Ticagrelor in Patients with Stable Coronary Disease and Diabetes.

BACKGROUND: Patients with stable coronary artery disease and diabetes mellitus who have not had a myocardial infarction or stroke are at high risk for cardiovascular events. Whether adding ticagrelor to aspirin improves outcomes in this population is unclear. METHODS: In this randomized, double-blind trial, we assigned patients who were 50 years of age or older and who had stable coronary artery disease and type 2 diabetes mellitus to receive either ticagrelor plus aspirin or placebo plus aspirin. Patients with previous myocardial infarction or stroke were excluded. The primary efficacy outcome was a composite of cardiovascular death, myocardial infarction, or stroke. The primary safety outcome was major bleeding as defined by the Thrombolysis in Myocardial Infarction (TIMI) criteria. RESULTS: A total of 19,220 patients underwent randomization. The median follow-up was 39.9 months. Permanent treatment discontinuation was more frequent with ticagrelor than placebo (34.5% vs. 25.4%). The incidence of ischemic cardiovascular events (the primary efficacy outcome) was lower in the ticagrelor group than in the placebo group (7.7% vs. 8.5%; hazard ratio, 0.90; 95% confidence interval [CI], 0.81 to 0.99; P = 0.04), whereas the incidence of TIMI major bleeding was higher (2.2% vs. 1.0%; hazard ratio, 2.32; 95% CI, 1.82 to 2.94; P<0.001), as was the incidence of intracranial hemorrhage (0.7% vs. 0.5%; hazard ratio, 1.71; 95% CI, 1.18 to 2.48; P = 0.005). There was no significant difference in the incidence of fatal bleeding (0.2% vs. 0.1%; hazard ratio, 1.90; 95% CI, 0.87 to 4.15; P = 0.11). The incidence of an exploratory composite outcome of irreversible harm (death from any cause, myocardial infarction, stroke, fatal bleeding, or intracranial hemorrhage) was similar in the ticagrelor group and the placebo group (10.1% vs. 10.8%; hazard ratio, 0.93; 95% CI, 0.86 to 1.02). CONCLUSIONS: In patients with stable coronary artery disease and diabetes without a history of myocardial infarction or stroke, those who received ticagrelor plus aspirin had a lower incidence of ischemic cardiovascular events but a higher incidence of major bleeding than those who received placebo plus aspirin. (Funded by AstraZeneca; THEMIS ClinicalTrials.gov number, NCT01991795.).

Ticagrelor does not impact patient-reported pain in young adults with sickle cell disease: a multicentre, randomised phase IIb study.

Ticagrelor is an antiplatelet agent for adults with coronary artery disease. The inhibition of platelet activation may decrease the frequency of vaso-occlusion crisis (VOC) in sickle cell disease (SCD). The HESTIA2 study (NCT02482298) randomised 87 adults with SCD (aged 18-30 years) 1:1:1 to twice-daily ticagrelor 10, 45 mg or placebo for 12 weeks. Numerical decreases from baseline in mean proportion of days with patient-reported pain (primary endpoint) were seen in all three groups, as well as in pain intensity and analgesic use, with no significant differences between placebo and ticagrelor treatment groups. Plasma ticagrelor concentrations and platelet inhibition increased with dose. Adverse events were distributed evenly across groups and two non-major bleeding events occurred per group. Ticagrelor was well tolerated with a low bleeding risk, but no effect on diary-reported pain was detected. Potential effects on frequency of VOCs will need to be evaluated in a larger and longer study.

Safety and Incidence of Cardiovascular Events in Chinese Patients with Acute Coronary Syndrome Treated with Ticagrelor: the 12-Month, Phase IV, Multicenter, Single-Arm DAYU Study.

PURPOSE: Ticagrelor is an orally administered, reversibly binding, direct-acting P2Y12 receptor antagonist previously evaluated in several phase III trials. This phase IV, multicenter, single-arm trial assessed the safety and incidence of cardiovascular (CV) events with ticagrelor in Chinese patients experiencing an acute coronary syndrome (ACS). METHODS: Patients hospitalized with an ACS received ticagrelor (180 mg loading dose, 90 mg twice daily thereafter) plus low-dose aspirin (75-100 mg/day) for up to 12 months. Safety was evaluated via PLATO-defined bleeding events, adverse events (AEs), serious AEs, and laboratory measurements. The incidence of major CV events was also evaluated. RESULTS: The safety population included 2001 patients. During ticagrelor treatment, 426 (21.3%) patients had at least one PLATO-defined bleeding AE, mainly minimal bleedings (n = 333). Major bleeding events occurred in 27 (1.3%) patients, including fatal/life-threatening bleeding in 17 (0.8%) patients and other major bleeding in 11 (0.5%) patients, with a Kaplan-Meier estimate of patients with the event (95% CI) of 1.6% (1.1-2.3%). In total, 784 (39.2%) patients had at least one non-bleeding AE, the majority of which were mild in severity. The composite endpoint of CV death, myocardial infarction, and stroke occurred in 83 (4.1%) patients. CONCLUSIONS: Ticagrelor plus low-dose aspirin for up to 1 year was associated with a low rate of major bleeding events and a low incidence of major CV events (CV death, myocardial infarction, stroke) in Chinese patients with ACS. The overall safety profile of ticagrelor in this population was in line with current prescribing information.

