MO470PATIROMER PHARMACOUTILIZATION IN REAL-WORLD GERMAN CKD PATIENTS WITH MODERATELY TO SEVERELY REDUCED EGFR

Background and Aims

Hyperkalemia (HK) (serum K>5.0 mEq/L) is a chronic condition in patients with chronic kidney disease (CKD) associated with high morbidity and mortality, and it is a frequent reasons for renin angiotensin aldosterone inhibition (RAASi) discontinuation. Patiromer is a non-absorbed, sodium-free, K+ binder that has been shown to reduce serum K+ in patients with HK, and thereby enable RAASi therapy, which is supported by randomized trial evidence. The description of patiromer utilization in patients with moderate to advanced CKD in the real-world setting in Europe is lacking. The objective of this analysis was to describe predictors of patiromer initiation and time to discontinuation among CKD patients using contemporary (April 2018-October 2020) data from German participants in CKD Outcomes and Practice Patterns Study (CKDopps).

Method

We identified 136 patiromer users (116 with matching K measurement) during the observation period. Patients with eGFR <60ml/min/1.73m2 and a serum potassium ≥4mEq/L who never initiated patiromer during the follow up were used as a comparison. We used the most recent lab and drug use information available within the 6-month period prior to baseline, which was defined as either first use of patiromer, April 1, 2018, or entry into the PDOPPS study. The median time between the most recent K+ measurement and baseline was 45 days for non-patiromer users and 4 days for patiromer users. Logistic regression models were used to test associations between patient factors and whether the patient was in the patiromer initiation group or the comparison group. Time on patiromer was estimated using a Kaplan-Meier curve, censoring for death, dialysis, transplantation, or loss of follow-up.

Results

Patiromer was prescribed to ≥2 patients in 11 clinics, one patient in 19 clinics, and zero patients in 57 clinics. Patients prescribed patiromer had lower eGFR (23.2 [15.8, 28.6] vs 36.9 [27.7, 46.3]ml/min) and higher serum K levels (5.6 [5.4, 6.1] vs 4.6 [4.3, 5.0]ml/min). There were no major differences according to patiromer use in other demographic, clinical, and biochemical characteristics. Despite the differences in serum K, use of RAAS inhibitors was similar in patiromer users (83%) versus non-users (80%). Thirty three percent of patiromer users were prescribed polystyrene sulfonate (SPS) before patiromer initiation. In a multiple logistic regression models (including serum K, CKD stage, gender, age, prescription of RAASi, diabetes, coronary artery disease, heart failure), patiromer use was strongly associated more advanced CKD stage (independently of high serum K), with odds ratios of initiation >3 for CKD stage 4 or 5 versus CKD stage 3. Among new users, 90% of patients had active prescription at 30 days and about one-half had active prescription at one year (Figure).

Conclusion

The main predictors of Patiromer initiation were advanced CKD stage and hyperkalemia. Treatment decisions did not appear to be based on other patient or clinical characteristics. Patiromer was often prescribed to patients already receiving alternative HK treatment (SPS), suggesting use for chronic hyperkalemia rather than response to acute event. Further analysis with a larger population and measurements of K+ before and after patiromer initiation may improve the understanding of its pharmacoutilization in moderate to advanced CKD.

FC 024SAFETY AND EFFICACY OF PATIROMER FOR HYPERKALAEMIA IN PATIENTS WITH STAGE 1-3A OR STAGE 3B-5 CHRONIC KIDNEY DISEASE: POOLED ANALYSIS OF THE AMETHYST-DN, OPAL-HK AND TOURMALINE TRIALS

Background and Aims

In patients with CKD and/or heart failure (HF), hyperkalaemia (HK) is a major problem which limits the use of guideline-recommended renin–angiotensin–aldosterone inhibitors (RAASi). Dose reduction or cessation of RAASi therapy results in increased morbidity and mortality. Improved strategies to mitigate HK are required to improve clinical outcomes. Patiromer is a non-absorbed, sodium-free, K+ binder that has been shown to reduce serum K+ in patients with HK, and thereby enable RAASi therapy. We conducted a post-hoc analysis to evaluate patiromer’s efficacy and safety in two HK subgroups by CKD severity: patients with Stage 3b-5 CKD and those with Stage 1-3a.

