Patiromer versus placebo to enable spironolactone use in patients with resistant hypertension and chronic kidney disease (AMBER): a phase 2, randomised, double-blind, placebo-controlled trial.

BACKGROUND: Spironolactone is effective at reducing blood pressure in patients with uncontrolled resistant hypertension. However, the use of spironolactone in patients with chronic kidney disease can be restricted by hyperkalaemia. We evaluated use of the potassium binder patiromer to allow more persistent use of spironolactone in patients with chronic kidney disease and resistant hypertension. METHODS: In this phase 2 multicentre, randomised, double-blind, placebo-controlled study, we enrolled participants aged 18 years and older with chronic kidney disease (estimated glomerular filtration rate 25 to ≤45 mL/min per 1·73 m2) and uncontrolled resistant hypertension from 62 outpatient centres in ten countries (Bulgaria, Croatia, Georgia, Hungary, Ukraine, France, Germany, South Africa, the UK, and the USA). Patients meeting all eligibility criteria at the final screening visit were stratified by local serum potassium measurement (4·3 to <4·7 mmol/L vs 4·7 to 5·1 mmol/L) and history of diabetes. Participants were randomly assigned (1:1) with an interactive web response system to receive either placebo or patiromer (8·4 g once daily), in addition to open-label spironolactone (starting at 25 mg once daily) and their baseline blood pressure medications. Participants, the study team that administered treatments and measured blood pressure, and the investigators were masked to assigned treatment groups. Dose titrations were permitted after 1 week (patiromer) and 3 weeks (spironolactone). The primary endpoint was the between-group difference at week 12 in the proportion of patients on spironolactone. Efficacy endpoints and safety were assessed in all randomised patients (intention to treat). The study was registered with Clinicaltrials.gov, NCT03071263. FINDINGS: Between Feb 13, 2017, and Aug 20, 2018, we screened 574 patients. 295 (51%) of 574 patients met all inclusion criteria and were randomly assigned to spironolactone in addition to double-blind treatment with either placebo (n=148) or patiromer (n=147). At week 12, 98 (66%) of 148 patients in the placebo group and 126 (86%) of 147 patients in the patiromer group remained on spironolactone (between-group difference 19·5%, 95% CI 10·0-29·0; p<0·0001). Adverse events were mostly mild or moderate in severity and occurred in 79 (53%) of 148 patients in the placebo group and 82 (56%) of 147 patients in the patiromer group. INTERPRETATION: In patients with resistant hypertension and chronic kidney disease, patiromer enabled more patients to continue treatment with spironolactone with less hyperkalaemia. Persistent spironolactone enablement in this population of patients has clinical relevance for the treatment of resistant hypertension. FUNDING: Relypsa, a Vifor Pharma Group Company.

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.).

Patiromer to Enable Spironolactone Use in the Treatment of Patients with Resistant Hypertension and Chronic Kidney Disease: Rationale and Design of the AMBER Study.

BACKGROUND: While chronic kidney disease (CKD) is common in resistant hypertension (RHTN), prior studies -evaluating mineralocorticoid receptor antagonists excluded patients with reduced kidney function due to risk of hyperkalemia. AMBER (ClinicalTrials.gov identifier NCT03071263) will evaluate if the potassium-binding polymer patiromer used concomitantly with spironolactone in patients with RHTN and CKD prevents hyperkalemia and allows more persistent spironolactone use for hypertension management. METHODS: Randomized, double-blind, placebo-controlled parallel group 12-week study of patiromer and spironolactone versus placebo and spironolactone in patients with uncontrolled RHTN and CKD. RHTN is defined as unattended systolic automated office blood pressure (AOBP) of -135-160 mm Hg during screening despite taking ≥3 antihypertensives, including a diuretic, and an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker -(unless not tolerated or contraindicated). The CKD inclusion criterion is an estimated glomerular filtration rate (eGFR) of 25 to ≤45 mL/min/1.73 m2. Screening serum potassium must be 4.3-5.1 mEq/L. The primary efficacy endpoint is the between-group difference (spironolactone plus patiromer versus spironolactone plus placebo) in the proportion of patients remaining on spironolactone at Week 12. RESULTS: Baseline characteristics have been analyzed as of March 2018 for 146 (of a targeted 290) patients. Mean (SD) baseline age is 69.3 (10.9) years; 52.1% are male, 99.3% White, and 47.3% have diabetes. Mean (SD) baseline serum potassium is 4.68 (0.25) mEq/L, systolic AOBP is 144.3 (6.8) mm Hg, eGFR is 35.7 (7.7) mL/min/1.73 m2. CONCLUSION: AMBER will define the ability of patiromer to facilitate the use of spironolactone, an effective antihypertensive therapy for patients with RHTN and CKD.

