Long-term administration of intravenous Trappsol® Cyclo™ (HP-ß-CD) results in clinical benefits and stabilization or slowing of disease progression in patients with Niemann-Pick disease type C1: Results of an international 48-week Phase I/II trial.

Background: Niemann-Pick disease type C (NPC) is a rare, fatal, pan-ethnic, autosomal recessive lysosomal storage disease characterized by progressive major organ failure and neurodegeneration. Preclinical studies confirmed a critical role of systemically administered hydroxypropyl-ß-cyclodextrin (HP-ß-CD; Trappsol® Cyclo™) in cholesterol metabolism and homeostasis in peripheral tissues of the body, including the liver, and in the central nervous system (CNS). Herein, the pharmacokinetics (PK), safety, and efficacy of HP-ß-CD, and biomarkers of NPC were assessed in pediatric and adult patients with NPC1. Methods: This was a multicenter, Phase I/II, randomized, double-blind, parallel-group, 48-week study (ClinicalTrials.gov identifier NCT02912793) to compare the PK of three different single intravenous (IV) doses of HP-ß-CD in pediatric and adult patients with NPC1 and to evaluate the efficacy and tolerability of three different dosages of HP-ß-CD in patients with NPC1 after long-term treatment. Twelve patients aged at least 2 years (2-39 years of age) with a confirmed diagnosis of NPC1 were randomized to receive one of three IV doses of HP-ß-CD (1500 mg/kg, 2000 mg/kg, or 2500 mg/kg) every 2 weeks for 48 weeks. All patients received HP-ß-CD; there was no placebo or other control. PK testing of plasma and cerebrospinal fluid (CSF) was at set times after the first infusion. Pharmacodynamic assessments included biomarkers of cholesterol metabolism (synthesis and breakdown products), N-palmitoyl-O-phosphocholineserine (PPCS), and specific biomarkers of CSF neurodegeneration (including total Tau), CNS inflammation (glial fibrillary acidic protein [GFAP] and tumor necrosis factor α [TNFα]), CNS cholesterol metabolism (24S-hydroxycholesterol) and inflammatory markers. Efficacy measures included clinical disease severity, neurologic symptoms, and clinical impressions of improvement. Safety assessment included physical examination, vital signs, clinical safety laboratory assessment and adverse events (AEs). Results: Nine patients completed the study, 2 in the 1500 mg/kg group, 4 in the 2000 mg/kg group and 3 in the 2500 mg/kg group. Three patients (all in the 1500 mg/kg group) discontinued the study because of either physician decision/site Principal Investigator (PI) discretion, withdrawal by subject/patient/parent/guardian, or other non-safety reasons. In 5 patients who underwent serial lumbar punctures, HP-ß-CD was detected in the CSF. Of the 9 patients who completed the study, 8 (88.9%) improved in at least two domains of the 17-Domain Niemann-Pick disease Type C-Clinical Severity Scale (17D-NPC-CSS), and 6 of these patients improved in at least one domain viewed by patients and their caregivers to be key to quality of life, namely, speech, swallow, fine and gross motor skills, and cognition. Of the 9 patients who completed the study, 7 were viewed by their treating physicians as having improved to some degree at the end of the study, and 2 remained stable; both outcomes are highly relevant in a progressive neurodegenerative disease. Some patients and families reported improvement in quality of life.All three doses of HP-ß-CD were well tolerated overall, with most treatment-emergent adverse events transient, mild-to-moderate in nature, and considered by the site PIs to be not related to study drug. Interpretation: This 48-week trial is the longest to date to evaluate the safety, tolerability, and efficacy across multiple clinical endpoints of IV administration of Trappsol® Cyclo™ (HP-ß-CD) in NPC1 patients. In pediatric and adult patients with NPC, Trappsol® Cyclo™ IV improved clinical signs and symptoms and was generally well tolerated. The findings presented here demonstrate a favorable benefit-risk profile and support the global pivotal trial now underway to evaluate the long-term treatment benefits and the potential of Trappsol® Cyclo™ as a disease-modifying treatment in this patient population.

Interim results from an ongoing, open-label, single-arm trial of odevixibat in progressive familial intrahepatic cholestasis.

