Lance Berman

Patiromer in Patients with Kidney Disease and Hyperkalemia Receiving RAAS Inhibitors

BACKGROUND Hyperkalemia increases the risk of death and limits the use of inhibitors of the renin-angiotensin-aldosterone system (RAAS) in high-risk patients. We assessed the safety and efficacy of patiromer, a nonabsorbed potassium binder, in a multicenter, prospective trial. METHODS Patients with chronic kidney disease who were receiving RAAS inhibitors and who had serum potassium levels of 5.1 to less than 6.5 mmol per liter received patiromer (at an initial dose of 4.2 g or 8.4 g twice a day) for 4 weeks (initial treatment phase); the primary efficacy end point was the mean change in the serum potassium level from baseline to week 4. Eligible patients at the end of week 4 (those with a baseline potassium level of 5.5 to <6.5 mmol per liter in whom the level decreased to 3.8 to <5.1 mmol per liter) entered an 8-week randomized withdrawal phase in which they were randomly assigned to continue patiromer or switch to placebo; the primary efficacy end point was the between-group difference in the median change in the serum potassium level over the first 4 weeks of that phase. RESULTS In the initial treatment phase, among 237 patients receiving patiromer who had at least one potassium measurement at a scheduled visit after day 3, the mean (±SE) change in the serum potassium level was -1.01±0.03 mmol per liter (P<0.001). At week 4, 76% (95% confidence interval, 70 to 81) of the patients had reached the target potassium level (3.8 to <5.1 mmol per liter). Subsequently, 107 patients were randomly assigned to patiromer (55 patients) or placebo (52 patients) for the randomized withdrawal phase. The median increase in the potassium level from baseline of that phase was greater with placebo than with patiromer (P<0.001); a recurrence of hyperkalemia (potassium level, ≥5.5 mmol per liter) occurred in 60% of the patients in the placebo group as compared with 15% in the patiromer group through week 8 (P<0.001). Mild-to-moderate constipation was the most common adverse event (in 11% of the patients); hypokalemia occurred in 3%. CONCLUSIONS In patients with chronic kidney disease who were receiving RAAS inhibitors and who had hyperkalemia, patiromer treatment was associated with a decrease in serum potassium levels and, as compared with placebo, a reduction in the recurrence of hyperkalemia. (Funded by Relypsa; OPAL-HK ClinicalTrials.gov number, NCT01810939.).

Effect of Patiromer on Serum Potassium Level in Patients With Hyperkalemia and Diabetic Kidney Disease: The AMETHYST-DN Randomized Clinical Trial