Use of QSPR Modeling to Characterize In Vitro Binding of Drugs to a Gut-Restricted Polymer.

PURPOSE: Polymeric drugs, including patiromer (Veltassa®), bind target molecules or ions in the gut, allowing fecal elimination. Non-absorbed insoluble polymers, like patiromer, avoid common systemic drug-drug interactions (DDIs). However, the potential for DDI via polymer binding to orally administered drugs during transit of the gastrointestinal tract remains. Here we elucidate the properties correlated with drug-patiromer binding using quantitative structure-property relationship (QSPR) models. METHODS: We selected 28 drugs to evaluate for binding to patiromer in vitro over a range of pH and ionic conditions intended to mimic the gut environment. Using this in vitro data, we developed QSPR models using step-wise linear regression and analyzed over 100 physiochemical drug descriptors. RESULTS: Four descriptors emerged that account for ~70% of patiromer-drug binding in vitro: the computed surface area of hydrogen bond accepting atoms, ionization potential, electron affinity, and lipophilicity (R 2 = 0.7, Q 2 = 0.6). Further, certain molecular properties are shared by nonbinding, weak, or strong binding compounds. CONCLUSIONS: These findings offer insight into drivers of in vitro binding to patiromer and describe a useful approach for assessing potential drug-binding risk of investigational polymeric drugs.

Treatment with patiromer decreases aldosterone in patients with chronic kidney disease and hyperkalemia on renin-angiotensin system inhibitors.

Elevated serum aldosterone can be vasculotoxic and facilitate cardiorenal damage. Renin-angiotensin system inhibitors reduce serum aldosterone levels and/or block its effects but can cause hyperkalemia. Patiromer, a nonabsorbed potassium binder, decreases serum potassium in patients with chronic kidney disease on renin-angiotensin system inhibitors. Here we examined the effect of patiromer treatment on serum aldosterone, blood pressure, and albuminuria in patients with chronic kidney disease on renin-angiotensin system inhibitors with hyperkalemia (serum potassium 5.1-6.5 mEq/l). We analyzed data from the phase 3 OPAL-HK study (4-week initial treatment phase of 243 patients; 8-week randomized withdrawal phase of 107 patients). In the treatment phase, the (mean ± standard error) serum potassium was decreased concordantly with the serum aldosterone (-1.99 ± 0.51 ng/dl), systolic/diastolic blood pressure (-5.64 ± 1.04 mm Hg/-3.84 ± 0.69 mm Hg), and albumin-to-creatinine ratio (-203.7 ± 54.7 mg/g), all in a statistically significant manner. The change in the plasma renin activity (-0.44 ± 0.63 µg/l/hr) was not significant. In the withdrawal phase, mean aldosterone levels were sustained with patiromer (+0.23 ± 1.07 ng/dl) and significantly increased with placebo (+2.78 ± 1.25 ng/dl). Patients on patiromer had significant reductions in mean systolic/diastolic blood pressure (-6.70 ± 1.59/-2.15 ± 1.06 mm Hg), whereas those on placebo did not (-1.21 ± 1.89 mm Hg/+1.72 ± 1.26 mm Hg). Significant changes in plasma renin activity were found only in the placebo group (-3.90 ± 1.41 µg/l/hr). Thus, patiromer reduced serum potassium and aldosterone levels independent of plasma renin activity in patients with chronic kidney disease and hyperkalemia on renin-angiotensin system inhibitors.

