Repeatability and reproducibility of the Forskolin-induced swelling (FIS) assay on intestinal organoids from people with Cystic Fibrosis.

BACKGROUND: The forskolin-induced swelling (FIS) assay measures CFTR function on patient-derived intestinal organoids (PDIOs) and may guide treatment selection for individuals with Cystic Fibrosis (CF). The aim of this study is to demonstrate the repeatability and reproducibility of the FIS assay following a detailed Standard Operating Procedure (SOP), thus advancing the validation of the assay for precision medicine (theranostic) applications. METHODS: Over a 2-year period, FIS responses to CFTR modulators were measured in four European labs. PDIOs from six subjects with CF carrying different CFTR genotypes were used to assess the repeatability and reproducibility across the dynamic range of the assay. RESULTS: Technical, intra-assay repeatability was high (Lin's concordance correlation coefficient (CCC) 0.95-0.98). Experimental, within-subject repeatability was also high within each lab (CCCs all >0.9). Longer-term repeatability (>1 year) showed more variability (CCCs from 0.67 to 0.95). The reproducibility between labs was also high (CCC ranging from 0.92 to 0.97). Exploratory analysis also found that between-lab percentage of agreement of dichotomized CFTR modulator outcomes for predefined FIS thresholds ranged between 78 and 100 %. CONCLUSIONS: The observed repeatability and reproducibility of the FIS assay within and across different labs is high and support the use of FIS as biomarker of CFTR function in the presence or absence of CFTR modulators.

Rationale and design for the randomized placebo-controlled double-blind trial studying the effect of single antiplatelet therapy (clopidogrel) versus dual antiplatelet therapy (clopidogrel/acetylsalicylic acid) on the occurrence of atherothrombotic events following lower extremity peripheral transluminal angioplasty (CLEAR-PATH).

RATIONALE: Antiplatelet therapy (APT) is the standard of care after endovascular revascularization (EVR) in patients with peripheral artery disease (PAD). APT aims to prevent both major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nonetheless, the rates of MACE and MALE after EVR remain high. In coronary artery and cerebrovascular disease, dual APT (DAPT)compared to acetylsalicylic acid alone has been proven to reduce MACE without increasing the risk of major bleeding when applied for a restricted number of weeks. However, within the PAD population, insufficient data are available to understand the potential attributable effect of DAPT over single APT (SAPT). Therefore, prospective randomized studies in targeted study populations are warranted. TRIAL DESIGN: CLEAR-PATH is a Dutch multicenter, double-blind, placebo-controlled, randomized trial comparing SAPT (clopidogrel 75 mg plus placebo) with DAPT (clopidogrel 75 mg plus acetylsalicylic acid 80 mg) in patients with PAD undergoing EVR. CLEAR-PATH includes a time-to-event analysis with a follow-up of one year. The primary composite efficacy endpoint consists of all-cause mortality, nonfatal stroke, nonfatal myocardial infarction, severe limb ischemia, (indication for) re-intervention due to any symptomatic restenosis, re-occlusion, or due to acute limb ischemia, and major amputation. The primary safety endpoint contains major bleeding following the Thrombolysis in Myocardial Infarction classification. The enrolment started in August 2022. In total 450 primary efficacy outcome events are required which expectedly amounts to 1696 subjects. Recruitment will take approximately 36 months. CONCLUSION: CLEAR-PATH will assess the efficacy and safety of DAPT compared to SAPT following EVR in PAD patients. TRIAL REGISTRATION NUMBER: NL80009.041.21.

The RISE study protocol: resilience impacted by positive stressful events for people with cystic fibrosis.

Introduction: For people with cystic fibrosis (CF), gaining access to elexacaftor/tezacaftor/ivacaftor (ETI) therapy, a new modulator drug combination, is perceived as a positive life event. ETI leads to a strong improvement of disease symptoms. However, some people with CF experience a deterioration in mental wellbeing after starting ETI therapy. The primary objective of this study is to investigate if and in which direction mental wellbeing of people with CF changes after starting ETI therapy. Our secondary objectives include, among others, investigation of underlying biological and psychosocial factors associated with a change in mental wellbeing of people with CF after starting ETI therapy. Methods and analysis: The Resilience lmpacted by Positive Stressful Events (RISE) study is a single-arm, observational, prospective longitudinal cohort. It has a timeframe of 60 weeks: 12 weeks before, 12 weeks after, 24 weeks after and 48 weeks after the start of ETI therapy. The primary outcome is mental well-being, measured at each of these four time points. Patients aged ≥12 years at the University Medical Center Utrecht qualifying for ETI therapy based on their CF mutation are eligible. Data will be analysed using a covariance pattern model with a general variance covariance matrix. Ethics: The RISE study was classified by the institutional review board as exempt from the Medical Research Involving Human Subjects Act. Informed consent was obtained by both the children (12-16 years) and their caregivers, or only provided by the participants themselves when aged ≥16 years.

