10 research outputs found
Pharmacometric Modeling of the Impact of Azelastine Nasal Spray on SARS-CoV-2 Viral Load and Related Symptoms in COVID-19 Patients
The histamine-1 receptor antagonist azelastine was recently found to impact SARS-CoV-2
viral kinetics in a Phase 2 clinical trial (CARVIN). Thus, we investigated the relationship between
intranasal azelastine administrations and viral load, as well as symptom severity in COVID-19
patients and analyzed the impact of covariates using non-linear mixed-effects modeling. For this, we
developed a pharmacokinetic (PK) model for the oral and intranasal administration of azelastine. A
one-compartment model with parallel absorption after intranasal administration described the PK
best, covering both the intranasal and the gastro-intestinal absorption pathways. For virus kinetic
and symptoms modeling, viral load and symptom records were gathered from the CARVIN study
that included data of 82 COVID-19 patients receiving placebo or intranasal azelastine. The effect of
azelastine on viral load was described by a dose–effect model targeting the virus elimination rate.
An extension of the model revealed a relationship between COVID-19 symptoms severity and the
number of infected cells. The analysis revealed that the intranasal administration of azelastine led to
a faster decline in viral load and symptoms severity compared to placebo. Moreover, older patients
showed a slower decline in viral load compared to younger patients and male patients experienced
higher peak viral loads than females
Significant impact of time-of-day variation on metformin pharmacokinetics
Aims/hypothesis The objective was to investigate if metformin pharmacokinetics is modulated by time-of-day in humans using
empirical and mechanistic pharmacokinetic modelling techniques on a large clinical dataset. This study also aimed to generate
and test hypotheses on the underlying mechanisms, including evidence for chronotype-dependent interindividual differences in
metformin plasma and efficacy-related tissue concentrations.
Methods A large clinical dataset consisting of individual metformin plasma and urine measurements was analysed using a newly
developed empirical pharmacokinetic model. Causes of daily variation of metformin pharmacokinetics and interindividual
variability were further investigated by a literature-informed mechanistic modelling analysis.
Results A significant effect of time-of-day on metformin pharmacokinetics was found. Daily rhythms of gastrointestinal, hepatic
and renal processes are described in the literature, possibly affecting drug pharmacokinetics. Observed metformin plasma levels
were best described by a combination of a rhythm in GFR, renal plasma flow (RPF) and organic cation transporter (OCT) 2
activity. Furthermore, the large interindividual differences in measured metformin concentrations were best explained by individual chronotypes affecting metformin clearance, with impact on plasma and tissue concentrations that may have implications
for metformin efficacy.
Conclusions/interpretation Metformin’s pharmacology significantly depends on time-of-day in humans, determined with the help of
empirical and mechanistic pharmacokinetic modelling, and rhythmic GFR, RPF and OCT2 were found to govern intraday variation.
Interindividual variation was found to be partly dependent on individual chronotype, suggesting diurnal preference as an interesting, but
so-far underappreciated, topic with regard to future personalised chronomodulated therapy in people with type 2 diabetes
Model-Based Analysis of SARS-CoV-2 Infections, Hospitalization and Outcome in Germany, the Federal States and Districts
The coronavirus disease 2019 (COVID-19) pandemic challenged many national health care
systems, with hospitals reaching capacity limits of intensive care units (ICU). Thus, the estimation of
acute local burden of ICUs is critical for appropriate management of health care resources. In this
work, we applied non-linear mixed effects modeling to develop an epidemiological SARS-CoV-2
infection model for Germany, with its 16 federal states and 400 districts, that describes infections as
well as COVID-19 inpatients, ICU patients with and without mechanical ventilation, recoveries, and
fatalities during the first two waves of the pandemic until April 2021. Based on model analyses, covariates influencing the relation between infections and outcomes were explored. Non-pharmaceutical
interventions imposed by governments were found to have a major impact on the spreading of
SARS-CoV-2. Patient age and sex, the spread of variant B.1.1.7, and the testing strategy (number of
tests performed weekly, rate of positive tests) affected the severity and outcome of recorded cases and
could reduce the observed unexplained variability between the states. Modeling could reasonably
link the discrepancies between fine-grained model simulations of the 400 German districts and the
reported number of available ICU beds to coarse-grained COVID-19 patient distribution patterns
within German regions
Motivations for Adolescent COVID-19 Vaccination: A Comparative Study of Adolescent and Caregiver Perspectives in Germany
Given the crucial role of vaccination in halting the COVID-19 pandemic, it is imperative to
understand the factors that motivate adolescents to get vaccinated. We surveyed adolescents and
their accompanying guardians scheduled to receive a COVID-19 vaccination (Comirnaty) in an urban
region in Germany in mid-2021 regarding their motivation for getting vaccinated and collected data
on their sociodemographic characteristics, medical history, vaccination status, and any history of
COVID-19 infection in the family. We also queried information strategies related to the SARS-CoV-2
pandemic. Motivations for getting vaccinated were similar among adolescents and their parents.
