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Pharmacokinetic/pharmacodynamic data extrapolation models for improved pediatric efficacy and toxicity estimation, with application to secondary hyperparathyroidism.
Basu, C, Ma, X, Mo, M, Xia, HA, Brundage, R, Al-Kofahi, M, Carlin, BP
Pharmaceutical statistics. 2020;(6):882-896
Abstract
In most drug development settings, the regulatory approval process is accompanied by extensive studies performed to understand the drug's pharmacokinetic (PK) and pharmacodynamic (PD) properties. In this article, we attempt to utilize the rich PK/PD data to inform the borrowing of information from adults during pediatric drug development. In pediatric settings, it is especially crucial that we are parsimonious with the patients recruited for experimentation. We illustrate our approaches in the context of clinical trials of cinacalcet for treating secondary hyperparathyroidism in pediatric and adult patients with chronic kidney disease, where we model both parathyroid hormone (efficacy endpoint) and corrected calcium levels (safety endpoint). We use population PK/PD modeling of the cinacalcet data to quantitatively assess the similarity between adults and children, and use this information in various hierarchical Bayesian adult borrowing rules whose statistical properties can then be evaluated. In particular, we simulate the bias and mean square error performance of our approaches in settings where borrowing is and is not warranted to inform guidelines for the future use of our methods.
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Computing and interpreting the Number Needed to Treat for Cardiovascular Outcomes Trials : Perspective on GLP-1 RA and SGLT-2i therapies.
Ludwig, L, Darmon, P, Guerci, B
Cardiovascular diabetology. 2020;(1):65
Abstract
The recent results of Cardiovascular Outcomes Trials (CVOTs) in type 2 diabetes have clearly established the cardiovascular (CV) safety or even the benefit of two therapeutic classes, Glucagon-Like Peptide-1 receptor agonists (GLP-1 RA) and Sodium-Glucose Co-Transporter-2 inhibitors (SGLT-2i). Publication of the latest CVOTs for these therapeutic classes also led to an update of ESC guidelines and ADA/EASD consensus report in 2019, which considers using GLP-1 RA or SGLT-2i with proven cardiovascular benefit early in the management of type 2 diabetic patient with established cardiovascular disease (CVD) or at high risk of atherosclerotic CVD. The main beneficial results of these time-to event studies are supported by conventional statistical measures attesting the effectiveness of GLP-1 RA or SGLT2i on cardiovascular events (absolute risk, absolute risk difference, relative risk, relative risk reduction, odds ratio, hazard ratio). In addition, another measure whose clinical meaning appears to be easier, the Number Needed to Treat (NNT), is often mentioned while discussing the results of CVOTs, in order to estimating the clinical utility of each drug or sometimes trying to establish a power ranking. While the value of the measure is admittedly of interest, the subtleties of its computation in time-to-event studies are little known. We provide in this article a clear and practical explanation on NNT computation methods that should be used in order to estimate its value, according to the type of study design and variables available to describe the event of interest, in any randomized controlled trial. More specifically, a focus is made on time-to-event studies of which CVOTs are part, first to describe in detail an appropriate and adjusted method of NNT computation and second to help properly interpreting NNTs with the example of CVOTs conducted with GLP-1 RA and SGLT-2i. We particularly discuss the risk of misunderstanding of NNT values in CVOTs when some specific parameters inherent in each study are not taken into account, and the following risk of erroneous comparison between NNTs across studies. The present paper highlights the importance of understanding rightfully NNTs from CVOTs and their clinical impact to get the full picture of a drug's effectiveness.
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Approaches to Disease Modification for Parkinson's Disease: Clinical Trials and Lessons Learned.