Estimation and expected sample size in Simon's two-stage designs that stop as early as possible.

In early phase clinical studies in oncology, Simon's two-stage designs are widely used. The trial design could be made more efficient by stopping early in the second stage when the required number of responses is reached, or when it has become clear that this target can no longer be met (a form of non-stochastic curtailment). Early stopping, however, will affect proper estimation of the response rate. We propose a uniformly minimum-variance unbiased estimator (UMVUE) for the response rate in this setting. The estimator is proven to be UMVUE using the Rao-Blackwell theorem. We evaluate the estimator's properties in terms of bias and mean squared error, both analytically and via simulations. We derive confidence intervals based on sample space orderings, and assess the coverage. For various design options, we evaluate the reduction in expected sample size as a function of the true response rate. Our method provides a solution for estimating response rates in case of a non-stochastic curtailment Simon's two-stage design.

Prediction of Real-World Long-Term Outcomes of People with CF Homozygous for the F508del Mutation Treated with CFTR Modulators.

The clinical response to cystic fibrosis transmembrane conductance regulator (CFTR) modulators is variable within people with cystic fibrosis (pwCF) homozygous for the F508del mutation. The prediction of clinical effect in individual patients would be useful to target therapy to those who would benefit from it. A multicenter observational cohort study was conducted including 97 pwCF (F508del/F508del), who started lumacaftor/ivacaftor (LUM/IVA) treatment before June 2018. In order to assess the associations of individual in vivo and in vitro biomarkers with clinical outcomes, we collected clinical data regarding sex, age, and sweat chloride concentration (SwCl) at baseline and after six months of LUM/IVA; the percent predicted forced expiratory volume in 1 s (ppFEV1) and the number of pulmonary exacerbations (PEx) during the three years before up to three years after modulator initiation; and the forskolin-induced swelling (FIS) responses to LUM/IVA, quantified in intestinal organoids. On a group level, the results showed an acute change in ppFEV1 after LUM/IVA initiation (2.34%, 95% CI 0.85-3.82, p = 0.003), but no significant change in annual ppFEV1 decline in the three years after LUM/IVA compared to the three years before (change: 0.11% per year, 95%CI: -1.94-2.19, p = 0.913). Neither of these two outcomes was associated with any of the candidate predictors on an individual level. The median number of pulmonary exacerbations (PEx) per patient year did not significantly change in the three years after LUM/IVA compared to the years before (median: 0.33/patient year, IQR: 0-0.67 before vs. median: 0/patient year, IQR: 0-0.67 after p = 0. 268). The PEx rate after modulator initiation was associated with the PEx rate before (IRR: 2.26, 95%CI: 1.67-3.08, p < 0.001), with sex (males vs. females IRR: 0.36, 95%CI: 0.21-0.63, p = 0.001) and with sweat chloride concentration (SwCl) at baseline (IRR: 0.96, 95%CI: 0.94-0.98, p = 0.001). The change in SwCl was also significant (-22.9 mmol/L (95%CI: -27.1--18.8, p < 0.001) and was associated with SwCl at baseline (-0.64, 95%CI: -0.90--0.37, p < 0.001) and with sex (males vs. females 8.32, 95%CI: 1.82-14.82, p = 0.013). In conclusion, ppFEV1 decline after CFTR modulator initiation remains difficult to predict in individual patients in a real-world setting, with limited effectiveness for double CFTR modulator therapies. The PEx rate prior to CFTR modulator treatment initiation, sex and SwCl at baseline could be potential predictors of long-term PEx rate and of changes in SwCl after modulator initiation.

Randomized All-Comers Evaluation of a Permanent Polymer Zotarolimus-Eluting Stent Versus a Polymer-Free Amphilimus-Eluting Stent.

