Safety, tolerability and pharmacokinetic characterisation of DACRA KBP-042 in healthy male subjects.

There is a need for antidiabetic agents successfully targeting insulin sensitivity and treating obesity control at the same time. The aim of this first-in-human study was (a) to evaluate safety and tolerability, (b) to evaluate pharmacokinetics and (c) to assess indications of receptor engagement of single ascending doses of KBP-042, a dual amylin and calcitonin receptor agonist (DACRA) that has shown promising preclinical data, with superior activity in terms of typical amylin-induced responses including reduction of food intake, weight loss and gluco-regulatory capacities. A randomised double-blind placebo-controlled single ascending dose study was performed with six dose levels of KBP-042 (5, 7.5, 10, 20, 20 (evening), 40 ug) in healthy male adults. KBP-042 or placebo was administered as a single dose after an overnight fast, followed by a standardized lunch after 4 hours. KBP-042 was associated with dose-dependent complaints of nausea and vomiting, with a lack of tolerability at doses of 20 µg and above. Doses of 5-40 µg KBP-042 behaved according to a linear pharmacokinetic profile. Indications of target receptor engagement were observed at the level of glucose control and lowering of bone resorption, compared to placebo. The results of this study showed that doses up to 40 µg were safe, although tolerability was not present at the highest doses. The study confirmed target receptor engagement at the studied doses.

Quantification of tremor using consumer product accelerometry is feasible in patients with essential tremor and Parkinson's disease: a comparative study.

BACKGROUND: To quantify pharmacological effects on tremor in patients with essential tremor (ET) or Parkinson's Disease (PD), laboratory-grade accelerometers have previously been used. Over the last years, consumer products such as smartphones and smartwatches have been increasingly applied to measure tremor in an easy way. However, it is unknown how the technical performance of these consumer product accelerometers (CPAs) compares to laboratory-grade accelerometers (LGA). This study was performed to compare the technical performance of CPAs with LGA to measure tremor in patients with Parkinson's Disease (PD) and essential tremor (ET). METHODS: In ten patients with PD and ten with ET, tremor peak frequency and corresponding amplitude were measured with 7 different CPAs (Apple iPhone 7, Apple iPod Touch 5, Apple watch 2, Huawei Nexus 6P, Huawei watch, mbientlabMetaWear (MW) watch, mbientlab MW clip) and compared to a LGA (Biometrics ACL300) in resting and extended arm position. RESULTS: Both in PD and ET patients, the peak frequency of CPAs did not significantly differ from the LGA in terms of limits of agreement. For the amplitude at peak frequency, only the iPhone and MW watch performed comparable to the LGA in ET patients, while in PD patients all methods performed comparable except for the iPod Touch and Huawei Nexus. Amplitude was higher when measured with distally-located CPAs (Clip, iPhone, iPod) compared with proximally-located CPAs (all watches). The variability between subjects was higher than within subjects for frequency (25.1% vs. 13.4%) and amplitude measurement (331% vs. 53.6%). Resting arm position resulted in lower intra-individual variability for frequency and amplitude (13.4 and 53.5%) compared to extended arm position (17.8 and 58.1%). CONCLUSIONS: Peak frequencies of tremor could be measured with all tested CPAs, with similar performance as LGA. The amplitude measurements appeared to be driven by anatomical location of the device and can therefore not be compared. Our results show that the tested consumer products can be used for tremography, allowing at-home measurements, in particular in studies with a cross-over or intra-individual comparison design using the resting arm position. TRIAL REGISTRATION: This trial was registered in the Dutch Competent Authority (CCMO) database with number NL60672.058.17 on May 30th 2017.

The Pharmacodynamic Effects of a Dopamine-Somatostatin Chimera Agonist on the Cardiovascular System.