IMPORTANCE Hyperkalemia is a potentially life-threatening condition predominantly seen in patients treated with renin-angiotensin-aldosterone system (RAAS) inhibitors with stage 3 or greater chronic kidney disease (CKD) who may also have diabetes, heart failure, or both. OBJECTIVES To select starting doses for a phase 3 study and to evaluate the long-term safety and efficacy of a potassium-binding polymer, patiromer, in outpatients with hyperkalemia. DESIGN, SETTING, AND PARTICIPANTS Phase 2, multicenter, open-label, dose-ranging, randomized clinical trial (AMETHYST-DN), conducted at 48 sites in Europe from June 2011 to June 2013 evaluating patiromer in 306 outpatients with type 2 diabetes (estimated glomerular filtration rate, 15 to <60 mL/min/1.73 m2 and serum potassium level >5.0 mEq/L). All patients received RAAS inhibitors prior to and during study treatment. INTERVENTIONS Patients were stratified by baseline serum potassium level into mild or moderate hyperkalemia groups and received 1 of 3 randomized starting doses of patiromer (4.2 g [n = 74], 8.4 g [n = 74], or 12.6 g [n = 74] twice daily [mild hyperkalemia] or 8.4 g [n = 26], 12.6 g [n = 28], or 16.8 g [n = 30] twice daily [moderate hyperkalemia]). Patiromer was titrated to achieve and maintain serum potassium level 5.0 mEq/L or lower. MAIN OUTCOMES AND MEASURES The primary efficacy end point was mean change in serum potassium level from baseline to week 4 or prior to initiation of dose titration. The primary safety end point was adverse events through 52 weeks. Secondary efficacy end points included mean change in serum potassium level through 52 weeks. RESULTS A total of 306 patients were randomized. The least squares mean reduction from baseline in serum potassium level at week 4 or time of first dose titration in patients with mild hyperkalemia was 0.35 (95% CI, 0.22-0.48) mEq/L for the 4.2 g twice daily starting-dose group, 0.51 (95% CI, 0.38-0.64) mEq/L for the 8.4 g twice daily starting-dose group, and 0.55 (95% CI, 0.42-0.68) mEq/L for the 12.6 g twice daily starting-dose group. In those with moderate hyperkalemia, the reduction was 0.87 (95% CI, 0.60-1.14) mEq/L for the 8.4 g twice daily starting-dose group, 0.97 (95% CI, 0.70-1.23) mEq/L for the 12.6 g twice daily starting-dose group, and 0.92 (95% CI, 0.67-1.17) mEq/L for the 16.8 g twice daily starting-dose group (P < .001 for all changes vs baseline by hyperkalemia starting-dose groups within strata). From week 4 through week 52, statistically significant mean decreases in serum potassium levels were observed at each monthly point in patients with mild and moderate hyperkalemia. Over the 52 weeks, hypomagnesemia (7.2%) was the most common treatment-related adverse event, mild to moderate constipation (6.3%) was the most common gastrointestinal adverse event, and hypokalemia (<3.5 mEq/L) occurred in 5.6% of patients. CONCLUSIONS AND RELEVANCE Among patients with hyperkalemia and diabetic kidney disease, patiromer starting doses of 4.2 to 16.8 g twice daily resulted in statistically significant decreases in serum potassium level after 4 weeks of treatment, lasting through 52 weeks. TRIAL REGISTRATION clinicaltrials.gov Identifier:NCT01371747.

Effect of patiromer on reducing serum potassium and preventing recurrent hyperkalaemia in patients with heart failure and chronic kidney disease on RAAS inhibitors

We evaluated the effects of patiromer, a potassium (K+)‐binding polymer, in a pre‐specified analysis of hyperkalaemic patients with heart failure (HF) in the OPAL‐HK trial.

Patiromer induces rapid and sustained potassium lowering in patients with chronic kidney disease and hyperkalemia

Patients with chronic kidney disease (CKD) have a high risk of hyperkalemia, which increases mortality and can lead to renin–angiotensin–aldosterone system inhibitor (RAASi) dose reduction or discontinuation. Patiromer, a nonabsorbed potassium binder, has been shown to normalize serum potassium in patients with CKD and hyperkalemia on RAASi. Here, patiromers onset of action was determined in patients with CKD and hyperkalemia taking at least one RAASi. After a 3-day potassium- and sodium-restricted diet in an inpatient research unit, those with sustained hyperkalemia (serum potassium 5.5 – under 6.5 mEq/l) received patiromer 8.4 g/dose with morning and evening meals for a total of four doses. Serum potassium was assessed at baseline (0 h), 4 h postdose, then every 2–4 h to 48 h, at 58 h, and during outpatient follow-up. Mean baseline serum potassium was 5.93 mEq/l and was significantly reduced by 7 h after the first dose and at all subsequent times through 48 h. Significantly, mean serum potassium under 5.5 mEq/l was achieved within 20 h. At 48 h (14 h after last dose), there was a significant mean reduction of 0.75 mEq/l. Serum potassium did not increase before the next dose or for 24 h after the last dose. Patiromer was well tolerated, without serious adverse events and no withdrawals. The most common gastrointestinal adverse event was mild constipation in two patients. No hypokalemia (serum potassium under 3.5 mEq/l) was observed. Thus, patiromer induced an early and sustained reduction in serum potassium and was well tolerated in patients with CKD and sustained hyperkalemia on RAASis.

Effectiveness of patiromer in the treatment of hyperkalemia in chronic kidney disease patients with hypertension on diuretics.