Hung, AY, Schwarzschild, MA
Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics. 2020;(4):1393-1405
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Abstract
Despite many clinical trials over the last three decades, the goal of demonstrating that a treatment slows the progression of Parkinson's disease (PD) remains elusive. Research advances have shed new insight into cellular pathways contributing to PD pathogenesis and offer increasingly compelling therapeutic targets. Here we review recent and ongoing clinical trials employing novel strategies toward disease modification, including those targeting alpha-synuclein and those repurposing drugs approved for other indications. Active and passive immunotherapy approaches are being studied with the goal to modify the spread of alpha-synuclein pathology in the brain. Classes of currently available drugs that have been proposed to have potential disease-modifying effects for PD include calcium channel blockers, antioxidants, anti-inflammatory agents, iron-chelating agents, glucagon-like peptide 1 agonists, and cAbl tyrosine kinase inhibitors. The mechanistic diversity of these treatments offers hope, but to date, results from these trials have been disappointing. Nevertheless, they provide useful lessons in guiding future therapeutic development.
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Personalized treatment selection using data from crossover designs with carry-over effects.
Siriwardhana, C, Kulasekera, KB, Datta, S
Statistics in medicine. 2019;(28):5391-5412
Abstract
In this work, we propose a semiparametric method for estimating the optimal treatment for a given patient based on individual covariate information for that patient when data from a crossover design are available. Here, we assume there are carry-over effects for patients switching from one treatment to another. For the K treatment (K ≥ 2) scenario, we show that nonparametric estimation of carry-over effects can have the undesirable property that comparison of treatment means can only be done using independent outcome measurements from different groups of patients rather than using available joint measurements for each patient. To overcome this barrier, we compare probabilities of outcome variable of each treatment dominating outcome variables for all other treatments conditional on patient-specific scores constructed from patient covariates. We suggest single-index models as appropriate models connecting outcome variables to covariates and our empirical investigations show that frequencies of correct treatment assignments are highly accurate. The proposed method is also rather robust against departures from a single-index model structure. We also conduct a real data analysis to show the applicability of the proposed procedure.
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Changes in the Use of Comprehensive Geriatric Assessment in Clinical Trials for Older Patients with Cancer over Time.
Le Saux, O, Falandry, C, Gan, HK, You, B, Freyer, G, Péron, J
The oncologist. 2019;(8):1089-1094
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Abstract
BACKGROUND The objective of this study was to describe the implementation of comprehensive geriatric assessment (CGA) in clinical trials dedicated to older patients before and after the creation of the International Society of Geriatric Oncology in the early 2000s. SUBJECTS, MATERIALS, AND METHODS All phase I, II, and III trials dedicated to the treatment of cancer among older patients published between 2001 and 2004 and between 2011 and 2014 were reviewed. We considered that a CGA was performed when the authors indicated an intention to do so in the Methods section of the article. We collected each geriatric domain assessed using a validated tool even in the absence of a clear CGA, including nutritional, functional, cognitive, and psychological status, comorbidity, comedication, overmedication, social status and support, and geriatric syndromes. RESULTS A total of 260 clinical trials dedicated to older patients were identified over the two time periods: 27 phase I, 193 phase II, and 40 phase III trials. CGA was used in 9% and 8% of phase II and III trials, respectively; it was never used in phase I trials. Performance status was reported in 67%, 79%, and 75% of phase I, II, and III trials, respectively. Functional assessment was reported in 4%, 11%, and 13% of phase I, II, and III trials, respectively. Between the two time periods, use of CGA increased from 1% to 11% (p = .0051) and assessment of functional status increased from 3% to 14% (p = .0094). CONCLUSION The use of CGA in trials dedicated to older patients increased significantly but remained insufficient. IMPLICATIONS FOR PRACTICE This article identifies the areas in which research efforts should be focused in order to offer physicians well-addressed clinical trials with results that can be extrapolated to daily practice.
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Pivotal clinical trials, meta-analyses and current guidelines in the treatment of hyperkalemia.