Background & Aims: PEDFIC 2, an ongoing, open-label, 72-week study, evaluates odevixibat, an ileal bile acid transporter inhibitor, in patients with progressive familial intrahepatic cholestasis. Methods: PEDFIC 2 enrolled and dosed 69 patients across two cohorts; all received odevixibat 120 µg/kg per day. Cohort 1 comprised children from PEDFIC 1, and cohort 2 comprised new patients (any age). We report data through 15 July 2020, with Week 24 of PEDFIC 2 the main time point analysed. This represents up to 48 weeks of cumulative exposure for patients treated with odevixibat from the 24-week PEDFIC 1 study (cohort 1A) and up to 24 weeks of treatment for those who initiated odevixibat in PEDFIC 2 (patients who received placebo in PEDFIC 1 [cohort 1B] or cohort 2 patients). Primary endpoints for this prespecified interim analysis were change from baseline to Weeks 22-24 in serum bile acids (sBAs) and proportion of positive pruritus assessments (≥1-point drop from PEDFIC 2 baseline in pruritus on a 0-4 scale or score ≤1) over the 24-week period. Safety monitoring included evaluating treatment-emergent adverse events (TEAEs). Results: In cohort 1A, mean change from PEDFIC 1 baseline to Weeks 22-24 of PEDFIC 2 in sBAs was -201 µmol/L (p <0.0001). For cohort 1B and cohort 2, mean changes from odevixibat initiation to weeks 22-24 in sBAs were -144 and -104 µmol/L, respectively. The proportion of positive pruritus assessments in the first 24-week period of PEDFIC 2 was 33%, 56%, and 62% in cohorts 1A, 1B, and 2, respectively. Most TEAEs were mild or moderate. No drug-related serious TEAEs occurred. Conclusions: Odevixibat in patients with progressive familial intrahepatic cholestasis was generally well tolerated and associated with sustained reductions in sBAs and pruritus. Clinical Trials Registration: This study is registered at ClinicalTrials.gov (NCT03659916). Impact and Implications: Disrupted bile flow is a hallmark feature of patients with progressive familial intrahepatic cholestasis and can result in build-up of bile constituents in the liver with spill over into the bloodstream; other effects that patients can experience include extremely itchy skin, and because not enough bile reaches the gut, patients can have problems digesting food, which may lead to poor growth. Odevixibat is an orally administered medication that shunts bile acids away from the liver. The current study, called PEDFIC 2, suggested that odevixibat can improve the problematic signs and symptoms of progressive familial intrahepatic cholestasis and was generally safe for patients.

Development of the Patient- and Observer-Reported PRUCISION Instruments to Assess Pruritus and Sleep Disturbance in Pediatric Patients with Cholestatic Liver Diseases.

INTRODUCTION: Understanding how patients experience their disease is a vital step in optimal disease management, and patient- and observer-reported outcome (PRO and ObsRO, respectively) measures can add important details to clinical information that is obtained as novel treatments are developed. Instruments that measure meaningful symptoms and impacts from the perspective of pediatric patients with cholestatic liver disease or their caregivers are needed. This study aimed to identify salient concepts in pediatric cholestatic liver disease, develop novel PRO and ObsRO instruments, and establish the instruments' content validity. METHODS: Relevant signs, symptoms, and impacts of cholestatic liver disease were identified through a literature review, interviews with expert clinicians, and concept elicitation interviews with children and caregivers of children who had progressive familial intrahepatic cholestasis (PFIC), Alagille syndrome, biliary atresia, or primary sclerosing cholangitis. Additional cognitive debriefing interviews with patients and caregivers were performed to ensure that participants could understand the instructions, questions, and response scales of the PRO and ObsRO instruments, with modifications made as necessary to improve comprehension and/or usability. RESULTS: A total of 36 interviews with patients and caregivers were conducted. Pruritus and sleep disturbance (e.g., difficulty falling or staying asleep due to itch) were identified as the most problematic symptom and significant impact, respectively, of the pediatric cholestatic liver diseases assessed. The ObsRO and PRO instruments, called PRUCISION, focus on these key disease features in the morning and evening. Several modifications were made to the draft instruments following cognitive interviews. The final PRUCISION PRO and ObsRO measures are designed as an electronic diary to be completed twice daily. The response scales include pictorial, verbal, and numeric scales. CONCLUSION: Novel PRO and ObsRO PRUCISION instruments were created that evaluate the patient experience of cholestatic pruritus in children with PFIC and other cholestatic liver diseases. The content validity of the PRUCISION instruments is established.

Bile, a greenish liquid that is made in the liver, is released into the gut to help digest food. In cholestatic liver disease (CLD), bile flow is interrupted, and bile can build up in the body. One potential effect of this buildup is pruritus, or itchiness of the skin, which can be so intense that it interferes with daily activities. In this study, interviews were done with doctors, patients, and their caregivers to develop new tools to evaluate the most impactful symptoms of CLD in children. After interviewing five doctors and 36 patients and caregivers, two questionnaires called PRUCISION were developed and refined. During this process, participants were first asked about the frequency, severity, duration, and impact of their or their child's symptoms; pruritus was identified as the most common and disruptive symptom associated with CLD, even interfering with sleep. Then, the wording of the questionnaires was modified to make them easier to understand, particularly for younger children. The researchers also had patients do a card-sorting task to ensure that they understood the picture-based responses used in the questionnaires. Finally, more details were added to the instructions for caregivers to more clearly define scratching behaviors. In summary, the questionnaires developed in this study include the perspective of the patient or their caregiver and may be useful to see if new treatments can impact the most prominent symptoms and impacts associated with CLD.

