Effects of exenatide and open-label SGLT2 inhibitor treatment, given in parallel or sequentially, on mortality and cardiovascular and renal outcomes in type 2 diabetes: insights from the EXSCEL trial.

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1 RA) improve cardiovascular and renal outcomes in patients with type 2 diabetes through distinct mechanisms. However, evidence on clinical outcomes in patients treated with both GLP-1 RA and SGLT2i is lacking. We aim to provide insight into the effects of open-label SGLT2i use in parallel with or shortly after once-weekly GLP-1 RA exenatide (EQW) on cardiorenal outcomes. METHODS: In the EXSCEL cardiovascular outcomes trial EQW arm, SGLT2i drop-in occurred in 8.7% of participants. These EQW+SGLT2i users were propensity-matched to: (1) placebo-arm participants not taking SGLT2i (n = 572 per group); and to (2) EQW-arm participants not taking SGLT2i (n = 575), based on their last measured characteristics before SGLT2i initiation, and equivalent study visit in comparator groups. Time-to-first major adverse cardiovascular event (MACE) and all-cause mortality (ACM) were compared using Cox regression analyses. eGFR slopes were quantified using mixed model repeated measurement analyses. RESULTS: In adjusted analyses, the risk for MACE with combination EQW+SGLT2i use was numerically lower compared with both placebo (adjusted hazard ratio 0.68, 95% CI 0.39-1.17) and EQW alone (0.85, 0.48-1.49). Risk of ACM was nominally significantly reduced compared with placebo (0.38, 0.16-0.90) and compared with EQW (0.41, 0.17-0.95). Combination EQW+SGLT2i use also nominally significantly improved estimated eGFR slope compared with placebo (+ 1.94, 95% CI 0.94-2.94 mL/min/1.73 m2/year) and EQW alone (+ 2.38, 1.40-3.35 mL/min/1.73 m2/year). CONCLUSIONS: This post hoc analysis supports the hypothesis that combinatorial EQW and SGLT2i therapy may provide benefit on cardiovascular outcomes and mortality. Trial registration Clinicaltrials.gov, Identifying number: NCT01144338, Date of registration: June 15, 2010.

Exenatide once weekly improved 24-hour glucose control and reduced glycaemic variability in metformin-treated participants with type 2 diabetes: a randomized, placebo-controlled trial.

AIM: To assess the effects of once-weekly exenatide on 24-hour glucose control and variability. MATERIALS AND METHODS: This double-blind, placebo-controlled trial randomized metformin-treated adults with type 2 diabetes to once-weekly exenatide 2.0 mg or placebo. Continuous glucose monitoring (CGM) was performed at baseline and weeks 4 and 10. The primary outcome was change in CGM-measured 24-hour mean glucose level. RESULTS: In the once-weekly exenatide (n = 60) and placebo (n = 56) groups (modified intention-to-treat population), the baseline glycated haemoglobin (HbA1c) concentrations were 8.2% and 8.0%, respectively, and the fasting plasma glucose (FPG) concentration was 9.86 and 9.32 mmol/L, respectively. Once-weekly exenatide significantly (p < 0.001) reduced 24-hour mean glucose level versus placebo (week 4, -1.44 vs -0.29 mmol/L; week 10, -1.71 vs -0.17 mmol/L), with consistent control throughout the week. Once-weekly exenatide significantly reduced FPG and 2-hour postprandial glucose (PPG) levels versus placebo at week 4 (FPG, -1.65 vs -0.11 mmol/L; PPG, -1.79 vs -0.11 mmol/L) and week 10 (FPG, -2.32 vs -0.28 mmol/L; PPG, -2.46 vs -0.33 mmol/L). At week 10, once-weekly exenatide reduced the mean amplitude of glucose excursions (MAGE; -0.84 vs 0.16 mmol/L) and standard deviation (s.d.) of mean glucose (-0.35 vs 0.04 mmol/L). By week 10, once-weekly exenatide-treated participants spent more time in euglycaemia (once-weekly exenatide, 77% vs placebo, 58%), less time in hyperglycaemia (22% vs 42%), and a similar time in hypoglycaemia (0.7% vs 0.3%). Common adverse events were injection-site nodule (once-weekly exenatide, 10.0% vs placebo, 0.0%), urinary tract infection (6.7% vs 8.9%) and nausea (6.7% vs 0.0%). CONCLUSIONS: In metformin-treated participants with type 2 diabetes, once-weekly exenatide significantly improved daily glucose control and reduced glycaemic variability at weeks 4 and 10, as shown by reductions in 24-hour glucose, FPG and PPG levels, MAGE and s.d., and increased time spent in euglycaemia.