The primary reasons for vaccination were protection against SARS-CoV-2-related illness and gaining
access to leisure facilities. This was not influenced by gender, health status, migration background, or
the presence of chronic or acute diseases. The percentage of parents who had received SARS-CoV-2
immunization and the proportion of parents with a high level of education were higher among study
participants than in the general population. Adolescents were especially willing to be vaccinated
if they came from a better educational environment and had a high vaccination rate in the family.
Emphasizing the importance of vaccination among all segments of the population and removing
barriers to vaccines may lead to an ameliorated acceptance of COVID-19 vaccines
Significant impact of time-of-day variation on metformin pharmacokinetics
Aims/hypothesis
The objective was to investigate if metformin pharmacokinetics is modulated by time-of-day in humans using empirical and mechanistic pharmacokinetic modelling techniques on a large clinical dataset. This study also aimed to generate and test hypotheses on the underlying mechanisms, including evidence for chronotype-dependent interindividual differences in metformin plasma and efficacy-related tissue concentrations.
Methods
A large clinical dataset consisting of individual metformin plasma and urine measurements was analysed using a newly developed empirical pharmacokinetic model. Causes of daily variation of metformin pharmacokinetics and interindividual variability were further investigated by a literature-informed mechanistic modelling analysis.
Results
A significant effect of time-of-day on metformin pharmacokinetics was found. Daily rhythms of gastrointestinal, hepatic and renal processes are described in the literature, possibly affecting drug pharmacokinetics. Observed metformin plasma levels were best described by a combination of a rhythm in GFR, renal plasma flow (RPF) and organic cation transporter (OCT) 2 activity. Furthermore, the large interindividual differences in measured metformin concentrations were best explained by individual chronotypes affecting metformin clearance, with impact on plasma and tissue concentrations that may have implications for metformin efficacy.
Conclusions/interpretation
Metformin’s pharmacology significantly depends on time-of-day in humans, determined with the help of empirical and mechanistic pharmacokinetic modelling, and rhythmic GFR, RPF and OCT2 were found to govern intraday variation. Interindividual variation was found to be partly dependent on individual chronotype, suggesting diurnal preference as an interesting, but so-far underappreciated, topic with regard to future personalised chronomodulated therapy in people with type 2 diabetes
Genetic studies of abdominal MRI data identify genes regulating hepcidin as major determinants of liver iron concentration
Background & Aims: Excess liver iron content is common and is linked to hepatic and extrahepatic disease risk. We aimed to identify genetic variants influencing liver iron content and use genetics to understand its link to other traits and diseases.
Methods: First, we performed a genome-wide association study (GWAS) in 8,289 individuals in UK Biobank with MRI quantified liver iron, and validated our findings in an independent cohort (n=1,513 from IMI DIRECT). Second, we used Mendelian randomisation to test the causal effects of 29 predominantly metabolic traits on liver iron content. Third, we tested phenome-wide associations between liver iron variants and 770 anthropometric traits and diseases.
Results: We identified three independent genetic variants (rs1800562 (C282Y) and rs1799945 (H63D) in HFE and rs855791 (V736A) in TMPRSS6) associated with liver iron content that reached the GWAS significance threshold (p<5x10-8). The two HFE variants account for ~85% of all cases of hereditary haemochromatosis. Mendelian randomisation analysis provided evidence that higher central obesity plays a causal role in increased liver iron content. Phenome-wide association analysis demonstrated shared aetiopathogenic mechanisms for elevated liver iron, high blood pressure, cirrhosis, malignancies, neuropsychiatric and rheumatological conditions, while also highlighting inverse associations with anaemias, lipidaemias and ischaemic heart disease.
Conclusion: Our study provides genetic evidence that mechanisms underlying higher liver iron content are likely systemic rather than organ specific, that higher central obesity is causally associated with higher liver iron, and that liver iron shares common aetiology with multiple metabolic and non-metabolic diseases
Identification of regulatory variants associated with genetic susceptibility to meningococcal disease.
Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes
Efficacy and safety of MP1032 plus standard-of-care compared to standard-of-care in hospitalised patients with COVID-19: a multicentre, randomised double-blind, placebo-controlled phase 2a trialResearch in context
Summary: Background: SARS-CoV-2 infections still have a significant impact on the global population. The existing vaccinations have contributed to reducing the severe disease courses, decreasing hospitalisations, and lowering the mortality rate. However, due to the variability of COVID-19 symptoms, the emergence of new variants and the uneven global distribution of vaccines there is still a great need for new therapy options. One promising approach is provided by host-directed therapies. We assessed here the efficacy and safety of MP1032, a host-directed anti-viral/anti-inflammatory drug in hospitalised patients with moderate to severe COVID-19. Methods: In a randomised, double-blind, placebo-controlled, Phase IIa study, patients were randomised 2:1 to receive either 300 mg MP032 bid + Standard-of-Care (SoC) or placebo bid + SoC for 28 days. Eligible patients were ≥18 years old, tested positive for SARS-CoV-2, and had moderate to severe COVID-19 symptoms. The study spanned 20 sites in six countries (Bulgaria, France, Hungary, Italy, Romania, Spain), assessing disease progression according the NIAID scale as the primary outcome on day 14. Secondary objectives included disease progression (day 28), disease resolution (days 14 and 28), mortality rate, COVID-19 related parameters and safety. Exposure-response analyses were performed, linking MP1032 to COVID-19 biomarkers (eGFR, D-dimer). Findings: 132 patients were enrolled to receive MP1032 + SoC (n = 87) or placebo + SoC (n = 45). The patients were all white or Caucasian with a mean (median) age of 60.5 (63) years. Overall, only 10 patients were vaccinated, 5 in each group. No significant risk difference of disease progression could be detected between groups on both day 14 (9.8% MP1032 vs. 11.6% placebo) and day 28 with MH common risk differences of −0.276% (95% CI, −11.634 to 11.081; p = 0.962) and 1.722% (95% CI, −4.576 to 8.019; p = 0.592), respectively.The treatment with MP1032 + SoC was safe and well-tolerated. Overall, 182 TEAEs including 10 SAEs were reported in 53.5% (46/86) of patients of the verum group and in 57.8% (26/45) of patients of the placebo group; the SAEs occurred in 5.8% (5/86) and 6.7% (3/45) of verum and placebo patients, respectively. None of the SAEs was considered as related. Interpretation: Despite the study's limitation in size and the variation in concurrent SoCs, these findings warrant further investigation of MP1032 as a host-directed anti-viral drug candidate. Funding: The study was funded by the COVID-19 Horizon Europe work programme and MetrioPharm AG
Population kinetic/pharmacodynamic modelling of the haemodynamic effects of cafedrine/theodrenaline (Akrinor) under general anaesthesia
Aims: The 20:1 combination of cafedrine and theodrenaline (C/T) is widely used in
Germany for the treatment of arterial hypotension. Since there is little knowledge
about the impact of covariates on the effect, the aim was to develop a
kinetic/pharmacodynamic covariate model describing mean arterial pressure (MAP),
systolic (SBP) and diastolic blood pressure (DBP), and heart rate (HR) for 30 min after
the administration of C/T.
Methods: Data of patients receiving C/T from the HYPOTENS study
(NCT02893241, DRKS00010740) were analysed using nonlinear mixed-effects
modelling techniques.
Results: Overall, 16 579 measurements from 315 patients were analysed. The
combination of two kinetic compartments and a delayed effect model, coupled
with distinct Emax models for HR, SBP and DBP, described the data best. The
model included age, sex, body mass index (BMI), antihypertensive medication,
American Society of Anaesthesiologists (ASA) physical status classification grade,
baseline SBP at the time of hypotension and pre-surgery HR as covariates
(all P < .001). A higher baseline SBP led to a lower absolute increase in MAP.
Patients with higher age, higher BMI and lower ASA grade showed smaller
increases in MAP. The initial increase was similar for male and female patients.
The long-term effect was higher in women. Concomitant antihypertensive
medication caused a delayed effect and a lower maximum MAP. The HR increased
only slightly (median increase 2.6 bpm, P < .001).
Conclusions: Seven covariates with an impact on the effect of C/T could be identified. The results will enable physicians to optimize the dose with respect to individual
patients
Motivations for adolescent COVID-19 aaccination
Given the crucial role of vaccination in halting the COVID-19 pandemic, it is imperative to understand the factors that motivate adolescents to get vaccinated. We surveyed adolescents and their accompanying guardians scheduled to receive a COVID-19 vaccination (Comirnaty) in an urban region in Germany in mid-2021 regarding their motivation for getting vaccinated and collected data on their sociodemographic characteristics, medical history, vaccination status, and any history of COVID-19 infection in the family. We also queried information strategies related to the SARS-CoV-2 pandemic. Motivations for getting vaccinated were similar among adolescents and their parents. The primary reasons for vaccination were protection against SARS-CoV-2-related illness and gaining access to leisure facilities. This was not influenced by gender, health status, migration background, or the presence of chronic or acute diseases. The percentage of parents who had received SARS-CoV-2 immunization and the proportion of parents with a high level of education were higher among study participants than in the general population. Adolescents were especially willing to be vaccinated if they came from a better educational environment and had a high vaccination rate in the family. Emphasizing the importance of vaccination among all segments of the population and removing barriers to vaccines may lead to an ameliorated acceptance of COVID-19 vaccines