Validation of the PRUCISION Instruments in Pediatric Patients with Progressive Familial Intrahepatic Cholestasis.

INTRODUCTION: Patients with cholestatic liver disease, including progressive familial intrahepatic cholestasis (PFIC) and Alagille syndrome, may have debilitating pruritus, and reducing pruritus is a key therapeutic goal. However, few instruments are available that adequately measure pruritus in pediatric patients with cholestatic liver disease. The objectives of the current study were to establish the measurement properties of the novel PRUCISION patient-reported outcome (PRO) and observer-reported outcome (ObsRO) instruments and to estimate a threshold for clinically meaningful change in pruritus score. METHODS: The PRO/ObsRO instruments are completed twice daily via electronic diary and include 5-point pictorial responses to assess pruritus. Sleep disturbance and tiredness were quantified using 5-point pictorial responses, yes/no responses, and numerical ratings. Data from PEDFIC 1 (NCT03566238), a phase 3 study evaluating odevixibat efficacy and safety in children with PFIC, were used to assess the psychometric properties of these instruments. Quantitative assessments included evaluation of test-retest reliability, determination of construct validity via convergent and known-group validity analyses, and characterization of sensitivity to change. A threshold for within-patient meaningful change from baseline to week 24 was determined using blinded data from PEDFIC 1 and distribution- and anchor-based analyses. RESULTS: Because the majority of patients in PEDFIC 1 were aged < 8 years (n = 52/62) and thus too young to complete the PRO instrument, which was intended for patients aged ≥ 8 years, the small sample size of patients who completed the PRO precluded a full psychometric analysis of the PRO instrument. The ObsRO was completed by a caregiver of every patient in PEDFIC 1. The ObsRO instrument had acceptable test-retest reliability based on intraclass correlation values (most > 0.75). Convergent validity analyses revealed moderate-to-strong correlations (r ≥ 0.3) between baseline ObsRO pruritus scores and baseline Global Impression of Symptoms (GIS) items. In known-groups validity analyses, there were significant differences between baseline groups defined by the GIS for ObsRO pruritus scores and for some sleep disturbance scores. Week 24 ObsRO scores were in the expected direction in groups defined by the Global Impression of Change scale (i.e., improved or not improved); many mean differences between these groups were significant. Sensitivity to change for the ObsRO PRUCISION instrument was also demonstrated by moderate-to-strong Pearson correlations between change from baseline to weeks 21-24 in ObsRO scores and GIS items (r ≥ 0.3). Based on these analyses, a within-patient change of -1.00 from baseline in ObsRO pruritus score was determined to be clinically meaningful. CONCLUSION: The PRUCISION ObsRO instrument is reliable, valid, and sensitive to change, supporting its use as a tool to measure pruritus and sleep disturbance in patients with PFIC and other pediatric cholestatic liver diseases.

Progressive familial intrahepatic cholestasis (PFIC) is a collection of liver diseases that typically affects very young children. A problematic symptom of PFIC is extremely itchy skin, or pruritus, that can keep patients and their families up at night. The PRUCISION questionnaire was developed to measure the severity of a patient's pruritus and sleep disturbance from the perspective of the patient's caregiver. The current study had two primary goals: (1) to assess whether PRUCISION could reliably measure these symptoms and detect changes over time relative to other established rating scales that assess related concepts, and (2) to identify what score change on PRUCISION could be considered clinically meaningful. To do this, data from a clinical study, called PEDFIC 1, in patients with PFIC were used: patient's scores on PRUCISION from their caregiver's perspective were compared with scores on other established scales, first before any treatment was given in PEDFIC 1, and then again after 24 weeks of treatment with a drug called odevixibat. In general, there was good agreement between PRUCISION scores and scores on other scales. For example, when PRUCISION scores indicated that symptoms improved, this tended to correlate with improvement on other measures. Additionally, these analyses indicated that if the PRUCISION score drops by 1 point or more, that can be considered a clinically important change. Overall, this study found that the caregiver-reported PRUCISION questionnaire is valid for assessing changes in pruritus and sleep symptoms in patients with PFIC, which may benefit patients as new treatments are developed.

Odevixibat treatment in progressive familial intrahepatic cholestasis: a randomised, placebo-controlled, phase 3 trial.