BACKGROUND: Polymer-free amphilimus-eluting stents (PF-AES) represent a novel elution technology in the current era of drug-eluting stents. The clinical safety and efficacy of PF-AES as compared with latest-generation permanent-polymer zotarolimus-eluting stents (PP-ZES) have not yet been investigated in a large randomized trial. METHODS: In this physician-initiated, prospective, multicenter, randomized, noninferiority trial, an all-comers population requiring percutaneous coronary intervention was enrolled across 3 European sites. Randomization (1:1 ratio) to PP-ZES or PF-AES was performed after stratification for troponin status and diabetes mellitus. In both treatment arms, troponin-positive patients were planned for 12-month dual antiplatelet therapy, whereas troponin-negative patients were planned for 1-month dual antiplatelet therapy. Outcome assessors were blinded to the allocated treatment. The device-oriented primary end point of target-lesion failure was defined as cardiac death, target-vessel myocardial infarction, or target-lesion revascularization at 12-months as analyzed by modified intention-to-treat (80% power, and a 3.5% noninferiority margin). RESULTS: In total, 1502 patients were randomized and 1491 treated with the assigned stent and available for follow-up. The primary end point occurred in 42 (5.6%) of the 744 patients receiving PP-ZES versus 46 (6.2%) of the 747 patients receiving PF-AES. PF-AES were clinically noninferior to PP-ZES (risk difference, 0.5%; upper limit 1-sided 95% confidence interval, 2.6%; Pnoninferiority=0.0086). Cardiac death occurred in 10 (1.3%) versus 10 patients (1.3%; P value for difference, 1.00), target-vessel myocardial infarction occurred in 18 (2.4%) versus 17 patients (2.3%; P value for difference, 0.87), and target-lesion revascularization occurred in 22 (2.9%) versus 20 patients (2.6%; P value for difference, 0.75) for PF-AES as compared with PP-ZES. Overall, definite or probable stent thrombosis occurred in 1.0%. CONCLUSIONS: PF-AES were noninferior to PP-ZES regarding target-lesion failure at 12 months. Findings regarding the secondary end point and prespecified subgroups were generally consistent with that of the primary end point. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02328898.

Safety of switching from vitamin K antagonist to non-vitamin K antagonist oral anticoagulant in frail elderly with atrial fibrillation: rationale and design of the FRAIL-AF randomised controlled trial.

INTRODUCTION: Clinical guidelines recommend non-vitamin K antagonist oral anticoagulants (NOACs) over vitamin K antagonists (VKAs) for stroke prevention in most patients with atrial fibrillation (AF). Frail elderly were under-represented in the landmark NOAC-trials, leaving a knowledge gap on the optimal anticoagulant management (VKA or NOAC) in this increasing population. The aim of the Frail-AF (FRAIL-AF) study is to assess whether switching from international normalised ratio (INR)-guided VKA-management to a NOAC-based treatment strategy compared with continuing VKA-management is safe in frail elderly patients with AF. METHODS AND ANALYSIS: The FRAIL-AF study is a pragmatic, multicentre, open-label, randomised controlled clinical trial. Frail elderly (age ≥75 years plus a Groningen Frailty Indicator score ≥3) who receive VKA-treatment for AF in the absence of a mechanical heart valve or severe mitral valve stenosis will be randomised to switch to a NOAC-based treatment strategy or to continue INR-guided VKA-management. Patients with severe renal impairment (estimated glomerular filtration rate <30 mL/min/1.73 m2) will be excluded from randomisation. Based on existing trial evidence in non-frail patients, we will aim to explore whether NOAC-treatment is superior to VKA-therapy in reducing major or clinically relevant non-major bleeding events. Secondary outcomes include minor bleeding, the composite of ischaemic and haemorrhagic stroke, health-related quality of life and cost-effectiveness. The follow-up period for all subjects is 12 months. ETHICS AND DISSEMINATION: The protocol was approved by the Medical Research Ethics Committee of the University Medical Center Utrecht, the Netherlands and by the Central Committee on Research Involving Human Subjects, the Netherlands. All patients are asked written informed consent. Results are expected in 2022 and will be disseminated through peer-reviewed journals as well as presentations at national and international conferences. TRIAL REGISTRATION NUMBER: EudraCT: 2017-000393-11; The Netherlands Trial Registry: 6721 (FRAIL-AF study).

Series: Pragmatic trials and real world evidence: Paper 7. Safety, quality and monitoring.

OBJECTIVE: Pragmatic trials offer the opportunity to obtain real-life data on the relative effectiveness and safety of a treatment before or after market authorization. This is the penultimate paper in a series of eight, describing the impact of design choices on the practical implementation of pragmatic trials. STUDY DESIGN AND SETTING: This paper focuses on the practical challenges of collecting and reporting safety data and of monitoring trial conduct while maintaining routine clinical care practice. CONCLUSION: Current ICH guidance recommends that all serious adverse events and all drug-related events must be reported in an interventional trial. In line with current guidance, we propose a risk-based approach to the collection of non-drug-related non-serious adverse events and even serious events not related to treatment based on the risk profile of the medicine/class in the patient population of interest. Different options available to support the collection and reporting of safety data while minimizing study-related follow-up visits are discussed. A risk-based approach to monitoring trial conduct is also discussed, highlighting the difference in the balance of risks likely to occur in a pragmatic trial compared to traditional clinical trials and the careful consideration that must be given to the mitigation and management of these risks to maintain routine care.