Peginesatide in patients with anemia undergoing hemodialysis.

BACKGROUND: Peginesatide, a synthetic peptide-based erythropoiesis-stimulating agent (ESA), is a potential therapy for anemia in patients with advanced chronic kidney disease. METHODS: We conducted two randomized, controlled, open-label studies (EMERALD 1 and EMERALD 2) involving patients undergoing hemodialysis. Cardiovascular safety was evaluated by analysis of an adjudicated composite safety end point--death from any cause, stroke, myocardial infarction, or serious adverse events of congestive heart failure, unstable angina, or arrhythmia--with the use of pooled data from the two EMERALD studies and two studies involving patients not undergoing dialysis. In the EMERALD studies, 1608 patients received peginesatide once monthly or continued to receive epoetin one to three times a week, with the doses adjusted as necessary to maintain a hemoglobin level between 10.0 and 12.0 g per deciliter for 52 weeks or more. The primary efficacy end point was the mean change from the baseline hemoglobin level to the mean level during the evaluation period; noninferiority was established if the lower limit of the two-sided 95% confidence interval was -1.0 g per deciliter or higher in the comparison of peginesatide with epoetin. The aim of evaluating the composite safety end point in the pooled cohort was to exclude a hazard ratio with peginesatide relative to the comparator ESA of more than 1.3. RESULTS: In an analysis involving 693 patients from EMERALD 1 and 725 from EMERALD 2, peginesatide was noninferior to epoetin in maintaining hemoglobin levels (mean between-group difference, -0.15 g per deciliter; 95% confidence interval [CI], -0.30 to -0.01 in EMERALD 1; and 0.10 g per deciliter; 95% CI, -0.05 to 0.26 in EMERALD 2). The hazard ratio for the composite safety end point was 1.06 (95% CI, 0.89 to 1.26) with peginesatide relative to the comparator ESA in the four pooled studies (2591 patients) and 0.95 (95% CI, 0.77 to 1.17) in the EMERALD studies. The proportions of patients with adverse and serious adverse events were similar in the treatment groups in the EMERALD studies. The cardiovascular safety of peginesatide was similar to that of the comparator ESA in the pooled cohort. CONCLUSIONS: Peginesatide, administered monthly, was as effective as epoetin, administered one to three times per week, in maintaining hemoglobin levels in patients undergoing hemodialysis. (Funded by Affymax and Takeda Pharmaceutical; ClinicalTrials.gov numbers, NCT00597753 [EMERALD 1], NCT00597584 [EMERALD 2], NCT00598273 [PEARL 1], and NCT00598442 [PEARL 2].).

Peginesatide for anemia in patients with chronic kidney disease not receiving dialysis.