Bianchi, S, Regolisti, G
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 2019;(Suppl 3):iii51-iii61
Abstract
Hyperkalemia (HK) is the most common electrolyte disturbance observed in patients with advanced stages of chronic kidney disease (CKD), is a potentially life-threatening clinical condition due to an increased risk of fatal arrhythmias, and strongly impacts the quality of life and prognosis of CKD patients. Moreover, while renin-angiotensin-aldosterone system inhibitors (RAASIs) represent the most cardio-nephro-protective drugs used in clinical practice, the treatment with these drugs per se increases serum potassium (sK) values, particularly when heart failure and diabetes mellitus coexist. In fact, the onset or recurrence of HK is frequently associated with not starting, down-titrating or withdrawing RAASIs, and is an indication to begin renal replacement treatment in end-stage renal disease. Current strategies aimed at preventing and treating chronic HK are still unsatisfactory, as evidenced by the relatively high prevalence of HK also in patients under stable nephrology care, and even in the ideal setting of randomized clinical trials. Indeed, dietary potassium restriction, the use of sodium bicarbonate or diuretics, the withdrawal or down-titration of RAASIs, or the administration of old potassium binders, namely sodium polystyrene sulphonate and calcium polystyrene sulphonate, have limited efficacy and are poorly tolerated; therefore, these strategies are not suitable for long-term control of sK. As such, there is an important unmet need for novel therapeutic options for the chronic management of patients at risk for HK. The development of new potassium binders may change the treatment landscape in the near future. This review summarizes the current evidence on the treatment of chronic HK in cardio-renal patients.
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Children of a lesser god: exclusion of chronic kidney disease patients from clinical trials.
Zoccali, C, Blankestijn, PJ, Bruchfeld, A, Capasso, G, Fliser, D, Fouque, D, Goumenos, D, Ketteler, M, Massy, Z, Rychlık, I, et al
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 2019;(7):1112-1114
Abstract
The exclusion of chronic kidney disease (CKD) patients from clinical trials-particularly cardiovascular trials-remains a long-standing, unsolved problem, which prevents the optimization of clinical care in these patients. The situation recalls the insufficient recruitment of women in cardiovascular trials until the 1980s, a problem that was only resolved following regulatory interventions. Regulatory agencies are in a unique position to promote recruitment of CKD patients in clinical trials. The main stakeholders, namely patients' associations and scientific societies, should make major lobbying efforts to persuade these agencies that the issue is an absolute public health priority.
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Report on the AASLD/EASL joint workshop on clinical trial endpoints in NAFLD.
Rinella, ME, Tacke, F, Sanyal, AJ, Anstee, QM, ,
Journal of hepatology. 2019;(4):823-833
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a global public health concern. Its natural history, the development of non-alcoholic steatohepatitis (NASH) and fibrosis, is highly variable, prone to endogenous (e.g., genetics, microbiota) and exogenous (e.g., nutrition, alcohol, physical activity) disease modifiers, and can fluctuate over time. The complexity of its pathophysiology is reflected by the multitude of pharmacological targets in development. NASH clinical trials have provided valuable insight that is applicable to future trial design. Endpoints for NASH have evolved over the past decade and will continue to be refined. Currently accepted endpoints for conditional approval include resolution of NASH without worsening of fibrosis and/or improvement in fibrosis without worsening of NASH by standardized evaluation of paired liver histology. In pediatric NASH, practical obstacles, pubertal hormonal changes, and stringent safety requirements mandate adaptations in trial design. In adult patients with NASH-related cirrhosis, decrease in portal pressure as well as clinical events (e.g. decompensation, hepatocellular carcinoma, transplantation, death) are more prevalent and thereby are viable primary endpoints for clinical trials. Consideration of the natural fluctuation of disease, the clinical implication of the chosen primary endpoint, and factors that may affect placebo response will facilitate an accurate determination of efficacy of emerging therapeutics for NASH. Conclusion: The June 2018 American Association for the Study of Liver Diseases and European Association for the Study of the Liver joint workshop on NAFLD endpoints summarized important findings from ongoing and completed trials, defined the scientific evidence supporting distinct endpoints, and provided guidance for future trial design.