The quantification of the effect of pharmacological treatment on the cardiovascular system is complicated because of the high level of interindividual and circadian variability. Recently, a dopamine-somatostatin chimera, BIM23B065, was under investigation to concurrently target the somatostatin and dopamine D2 receptors for the treatment of neuroendocrine tumors. However, both dopamine and somatostatin interact with different components of the cardiovascular system. This study established the response of the heart rate and the systolic blood pressure after administration of BIM23B065 in healthy male volunteers by analysis of the rate-pressure product (RPP), in a model-informed analysis. The RPP in the supine position of placebo-treated subjects showed a clear circadian component, best described by 2 cosine functions. The pharmacokinetics of BIM23B065 and its metabolite were best described using 2-compartment models with different forms of elimination kinetics. The administration of BIM23B065 gave a statistically significant reduction in the RPP, after which the effect diminished because of the tolerance to the cardiovascular effects after prolonged exposure to BIM23B065. This model provided insight in the circadian rhythm of the RPP in the supine position and the level of interindividual variability in healthy male volunteers. The developed population pharmacokinetic/pharmacodynamic model quantified the interaction between BIM23B065 and the RPP, informing on the clinical pharmacological properties of BIM23B065.

A Novel Somatostatin-Dopamine Chimera (BIM23B065) Reduced GH Secretion in a First-in-Human Clinical Trial.

Context: A somatostatin-dopamine chimera (BIM23B065) was under investigation to reduce GH secretion for the treatment of pituitary adenomas. Objective: To determine pharmacokinetics, safety, and tolerability and to monitor hormonal changes after single and multiple subcutaneous BIM23B065 administrations. Design: Randomized, double-blind, placebo-controlled, parallel-group design with five single and three 13-day multiple ascending-dose cohorts. Patients: A total of 63 healthy male white volunteers were enrolled (47 active, 16 placebo). Main Outcome Measures: Pharmacokinetics, GH, prolactin (PRL), IGF-1, GH after GHRH administration, and general clinical safety criteria. Results: The maximum dosage of BIM23B065 administered in this study was 1.5 mg. BIM23B065 reduced the mean GH concentrations after 8 and 13 days of treatment. A decrease in GH release after GHRH administration indicated inhibition of the hypothalamic-pituitary-somatotropic axis. IGF-1 was not altered after single doses but showed a significant change from baseline after multiple dosing. PRL secretion was reduced in all subjects who were treated. Orthostatic hypotension and injection site reactions were commonly observed at high dosages. A 6-day uptitration period was included to successfully lower the cardiovascular effects in the multiple ascending dose part of the study. Conclusions: Proof of pharmacology of BIM23B065 was shown by a reduction in GH, IGF-1, and PRL concentrations in healthy male volunteers, supporting activity of the somatostatin analog and dopamine agonist moieties. The safety and tolerability of the higher dosing regions was limited mainly by orthostatic hypotension.

Laser-assisted vessel welding: state of the art and future outlook.

Laser-assisted vascular welding (LAVW) is an experimental technique being developed as an alternative to suture anastomosis. In comparison to mechanical anastomosis, LAVW is less traumatic, non-immunogenic, provides immediate water tight sealant, and possibly a faster and easier procedure for minimally invasive surgery. This review focuses on technical advances to improve welding strength and to reduce thermal damage in LAVW. In terms of welding strength, LAVW has evolved from the photothermally-induced microvascular anastomosis, requiring stay sutures to support welding strength, to sutureless anastomoses of medium-sized vessels, withstanding physiological and supraphysiological pressure. Further improvements in anastomotic strength could be achieved by the use of chromophore-containing albumin solder and the employment of (biocompatible) polymeric scaffolds. The anastomotic strength and the stability of welds achieved with such a modality, referred to as scaffold- and solder-enhanced LAVW (ssLAVW), are dependent on the intermolecular bonding of solder molecules (cohesive bonding) and the bonding between solder and tissue collagen (adhesive bonding). Presently, the challenges of ssLAVW include (1) obtaining an optimal balance between cohesive and adhesive bonding and (2) minimizing thermal damage. The modulation of thermodynamics during welding, the application of semi-solid solder, and the use of a scaffold that supports both cohesive and adhesive strength are essential to improve welding strength and to limit thermal damage.

Ex vivo proof-of-concept of end-to-end scaffold-enhanced laser-assisted vascular anastomosis of porcine arteries.

