Serum endotrophin identifies optimal responders to PPARγ agonists in type 2 diabetes.

AIMS/HYPOTHESIS: The treatment of type 2 diabetes with full peroxisome proliferator-activated receptor gamma (PPARγ) agonists improves insulin sensitivity, but is associated with weight gain, heart failure, peripheral oedema and bone loss. Endotrophin, the C-terminal fragment of the α3 chain of procollagen type VI (also called Pro-C6), is involved in both adipose tissue matrix remodelling and metabolic control. We established a serum assay for endotrophin to assess if this novel adipokine could identify type 2 diabetic patients who respond optimally to PPARγ agonists, improving the risk-to-benefit ratio. METHODS: The BALLET trial (NCT00515632) compared the glucose-lowering effects and safety of the partial PPARγ agonist balaglitazone with those of pioglitazone in individuals with type 2 diabetes on stable insulin therapy. The per protocol population (n = 297) was stratified into tertiles based on baseline endotrophin levels. Participants were followed-up after 26 weeks, after which correlational analysis was carried out between endotrophin levels and measures of glucose control. This is a secondary post hoc analysis. RESULTS: Endotrophin was significantly associated with therapeutic response to balaglitazone and pioglitazone. At week 26, only individuals in the upper two tertiles showed significant reductions in HbA1c and fasting serum glucose compared with baseline. The OR for a 1% and a 0.5% reduction in HbA1c for individuals in the upper two tertiles were 3.83 (95% CI 1.62, 9.04) p < 0.01, and 3.85 (95% CI 1.94, 7.61) p < 0.001, respectively. Endotrophin levels correlated with adipose tissue mass, insulin resistance and fatty liver index. Notably, PPARγ-associated adverse effects, such as moderate-to-severe lower extremity oedema, only occurred in the lower tertile. CONCLUSIONS/INTERPRETATION: Elevated endotrophin serum levels predict response to two insulin sensitisers and reduce the risk of associated adverse effects, thereby, identifying patients with type 2 diabetes who may profit from PPARγ agonist treatment.

Efficacy and safety of the PPARγ partial agonist balaglitazone compared with pioglitazone and placebo: a phase III, randomized, parallel-group study in patients with type 2 diabetes on stable insulin therapy.

BACKGROUND: Treatment of patients with perioxisome proliferator-activated receptor-γ full agonists are associated with weight gain, heart failure, peripheral oedema, and bone loss. However, the safety of partial perioxisome proliferator-activated receptor-γ agonists has not been established in a clinical trial. The BALaglitazone glucose Lowering Efficacy Trial aimed to establish the glucose-lowering effects and safety parameters of the perioxisome proliferator-activated receptor-γ partial agonist balaglitazone in diabetic patients on stable insulin therapy. METHODS: Four hundred and nine subjects from three countries with type 2 diabetes on stable insulin therapy were randomized to 26 weeks of double-blind treatment with once daily doses of 10 or 20 mg balaglitazone, 45 mg pioglitazone, or matching placebo (n ≥ 99 in each group). The primary endpoint was the efficacy of balaglitazone 10 and 20 mg versus placebo on the absolute change in haemoglobin A(1c) . Secondary endpoints included levels of fasting serum glucose, and changes in body composition and bone mineral density as measured by dual energy X-ray absorptiometry, in comparison to pioglitazone 45 mg. This study is registered with Clinicaltrials.gov identifier: NCT00515632. RESULTS: In the 10- and 20-mg balaglitazone groups, and in the 45-mg pioglitazone group, significant reductions in haemoglobin A(1c) levels were observed (−0.99, −1.11, and −1.22%, respectively; p < 0.0001) versus placebo. Fasting serum glucose was similarly reduced in all treatment arms. Dual energy X-ray absorptiometry analyses showed that, while balaglitazone at 10 mg caused weight gain and fluid retention compared to placebo, the magnitude of these effects was significantly smaller than that of pioglitazone 45 mg and balaglitazone 20mg. Balaglitazone at either dose did not appear to reduce bone mineral density, while Pioglitazone showed a trend towards a reduction. CONCLUSION: Patients treated with balaglitazone at 10 mg and 20 mg and pioglitazone at 45 mg showed clinically meaningful improvements in glucose levels and HbA(1c) . With the 10 mg dose, the benefits (glucose & HgA(1c) lowering) and untoward effects (fluid and fat accumulation) were less, results that encourage further studies of this drug candidate.

Investigations of inter- and intraindividual relationships between exposure to oral salmon calcitonin and a surrogate marker of pharmacodynamic efficacy.