BACKGROUND: Progressive familial intrahepatic cholestasis (PFIC) is a group of inherited paediatric liver diseases resulting from mutations in genes that impact bile secretion. We aimed to evaluate the effects of odevixibat, an ileal bile acid transporter inhibitor, versus placebo in children with PFIC. METHODS: Patients eligible for this 24-week, randomised, double-blind, completed, phase 3 study were paediatric outpatients diagnosed with PFIC1 or PFIC2 who had pruritus and elevated serum bile acids at screening. Patients were randomly assigned (1:1:1) using an interactive web-based system to once a day oral placebo, odevixibat 40 µg/kg, or odevixibat 120 µg/kg. Randomisation was done in a block size of six and stratified by PFIC type and patient age; patients, clinicians, and study staff were blinded to treatment allocation. Patients were enrolled at one of 33 global sites. Two primary endpoints were evaluated: proportion of positive pruritus assessments (PPAs; ie, scratching score of ≤1 or ≥1-point decrease as assessed by caregivers using the Albireo observer-reported outcome [ObsRO] PRUCISION instrument) over 24 weeks, and proportion of patients with serum bile acid response (ie, serum bile acids reduced by ≥70% from baseline or concentrations of ≤70 µmol/L) at week 24. Efficacy and safety were analysed in randomly allocated patients who received one or more doses of study drug. This study is registered with ClinicalTrials.gov, NCT03566238. FINDINGS: Between June 21, 2018, and Feb 10, 2020, 62 patients (median age 3·2 [range 0·5-15·9] years) were randomly allocated to placebo (n=20), odevixibat 40 µg/kg per day (n=23), or odevixibat 120 µg/kg per day (n=19). Model-adjusted (least squares) mean proportion of PPAs was significantly higher with odevixibat versus placebo (55% [SE 8] in the combined odevixibat group [58% in the 40 µg/kg per day group and 52% in the 120 µg/kg per day group] vs 30% [SE 9] in the placebo group; model-adjusted mean difference 25·0% [95% CI 8·5-41·5]; p=0·0038). The percentage of patients with serum bile acid response was also significantly higher with odevixibat versus placebo (14 [33%] of 42 patients in the combined odevixibat group [10 in the 40 µg/kg per day group and four in the 120 µg/kg per day group] vs none of 20 in the placebo group; adjusting for stratification factor [PFIC type], the proportion difference was 30·7% [95% CI 12·6-48·8; p=0·0030]). The most common treatment-emergent adverse events (TEAEs) were diarrhoea or frequent bowel movements (13 [31%] of 42 for odevixibat vs two [10%] of 20 for placebo) and fever (12 [29%] of 42 vs five [25%] of 20); serious TEAEs occurred in three (7%) of 42 odevixibat-treated patients and in five (25%) of 20 placebo-treated patients. INTERPRETATION: In children with PFIC, odevixibat effectively reduced pruritus and serum bile acids versus placebo and was generally well tolerated. Odevixibat, administered as once a day oral capsules, is a non-surgical, pharmacological option to interrupt the enterohepatic circulation in patients with PFIC. FUNDING: Albireo Pharma.

Clinical Impact of ITCA 650, a Novel Drug-Device GLP-1 Receptor Agonist, in Uncontrolled Type 2 Diabetes and Very High Baseline HbA1c: The FREEDOM-1 HBL (High Baseline) Study.

OBJECTIVE: ITCA 650 is a subdermal osmotic mini-pump that continuously delivers exenatide subcutaneously for 3-6 months. The efficacy, safety, and tolerability of ITCA 650 added to diet and exercise alone or combined with metformin, sulfonylurea, or thiazolidinedione monotherapy or a combination of these drugs was evaluated in poorly controlled patients with type 2 diabetes (T2D) who were ineligible for participation in a placebo-controlled study (FREEDOM-1) because of severe hyperglycemia (HbA1c >10% [86 mmol/mol]). RESEARCH DESIGN AND METHODS: This 39-week, open-label, phase 3 trial enrolled patients aged 18-80 years with HbA1c >10% to ≤12% (86-108 mmol/mol) and BMI 25-45 kg/m2. Patients received ITCA 650 20 µg/day for 13 weeks, then 60 µg/day for 26 weeks. The primary end point was change in HbA1c at week 39. RESULTS: Sixty patients were enrolled. At baseline, mean HbA1c was 10.8% (94.7 mmol/mol) and mean (± SD) duration of diabetes was 8.6 (± 5.3) years. At week 39, there was a mean reduction in HbA1c of -2.8% (-30.3 mmol/mol; P < 0.001 vs. baseline) and in body weight of -1.2 kg (P = 0.105), and 25% of patients achieved HbA1c <7% (53 mmol/mol). A reduction in HbA1c of ≥1% (≥10.9 mmol/mol) occurred in 90% of patients. The most common adverse events were nausea, vomiting, diarrhea, and headache. Gastrointestinal adverse events were generally transient and subsided over time; only 4 patients (6.7%) discontinued for gastrointestinal events. CONCLUSIONS: Treatment with ITCA 650, the first injection-free glucagon-like peptide 1 receptor agonist, resulted in significant improvements in glycemic control in poorly controlled long-standing T2D patients with a high baseline HbA1c >10%.