Objective: Recurrent hyperkalemia frequently limits use of renin–angiotensin–aldosterone system inhibitors (RAASi) in chronic kidney disease (CKD) patients with hypertension, diabetes, and/or heart failure. Patiromer is a sodium-free, nonabsorbed potassium (K+)-binding polymer approved by the US Food and Drug Administration for the treatment of hyperkalemia. This post-hoc analysis of OPAL-HK examined the effectiveness and safety of patiromer in reducing serum K+ in hyperkalemic CKD patients on RAASi, with hypertension, receiving diuretic therapy versus those not on diuretics. Methods: Depending on the degree of hyperkalemia at baseline, CKD patients with serum K+ from 5.1 to less than 6.5 mmol/l on RAASi (n = 243) were assigned to a patiromer of total dose 8.4 or 16.8 g, divided twice daily. Changes in serum K+, and tolerability and safety were assessed over 4 weeks in patients on and not on diuretics. Results: At baseline, 132 patients used diuretics and 111 were not on diuretics, mean age was 64.3 and 64.0 years, respectively, and 63 and 51% were men. Similar reductions in serum K+ were seen over 4 weeks in both subgroups. At week 4, serum K+ fell by −0.95 ± 0.04 mmol/l with any diuretic and −1.04 ± 0.05 mmol/l with no diuretic. Patiromer was well tolerated, with mild-to-moderate constipation reported as the most common adverse event (7.6 and 14.4% of patients on any diuretic or no diuretic, respectively). Hypokalemia (s-K+ <3.5 mEq/l) was reported in 2.3% of patients on any diuretic and in 3.7% not on diuretics. Conclusion: The serum K+-lowering efficacy and safety profile of patiromer in hyperkalemia patients with CKD was not compromised by diuretic therapy.

New approaches to hyperkalemia in patients with indications for renin angiotensin aldosterone inhibitors: Considerations for trial design and regulatory approval

Hyperkalemia is a common clinical problem, especially in patients with chronic kidney disease, diabetes mellitus, or heart failure. Treatment with renin angiotensin aldosterone system inhibitors exacerbates the risk of hyperkalemia in these patients. Concern about hyperkalemia can result in the failure to initiate, suboptimal dosing, or discontinuation of renin angiotensin aldosterone system inhibitor therapy in patients; effective treatments for hyperkalemia might mitigate such undertreatment. New treatments for hyperkalemia in development may offer better efficacy, tolerability and safety profiles than do existing approved treatments. These compounds might enable more eligible patients to receive renin angiotensin aldosterone system inhibitor therapy or to receive renin angiotensin aldosterone system inhibitors at target doses. The evidence needed to support a treatment claim (reduction in serum potassium) differs from that needed to support a prevention claim (preventing hyperkalemia to allow renin angiotensin aldosterone system inhibitor treatment). Thus, several issues related to clinical trial design and drug development need to be considered. This paper summarizes and expands upon a discussion at the Global Cardiovascular Clinical Trialists 2014 Forum and examines methodologic considerations for trials of new potassium binders for the prevention and management of hyperkalemia in patients with renin angiotensin aldosterone system inhibitor indications.

Are high-risk hypertensive patients being prescribed concomitant statin therapy?: a retrospective cohort study.

BackgroundTreatment guidelines for dyslipidemic patients have focused on lipid levels and risk assessments. However, normolipidemic patients who have multiple risk factors for cardiovascular disease may also benefit from HMG-CoA reductase inhibitor (statin) therapy.ObjectiveWe examined the frequency of statin prescriptions in patients initiating antihypertensive drug treatment in a US managed-care setting.Study Design and PatientsThis retrospective cohort study used the PharMetrics’ Patient-Centric Database to identify enrollees initiating antihypertensive treatment (September 2001 to February 2004). Patients newly treated with antihypertensives and with various levels of coronary heart disease (CHD) risk (including dyslipidemia, established CHD, type 2 diabetes mellitus, and no CHD but three or more cardiovascular risk factors) were included in the study.Main Outcome MeasureCumulative probability of receiving statin therapy each month after antihypertensive initiation. Multivariable logistic regression was used to identify factors associated with receiving concomitant statin therapy.ResultsOf 142 389 patients (mean age 51.7 years) newly treated with antihypertensives, 32 056 (22.5%) were prescribed statins within 1 year. The cumulative probability of being prescribed a statin increased with increasing numbers of CHD risk factors, irrespective of dyslipidemia status. After adjusting for age, sex, and other potential predictors, patients were more likely to receive statin therapy if they had a history of dyslipidemia (adjusted odds ratio [AOR] 5.68 [95% CI 5.52, 5.85]), established CHD/congestive heart failure (AOR 3.39 [95% CI 3.16, 3.63]), or three or more additional cardiovascular risk factors but no CHD (AOR 3.01 [95% CI 2.74, 3.30]).ConclusionAmong patients beginning antihypertensive treatment, those with established CHD or CHD risk factors were more likely to receive statins, but a substantial fraction did not fill any statin prescription. The increased use of statin therapy could benefit many hypertensive patients with additional CHD risk factors.