Method

Data were combined from the initial 4 weeks of treatment of three studies (AMETHYST-DN, OPAL-HK and TOURMALINE). Eligible patients had a diagnosis of CKD and HK (local laboratory serum K+ >5.0 mmol/L) and received patiromer 8.4 to 33.6 g/day to start. Subgroups were identified by baseline estimated glomerular filtration rate (eGFR): stage 3b–5 (severe/end-stage CKD) and stage 1–3a (mild/moderate CKD). The efficacy population comprised randomised patients who received ≥1 dose patiromer and had ≥1 post-baseline serum K+ assessment available. Efficacy was evaluated as the mean (± standard error [SE]) change in central laboratory serum K+ from baseline to Week 4 (primary endpoint in AMETHYST-DN and OPAL-HK; secondary endpoint in TOURMALINE). Safety outcomes, including incidence and severity of adverse events (AEs) with onset during the 4-week evaluation period, were assessed in all randomised patients who received ≥1 dose of patiromer.

Results

Of the 626 patients evaluable for efficacy, 61.8% were male, mean±standard deviation (SD) age was 65.6±9.8 years and 417 (66.6%) had stage 3b-5 CKD, including 27 (6.5%) patients with stage 5 CKD. Approximately 34% of patients in both subgroups had HF, predominantly NYHA Class II. Baseline characteristics were similar between the stage 3b–5 and stage 1–3a CKD subgroups, except for serum K+ (mean±SD: 5.47±0.41 and 5.32±0.42 mmol/L, respectively), eGFR (mean±SD: 27.9±9.0 and 58.0±12.8 mL/min/1.73m2), and spot urine albumin:creatinine ratio (mean±SD: 1263±1921 and 606±1241 mg/g). In total, 91.8% of patients with stage 3b-5 CKD and 97.6% of patients with stage 1-3a CKD were receiving RAASi therapy at baseline. Patiromer induced early reductions in serum K+, with mean levels decreasing from baseline to below 5.0 mmol/L by Day 3 or Week 1 in the stage 3b–5 and stage 1–3a CKD subgroups, respectively (Figure). The mean change in serum K+ from baseline to Week 4 was −0.84±0.03 and −0.60±0.04 mmol/L in patients with stage 3b–5 and stage 1–3a CKD, respectively. Overall, 96.4% and 99.0% of patients with stage 3b–5 and stage 1–3a CKD, respectively, achieved normokalaemia (≥1 serum K+ value 3.8–5.0 mEq/L) during the 4 weeks of treatment. In total, 421 patients with CKD stage 3b–5 and 211 with CKD stage 1–3a were evaluable for safety. AEs were reported by 168 (39.9%) and 58 (27.5%) patients with stage 3b–5 and stage 1–3a CKD, respectively. The most frequent AEs in stage 3b–5 and stage 1–3a CKD patients, respectively, were constipation (7.8% and 2.8%) and diarrhoea (4.0% and 1.9%); all cases were mild or moderate in severity. AEs leading to patiromer discontinuation occurred in 5.7% and 2.4% of stage 3b–5 CKD and stage 1–3a CKD patients, respectively.

Conclusion

This pooled analysis of three clinical trials clearly demonstrated the efficacy of patiromer to effectively treat HK in patients with CKD, regardless of early or advanced disease, the majority of whom were receiving guideline-recommended RAASi blockade. Patiromer was well tolerated with mild gastrointestinal events in a small percentage of patients, and very few discontinuations. Patiromer is an appropriate choice for the control of HK in patients with CKD stage 3b–5.