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.

A phase 1 study of the safety, tolerability, pharmacodynamics, and pharmacokinetics of tenapanor in healthy Japanese volunteers.

BACKGROUND: Tenapanor (RDX5791, AZD1722), a small molecule with minimal systemic availability, is an inhibitor of the sodium/hydrogen exchanger isoform 3 (NHE3). Tenapanor acts locally in the gut to reduce absorption of sodium and phosphate. It is being developed for the treatment of patients with hyperphosphatemia in CKD requiring dialysis and patients with constipation-predominant irritable bowel syndrome. We report the safety, pharmacodynamics, and pharmacokinetics of tenapanor in Japanese volunteers. METHODS: In this phase 1, double-blind study (NCT02176252), healthy Japanese adults (aged 20-45 years) received single-dose tenapanor 180 mg (n = 6), repeated-dose tenapanor 15, 30, 60, or 90 mg twice daily (n = 12 each) for 7 days, or placebo (n = 14). All participants received a standardized diet. RESULTS: Single and repeated doses of tenapanor resulted in higher mean stool sodium content vs. placebo (single dose, 41.9 mmol/day; repeated dose, range of means 21.3-32.2 mmol/day; placebo, 4.1 mmol/day) accompanied by lower urinary sodium content (single dose, 110 mmol/day; repeated dose, 101-112 mmol/day; placebo, 143 mmol/day). Additionally, stool phosphorus content was increased (single dose, 31.0 mmol/day; repeated dose, 17.6-24.8 mmol/day; placebo, 16.8 mmol/day) and urinary phosphorus content decreased (single dose, 18.7 mmol/day; repeated dose, 15.3-19.4 mmol/day; placebo, 25.5 mmol/day). Tenapanor had minimal systemic exposure, provided a softer stool consistency, and was well tolerated. CONCLUSIONS: Tenapanor treatment reduced absorption of intestinal sodium and phosphate from the gut in Japanese adults. Tenapanor had minimal systemic exposure and was well tolerated. Further research into the clinical benefits of tenapanor is warranted.

Balcinrenone plus dapagliflozin in patients with heart failure and chronic kidney disease: Results from the phase 2b MIRACLE trial.

AIMS: Many patients with heart failure (HF) have chronic kidney disease (CKD) and may not tolerate mineralocorticoid receptor antagonists. We investigated the efficacy and safety of the novel mineralocorticoid receptor modulator balcinrenone in combination with dapagliflozin in a phase 2b study. METHODS AND RESULTS: From January 2021 to October 2023, we randomized 133 adults with symptomatic HF, ejection fraction <60%, estimated glomerular filtration rate (eGFR) ≥30 to ≤60 ml/min/1.73 m2 and urinary albumin-to-creatinine ratio (UACR) ≥30 to <3000 mg/g, to receive balcinrenone 15, 50 or 150 mg/day plus dapagliflozin 10 mg/day, or dapagliflozin 10 mg/day plus placebo, for 12 weeks. Enrolment was stopped early because of slow recruitment. Relative reductions in UACR from baseline to week 12 (primary endpoint) were not significantly different between the balcinrenone plus dapagliflozin groups versus dapagliflozin plus placebo. There was no clear balcinrenone dose-response relationship. There were possible dose-dependent increases in serum potassium levels, reduced eGFR in the highest dose group, and non-significant trends towards reduced N-terminal pro-B-type natriuretic peptide levels. Hyperkalaemia adverse events led to discontinuation in two participants receiving balcinrenone plus dapagliflozin and none in those receiving dapagliflozin plus placebo. CONCLUSION: While the smaller than planned sample size limits interpretation, we did not see significant reduction in UACR in patients treated with balcinrenone plus dapagliflozin compared with dapagliflozin plus 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.

Ticagrelor versus placebo for the reduction of vaso-occlusive crises in pediatric sickle cell disease: Rationale and design of a randomized, double-blind, parallel-group, multicenter phase 3 study (HESTIA3).