BACKGROUND: Peginesatide is a peptide-based erythropoiesis-stimulating agent (ESA) that may have therapeutic potential for anemia in patients with advanced chronic kidney disease. We evaluated the safety and efficacy of peginesatide, as compared with another ESA, darbepoetin, in 983 such patients who were not undergoing dialysis. METHODS: In two randomized, controlled, open-label studies (PEARL 1 and 2), patients received peginesatide once a month, at a starting dose of 0.025 mg or 0.04 mg per kilogram of body weight, or darbepoetin once every 2 weeks, at a starting dose of 0.75 µg per kilogram. Doses of both drugs were adjusted to achieve and maintain hemoglobin levels between 11.0 and 12.0 g per deciliter for 52 weeks or more. The primary efficacy end point was the mean change from the baseline hemoglobin level to the mean level during the evaluation period; noninferiority was established if the lower limit of the two-sided 97.5% confidence interval was -1.0 g per deciliter or higher. Cardiovascular safety was evaluated on the basis of an adjudicated composite end point. RESULTS: In both studies and at both starting doses, peginesatide was noninferior to darbepoetin in increasing and maintaining hemoglobin levels. The mean differences in the hemoglobin level with peginesatide as compared with darbepoetin in PEARL 1 were 0.03 g per deciliter (97.5% confidence interval [CI], -0.19 to 0.26) for the lower starting dose of peginesatide and 0.26 g per deciliter (97.5% CI, 0.04 to 0.48) for the higher starting dose, and in PEARL 2 they were 0.14 g per deciliter (97.5% CI, -0.09 to 0.36) and 0.31 g per deciliter (97.5% CI, 0.08 to 0.54), respectively. The hazard ratio for the cardiovascular safety end point was 1.32 (95% CI, 0.97 to 1.81) for peginesatide relative to darbepoetin, with higher incidences of death, unstable angina, and arrhythmia with peginesatide. CONCLUSIONS: The efficacy of peginesatide (administered monthly) was similar to that of darbepoetin (administered every 2 weeks) in increasing and maintaining hemoglobin levels. However, cardiovascular events and mortality were increased with peginesatide in patients with chronic kidney disease who were not undergoing dialysis. (Funded by Affymax and Takeda Pharmaceutical; ClinicalTrials.gov numbers, NCT00598273 [PEARL 1], NCT00598442 [PEARL 2], NCT00597753 [EMERALD 1], and NCT00597584 [EMERALD 2].).

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.

An open-label, sequential, dose-finding study of peginesatide for the maintenance treatment of anemia in chronic hemodialysis patients.

BACKGROUND: Peginesatide is a peptide-based erythropoiesis-stimulating agent that was designed and engineered to stimulate specifically the erythropoietin receptor dimer that governs erythropoiesis. The primary objective of this phase 2 dose-finding study was to determine the once-monthly peginesatide dosing strategy that would maintain hemoglobin within ±1.0 g/dL of baseline values after conversion from epoetin alfa; the safety of peginesatide was evaluated concurrently. METHODS: Chronic hemodialysis patients on stable regimens of epoetin alfa were sequentially assigned to cohorts that differed on (1) how the peginesatide starting dose was determined (using a single epoetin alfa-to-peginesatide dose conversion ratio or a tiered, weight-based or absolute-dose conversion table) and on (2) whether or not a 1-week erythropoiesis-stimulating agent-free interval was used. Peginesatide doses were titrated to maintain hemoglobin levels within ±1.0 g/dL from baseline. RESULTS: A total of 164 patients were enrolled and received intravenous peginesatide every 4 weeks for up to 6 doses; the duration of the study including follow-up was ≤29 weeks. Overall, the proportion of patients with hemoglobin levels within ±1.0 g/dL of baseline increased over the course of the study from 39% (Weeks 2-13) to 54% (Weeks 18-25). Cohorts that used tiered dose conversion tables trended towards having more stable peginesatide doses than did those cohorts that used a single dose conversion ratio. Moreover, cohorts that used an erythropoiesis-stimulating agent-free interval did not have the substantial initial increase in hemoglobin levels that was seen in those cohorts that did not use such an interval. In this study, the safety profile of peginesatide was consistent with those of marketed erythropoiesis-stimulating agents. CONCLUSIONS: The results of this study were used to guide the dosing regimens used subsequently in phase 3 studies. Once-monthly peginesatide is feasible in hemodialysis patients. TRIAL REGISTRATION: ClinicalTrials.gov registration: NCT00228449.

Patiromer and Spironolactone in Resistant Hypertension and Advanced CKD: Analysis of the Randomized AMBER Trial.