Evaluation of an individualized dose titration regimen of patiromer to prevent hyperkalaemia in patients with heart failure and chronic kidney disease

AIMS Hyperkalaemia risk precludes optimal renin-angiotensin-aldosterone system inhibitor use in patients with heart failure (HF), particularly those with chronic kidney disease (CKD). Patiromer is a sodium-free, non-absorbed potassium (K)-binding polymer approved for the treatment of hyperkalaemia. In PEARL-HF, patiromer 25.2 g (fixed dose) prevented hyperkalaemia in HF patients with or without CKD initiating spironolactone. The current study evaluated the effectiveness of a lower starting dose of patiromer (16.4 g/day) followed by individualized titration in preventing hyperkalaemia and hypokalaemia when initiating spironolactone. METHODS AND RESULTS This open-label 8-week study enrolled 63 patients with CKD, serum K4.3-5.1 mEq/L, and chronic HF, who, based on investigator opinion, should receive spironolactone. Eligible patients started spironolactone 25 mg/day and patiromer 16.8 g/day (divided into two doses), with patiromer titrated to maintain serum K4.0-5.1 mEq/L. Mean (standard deviation) serum Kwas 4.78 (0.51) mEq/L at baseline; weekly values were 4.48-4.70 mEq/L during treatment. Serum Kof 3.5-5.5 mEq/L at the end of study treatment (primary endpoint) was achieved by 57 (90.5%) patients; 53 (84.1%) had serum K4.0-5.1 mEq/L. One patient (1.6%) developed hypokalaemia, and two patients (3.2%) developed hypomagnesaemia. Spironolactone was increased to 50 mg/day in all patients; 43 (68%) patients required one or more patiromer dose titration. Adverse events (AEs) occurred in 36 (57.1%) patients, with a low rate of discontinuations [four (6.3%) patients]. The most common AE was mild to moderate abdominal discomfort [four (6.3%) patients]. CONCLUSIONS In this open-label study, patiromer 16.8 g/day followed by individualized titration maintained serum Kwithin the target range in the majority of patients with HF and CKD, all of whom were uptitrated to spironolactone 50 mg/day, patiromer was well tolerated, with a low incidence of hyperkalaemia, hypokalaemia, and hypomagnesaemia.

Evaluation of an individualized dose titration regimen of patiromer to prevent hyperkalaemia in patients with heart failure and chronic kidney disease: Patiromer: controlling serum K+ in patients with HF and CKD

Hyperkalaemia risk precludes optimal renin–angiotensin–aldosterone system inhibitor use in patients with heart failure (HF), particularly those with chronic kidney disease (CKD). Patiromer is a sodium‐free, non‐absorbed potassium (K+)‐binding polymer approved for the treatment of hyperkalaemia. In PEARL‐HF, patiromer 25.2 g (fixed dose) prevented hyperkalaemia in HF patients with or without CKD initiating spironolactone. The current study evaluated the effectiveness of a lower starting dose of patiromer (16.4 g/day) followed by individualized titration in preventing hyperkalaemia and hypokalaemia when initiating spironolactone.

Long-term effects of patiromer for hyperkalaemia treatment in patients with mild heart failure and diabetic nephropathy on angiotensin-converting enzymes/angiotensin receptor blockers: results from AMETHYST-DN: Patiromer for heart failure patients

Chronic kidney disease (CKD) in heart failure (HF) increases the risk of hyperkalaemia (HK), limiting angiotensin‐converting enzyme inhibitor (ACE‐I) or angiotensin receptor blocker (ARB) use. Patiromer is a sodium‐free, non‐absorbed potassium binder approved for HK treatment. We retrospectively evaluated patiromers long‐term safety and efficacy in HF patients from AMETHYST‐DN.