BACKGROUND: An unmet need for therapies exists to reduce sickle cell disease (SCD) complications in pediatric patients. Activated platelets contribute to the formation of cellular aggregates during sickling and vaso-occlusive crises (VOCs). Ticagrelor is an oral, direct-acting, and reversible adenosine diphosphate P2Y12 receptor antagonist that inhibits platelet activation and aggregation. Although ticagrelor was well tolerated in two phase 2 studies in children and young adults with SCD, larger and longer-term treatment studies are needed to assess ticagrelor's efficacy to reduce VOCs. HESTIA3 will evaluate the efficacy, safety, and tolerability of ticagrelor versus placebo over a minimum of 1 year (maximum 2 years) in pediatric patients with SCD. METHODS: Approximately 180 patients (aged ≥ 2 to <18 years) with SCD (≥ 2 VOCs in the prior year) from 18 countries will be randomized 1:1 to ticagrelor or placebo. Primary endpoint: number of VOCs (a composite endpoint of painful crises and/or acute chest syndrome); key secondary endpoints: hospitalizations, pain intensity and analgesic use during VOCs, acceptability of formulation, and health-related quality of life. The weight-based doses of ticagrelor are set by modeling and simulation. Platelet inhibition data, measured by the vasodilator-stimulated phosphoprotein assay, will be collected for exploratory purposes. CONCLUSIONS: HESTIA3 aims to demonstrate that using greater target platelet inhibition than previous studies on SCD, ticagrelor will decrease the frequency of VOC in pediatric patients. Trial Identifier: NCT03615924; EudraCT2017-002421-38.

YINGLONG: A Multicenter, Prospective, Non-Interventional Study Evaluating the Safety and Tolerability of Ticagrelor in Chinese Patients with Acute Coronary Syndrome.

INTRODUCTION: Ticagrelor is an oral, reversible, direct-acting P2Y12 receptor inhibitor approved for the prevention of cardiovascular events in acute coronary syndrome (ACS). In China, drug intensive monitoring regulations for new drugs require additional safety data post-approval. METHODS: YINGLONG, a single-arm, phase-IV, 1-year, non-interventional study, described the safety of ticagrelor 90 mg twice daily in Chinese patients (≥ 18 years) with ACS treated with ≥ 1 dose of ticagrelor. Primary outcomes were the incidence of adverse events (AEs), in particular, PLATelet inhibition and patient Outcomes (PLATO)-defined bleeding AEs, and other serious AEs during the 1-year follow-up. Key secondary outcomes were the incidence of major cardiovascular events. RESULTS: Patients (n = 1041, median age 61.0 years) had started ticagrelor and had post-dose data. Median duration of ticagrelor treatment was 357 days; 577 patients (55.4%) completed 1-year ticagrelor treatment; 973 patients (93.5%) completed 1-year follow-up. Overall, 38.7% of patients reported an AE during treatment. The most common AEs were dyspnea (n = 37, 3.6%), petechiae (n = 30, 2.9%), and chest discomfort (n = 28, 2.7%). Serious AEs, excluding bleeding, were reported in 9.8% of patients during treatment. Incidence of PLATO-defined major bleeding events was 1.1% (n = 11). Of the 21 deaths that occurred during the study (8 post-treatment), 1 was a fatal bleed. Major cardiovascular events were reported in 37 patients (3.6%). CONCLUSIONS: Ticagrelor was well tolerated with a low rate of PLATO-defined major bleeding events in Chinese ACS patients. Safety results were consistent with the known ticagrelor profile. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02430493. FUNDING: AstraZeneca Investment (China) Co., Ltd.

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.

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

Context: Patients with Addison's 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.

Premature mortality in patients with Addison's disease: a population-based study.

BACKGROUND: The survival rate of patients with primary adrenal insufficiency (Addison's disease) undergoing currently accepted replacement therapy is not known, although well-informed patients are considered to have a normal survival rate. In this study, we evaluated the mortality of patients with Addison's disease in Sweden. METHODS: A population-based, retrospective, observational study was performed, using the National Swedish Hospital and Cause of Death Registers, covering the period from 1987-2001. After a diagnosis of Addison's disease, each patient was followed until the end of follow-up or death. Mortality was compared with that of the Swedish background population. FINDINGS: We identified 1675 patients (995 women and 680 men) diagnosed with primary adrenal insufficiency. The average follow-up from initial diagnosis was 6.5 yr. Five hundred seven patients died during the study period compared with an expected 199. The risk ratio for all-cause mortality was 2.19 (confidence interval 1.91-2.51) for men and 2.86 (confidence interval 2.54-3.20) for women. The excess mortality in both men and women was attributed to cardiovascular, malignant, and infectious diseases. Concomitant diabetes mellitus was observed in 12% of the patients, but only contributed to the increased mortality to a minor extent. INTERPRETATION: Compared with the background population, we observed that the risk ratio for death was more than 2-fold higher in patients with Addison's disease. Cardiovascular, malignant, and infectious diseases were responsible for the higher mortality rate.

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.

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.