ≤ 6.5 mmol/L (as measured by i-STAT, a portable blood analyser) were enrolled into 24 study sites in Japan from June 2017 to February 2018.

103 patients were randomised 1:1:1 to receive double-blind treatment of sodium zirconium cyclosilicate (ZS) 5 grams (g) three times daily (TID), ZS 10 g TID, or placebo TID for 48 hours.

ZS Ph2/3 Dose-response Study in Japan

Blood samples for determination of potassium were collected pre-dose, and at 1, 2, and 4 hours post Dose 1 on Day 1. An additional sample was collected at 90 minutes post Dose 2 on Day 1 if i-STAT potassium values at the 4-hour post Dose 1 time point was ≥ 6.1 or \<4.0 mmol/L. On Day 2 samples were analysed pre-dose, and 1 and 4 hours post Dose 1. S-K levels were analysed at the Central Laboratory. Natural logarithm of S-K from 0 to 48 hours post dose are modelled by the random coefficients model including fixed effects of intercept, time, time x treatment and patient-level random effects for time and intercept. Exponential rate of change refers to the slope estimate from the random coefficients model.

The percentage of patients who achieved normokalaemia (normalisation of S-K values to between 3.5 mmol/L and 5.0 mmol/L, inclusive) at 48 hours after start of dosing was determined. Patients with missing S-K values at 48 hours were regarded as not normokalaemic.

Blood samples for determination of potassium were collected pre-dose, and at 1, 2, and 4 hours post Dose 1 on Day 1. An additional sample was collected at 90 minutes post Dose 2 on Day 1 if i-STAT potassium values at the 4-hour post Dose 1 time point was ≥ 6.1 or \<4.0 mmol/L. On Day 2 samples were analysed pre-dose, and 1 and 4 hours post Dose 1. S-K levels were analysed at the Central Laboratory. Natural logarithm of S-K from 0 to 24 hours post dose are modelled by the random coefficients model including fixed effects of intercept, time, time x treatment and patient-level random effects for time and intercept. Exponential rate of change refers to the slope estimate from the random coefficients model.

The percentage of patients who achieved normokalaemia (normalisation of S-K values to between 3.5 mmol/L and 5.0 mmol/L, inclusive) at 24 hours after start of dosing was determined. Patients with missing S-K values at 24 hours were regarded as not normokalaemic.

The percentage of patients who achieved normokalaemia (normalisation of S-K values to between 3.5 mmol/L and 5.0 mmol/L, inclusive) at each each scheduled potassium assessment time point after the start of dosing was determined. Patients with missing S-K values were regarded as not normokalaemic.

Blood samples for determination of potassium were collected pre-dose, and at 1, 2, and 4 hours post Dose 1 on Day 1. An additional sample was collected at 90 minutes post Dose 2 on Day 1 if i-STAT potassium values at the 4-hour post Dose 1 time point was ≥ 6.1 or \<4.0 mmol/L. On Day 2 samples were analysed pre-dose, and 1 and 4 hours post Dose 1. S-K levels were analysed locally using i-STAT devices, and at the Central Laboratory. S-K values measured at each time point and end of study visit were recorded and mean change from baseline is displayed.

Blood samples for determination of potassium were collected pre-dose, and at 1, 2, and 4 hours post Dose 1 on Day 1. An additional sample was collected at 90 minutes post Dose 2 on Day 1 if i-STAT potassium values at the 4-hour post Dose 1 time point was ≥ 6.1 or \<4.0 mmol/L. On Day 2 samples were analysed pre-dose, and 1 and 4 hours post Dose 1. S-K levels were analysed locally using i-STAT devices, and at the Central Laboratory. S-K values measured at each time point and end of study visit were recorded and mean percent change from baseline is displayed.

The distribution of time to normalisation of S-K values (defined as S-K values between 3.5 mmol/L and 5.0 mmol/L, inclusive) was measured. A patient who reached at least one S-K within normal range was counted as an event regardless of S-K value after that time point. Patients who did not achieve normokalaemia within 48 hours were censored.

The median time (hours) for S-K values to decrease by 0.5 mmol/L was measured.