Efficacy and Safety of ITCA 650, a Novel Drug-Device GLP-1 Receptor Agonist, in Type 2 Diabetes Uncontrolled With Oral Antidiabetes Drugs: The FREEDOM-1 Trial.

OBJECTIVE: ITCA 650 (exenatide in osmotic mini-pump) continuously delivers exenatide subcutaneously for 3-6 months. Two doses of ITCA 650 were compared with placebo in patients with uncontrolled type 2 diabetes. RESEARCH DESIGN AND METHODS: This 39-week, phase 3, double-blind, placebo-controlled trial randomized 460 patients aged 18-80 years with glycated hemoglobin (HbA1c) 7.5-10% [58-86 mmol/mol] 1:1:1 to placebo, ITCA 650 40 µg/day, or ITCA 650 60 µg/day. Primary end point was change in HbA1c at 39 weeks. RESULTS: Least squares (LS) mean change from baseline HbA1c was -1.1% [-12.2 mmol/mol] and -1.2% [-13.2 mmol/mol] for ITCA 650 40 and 60 µg/day, respectively (P < 0.001 vs. placebo -0.1% [-1.3 mmol/mol]). In a prespecified analysis, greater HbA1c reductions occurred in patients not receiving sulfonylureas (SUs) versus those receiving SUs (-1.7% vs. -1.2% [-18.6 and -13.1 mmol/mol]). At week 39, HbA1c <7% [53 mmol/mol] was attained in 37%, 44%, and 9% of ITCA 650 40 µg/day, ITCA 650 60 µg/day, and placebo groups, respectively (P < 0.001 each dose vs. placebo). LS mean change from baseline body weight was -2.3 kg and -3.0 kg for ITCA 650 40 and 60 µg/day, respectively (P ≤ 0.015 vs. placebo -1.0 kg). Nausea was the most common adverse event (AE) and subsided over time. Discontinuation for gastrointestinal AEs occurred in 7.2% with ITCA and 1.3% with placebo. Most AEs associated with procedures to place and remove ITCA 650 were mild and transient. CONCLUSIONS: ITCA 650 significantly reduced HbA1c and weight compared with placebo and was well tolerated in patients with uncontrolled type 2 diabetes on oral antidiabetes medications.

Quantification of the Contribution of GLP-1 to Mediating Insulinotropic Effects of DPP-4 Inhibition With Vildagliptin in Healthy Subjects and Patients With Type 2 Diabetes Using Exendin [9-39] as a GLP-1 Receptor Antagonist.

We quantified the contribution of GLP-1 as a mediator of the therapeutic effects of dipeptidyl peptidase 4 (DPP-4) inhibition (vildagliptin) by using the GLP-1 receptor antagonist exendin [9-39] in patients with type 2 diabetes and in healthy subjects. Thirty-two patients with type 2 diabetes and 29 age- and weight-matched healthy control subjects were treated in randomized order with 100 mg once daily vildagliptin or placebo for 10 days. Meal tests were performed (days 9 and 10) without and with a high-dose intravenous infusion of exendin [9-39]. The main end point was the ratio of the areas under the curve (AUCs) of integrated insulin secretion rates (total AUCISR) and glucose (total AUCglucose) over 4 h after the meal. Vildagliptin treatment more than doubled responses of intact GLP-1 and glucose-dependent insulinotropic polypeptide and lowered glucose responses without changing AUCISR/AUCglucose in healthy subjects. Vildagliptin significantly increased this ratio by 10.5% in patients with type 2 diabetes, and exendin [9-39] reduced it (both P < 0.0001). The percentage reduction in the AUCISR/AUCglucose ratio achieved with exendin [9-39] was significantly smaller after vildagliptin treatment than after placebo treatment (P = 0.026) and was equivalent to 47 ± 5% of the increments due to vildagliptin. Thus, other mediators appear to contribute significantly to the therapeutic effects of DPP-4 inhibition.

Skeletal muscle mitochondrial capacity and insulin resistance in type 2 diabetes.