AIMS: The aims of the study were to investigate interindividual variations in the bioavailability of salmon calcitonin (sCT) following single oral 0.8 mg doses at three different times of the day, and intraindividual variation in sCT bioavailability at each end of a 14-day treatment period. We also investigated correlations between exposure to sCT and levels of the bone resorption biomarker serum C-terminal telopeptide of collagen type I (CTX-I). METHODS: Participants were from two randomized, double-blind, placebo-controlled studies. In study I, healthy postmenopausal women received a single dose of 0.8 mg of oral sCT or placebo at 08:00 (n = 42), 17:00 (n = 20), or at 22:00 (n = 19). In study II, age-matched men or postmenopausal women with osteoarthritis received 0.8 mg oral sCT (n = 26) or placebo (n = 23) twice daily for 14 days, with dosing at 08:00 and 17:00. In both studies, drug exposure was assessed by plasma sCT concentrations, and bone resorption by CTX-I levels. RESULTS: The variability in exposure between patients, measured as coefficient of variation (CV), was as follows: 22% for the morning dose, 30% for the predinner dose, and 34% for the evening dose. In study 1, a high degree of correlation was seen between the level of exposure following a single 0.8 mg dose of sCT and suppression of serum CTX-I, with Pearson correlation coefficients of r = -0.74, -0.96, and -0.78, following doses at 08:00, 17:00, and 22:00, respectively. In study II, exposure to sCT varied widely within the same individuals between dosing days 1 and 14, with weak correlations of r = 0.40 and 0.38 at the dose times 08:00 and 17:00, respectively. As expected from this finding, the intraindividual response in serum CTX-I levels was non-significantly associated on dosing days 1 and 14 (r = 0.34 and r = 0.27 at dose times 08:00 and 17:00, respectively). CONCLUSION: Increased bioavailability of orally administered 0.8 mg sCT was highly correlated with increased suppression of the bone resorption marker serum CTX-I irrespective of the time of day. However, the high inter- and intraindividual variability in sCT exposure demonstrates the importance of determining the optimum conditions for ensuring the most beneficial sCT uptake.

Atrial fibrillation is associated with lean body mass in postmenopausal women.

This study investigated the association between body composition and risk of atrial fibrillation (AF) in postmenopausal women. In a retrospective analysis we assessed data from 5704 postmenopausal women (age 70.7 ± 6.5 yrs.) who in 1999-2001 participated in The Prospective Epidemiological Risk Factor study with body composition assessed by dual-energy X-ray absorptiometry. Outcomes were obtained from Danish Health Registries and body composition association to risk of AF was evaluated by univariable and multivariable Cox Hazard regression. 850 women developed AF after baseline. High lean body mass was associated with increased risk of AF in multivariable analyses, adjusting for body mass index (BMI), height or weight (adjusted for: BMI, hazard ratio (HR) 1.49, 95% Confidence Interval (1.22-1.80); height, HR 1.27 (1.03-1.56); weight, 1.33 (1.06-1.65)). Height and weight were associated with increased risk of AF in multivariable analyses adjusting for body composition measures. When adjusting for total lean mass, only height remained statistically significant (HR 1.34 (1.09-1.64)). In a cohort of elderly Caucasian women, high lean body mass, height and weight were associated with increased risk of AF and the variables remained significant after adjusting for age and other known risk factors of AF.

A pharmacokinetic and pharmacodynamic comparison of synthetic and recombinant oral salmon calcitonin.

The aim of this study was to assess the bioavailability and pharmacodynamic efficacy of synthetic salmon calcitonin (ssCT) and recombinant salmon calcitonin (rsCT) in healthy postmenopausal women. The study was a single-blind, randomized study. Participants were 36 postmenopausal women 62 to 74 years old, randomly assigned to a comparison of dosing with ssCT (n = 12) or rsCT (n = 24) given in the morning at 08:00. Study parameters were plasma CT levels measured up to 2 hours postdose and changes in the bone resorption marker serum CTX-I and the cartilage degradation marker urine CTX-II measured up to 4 hours postdose. For both formulations, peak plasma concentrations were obtained 15 minutes after dosage, and no statistically significant differences in the uptake of CT were observed. Measurement of bone resorption and cartilage degradation markers displayed comparable responses, with AUCs of relative change of serum CTX-I of -250% x hours and relative change of urine CTX-II of -180% x hours during the 4-hour observation period. In conclusion, oral synthetic and recombinant calcitonin displayed comparable pharmacodynamic and kinetic properties.

Influence of food intake on the bioavailability and efficacy of oral calcitonin.

