Maria Leonsson-Zachrisson

Dose‐ranging study with the glucokinase activator AZD1656 in patients with type 2 diabetes mellitus on metformin

To investigate the effect of glucokinase activator AZD1656 on glycated haemoglobin (HbA1c) as an add‐on to metformin in patients with type 2 diabetes.

Effect of Tenapanor on Serum Phosphate in Patients Receiving Hemodialysis

Hyperphosphatemia is common among patients with CKD stage 5D and is associated with morbidity and mortality. Current guidelines recommend lowering serum phosphate concentrations toward normal. Tenapanor is a minimally absorbed small molecule inhibitor of the sodium/hydrogen exchanger isoform 3 that functions in the gut to reduce sodium and phosphate absorption. This randomized, double-blind, placebo-controlled trial assessed the effects of tenapanor on serum phosphate concentration in patients with hyperphosphatemia receiving hemodialysis. After a 1- to 3-week washout of phosphate binders, we randomly assigned 162 eligible patients (serum phosphate =6.0 to <10.0 mg/dl and a 1.5-mg/dl increase from before washout) to one of six tenapanor regimens (3 or 30 mg once daily or 1, 3, 10, or 30 mg twice daily) or placebo for 4 weeks. The primary efficacy end point was change in serum phosphate concentration from baseline (randomization) to end of treatment. In total, 115 patients (71%) completed the study. Mean serum phosphate concentrations at baseline (after washout) were 7.32-7.92 mg/dl for tenapanor groups and 7.87 mg/dl for the placebo group. Tenapanor provided dose-dependent reductions in serum phosphate level from baseline (least squares mean change: tenapanor =0.47-1.98 mg/dl; placebo =0.54 mg/dl; P=0.01). Diarrhea was the most common adverse event (tenapanor =18%-68%; placebo =12%) and frequent at the highest tenapanor doses. In conclusion, tenapanor treatment resulted in statistically significant, dose-dependent reductions in serum phosphate concentrations in patients with hyperphosphatemia receiving hemodialysis. Additional studies are required to clarify the optimal dosing of tenapanor in patients with CKD-related hyperphosphatemia.

Glucokinase Activators AZD6370 and AZD1656 Do Not Affect the Central Counterregulatory Response to Hypoglycemia in Healthy Males

CONTEXT Glucokinase is expressed in the hypothalamus, but effects of glucokinase activators (GKAs) on counterregulatory responses to hypoglycemia are unknown. OBJECTIVE Two separate studies assessed the counterregulatory hormone responses to hypoglycemia induced by the GKAs, AZD6370 and AZD1656, compared with insulin infusion. DESIGN AND SETTING Both studies were randomized, open, two-way crossover studies, conducted in separate clinical research centers. PARTICIPANTS Both studies involved 12 healthy adult male volunteers. INTERVENTIONS Each subject received two treatments in randomized order, separated by a washout. In the AZD6370 study, overnight-fasted subjects received either a single oral AZD6370 dose (300 mg) or insulin infusion (0.8 mU/kg · min). In the AZD1656 study, overnight-fasted subjects received either a single oral dose of AZD1656 (80 mg) plus supporting insulin (1 mU/kg · min) or insulin alone (1 mU/kg · min). Insulin was added to support AZD1656 because AZD1656 alone did not produce the desired hypoglycemia. Plasma glucose was lowered during a stepwise hypoglycemic clamp with a glycemic nadir of 2.7 mmol/liter for 30 min. MAIN OUTCOME MEASURES Epinephrine, norepinephrine, GH, cortisol, and glucagon plasma levels were assessed. RESULTS No safety issues were raised. AZD6370 and AZD1656 had no effect on counterregulatory responses for norepinephrine, GH, or cortisol, but epinephrine increased slightly with AZD1656. Glucagon responses were reduced by approximately 30% with both GKAs vs. insulin. CONCLUSIONS These data suggest the central nervous system-mediated counterregulatory response during GKA-induced hypoglycemia was preserved, whereas the glucagon response was attenuated; the latter was possibly mediated by a local pancreatic effect (intraislet hyperinsulinemia) rather than by impairment of the central nervous system-mediated response.

Dose-ranging study with the glucokinase activator AZD1656 as monotherapy in Japanese patients with type 2 diabetes mellitus.

To assess the glucose‐lowering effects of monotherapy with the glucokinase activator AZD1656 in Japanese patients with type 2 diabetes mellitus.