Effects of pramlintide on postprandial glucose excursions and measures of oxidative stress in patients with type 1 diabetes.

OBJECTIVE: Oxidative stress has been shown to be increased in the postprandial period in patients with diabetes and has been implicated in the pathogenesis of micro- and macrovascular complications. The aim of this post hoc analysis was to assess the effects of pramlintide, an amylin analog shown to reduce postprandial glucose excursions in patients with diabetes, on markers of oxidative stress in the postprandial period. RESEARCH DESIGN AND METHODS: In a randomized, single-blind, placebo-controlled, crossover study, 18 evaluable subjects with type 1 diabetes underwent two standardized breakfast meal tests and received pramlintide or placebo in addition to their preprandial insulin. The plasma concentrations of glucose and markers of oxidative stress (nitrotyrosine, oxidized LDL [ox-LDL], and total radical-trapping antioxidant parameter [TRAP]) were measured at baseline and during the 4-h postprandial period. RESULTS: Compared with placebo, pramlintide treatment significantly reduced postprandial excursions of glucose, nitrotyrosine, and ox-LDL and prevented a decline in TRAP (P < 0.03 for all comparisons). Correlation analyses adjusted for treatment revealed a significant association between postprandial mean incremental area under the curve from 0 to 4 h (AUC(0-4 h)) for glucose and postprandial mean incremental AUC(0-4 h) for each measure of oxidative stress (r = 0.75, 0.54, and -0.63 for nitrotyrosine, ox-LDL, and TRAP, respectively; P < 0.001 for all correlations). CONCLUSIONS: These findings indicate that the postprandial glucose-lowering effect of pramlintide in type 1 diabetes is associated with a significant reduction in postprandial oxidative stress.

Pharmacokinetics, pharmacodynamics, and safety of exenatide in patients with type 2 diabetes mellitus.

PURPOSE: The pharmacology and tolerability of exenatide in patients with type 2 diabetes mellitus were studied. METHODS: Two randomized, single-blind, placebo-controlled studies were conducted. Treatment with oral antidiabetic agents was stopped 14 days before study initiation. In the first study (study A), eight subjects received placebo, 0.1-, 0.2-, 0.3-, and either 0.4-microg/kg exenatide or placebo five minutes before a meal combined with liquid acetaminophen (to assess the rate of gastric emptying) on days 1, 3, 5, 7, and 9. In the second study (study B), subjects received a single s.c. dose of exenatide or placebo on consecutive days. Part 1 of study B used exenatide doses of 0.01 and 0.1 microg/ kg; 0.02-, 0.05-, and 0.1-microg/kg doses were given in part 2. After an overnight fast, the study drug was injected 15 minutes before a meal (part 1) and before a meal and acetaminophen (part 2). Parts 1 and 2 of study B enrolled six and eight patients, respectively. RESULTS: In both studies, plasma exenatide pharmacokinetic profiles appeared dose proportional. Exenatide doses of 0.02-0.2 microg/kg dose-dependently lowered postprandial glucose excursions. Exenatide suppressed postprandial plasma glucagon and slowed gastric emptying. There were no serious adverse events and no patient withdrawals related to treatment. Nausea and vomiting were the most common adverse events and were mild to moderate in severity at doses ranging from 0.02 to 0.2 microg/kg. CONCLUSION: Administration of preprandial exenatide by s.c. injection resulted in dose-proportional exenatide pharmacokinetics and antidiabetic pharmacodynamic activity. At doses ranging from 0.02 to 0.2 microg/kg, exenatide dose-dependently reduced postprandial plasma glucose excursion by insulinotropism, suppression of plasma glucagon, and slowing of gastric emptying.

Effect of pramlintide on weight in overweight and obese insulin-treated type 2 diabetes patients.

OBJECTIVE: Several randomized, placebo-controlled, double-blind trials in insulin-treated patients with type 2 diabetes have shown that adjunctive therapy with pramlintide reduces hemoglobin (Hb)A1c with concomitant weight loss. This analysis further characterizes the weight-lowering effect of pramlintide in this patient population. RESEARCH METHODS AND PROCEDURES: This pooled post hoc analysis of two long-term trials included all patients who were overweight/obese at baseline (BMI > 25 kg/m2), and who were treated with either 120 microg pramlintide BID (n = 254; HbA1c 9.2%; weight, 96.1 kg) or placebo (n = 244; HbA1c 9.4%; weight, 95.0 kg). Statistical endpoints included changes from baseline to week 26 in HbA1c, body weight, and insulin use. RESULTS: Pramlintide treatment resulted in significant reductions from baseline to week 26, compared with placebo, in HbA1c and body weight (both, p < 0.0001), for placebo-corrected reductions of -0.41% and -1.8 kg, respectively. Approximately three times the number of patients using pramlintide experienced a > or = 5% reduction of body weight than with placebo (9% vs. 3%, p = 0.0005). Patients using pramlintide also experienced a proportionate decrease in total daily insulin use (r = 0.39, p < 0.0001). The greatest placebo-corrected reductions in weight at week 26 were observed in pramlintide-treated patients with a BMI >40 kg/m2 and in those concomitantly treated with metformin (both, p < 0.001), for placebo-corrected reductions of -3.2 kg and -2.5 kg, respectively. DISCUSSION: These findings support further evaluation of the weight-lowering potential of pramlintide in obese patients with type 2 diabetes.