OBJECTIVE: The objective of this study was to determine the role of maximum mitochondrial capacity on the variation in insulin sensitivity within a population of patients with type 2 diabetes mellitus (T2DM). RESEARCH DESIGN AND METHODS: Fifty-eight participants enrolled in a cross-sectional design: eight active controls [maximum aerobic capacity (VO(2max)) > 40 ml/kg · min], 17 healthy sedentary controls without a family history (FH-) and seven with a family history (FH+) of diabetes, four obese participants, and 21 patients with T2DM. Mitochondrial capacity was measured noninvasively using (31)P magnetic resonance spectroscopy of the vastus lateralis. Maximal ATP synthetic rate (ATP(max)) was determined from the rate of phosphocreatine (PCr) recovery after short-term isometric exercise. RESULTS: ATP(max) was lower (P < 0.001) in T2DM and higher (P < 0.001) in active as compared with healthy sedentary FH- (active, 1.01 ± 0.2; FH-, 0.7 ± 0.2; FH+, 0.6 ± 0.1; obese, 0.6 ± 0.1; T2DM, 0.5 ± 0.2 mm ATP/sec; ANOVA P < 0.0001). Insulin sensitivity, measured by euglycemic-hyperinsulinemic (80 mIU/m(2) · min) clamp was also reduced in T2DM (P < 0.001) (active, 12.0 ± 3.2; FH-, 7.8 ± 2.2; FH+, 6.8 ± 3.5; obese, 3.1 ± 1.0; T2DM, 3.4 ± 1.6; mg/kg estimated metabolic body size · min; ANOVA P < 0.0001). Unexpectedly, there was a broad range of ATP(max) within the T2DM population where 52% of subjects with T2DM had ATP(max) values that were within the range observed in healthy sedentary controls. In addition, 24% of the T2DM subjects overlapped with the active control group (range, 0.65-1.27 mm ATP/sec). In contrast to the positive correlation between ATP(max) and M-value in the whole population (r(2) = 0.35; P < 0.0001), there was no correlation between ATP(max) and M-value in the patients with T2DM (r(2) = 0.004; P = 0.79). CONCLUSIONS: Mitochondrial capacity is not associated with insulin action in T2DM.

Treatment of patients with cardiovascular disease with L-4F, an apo-A1 mimetic, did not improve select biomarkers of HDL function.

L-4F, an apolipoprotein A-I (apoA-I) mimetic peptide (also known as APL180), was administered daily by either intravenous (IV) infusion for 7 days or by subcutaneous (SC) injection for 28 days in patients with coronary heart disease in two distinct clinical studies. L-4F was well tolerated at all doses tested. Despite achieving plasma levels (mean maximal plasma concentration of 2,907 ng/ml and 395 ng/ml, following IV infusion and SC injection, respectively), that were effective in previously published animal models, treatment with L-4F, as assessed by biomarkers of HDL function such as HDL-inflammatory index (HII), and paraoxonase activity, did not improve. Paradoxically, there was a 49% increase in high-sensitivity C-reactive protein (hs-CRP) levels after seven IV infusions of 30 mg L-4F (P < 0.05; compared with placebo) and a trend for hs-CRP increase in subjects receiving 30 mg SC injection for 28 days. In a subsequent, ex vivo study, addition of L-4F at concentrations of 150, 375, or 1,000 ng/ml to plasma from subjects prior to L-4F treatment resulted in significant dose-dependent HII improvement. In conclusion, in vivo L-4F treatment, delivered by either SC injection or IV infusion, did not improve HDL functional biomarkers despite achieving plasma levels that improved identical biomarkers ex vivo and in animal models.

Pharmacokinetics and pharmacodynamics of vildagliptin in healthy Chinese volunteers.

Vildagliptin is an orally effective, potent, and selective inhibitor of dipeptidyl peptidase IV (DPP-4) that improves glycemic control in patients with type 2 diabetes. This was a randomized, double-blind, placebo-controlled, time-lagged, parallel-group study in a total of 60 healthy Chinese participants. Single- and multiple-dose pharmacokinetics and pharmacodynamics, and safety and tolerability of vildagliptin were assessed following administration of 25, 50, 100, or 200 mg qd, or 50 mg bid. Vildagliptin was rapidly absorbed (tmax 1.5-2.0 hours) across the dose range of 25 to 200 mg and was quickly eliminated with a terminal elimination half-life (t1/2) of approximately 2 hours. Consistent with the short t1/2, no accumulation of vildagliptin was observed following the administration of multiple doses (accumulation factors were 1.00-1.05 across the 25- to 200-mg dose range). Vildagliptin AUC and Cmax values increased in an approximately dose-proportional fashion (dose proportionality constant beta 1.00-1.16). Administration of vildagliptin 25 to 200 mg led to rapid and near-complete (>95%) inhibition of DPP-4 activity for at least 4 hours after dosing, which was associated with increases in plasma active glucagon-like peptide-1 of up to 2- to 3-fold compared with placebo. The duration of DPP-4 inhibition increased with dose. Glucose and insulin levels were not affected by vildagliptin in healthy participants, consistent with the fact that the glucose-lowering effects of vildagliptin occur in a glucose-dependent fashion. Vildagliptin was well tolerated at the highest tested dose of 200 mg qd. Vildagliptin 25 to 200 mg qd exhibits approximately dose-proportional pharmacokinetics with no evidence of accumulation after multiple dosing in healthy Chinese participants. Vildagliptin demonstrates potent inhibition of DPP-4 activity with excellent tolerability at doses of up to and including 200 mg qd.