A computationally simple central monitoring procedure, effectively applied to empirical trial data with known fraud.

OBJECTIVES: Central monitoring of multicenter clinical trials becomes an ever more feasible quality assurance tool, in particular for the detection of data fabrication. More widespread application, across both industry sponsored as well as academic clinical trials, requires central monitoring methodologies that are both effective and relatively simple in implementation. STUDY DESIGN AND SETTING: We describe a computationally simple fraud detection procedure intended to be applied repeatedly and (semi-)automatically to accumulating baseline data and to detect data fabrication in multicenter trials as early as possible. The procedure is based on anticipated characteristics of fabricated data. It consists of seven analyses, each of which flags approximately 10% of the centers. Centers that are flagged three or more times are considered "potentially fraudulent" and require additional investigation. The procedure is illustrated using empirical trial data with known fraud. RESULTS: In the illustration data, the fraudulent center is detected in most repeated applications to the accumulating trial data, while keeping the proportion of false-positive results at sufficiently low levels. CONCLUSION: The proposed procedure is computationally simple and appears to be effective in detecting center-level data fabrication. However, assessment of the procedure on independent trial data sets with known data fabrication is required.

Predicting enrollment performance of investigational centers in phase III multi-center clinical trials.

Failure to meet subject recruitment targets in clinical trials continues to be a widespread problem with potentially serious scientific, logistical, financial and ethical consequences. On the operational level, enrollment-related issues may be mitigated by careful site selection and by allocating monitoring or training resources proportionally to the anticipated risk of poor enrollment. Such procedures require estimates of the expected recruitment performance that are sufficiently reliable to allow centers to be sensibly categorized. In this study, we investigate whether information obtained from feasibility questionnaires can potentially be used to predict which centers will and which centers will not meet their enrollment targets by means of multivariable logistic regression analysis. From a large set of 59 candidate predictors, we determined the subset that is optimal for predictive purposes using Least Absolute Shrinkage and Selection Operator (LASSO) regularization. Although the extent to which the results are generalizable remains to be determined, they indicate that the prediction accuracy of the optimal model is only a marginal improvement over the intercept-only model, illustrating the difficulty of prediction in this setting.

Efficient Source Data Verification Using Statistical Acceptance Sampling: A Simulation Study.

BACKGROUND: One approach to increase the efficiency of clinical trial monitoring is to replace 100% source data verification (SDV) by verification of samples of source data. An intuitive strategy for determining appropriate sampling plans (ie, sample sizes and the maximum tolerable number of transcription errors in the samples) is to use acceptance sampling methodology. Expanding upon earlier work in which the use of acceptance sampling strategies for sampling-based SDV was proposed, we describe an alternative acceptance sampling strategy that, instead of relying on sampling standards, evaluates all possible sampling plans algorithmically, thereby ensuring that selected sampling plans conform to prespecified criteria. METHODS: Empirical trial data guided the design of the proposed strategy. In addition, extensive simulations, also based on the empirical data, were performed to assess the performance in terms of workload reductions and the post-SDV error proportion of applying the proposed strategy. RESULTS: 13 different scenarios were simulated, but results of the default scenario show that the average pre-SDV error proportion per trial of .056 was reduced to .023 by inspecting only 40.5% of the case report form entries. Of the inspected data entries, almost half (18.0/40.5) was, on average, SDV-ed as part of the sampling process; remaining entries were inspected during full inspections after too many errors were observed in the samples. CONCLUSION: Our results suggest that major reductions in workload can be achieved, while maintaining acceptable data quality levels. However, the results also indicate that the proposed strategy is conservative and further improvement is possible.

Development of macular edema and impact on visual acuity in uveitis associated with juvenile idiopathic arthritis.

PURPOSE: To investigate the development of macular edema (ME) in relation to the duration of uveitis and visual outcome in uveitis associated with juvenile idiopathic arthritis (JIA). METHODS: Sixty-one patients with JIA-uveitis (116 eyes) were investigated by Cirrus OCT for macular thickness. The relation between macular thickness and time interval since onset of uveitis and best corrected visual acuity (BCVA) was analyzed by linear mixed effect models. RESULTS: Duration of follow-up showed significant positive linear relation with central macular thickness. The central macular thickness showed a significant linear relation with BCVA, but not with disease activity. Thirteen patients developed ME (central field thickness >304.4 µm) after a mean time interval of 11.6 years. Thirteen patients had macular thinning after a significant longer interval of uveitis compared to patients with normal or thickened macula. CONCLUSIONS: Duration of JIA-uveitis is positively correlated with the development of ME, compromising the visual acuity.