Background: Mineralocorticoid receptor antagonists reduce mortality in patients with heart failure with reduced ejection fraction and have become a standard of care in those with resistant hypertension (rHTN). Yet, their use is limited among patients with CKD, primarily due to hyperkalemia. Methods: AMBER was a multicenter, randomized, double-blind, placebo-controlled, parallel-group study that reported that the use of the potassium-binding drug patiromer allowed a more persistent use of spironolactone in patients with CKD and rHTN. In this report, we compare the safety and efficacy of patiromer in advanced CKD as a prespecified analysis. Results: Of the 295 patients randomized, 66 fell into the eGFR 25 to <30 subgroup. In this subgroup, persistent use of spironolactone was seen in 19 of 34 (56%) in the placebo group and 27 of 32 (84%) in the patiromer group (absolute difference 29%; P<0.02). In the eGFR 30-45 subgroup, persistent use of spironolactone was seen in 79 of 114 (69%) in the placebo group and 99 of 115 (86%) in the patiromer group (absolute difference 17%; P=0.003). There was no significant interaction between eGFR subgroups (P=0.46). Systolic BP reduction with spironolactone in the eGFR 25 to <30 subgroup was 6-7 mm Hg; in the eGFR 30-45 subgroup, it was 12-13 mm Hg. There was no significant interaction between eGFR subgroups on BP reduction (P=0.79). Similar proportions of patients reported adverse events (59% in the eGFR 25 to <30 subgroup; 53% in the eGFR 30-45 subgroup). Conclusions: Patiromer facilitates the use of spironolactone among patients with rHTN, and its efficacy and safety are comparable in those with eGFR 25 to <30 and 30-45 ml/min per 1.73 m2. Clinical Trial registry name and registration number: Clinicaltrials.gov, NCT03071263.

NRF2 activator A-1396076 ameliorates inflammation in autoimmune disease models by inhibiting antigen dependent T cell activation.

Nuclear factor (erythroid-derived 2) like 2 (NRF2) is a nuclear transcription factor activated in response to oxidative stress that induces a gene program that dampens inflammation and can limit cell damage that perpetuates the inflammatory response. We have identified A-1396076, a potent and selective NRF2 activator with demonstrated KEAP1 binding and modulation of cellular NRF2 mediated effects. In vivo administration of A-1396076 inhibits inflammation across several rodent models of autoimmunity when administered at or before the time of antigen challenge while also inducing NRF2 modulated gene transcription in the liver of the animals. It was not effective when administered after the time of antigen challenge or in a T cell independent model of arthritis induced by passive transfer of anti-collagen antibodies. A-1396076 inhibited antigen dependent T cell activation as measured by IFN-γ production in an ex vivo re-stimulation assay and following anti-CD3 challenge of MOG-sensitized mice. A-1396076 reduced costimulatory molecule expression on dendritic cells in the lungs of OVA LPS challenged mice suggesting that the mechanism of T cell inhibition was mediated at least partially by interfering with antigen presentation. These data suggest that NRF2 activation may be an effective strategy to dampen inflammation for treatment of autoimmune disease.

Mechanisms and regulation of IL-22-mediated intestinal epithelial homeostasis and repair.

AIMS: Ulcerative colitis and Crohn's disease, collectively known as inflammatory bowel disease (IBD), are chronic inflammatory disorders of the intestine for which key elements in disease initiation and perpetuation are defects in epithelial barrier integrity. Achieving mucosal healing is essential to ameliorate disease outcome and so new therapies leading to epithelial homeostasis and repair are under investigation. This study was designed to determine the mechanisms by which IL-22 regulates intestinal epithelial cell function. MAIN METHODS: Human intestinal organoids and resections, as well as mice were used to evaluate the effect of IL-22 on stem cell expansion, proliferation and expression of mucus components. IL-22 effect on barrier function was assessed in polarized T-84 cell monolayers. Butyrate co-treatments and organoid co-cultures with immune cells were performed to monitor the impact of microbial-derived metabolites and inflammatory environments on IL-22 responses. KEY FINDINGS: IL-22 led to epithelial stem cell expansion, proliferation, barrier dysfunction and anti-microbial peptide production in human and mouse models evaluated. IL-22 also altered the mucus layer by inducing an increase in membrane mucus but a decrease in secreted mucus and goblet cell content. IL-22 had the same effect on anti-microbial peptides and membrane mucus in both healthy and IBD human samples. In contrast, this IL-22-associated epithelial phenotype was different when treatments were performed in presence of butyrate and organoids co-cultured with immune cells. SIGNIFICANCE: Our data indicate that IL-22 promotes epithelial regeneration, innate defense and membrane mucus production, strongly supporting the potential clinical utility of IL-22 as a mucosal healing therapy in IBD.