Pramlintide reduces postprandial glucose excursions when added to insulin lispro in subjects with type 2 diabetes: a dose-timing study.

BACKGROUND: To assess the postprandial glucose-lowering effect of the human amylin analog pramlintide when given with insulin lispro in subjects with type 2 diabetes, with an emphasis on the optimal dose timing relative to meals. METHODS: In this randomized, single-blind, placebo-controlled, five-way crossover study, 19 subjects with type 2 diabetes using insulin lispro underwent five consecutive mixed-meal tests. In randomized order, subjects received subcutaneous injections of placebo at -15 min or 120-microg pramlintide at -15, 0, +15, or +30 min relative to the standardized breakfast after an overnight fast. Insulin lispro was injected at 0 min at doses that were adjusted appropriately for both the content of the standardized meal and the anticipated effects of pramlintide. Plasma glucose concentrations were measured before and during the 4-h postmeal period. RESULTS: When injected at 0 min, pramlintide reduced the postprandial glucose excursion by 81% compared to insulin lispro + placebo (incremental AUC(0-4 h) (mean +/- SE) 2.0 +/- 1.5 vs. 10.4 +/- 2.2 mmol/h/L, P<0.05). When pramlintide was injected at -15, +15, and +30 min, the postprandial incremental glucose AUC(0-4 h) was also significantly reduced (P<0.05), but to a lesser extent (42 to 73%). Pramlintide treatment was well tolerated and no serious adverse events were reported. CONCLUSIONS: Administration of pramlintide either at or just prior to a meal caused a greater reduction in postprandial glucose than either administration of placebo or postmeal pramlintide injections in subjects with type 2 diabetes treated with a rapid-acting insulin analog, insulin lispro.

Pramlintide reduces postprandial glucose excursions when added to regular insulin or insulin lispro in subjects with type 1 diabetes: a dose-timing study.

OBJECTIVE: To assess the postprandial glucose-lowering effect of the human amylin analog pramlintide when given with either regular insulin or insulin lispro in subjects with type 1 diabetes, with an emphasis on the optimal dose timing relative to meals. RESEARCH DESIGN AND METHODS: In this randomized, single-blind, placebo-controlled, five-way crossover study, 19 subjects with type 1 diabetes using regular insulin and 21 subjects with type 1 diabetes using insulin lispro underwent five consecutive mixed meal tests. In randomized order, subjects received subcutaneous injections of placebo at -15 min or 60 microg pramlintide at -15, 0, +15, or +30 min relative to the meal after an overnight fast. Regular insulin or insulin lispro was injected at -30 and 0 min, respectively, at doses that were adjusted appropriately for both the content of the standardized meal and the anticipated effects of pramlintide. Plasma glucose concentrations were measured before and during the 4-h postmeal period. RESULTS: In both the regular insulin and insulin lispro groups, pramlintide injections at all four time points lowered the postprandial glucose excursion (36 to >100% reduction in incremental area under the concentration time curve from 0 to 4 h (AUC(0-4 h)) compared with placebo. However, only preprandial injections of pramlintide (-15 and 0 min) were able to prevent the initial postprandial surge in glucose. The optimal time for pramlintide injection was 0 min, which reduced the postprandial glucose excursion by >100% compared with regular insulin plus placebo (incremental AUC(0-4 h): -0.6 +/- 2.5 vs. 11.0 +/- 2.9 mmolx h(-1) x l(-1), P < 0.0007) and by 75% compared with insulin lispro plus placebo (incremental AUC(0-4 h): 2.5 +/- 2.1 vs. 10.0 +/- 2.5 mmol x h(-1) x l(-1), P < 0.0098). No serious adverse events were reported. CONCLUSIONS: Pramlintide, given at or just before a meal, reduces the postprandial glucose excursion in subjects with type 1 diabetes, regardless of whether added to regular insulin or a rapid-acting insulin analog.