Effects of short-term caloric restriction on circulating free IGF-I, acid-labile subunit, IGF-binding proteins (IGFBPs)-1-4, and IGFBPs-1-3 protease activity in obese subjects.

OBJECTIVE: Decreased levels of GH and total IGF-I have been reported in obesity. It has been hypothesized that increased free (biologically active) IGF-I levels generated from IGF-binding protein (IGFBP) protease activity could be the mechanism for the low GH release in dieting obese subjects. However, no published data exist on free IGF-I levels, acid labile subunit (ALS), or IGFBP protease activity in relation to GH release during a hypocaloric diet. The main purpose of this study was to determine free IGF-I, ALS, IGFBPs-1-4, and IGFBPs-1-3 protease activity in relation to 24-h GH release before and after a short-term very low-calorie diet (VLCD). DESIGN: Six obese subjects before weight loss, five after an average weight loss of 36.1 kg, and five age-and sex-matched lean controls underwent a 4-day VLCD. All subjects were studied on two occasions, once during normal basic diet and again during the last day of the VLCD (1.6 MJ). METHODS: Free IGF-I was determined by a non-competitive immunoradiometric assay. RESULTS: Free IGF-I levels decreased in concert with increased ALS and unchanged blunted GH release after a VLCD in the obese subjects. IGFBPs-1-3 proteolytic activity was found to be unchanged by hypocaloric diet in all groups. CONCLUSIONS: We conclude that free IGF-I decreases after a short-term hypocaloric diet in obese subjects with no concomitant change in 24-h GH release. Circulating free IGF-I per se cannot be the main mechanism of the attenuated GH release in dieting obese subjects.

Postprandial suppression of glucagon secretion depends on intact pulsatile insulin secretion: further evidence for the intraislet insulin hypothesis.

Type 2 diabetes is characterized by an approximately 60% loss of beta-cell mass, a marked defect in postprandial insulin secretion, and a failure to suppress postprandial glucagon concentrations. It is possible that postprandial hyperglucagonemia in type 2 diabetes is due to impaired postprandial insulin secretion. To address this, we studied eight adult Goettingen minipigs before and after an approximately 60% reduction in beta-cell mass induced by alloxan. Pigs were studied fasting and after ingestion of a mixed meal. Insulin and glucagon secretion were determined by deconvolution of blood hormone concentrations measured at 1-min intervals. The relationship between insulin and glucagon release was analyzed using cross-correlation and forward versus reverse cross-approximate entropy. We report that glucagon and insulin were secreted in approximately 4-min pulses. Prealloxan, postprandial insulin secretion drove an approximately 20% suppression of glucagon concentrations (P < 0.01), through inhibition of glucagon pulse mass. The alloxan-induced approximately 60% deficit in beta-cell mass lead to an approximately 70% deficit in postprandial insulin secretion and loss of the postprandial insulin-driven suppression of glucagon secretion. We conclude that postprandial hyperglucagonemia in type 2 diabetes is likely due to loss of intraislet postprandial suppression of glucagon secretion by insulin.

The influence of GLP-1 on glucose-stimulated insulin secretion: effects on beta-cell sensitivity in type 2 and nondiabetic subjects.