Patiromer versus placebo to enable spironolactone use in patients with resistant hypertension and chronic kidney disease (AMBER): results in the pre-specified subgroup with heart failure.

AIMS: The AMBER trial demonstrated that concomitant use of patiromer enabled the more persistent use of spironolactone by reducing the risk of hyperkalaemia in patients with resistant hypertension and advanced chronic kidney disease. We report herein the pre-specified subgroup analysis in patients with heart failure (HF). METHODS AND RESULTS: Participants were randomly assigned (1:1) to receive either placebo or patiromer (8.4 g once daily), in addition to open-label spironolactone (starting at 25 mg once daily) and their baseline blood pressure medications. Dose titrations were permitted after 1 week for patiromer/placebo and after 3 weeks for spironolactone. The primary endpoint was the between-group difference at week 12 in the proportion of patients on spironolactone. Efficacy endpoints and safety were assessed in all randomized patients (intention to treat). A total of 295 patients were enrolled, of whom 132 (45%) had HF. In the HF subgroup, 68.1% of patients receiving placebo remained on spironolactone at week 12, compared with 84.1% of patients receiving patiromer (P = 0.0504). The reason for discontinuation from spironolactone use was hyperkalaemia in the majority of both groups. There was no significant interaction between the subgroups with HF and without HF (P = 0.8085) for the primary endpoint. CONCLUSIONS: Consistent with the overall AMBER trial results, this pre-specified subgroup analysis in patients with HF, resistant hypertension and advanced chronic kidney disease demonstrated that patiromer enabled more persistent use of spironolactone by reducing the risk of hyperkalaemia.

Optimized Culture Conditions for Improved Growth and Functional Differentiation of Mouse and Human Colon Organoids.

Background & Aims: Diligent side-by-side comparisons of how different methodologies affect growth efficiency and quality of intestinal colonoids have not been performed leaving a gap in our current knowledge. Here, we summarize our efforts to optimize culture conditions for improved growth and functional differentiation of mouse and human colon organoids. Methods: Mouse and human colon organoids were grown in four different media. Media-dependent long-term growth was measured by quantifying surviving organoids via imaging and a cell viability readout over five passages. The impact of diverse media on differentiation was assessed by quantifying the number of epithelial cell types using markers for enterocytes, stem cells, Goblet cells, and enteroendocrine cells by qPCR and histology upon removal of growth factors. Results: In contrast to Wnt3a-conditioned media, media supplemented with recombinant Wnt3a alone did not support long-term survival of human or mouse colon organoids. Mechanistically, this observation can be attributed to the fact that recombinant Wnt3a did not support stem cell survival or proliferation as demonstrated by decreased LGR5 and Ki67 expression. When monitoring expression of markers for epithelial cell types, the highest level of organoid differentiation was observed after combined removal of Wnt3a, Noggin, and R-spondin from Wnta3a-conditioned media cultures. Conclusion: Our study defined Wnt3a-containing conditioned media as optimal for growth and survival of human and mouse organoids. Furthermore, we established that the combined removal of Wnt3a, Noggin, and R-spondin results in optimal differentiation. This study provides a step forward in optimizing conditions for intestinal organoid growth to improve standardization and reproducibility of this model platform.

Effect of Patiromer on Hyperkalemia Recurrence in Older Chronic Kidney Disease Patients Taking RAAS Inhibitors.