Adjunctive therapy with the amylin analogue pramlintide leads to a combined improvement in glycemic and weight control in insulin-treated subjects with type 2 diabetes.

The objective of this study was to assess the effect of mealtime amylin replacement with pramlintide on long-term glycemic and weight control in subjects with type 2 diabetes. This 52-week, randomized, placebo-controlled, multicenter, double-blind, dose-ranging study in 538 insulin-treated subjects with type 2 diabetes compared the efficacy and safety of 30-, 75-, or 150-microg doses of pramlintide, a synthetic analogue of the beta-cell hormone amylin, to placebo when injected subcutaneously three times daily (TID) with major meals. Pramlintide therapy led to a mean reduction in HbA1c of 0.9% and 1.0% from baseline to week 13 in the 75- and 150-microg dose groups, which was significant compared to placebo (p = 0.0004 and p = 0.0002, respectively). In the 150-microg dose group, there was a mean reduction in HbA1c of 0.6% from baseline to week 52 (p = 0.0068 compared to placebo). The greater reduction in HbA1c with pramlintide was achieved without increases in insulin use or severe hypoglycemia, and was accompanied by a significant (p < 0.05) reduction in body weight in all dose groups compared to placebo. Three times the proportion of subjects in the 150-microg pramlintide group compared to the placebo group achieved a concomitant reduction in both HbA1c and body weight from baseline to week 52 (48% versus 16%). The most common adverse event reported with pramlintide treatment was nausea, which was mild to moderate and dissipated early in treatment. The results from this study support the safety and efficacy of pramlintide administered three times a day with major meals, in conjunction with insulin therapy, for improving long-term glycemic and weight control in subjects with type 2 diabetes.

A randomized study and open-label extension evaluating the long-term efficacy of pramlintide as an adjunct to insulin therapy in type 1 diabetes.

OBJECTIVE: To assess the effect of mealtime amylin replacement with pramlintide on long-term glycemic and weight control in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS: In a 52-week, double-blind, placebo-controlled, multicenter study, 480 patients with type 1 diabetes were randomized to receive preprandial injections of placebo or 30 microg pramlintide q.i.d., in addition to existing insulin regimens. At week 20, pramlintide-treated patients were re-randomized to 30 or 60 microg pramlintide q.i.d. if decreases from baseline in HbA(1c) were <1% at week 13. Of the 342 patients who completed the 52-week study, 236 individuals ( approximately 70%) elected to participate in a 1-year open-label extension in which all patients received 30 or 60 microg pramlintide q.i.d. RESULTS: Treatment with pramlintide led to a mean reduction in HbA(1c) of 0.67% from baseline to week 13 that was significantly (P < 0.0001) greater than the placebo reduction (0.16%), and a significant placebo-corrected treatment difference was sustained through week 52 (P = 0.0071). The greater HbA(1c) reduction was associated with an average weight loss, rather than weight gain, and was not accompanied by an increased overall event rate of severe hypoglycemia. In the open-label extension, mean HbA(1c) levels decreased rapidly in patients receiving pramlintide for the first time and remained at reduced levels in patients who continued pramlintide treatment. The most common adverse events reported by the pramlintide group were mild nausea and anorexia, which both occurred during the initial weeks of treatment and dissipated over time. CONCLUSIONS: Mealtime pramlintide treatment as an adjunct to insulin improved long-term glycemic control without inducing weight gain or increasing the overall risk of severe hypoglycemia in patients with type 1 diabetes.

Dimeric structure of the Oxytricha nova telomere end-binding protein alpha-subunit bound to ssDNA.

Telomeres are the specialized protein--DNA complexes that cap and protect the ends of linear eukaryotic chromosomes. The extreme 3' end of the telomeric DNA in Oxytricha nova is bound by a two-subunit sequence-specific and 3' end-specific protein called the telomere end-binding protein (OnTEBP). Here we describe the crystal structure of the alpha-subunit of OnTEBP in complex with T4G4 single-stranded telomeric DNA. This structure shows an (alpha--ssDNA)2 homodimer with a large approximately 7,000 A2 protein--protein interface in which the domains of alpha are rearranged extensively from their positions in the structure of an alpha--beta--ssDNA ternary complex. The (alpha--ssDNA)2 complex can bind two telomeres on opposite sides of the dimer and, thus, acts as a protein mediator of telomere--telomere associations. The structures of the (alpha--ssDNA)2 dimer presented here and the previously described alpha--beta--ssDNA complex demonstrate that OnTEBP forms multiple telomeric complexes that potentially mediate the assembly and disassembly of higher order telomeric structures.