Effect of Tenapanor on Interdialytic Weight Gain in Patients on Hemodialysis

BACKGROUND AND OBJECTIVES Interdialytic weight gain in patients on hemodialysis is associated with adverse cardiovascular outcomes and increased mortality. The degree of interdialytic weight gain is influenced by sodium intake. We evaluated the effects of tenapanor (AZD1722 and RDX5791), a minimally systemically available inhibitor of the sodium/hydrogen exchanger isoform 3, on interdialytic weight gain in patients with CKD stage 5D treated with hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This phase 2, randomized, double-blind study (NCT01764854; conducted January to September of 2013) enrolled adults on maintenance hemodialysis with interdialytic weight gain ≥3.0% of postdialysis weight and ≥2 kg. Patients were randomly assigned (1:1) to receive tenapanor or placebo. The primary end point was change in mean interdialytic weight gain (percentage of baseline postdialysis weight) from baseline (mean across a 2-week run-in period) to week 4. In a subgroup of inpatients, 24-hour stool sodium and stool weight were assessed for 1 week. RESULTS Sixteen patients received 1 week of inpatient treatment (tenapanor, eight; placebo, eight), and 72 patients received 4 weeks of treatment in an outpatient setting (tenapanor, 37; placebo, 35; completers: tenapanor, 31; placebo, 33). In the outpatient cohort, no significant effect on interdialytic weight gain was detected; least squares mean changes in relative interdialytic weight gain from baseline to week 4 were tenapanor, -0.26% (95% confidence interval, -0.57% to 0.06%) and placebo, -0.23% (95% confidence interval, -0.54% to 0.07%; P=0.46). During week 1 (inpatient cohort only), compared with placebo, tenapanor treatment resulted in higher stool sodium content (mean [±SD]: tenapanor, 36.6 [±21.8] mmol/d; placebo, 2.8 [±2.7] mmol/d; P<0.001) and higher stool weight (tenapanor, 172.5 [±68.1] g/d; placebo, 86.3 [±30.0] g/d; P<0.01). A similar safety profile was observed across treatment groups with the exception of diarrhea, which occurred more frequently with tenapanor treatment. CONCLUSIONS Tenapanor treatment increased stool sodium and weight over placebo in patients undergoing hemodialysis. However, over 4 weeks of treatment, there was no difference in interdialytic weight gain between patients treated with tenapanor and those receiving placebo.

Tolerability, pharmacokinetics, and pharmacodynamics of the glucokinase activator AZD1656, after single ascending doses in healthy subjects during euglycemic clamp

OBJECTIVES AZD1656 is a novel glucokinase activator with a postulated dual mechanism of action by activating glucokinase in both the pancreas and the liver, and with the potential to deliver effective glucose-lowering in Type 2 diabetes mellitus. Here, we present the tolerability, pharmacokinetics and pharmacodynamics of AZD1656 in two single-blind, randomized, placebo-controlled studies, one with Western and the other with Japanese healthy adult male subjects. METHODS Both studies evaluated oral single ascending doses of AZD1656 of up to 180 mg, administered during euglycemic clamp conditions to explore a wide dose range without risking hypoglycemia. Safety, pharmacokinetics and effects on serum insulin and glucose infusion rate were assessed. A population pharmacokinetics analysis was also conducted. RESULTS AZD1656 was well tolerated in single doses up to 180 mg in both populations. AZD1656 was rapidly absorbed, and a dose-proportional increase in total exposure was observed for AZD1656 and the equipotent metabolite, AZD5658. Taking differences in body weight into account, there were no differences in pharmacokinetic parameters between Western and Japanese subjects. A dose-dependent blood glucose lowering effect was indirectly demonstrated by the increased glucose infusion rate required to maintain euglycemia, which was of similar magnitude in both populations. Dose-dependent increases in insulin secretion were also observed. CONCLUSIONS No safety concerns were raised. AZD1656 displayed uncomplicated pharmacokinetics and dose-dependent pharmacodynamics effects were observed. The results suggest no ethnic differences in AZD1656 tolerability, pharmacokinetics or pharmacodynamics.

Safety, pharmacokinetics and pharmacodynamics of multiple-ascending doses of the novel glucokinase activator AZD1656 in patients with type 2 diabetes mellitus.

To assess the safety, pharmacokinetics and pharmacodynamics of multiple‐ascending doses of the novel glucokinase activator AZD1656 in patients with type 2 diabetes mellitus (T2DM).