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Physics aspects of setting up a multicenter clinical trial involving internal dosimetry of radioiodine treatment of differentiated thyroid cancer.
Taprogge, J, Leek, F, Flux, GD
The quarterly journal of nuclear medicine and molecular imaging : official publication of the Italian Association of Nuclear Medicine (AIMN) [and] the International Association of Radiopharmacology (IAR), [and] Section of the Society of.... 2019;(3):271-277
Abstract
The field of molecular radiotherapy is expanding rapidly, with the advent of many new radiotherapeutics for the treatment of common as well as for rare cancers. Treatment outcome is dependent on the absorbed doses delivered to target volumes and to healthy organs-at-risk, which are shown to vary widely from fixed administrations of activity. There have been significant developments in quantitative imaging and internal dosimetry in recent years, although clinical implementation of these methods has been slow in comparison with external beam radiotherapy, partly due to there being relatively few patients treated at single centers. Multicenter clinical trials are therefore essential to acquire the data required to ensure best practice and to develop the personalized treatment planning that this area is well suited to, due to the unrivalled opportunity to image the therapeutic drug in vivo. Initial preparation for such trials requires a significant effort in terms of resources and trial design. Imaging systems in participating centers must be characterized and set up for quantitative imaging to allow for collation of data. Data transfer for centralized processing is usually necessary but is hindered in some cases by data protection regulations and local logistics. Recent multicenter clinical trials involving radioiodine therapy have begun to establish the procedures necessary for quantitative SPECT imaging in a multicenter setting using standard and anthropomorphic phantoms. The establishment of national and international multicenter imaging and dosimetry networks will provide frameworks to develop and harmonize best practice with existing therapeutic procedures and to ensure rapid and optimized clinical implementation of new radiotherapeutics across all centers of excellence that offer molecular radiotherapy. This will promote networks and collaborations that can provide a sound basis for further developments and will ensure that nuclear medicine maintains a key role in future developments.
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EvaluatioN of ApiXaban in strOke and systemic embolism prevention in patients with non-valvular atrial fibrillation in clinical practice Setting in France, rationale and design of the NAXOS: SNIIRAM study.
Picard, F, Van Ganse, E, Ducrocq, G, Danchin, N, Falissard, B, Hanon, O, Belhassen, M, Ginoux, M, Lefevre, C, Cotte, FE, et al
Clinical cardiology. 2019;(10):851-859
Abstract
Non-vitamin K antagonists oral anticoagulants (NOACs) have recently challenged vitamin-K antagonists (VKAs) for stroke and systemic embolism prophylaxis in patients with non-valvular atrial fibrillation (NVAF). Nevertheless, little information is available in routine clinical practice for France. The aim of this study is to describe the effectiveness and safety of apixaban, rivaroxaban, dabigatran or VKAs in routine clinical practice in adult NVAF patients for the prevention of stroke and systemic embolism in France. The NAXOS study is a nationwide observational retrospective cohort generated from the French national healthcare insurance database (SNIIRAM-a comprehensive in- and outpatient healthcare consumption database), consisting of eight distinct sub-cohorts of anticoagulant-naive or anticoagulant-experienced patients diagnosed with NVAF, newly initiated with either NOACs (dabigatran, rivaroxaban or apixaban) or VKAs. Patients will be included if initiating a new anticoagulant treatment for AF during the study period from 1 January 2014 to 31 December 2016. Primary effectiveness outcome will be the incidence of stroke or systemic thromboembolic events; primary safety outcome will be the incidence of major bleeding during the exposure period. The NAXOS study will provide routine clinical practice data on the effectiveness and safety profiles of apixaban vs other NOACs and VKAs in the prevention of stroke and systemic embolism in adult patients with NVAF in clinical practice conditions in France.