BACKGROUND: Older people are predisposed to hyperkalemia because of impaired renal function, comorbid conditions, and polypharmacy. Renin-angiotensin-aldosterone system inhibitors (RAASi), which are recommended to treat chronic kidney disease and heart failure augment the risk. Patiromer, a nonabsorbed potassium binder, was shown in the phase 3 OPAL-HK study to decrease serum potassium in patients with chronic kidney disease taking RAASi. We studied the efficacy and safety of patiromer in a prespecified subgroup of patients aged ≥65 years from OPAL-HK. METHODS: Chronic kidney disease patients with mild or moderate-to-severe hyperkalemia received patiromer, initially 8.4 g/d or 16.8 g/d, respectively, for 4 weeks (treatment phase, part A). Eligible patients entered an 8-week randomized withdrawal phase (part B) and continued patiromer or switched to placebo. RESULTS: Mean ± standard error change in serum potassium from baseline to week 4 of part A (primary endpoint) in patients aged ≥65 years was -1.01 ± 0.05 mEq/L (P < .001); 97% achieved serum potassium 3.8-<5.1 mEq/L. The serum potassium increase during the first 4 weeks of part B was greater in patients taking placebo than in those taking patiromer (P < .001). Fewer patients taking patiromer (30%) than placebo (92%) developed recurrent hyperkalemia (serum potassium ≥5.1 mEq/L). Mild-to-moderate constipation occurred in 15% (part A) and 7% (part B) of patients aged ≥65 years. Serum potassium <3.5 mEq/L and serum magnesium <1.4 mg/dL were infrequent (4% each in patients aged ≥65 years in part A). CONCLUSIONS: Patiromer reduced recurrent hyperkalemia and was well tolerated in older chronic kidney disease patients taking RAASi.

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.

AIMS: 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 patiromer's long-term safety and efficacy in HF patients from AMETHYST-DN. METHODS AND RESULTS: Patients with Type 2 diabetes, CKD, and HK [baseline serum potassium >5.0-5.5 mmol/L (mild) or >5.5-<6.0 mmol/L (moderate)], with or without HF (New York Heart Association Class I and II, by investigator judgement), on ACE-I/ARB, were randomized to patiromer 8.4-33.6 g to start, divided twice daily. Overall, 105/304 (35%) patients had HF (75%, Class II). Mean (standard deviation) ejection fraction (EF) was 44.9% (8.2) (n = 81) in patients with HF; 26 had EF ≤40%. In HF patients, mean serum potassium decreased by Day 3 through Week 52. At Week 4, estimated mean (95% confidence interval) change in serum potassium was -0.64 mmol/L (-0.72, -0.55) in mild and -0.97 mmol/L (-1.14, -0.80) in moderate HK (both P < 0.0001). Most HF patients with mild (>88%) and moderate (≥73%) HK had normokalaemia at each visit from Weeks 12 to 52. Three HF patients were withdrawn because of high (n = 1) or low (n = 2) serum potassium. The most common patiromer-related adverse event was hypomagnesaemia (8.6%). CONCLUSIONS: In patients with a clinical diagnosis of HF, diabetes, CKD, and HK on ACE-I/ARB, patiromer was well tolerated and effective for HK treatment over 52 weeks.

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 ±â€Š0.04 mmol/l with any diuretic and -1.04 ±â€Š0.05 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.

Evaluation of the Potential for Drug Interactions With Patiromer in Healthy Volunteers.