OBJECTIVE: The low welding strength of laser-assisted vascular anastomosis (LAVA) has hampered the clinical application of LAVA as an alternative to suture anastomosis. To improve welding strength, LAVA in combination with solder and polymeric scaffolds (ssLAVA) has been optimized in vitro. Currently, ssLAVA requires proof-of-concept in a physiologically representative ex vivo model before advancing to in vivo studies. This study therefore investigated the feasibility of ex vivo ssLAVA in medium-sized porcine arteries. METHODS: Scaffolds composed of poly(ε-caprolactone) (PCL) or poly(lactic-co-glycolic acid) (PLGA) were impregnated with semisolid solder and placed over coapted aortic segments. ssLAVA was performed with a 670-nm diode laser. In the first substudy, the optimum number of laser spots was determined by bursting pressure analysis. The second substudy investigated the resilience of the welds in a Langendorf-type pulsatile pressure setup, monitoring the number of failed vessels. The type of failure (cohesive vs adhesive) was confirmed by electron microscopy, and thermal damage was assessed histologically. The third substudy compared breaking strength of aortic repairs made with PLGA and semisolid genipin solder (ssLAVR) to repairs made with BioGlue. RESULTS: ssLAVA with 11 lasing spots and PLGA scaffold yielded the highest bursting pressure (923 ± 56 mm Hg vs 703 ± 96 mm Hg with PCL ssLAVA; P = .0002) and exhibited the fewest failures (20% vs 70% for PCL ssLAVA; P = .0218). The two failed PLGA ssLAVA arteries leaked at 19 and 22 hours, whereas the seven failed PCL ssLAVA arteries burst between 12 and 23 hours. PLGA anastomoses broke adhesively, whereas PCL welds failed cohesively. Both modalities exhibited full-thickness thermal damage. Repairs with PLGA scaffold yielded higher breaking strength than BioGlue repairs (323 ± 28 N/cm(2) vs 25 ± 4 N/cm(2), respectively; P = .0003). CONCLUSIONS: PLGA ssLAVA yields greater anastomotic strength and fewer anastomotic failures than PCL ssLAVA. Aortic repairs with BioGlue were inferior to those produced with PLGA ssLAVR. The results demonstrate the feasibility of ssLAVA/R as an alternative method to suture anastomosis or tissue sealant. Further studies should focus on reducing thermal damage.

Endothelial cell preservation at hypothermic to normothermic conditions using clinical and experimental organ preservation solutions.

INTRODUCTION: Endothelial barrier function is pivotal for the outcome of organ transplantation. Since hypothermic preservation (gold standard) is associated with cold-induced endothelial damage, endothelial barrier function may benefit from organ preservation at warmer temperatures. We therefore assessed endothelial barrier integrity and viability as function of preservation temperature and perfusion solution, and hypothesized that endothelial cell preservation at subnormothermic conditions using metabolism-supporting solutions constitute optimal preservation conditions. METHODS: Human umbilical vein endothelial cells (HUVEC) were preserved at 4-37°C for up to 20 h using Ringer's lactate, histidine-tryptophan-ketoglutarate solution, University of Wisconsin (UW) solution, Polysol, or endothelial cell growth medium (ECGM). Following preservation, the monolayer integrity, metabolic capacity, and ATP content were determined as positive parameters of endothelial cell viability. As negative parameters, apoptosis, necrosis, and cell activation were assayed. A viability index was devised on the basis of these parameters. RESULTS: HUVEC viability and barrier integrity was compromised at 4°C regardless of the preservation solution. At temperatures above 20°C, the cells' metabolic demands outweighed the preservation solutions' supporting capacity. Only UW maintained HUVEC viability up to 20°C. Despite high intracellular ATP content, none of the solutions were capable of sufficiently preserving HUVEC above 20°C except for ECGM. CONCLUSION: Optimal HUVEC preservation is achieved with UW up to 20°C. Only ECGM maintains HUVEC viability at temperatures above 20°C.

Oxygen-dependent delayed fluorescence measured in skin after topical application of 5-aminolevulinic acid.

Mitochondrial oxygen tension can be measured in vivo by means of oxygen-dependent quenching of delayed fluorescence of protoporphyrin IX (PpIX). Here we demonstrate that delayed fluorescence is readily observed from skin in rat and man after topical application of the PpIX precursor 5-aminolevulinic acid (ALA). Delayed fluorescence lifetimes respond to changes in inspired oxygen fraction and blood supply. The signals contain lifetime distributions and the fitting of rectangular distributions to the data appears more adequate than mono-exponential fitting. The use of topically applied ALA for delayed fluorescence lifetime measurements might pave the way for clinical use of this technique.