The intestinally derived hormone glucagon-like peptide 1 (GLP-1) (7-36 amide) has potent effects on glucose-mediated insulin secretion, insulin gene expression, and beta-cell growth and differentiation. It is, therefore, considered a potential therapeutic agent for the treatment of type 2 diabetes. However, the dose-response relationship between GLP-1 and basal and glucose-stimulated prehepatic insulin secretion rate (ISR) is currently not known. Seven patients with type 2 diabetes and seven matched nondiabetic control subjects were studied. ISR was determined during a graded glucose infusion of 2, 4, 6, 8, and 12 mg x kg(-1) x min(-1) over 150 min on four occasions with infusion of saline or GLP-1 at 0.5, 1.0, and 2.0 pmol x kg(-1) x min(-1). GLP-1 enhanced ISR in a dose-dependent manner during the graded glucose infusion from 332 +/- 51 to 975 +/- 198 pmol/kg in the patients with type 2 diabetes and from 711 +/- 123 to 2,415 +/- 243 pmol/kg in the control subjects. The beta-cell responsiveness to glucose, expressed as the slope of the linear relation between ISR and the glucose concentration, increased in proportion to the GLP-1 dose to 6 times relative to saline at the highest GLP-1 dose in the patients and 11 times in the control subjects, but it was 3 to 5 times lower in the patients with type 2 diabetes compared with healthy subjects at the same GLP-1 dose. During infusion of GLP-1 at 0.5 pmol x kg(-1) x min(-1) in the patients, the slope of ISR versus glucose became indistinguishable from that of the control subjects without GLP-1. Our results show that GLP-1 increases insulin secretion in patients with type 2 diabetes and control subjects in a dose-dependent manner and that the beta-cell responsiveness to glucose may be increased to normal levels with a low dose of GLP-1 infusion. Nevertheless, the results also indicate that the dose-response relation between beta-cell responsiveness to glucose and GLP-1 is severely impaired in patients with type 2 diabetes.

Pulsatile insulin secretion by human pancreatic islets.

Insulin is secreted in discrete bursts. These pulses are also present when individual or groups of islets are perifused. Interpretation of the measured frequency and magnitude of pulsatile hormone secretion requires an examination of the sensitivity and specificity of the methods for pulse detection and validation of these for the experimental apparatus and hormone assay in which they are applied. In the present study we achieve these aims for a perfusion method for measurement of pulsatile insulin release by human islets. A deconvolution technique previously developed for measurement of pulsatile hormone secretion in vivo was specifically validated for in vitro pulse detection in the present study. Deconvolution analysis reliably (>90%) detected insulin pulses with an amplitude 20% or more above baseline and recovered quantitatively the insulin secretion profile, insulin secretion rate, and insulin pulse mass from single as well as multiple perifused islets. Cluster analysis was less sensitive, but was able to detect most (>80%) pulses with an amplitude of 40% or more above baseline. With this limitation, cluster analysis is potentially useful for groups, but not single perifused human islets. Analysis of single human islets showed that enhanced insulin secretion by increased glucose concentrations in the perfusate is achieved by enhancing insulin pulse mass with no change in pulse frequency. Perfused single or groups of human islets exhibited an interpulse interval ( approximately 6-8 min) comparable to that observed in humans in vivo. Dynamic in vitro perifusion should facilitate studies of the mechanisms driving pulsatile insulin secretion.

Do oscillations of insulin secretion occur in the absence of cytoplasmic Ca2+ oscillations in beta-cells?

That oscillations of the cytoplasmic free Ca(2+) concentration ([Ca(2+)](i)) in beta-cells induce oscillations of insulin secretion is not disputed, but whether metabolism-driven oscillations of secretion can occur in the absence of [Ca(2+)](i) oscillations is still debated. Because this possibility is based partly on the results of experiments using islets from aged, hyperglycemic, hyperinsulinemic ob/ob mice, we compared [Ca(2+)](i) and insulin secretion patterns of single islets from 4- and 10-month-old, normal NMRI mice to those of islets from 7- and 10-month-old ob/ob mice (Swedish colony) and their lean littermates. The responses were subjected to cluster analysis to identify significant peaks. Control experiments without islets and with a constant insulin concentration were run to detect false peaks. Both ob/ob and NMRI islets displayed large synchronous oscillations of [Ca(2+)](i) and insulin secretion in response to repetitive depolarizations with 30 mmol/l K(+) in the presence of 0.1 mmol/l diazoxide and 12 mmol/l glucose. Continuous depolarization with high K(+) steadily elevated [Ca(2+)](i) in all types of islets, with no significant oscillation, and caused a biphasic insulin response. In islets from young (4-month-old) NMRI mice and 7-month-old lean mice, the insulin profile did not show significant peaks when [Ca(2+)](i) was stable. In contrast, two or more peaks were detected over 20 min in the response of most ob/ob islets. Similar insulin peaks appeared in the insulin response of 10-month-old lean and NMRI mice. However, the size of the insulin peaks detected in the presence of stable [Ca(2+)](i) was small, so that no more than 10-13% of total insulin secretion occurred in a pulsatile manner. In conclusion, insulin secretion does not oscillate when [Ca(2+)](i) is stably elevated in beta-cells from young normal mice. Some oscillations are observed in aged mice and are seen more often in ob/ob islets. These fluctuations of the insulin secretion rate at stably elevated [Ca(2+)](i), however, are small compared with the large oscillations induced by [Ca(2+)](i) oscillations in beta-cells.