INTRODUCTION: Patiromer is a potassium-binding polymer that is not systemically absorbed; however, it may bind coadministered oral drugs in the gastrointestinal tract, potentially reducing their absorption. METHODS: Twelve randomized, open-label, 3-period, 3-sequence crossover studies were conducted in healthy volunteers to evaluate the effect of patiromer (perpetrator drug) on absorption and single-dose pharmacokinetics (PK) of drugs (victims) that might be commonly used with patiromer. Subjects received victim drug alone, victim drug administered together with patiromer 25.2 g (highest approved dose), and victim drug administered 3 hours before patiromer 25.2 g. The primary PK endpoints were area under the curve (AUC), extrapolated to infinity (AUC0-∞), and maximum concentration ( Cmax). Results were reported as 90% confidence intervals (CIs) about the geometric mean AUC0-∞ and Cmax ratios with prespecified equivalence limits of 80% to 125%. RESULTS: Overall, 370 subjects were enrolled, with 365 receiving ≥1 dose of patiromer; 351 subjects completed the studies and all required treatments. When coadministered with patiromer, the 90% CIs for AUC0-∞ remained within 80% to 125% for 9 drugs (amlodipine, cinacalcet, clopidogrel, furosemide, lithium, metoprolol, trimethoprim, verapamil, and warfarin). The AUC0-∞ point estimate ratios for levothyroxine and metformin with patiromer coadministration were ≥80%, with the lower bounds of the 90% CIs at 76.8% and 72.8%, respectively. For ciprofloxacin, the point estimate for AUC0-∞ was 71.5% (90% CI: 65.3-78.4). For 8 of 12 drugs, point estimates for Cmax were ≥80% with patiromer coadministration; for ciprofloxacin, clopidogrel, metformin, and metoprolol, the point estimates were <80%. When patiromer was administered 3 hours after each victim drug, the 90% CIs for AUC0-∞ and Cmax for each drug were within the prespecified 80% to 125% limits. CONCLUSION: For 9 of the 12 drugs coadministered with patiromer, there were no clinically significant drug-drug interactions. For 3 drugs (ciprofloxacin, levothyroxine, and metformin), a 3-hour separation between patiromer and their administration resulted in no clinically significant drug-drug interactions.

Reassessing Phase II Heart Failure Clinical Trials: Consensus Recommendations.

The increasing burden and the continued suboptimal outcomes for patients with heart failure underlines the importance of continued research to develop novel therapeutics for this disorder. This can only be accomplished with successful translation of basic science discoveries into direct human application through effective clinical trial design and execution that results in a substantially improved clinical course and outcomes. In this respect, phase II clinical trials play a pivotal role in determining which of the multitude of potential basic science discoveries should move to the large and expansive registration trials in humans. A critical examination of the phase II trials in heart failure reveals multiple shortcomings in their concept, design, execution, and interpretation. To further a dialogue on the challenges and potential for improvement and the role of phase II trials in patients with heart failure, the Food and Drug Administration facilitated a meeting on October 17, 2016, represented by clinicians, researchers, industry members, and regulators. This document summarizes the discussion from this meeting and provides key recommendations for future directions.

Elevated cerebrospinal fluid pressure in patients with Alzheimer's disease.

BACKGROUND: Abnormalities in cerebrospinal fluid (CSF) production and turnover, seen in normal pressure hydrocephalus (NPH) and in Alzheimer's disease (AD), may be an important cause of amyloid retention in the brain and may relate the two diseases. There is a high incidence of AD pathology in patients being shunted for NPH, the AD-NPH syndrome. We now report elevated CSF pressure (CSFP), consistent with very early hydrocephalus, in a subset of AD patients enrolled in a clinical trial of chronic low-flow CSF drainage. Our objective was to determine the frequency of elevated CSFP in subjects meeting National Institutes of Neurological and Communicative Diseases and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria for AD, excluding those with signs of concomitant NPH. METHODS: AD subjects by NINCDS-ADRDA criteria (n = 222), were screened by history, neurological examination, and radiographic imaging to exclude those with clinical or radiographic signs of NPH. As part of this exclusion process, opening CSFP was measured supine under general anesthesia during device implantation surgery at a controlled pCO2 of 40 Torr (40 mmHg). RESULTS: Of the 222 AD subjects 181 had pressure measurements recorded. Seven subjects (3.9%) enrolled in the study had CSFP of 220 mmH20 or greater, mean 249 +/- 20 mmH20 which was significantly higher than 103 +/- 47 mmH2O for the AD-only group. AD-NPH patients were significantly younger and significantly less demented on the Mattis Dementia Rating Scale (MDRS). CONCLUSION: Of the AD subjects who were carefully screened to exclude those with clinical NPH, 4% had elevated CSFP. These subjects were presumed to have the AD-NPH syndrome and were withdrawn from the remainder of the study.