Short-term variability of the human serum metabolome depending on nutritional and metabolic health status.

The intra-individual variability of the human serum metabolome over a period of 4 weeks and its dependence on metabolic health and nutritional status was investigated in a single-center study under tightly controlled conditions in healthy controls, pre-diabetic individuals and patients with type-2 diabetes mellitus (T2DM, n = 10 each). Untargeted metabolomics in serum samples taken at three different days after overnight fasts and following intake of a standardized mixed meal showed that the human serum metabolome is remarkably stable: The median intra-class correlation coefficient (ICC) across all metabolites and all study participants was determined as 0.65. ICCs were similar for the three different health groups, before and after meal intake, and for different metabolic pathways. Only 147 out of 1438 metabolites (10%) had an ICC below 0.4 indicating poor stability over time. In addition, we confirmed previously identified metabolic signatures differentiating healthy, pre-diabetic and diabetic individuals. To our knowledge, this is the most comprehensive study investigating the temporal variability of the human serum metabolome under such tightly controlled conditions.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of macimorelin in healthy adults: Results of a single-dose, randomized controlled study.

OBJECTIVE: Macimorelin is an orally active ghrelin receptor agonist indicated for the diagnosis of adult growth hormone (GH) deficiency in the United States. This phase 1 study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending doses of macimorelin (including a supratherapeutic dose to be used in a thorough QT trial) in healthy adults. DESIGN: Participants were randomized to receive macimorelin 0.5, 1.0, or 2.0 mg/kg or placebo in 1 of 3 sequential ascending-dose cohorts. Blood samples for pharmacokinetic and pharmacodynamic assays were collected pre-dose and at specified time points over a 24-h period. Pharmacokinetic parameters assessed included area under the concentration-time curve (AUC), maximum concentration (Cmax) of macimorelin in plasma, time to Cmax (tmax), and terminal elimination half-life (t1/2). Pharmacodynamic assessments evaluated levels of GH, adrenocorticotropic hormone, thyroid-stimulating hormone, cortisol, and prolactin. Safety was assessed based on treatment-emergent adverse events (TEAEs), vital signs, 12­lead electrocardiograms, and laboratory parameters. RESULTS: A total of 28 healthy adults were enrolled and completed the study. Macimorelin AUC and Cmax showed less than dose-proportional increases following administration of 0.5 and 1.0 mg/kg. Mean t1/2 was 3.51 h for macimorelin 0.5 and 1.0 mg/kg and 8.29 h for macimorelin 2.0 mg/kg; median tmax occurred at 0.5 to 0.75 h. GH levels increased after dosing, with a tmax of 0.75 h to 1.0 h. Mean GH Cmax was similar with the macimorelin 0.5- and 1.0-mg/kg doses (31.9 and 37.8 ng/mL, respectively) and was ~50% lower with macimorelin 2.0 mg/kg (18.4 ng/mL). Transient increases were observed in adrenocorticotropic hormone, cortisol, and prolactin, which were not dose related. A total of 19 TEAEs were reported in 35.7% (10/28) of participants; all TEAEs were mild or moderate and resolved. A total of 12 drug-related TEAEs were reported in 8 participants. Headache was the most common drug-related TEAE. All doses of macimorelin prolonged mean QTcF by 10 to 11 ms. There were no clinically meaningful changes in vital signs or laboratory parameters. CONCLUSIONS: Single-dose administration of macimorelin 0.5 to 2.0 mg/kg was well tolerated. Macimorelin exposure was less than dose-proportional over the dose range studied. Administration of macimorelin stimulated GH production, with the greatest increases observed in the macimorelin 0.5- and 1.0-mg/kg groups.

Efficacy, Safety, and Mechanistic Insights of Cotadutide, a Dual Receptor Glucagon-Like Peptide-1 and Glucagon Agonist.

CONTEXT: Cotadutide is a dual receptor agonist with balanced glucagon-like peptide-1 and glucagon activity. OBJECTIVE: To evaluate different doses of cotadutide and investigate underlying mechanisms for its glucose-lowering effects. DESIGN/SETTING: Randomized, double-blind, phase 2a study conducted in 2 cohorts at 5 clinical trial sites. PATIENTS: Participants were 65 adult overweight/obese patients with type 2 diabetes mellitus; 63 completed the study; 2 were withdrawn due to AEs. INTERVENTION: Once-daily subcutaneous cotadutide or placebo for 49 days. Doses (50-300 µg) were uptitrated weekly (cohort 1) or biweekly (cohort 2). MAIN OUTCOME MEASURES: Co-primary end points (cohort 1) were percentage changes from baseline to end of treatment in glucose (area under the curve from 0 to 4 hours [AUC0-4h]) post-mixed-meal tolerance test (MMTT) and weight. Exploratory measures included postprandial insulin and gastric emptying time (GET; cohort 2). RESULTS: Patients received cotadutide (cohort 1, n = 26; cohort 2, n = 20) or placebo (cohort 1, n = 13; cohort 2, n = 6). Significant reductions were observed with cotadutide vs placebo in glucose AUC0-4h post MMTT (least squares mean [90% CI], -21.52% [-25.68, -17.37] vs 6.32% [0.45, 12.20]; P < 0.001) and body weight (-3.41% [-4.37, -2.44] vs -0.08% [-1.45, 1.28]; P = 0.002). A significant increase in insulin AUC0-4h post MMTT was observed with cotadutide (19.3 mU.h/L [5.9, 32.6]; P = 0.008) and GET was prolonged on day 43 with cotadutide vs placebo (t½: 117.2 minutes vs -42.9 minutes; P = 0.0392). CONCLUSION: These results suggest that the glucose-lowering effects of cotadutide are mediated by enhanced insulin secretion and delayed gastric emptying. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03244800.

A diagnostic algorithm to distinguish desmoplastic from spindle cell melanoma.

Spindle cell melanoma and desmoplastic melanoma differ clinically in prognosis and therapeutic implications; however, because of partially overlapping histopathological features, diagnostic distinction of spindle cell from desmoplastic melanoma is not always straightforward. A direct comparison of diagnostic and therapeutic biomarkers has not been performed. Meta-review of the literature discloses key clinicopathological differences between spindle cell and desmoplastic melanoma, including immunophenotypes. Using 50 biomarkers available in routine diagnostics, we examined 38 archival cases (n=16 spindle, 18 desmoplastic, 4 mixed spindle/desmoplastic melanoma). S100 remains as the most reliable routine marker to reach the diagnosis of melanoma in spindle cell and desmoplastic melanoma. We identified nine distinctly labeling markers with spindle cell melanoma showing positivity for laminin, p75, HMB45, c-kit, and MelanA, and desmoplastic melanoma preferentially labeling with collagen IV, trichrome, CD68, and MDM2. On the basis of comparisons of test performance measures, MelanA and trichrome were used to devise a 94% sensitive diagnostic algorithm for the distinction of desmoplastic from spindle cell melanoma. Gene amplification and expression status was assessed for a set of potentially drugable targets (HER2, EGFR, MET, MDM2, TP53, ALK, MYC, FLI-1, and KIT). Fluorescent in situ hybridizations did not reveal a significant number of gene aberrations/rearrangements; however, protein overexpression for at least one of these markers was identified in 35 of 38 cases (92%). In addition, we found BRAF mutations in 31% of spindle cell and 5% of desmoplastic melanoma, with an overall mutation frequency of 16% (n=6/38). We present the first comprehensive screening study of diagnostic and therapeutic biomarkers in spindle cell and desmoplastic melanoma. The devised algorithm allows diagnostic distinction of desmoplastic from spindle cell melanoma when routine histology is not decisive.