Visceral Fat and Novel Biomarkers of Cardiovascular Disease in Patients With Addison’s Disease: A Case-Control Study

Context: Patients with Addisons disease (AD) have increased cardiovascular mortality. Objective: To study visceral fat and conventional and exploratory cardiovascular risk factors in patients with AD. Design: A cross‐sectional, single‐center, case‐control study. Subjects: Patients (n = 76; n = 51 women) with AD and 76 healthy control subjects were matched for sex, age, body mass index (BMI), and smoking habits. Main outcome measures: The primary outcome variable was visceral abdominal adipose tissue (VAT) measured using computed tomography. Secondary outcome variables were prevalence of metabolic syndrome (MetS) and 92 biomarkers of cardiovascular disease. Results: The mean ± standard deviation age of all subjects was 53 ± 14 years; mean BMI, 25 ± 4 kg/m2; and mean duration of AD, 17 ± 12 years. The median (range) daily hydrocortisone dose was 30 mg (10 to 50 mg). Median (interquartile range) 24‐hour urinary free cortisol excretion was increased in patients vs controls [359 nmol (193 to 601 nmol) vs 175 nmol (140 to 244 nmol); P < 0.001]. VAT did not differ between groups. After correction for multiple testing, 17 of the 92 studied biomarkers differed significantly between patients and control subjects. Inflammatory, proinflammatory, and proatherogenic risk biomarkers were increased in patients [fold change (FC), >1] and vasodilatory protective marker was decreased (FC, <1). Twenty‐six patients (34%) vs 12 control subjects (16%) fulfilled the criteria for MetS (P = 0.01). Conclusion: Despite higher cortisol exposure, VAT was not increased in patients with AD. The prevalence of MetS was increased and several biomarkers of cardiovascular disease were adversely affected in patients with AD.

Preclinical and Healthy Volunteer Studies of Potential Drug–Drug Interactions Between Tenapanor and Phosphate Binders

Tenapanor (RDX5791, AZD1722), a first‐in‐class small molecule with minimal systemic availability, is an inhibitor of the sodium/hydrogen exchanger isoform 3. Tenapanor acts locally in the gut, where it reduces absorption of sodium and phosphate. It is being studied in patients with chronic kidney disease requiring dialysis, who are often administered phosphate binders such as sevelamer to help control hyperphosphatemia. We investigated whether coadministration of tenapanor with phosphate binders (sevelamer or calcium‐based binders) impacts the pharmacodynamic effects of tenapanor. In vitro studies suggested a binding interaction between tenapanor and sevelamer, but this did not translate into altered pharmacodynamic effects in rats. An open‐label, 2‐way crossover study was then conducted in healthy volunteers (NCT02346890). This showed that 4 days’ treatment with tenapanor hydrochloride (15 mg twice daily) with or without sevelamer carbonate (800 mg 3 times daily) resulted in comparable 24‐hour stool and urinary sodium and phosphorus levels. Stool frequency, consistency, and weight were also comparable between the treatments. These results suggest that the binding between sevelamer and tenapanor observed in vitro does not translate into altered pharmacodynamic effects in humans.

Effect of Food Intake on the Pharmacodynamics of Tenapanor: A Phase 1 Study

Tenapanor (RDX5791/AZD1722) is a minimally systemic small‐molecule inhibitor of the sodium/hydrogen exchanger NHE3. Tenapanor acts in the gut to reduce absorption of sodium and phosphate. This phase 1 open‐label, 3‐way crossover study (NCT02226783) evaluated the effect of food on the pharmacodynamics of tenapanor. Eighteen volunteers completed a randomized sequence of three 4‐day treatments with tenapanor hydrochloride 15 mg twice daily: before food, after food, and while fasting. Participants received a diet standardized for sodium content. Stool sodium was significantly higher with tenapanor administration before versus after food (difference, +8.8 mmol/day, P = .006) or while fasting (+11.8 mmol/day, P = .0004). Differences in urinary sodium were not significant. Stool phosphorus was not significantly different with tenapanor before versus after food and significantly higher before food versus while fasting (+4.9 mmol/day, P = .006). Urinary phosphorus was significantly lower when tenapanor was administered before (−3.9 mmol/day, P = .0005) or after food (−3.7 mmol/day, P = .0009) versus while fasting. No serious adverse events were reported. These data suggest the effect of tenapanor on sodium absorption is most pronounced when administered before meals, whereas the effect on phosphate is similar whether administered before or after meals. This may support different timings of tenapanor administration with respect to food for sodium‐ and phosphate‐related indications.