AIMS: To investigate the influence of food intake on the bioavailability and pharmacodynamic effects of salmon calcitonin (sCT). METHODS: A single-blind, randomized, partly placebo-controlled study was conducted in 36 healthy postmenopausal female volunteers aged 62-74 years. The influence of food intake on oral dosing with 0.8 mg of sCT at 22.00 h was evaluated for a (i) predose meal at 18.00 h, (ii) predose meal at 20.00 h, (iii) predose meal at 21.00 h, (iv) postdose meal at 22.10 h, (v) no meal, and (vi) meal at 20.00 h and placebo at 22.00 h. Study biomarkers were plasma sCT levels and changes in the bone resorption marker CTX-I (C-terminal telopeptide of collagen type I). RESULTS: The predose meal at 18.00 and 21.00 h significantly decreased relative oral bioavailability of sCT to 26% [95% confidence interval (CI) 0.09, 0.73 and 0.09, 0.75, P= 0.009 and P= 0.01]. The meal consumed 10 min after dosing decreased the oral bioavailability of sCT to 59% (95% CI 0.21, 1.68), although nonsignificant (P= 0.48). This decreased bioavailability led to lower relative suppression of serum CTX-I, with an AUC of the 4-h efficacy response of -91%-x-hours for those receiving a meal at 18.00 h, compared with -238%-x-hours for fasting subjects. The Dunnett-adjusted difference between these two treatment sequences was 147%-x-hours (95% CI 68, 225) (P= 0.0003). The AUC was comparable among fasting subjects and those consuming a meal 10 min after dosing. CONCLUSIONS: Postprandial dosing may limit the bioavailability of orally administered sCT. Maximal benefit can be achieved by dosing at least 10 min prior to meal time.

Optimizing bioavailability of oral administration of small peptides through pharmacokinetic and pharmacodynamic parameters: the effect of water and timing of meal intake on oral delivery of Salmon Calcitonin.

BACKGROUND: To investigate the influence of water intake and dose timing on the pharmacokinetic and pharmacodynamic parameters of an oral formulation of salmon calcitonin (sCT). METHODS: The study was a randomized, partially-blind, placebo-controlled, single dose, exploratory crossover phase I study. 56 healthy postmenopausal women were randomly assigned to receive five treatments. The treatments comprised a combination of study medication (SMC021 (0.8 mg sCT + 200 mg 5-CNAC), SMC021 placebo, or 200 IU Miacalcic NS nasal spray), water volume given with the tablet (50 or 200 ml water), and time between dosing and meal (10, 30, or 60 minutes pre-meal). Plasma sCT levels and changes in the bone resorption (C-terminal telopeptide of collagen type I) was investigated. Trial regristration. RESULTS: Oral delivery of 0.8 mg of sCT with 50 ml of water compared to that with 200 ml water resulted in a two-fold increase in maximum concentration (Cmax and AUC0-4) of plasma sCT but comparable time to reach maximum concentration (Tmax). The sCT AUC0-4 with 50 ml of water was 4-fold higher than that obtained with nasal calcitonin. The increased absorption of sCT resulted in increased efficacy demonstrated by AUC of the relative change of serum CTX-I measured in the 6 hours post dosing. CONCLUSION: 0.8 mg sCT with 50 ml of water taken 30 and 60 minutes prior to meal time resulted in optimal pharmacodynamic and pharmacokinetic parameters. The data suggest that this novel oral formulation may have improved absorption and reduction of bone resorption compared to that of the nasal form.

A randomized, double-blind, multicenter, placebo-controlled study to evaluate the efficacy and safety of oral salmon calcitonin in the treatment of osteoporosis in postmenopausal women taking calcium and vitamin D.

This randomized, double-blind, placebo-controlled phase III study was conducted to assess the efficacy and safety of oral calcitonin (SMC021) for the treatment of postmenopausal osteoporosis. A total of 4665 postmenopausal women with osteoporosis were randomized 1:1 to receive calcium and vitamin D plus either SMC021 tablets (0.8mg/d) or placebo for 36months. The primary endpoint was the proportion of patients with a new vertebral fracture. The two groups were well balanced at baseline with regards to demographic and clinical data. No effect of SMC021 on preventing new vertebral fractures was observed, nor was any effect seen on new hip or non-vertebral fractures. Women receiving SMC021 had a mean 1.02% (±0.12%) increase in lumbar spine bone mineral density (BMD) compared with a mean 0.18% (±0.12%) increase in the placebo group by the end of the study (p<0.0001). Similarly, small increases in BMD were observed at the femoral neck and hip in both groups. Levels of the biomarkers of bone turnover, urinary CTX-I and CTX-II, were 15% lower in the SMC021 group than in the placebo arm at 12 and 24months, but not at 36months. No change in quality of life between groups, assessed by the Qualeffo-14 questionnaire, was observed in either group between baseline and month 36. Pharmacokinetics analysis confirmed exposure to SMC021, but the drug levels were markedly lower than expected. Approximately 92% of subjects in each treatment group experienced an adverse event (AE), the majority of which were mild or moderate in intensity. AEs associated with SMC021 were primarily of gastrointestinal origin and included nausea, vomiting and abdominal pain, as well as hot flushes which were the reason for the slightly higher drop-out rate in the active treatment arm compared to placebo. The number of severe AEs was low in both groups. Thirty-five deaths were reported but none were considered treatment-related. Due to the lack of efficacy in preventing fractures, the development of the orally formulated calcitonin was terminated despite the promising results in earlier studies.