Drug Registries and Approval of Drugs:Promises, Placebo, or a Real Success?

Purpose: As part of the approval process, regulatory authorities often require postauthorization studies that involve patient registries; it is unknown, however, whether such registry studies are adequately completed. We investigated whether registry studies for new drugs were performed as agreed at time of approval. Methods: This study reviewed protocols and follow-up reports for 73 registry studies that were proposed for 43 drugs approved by the Committee for Medicinal Products for Human Use in Europe in the period 2007 to 2010. Results: The data lock point of January 1, 2016, was taken to allow a 5-year follow-up period for each drug after approval. At that time, 2 studies (3%) in registries had been finalized, 19 registries (26%) had not enrolled any patients, and 52 studies (71%) were ongoing. The median enrollment was 31% (interquartile range [IQR], 6–104) of the required number of patients for 41 registry studies that had a predefined sample size, 30% (IQR, 2–101) for nonimposed registries, and 61% (IQR, 18–144) for imposed registries. Implications: Enrollment of patients into postapproval registries is poor, although the results for imposed registries seem better. Currently, registries only have a limited impact on resolving gaps in the knowledge of a drug's benefits and risks at time of marketing authorization

Nonequilibrium spectral diffusion due to laser heating in stimulated photon echo spectroscopy of low temperature glasses

A quantitative theory is developed, which accounts for heating artifacts in three-pulse photon echo (3PE) experiments. The heat diffusion equation is solved and the average value of the temperature in the focal volume of the laser is determined as a function of the 3PE waiting time. This temperature is used in the framework of nonequilibrium spectral diffusion theory to calculate the effective homogeneous linewidth of an ensemble of probe molecules embedded in an amorphous host. The theory fits recently observed plateaus and bumps without introducing a gap in the distribution function of flip rates of the two-level systems or any other major modification of the standard tunneling model.Comment: 10 pages, Revtex, 6 eps-figures, accepted for publication in Phys. Rev.

International Guillain-Barré Syndrome Outcome Study (IGOS): protocol of a prospective observational cohort study on clinical and biological predictors of disease course and outcome in Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an acute polyradiculoneuropathy with a highly variable clinical presentation, course, and outcome. The factors that determine the clinical variation of GBS are poorly understood which complicates the care and treatment of individual patients. The protocol of the ongoing International GBS Outcome Study (IGOS), a prospective, observational, multi-centre cohort study that aims to identify the clinical and biological determinants and predictors of disease onset, subtype, course and outcome of GBS is presented here. Patients fulfilling the diagnostic criteria for GBS, regardless of age, disease severity, variant forms, or treatment, can participate if included within two weeks after onset of weakness. Information about demography, preceding infections, clinical features, diagnostic findings, treatment, course and outcome is collected. In addition, cerebrospinal fluid and serial blood samples for serum and DNA is collected at standard time points. The original aim was to include at least 1000 patients with a follow-up of 1-3 years. Data are collected via a web-based data entry system and stored anonymously. IGOS started in May 2012 and by January 2017 included more than 1400 participants from 143 active centres in 19 countries across 5 continents. The IGOS data/biobank is available for research projects conducted by expertise groups focusing on specific topics including epidemiology, diagnostic criteria, clinimetrics, electrophysiology, antecedent events, antibodies, genetics, prognostic modelling, treatment effects and long-term outcome of GBS. The IGOS will help to standardize the international collection of data and biosamples for future research of GBS. ClinicalTrials.gov Identifier: NCT01582763

A perturbation approach for ultrafast calculation of RF field enhancements near medical implants in MRI

Patients with medical implants often are deprived of magnetic resonance imaging examination because of safety risks. One specific risk is the enhancement of the radiofrequency fields around the medical implant potentially resulting in significant tissue heating and damage. The assessment of this enhancement is a computationally demanding task, with simulations taking hours or days to converge. Conventionally the source of the radiofrequency fields, patient anatomy, and the medical implant are simulated concurrently. To alleviate the computational burden, we reformulate a fast simulation method that views the medical implant as a small perturbation of the simulation domain without the medical implant and calculates the radiofrequency fields associated with this perturbation. Previously, this method required an extensive offline stage where the result is intractable for large simulation domains. Currently, this offline stage is no longer required and the method is completely online. The proposed method results in comparable radiofrequency fields but is orders of magnitude faster compared to standard simulation technique; the finite-difference time-domain, the finite-sums, and the finite element methods. This acceleration could enable patient-specific and potentially online radiofrequency safety assessment

The value of genetic testing in the diagnosis and risk stratification of arrhythmogenic right ventricular cardiomyopathy

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by risk of malignant ventricular arrhythmias (VA). ARVC is diagnosed using an array of clinical tests in the consensus-based task force criteria (TFC), one of which is genetic testing. OBJECTIVE: To investigate the value of genetic testing in diagnosing ARVC and its relation to the occurrence of first malignant VA. METHODS: A multicenter cohort of ARVC patients was scored using the revised 2010 TFC with and without genetic criterion, analyzing any resulting loss or delay of diagnosis. Malignant VA was defined as sustained ventricular arrhythmia (≥30s duration at ≥100 bpm or requiring intervention). RESULTS: We included 402 subjects (55% male, 54% proband, 40 [27-51] years old at presentation) who were diagnosed with definite ARVC. A total of 232 (58%) subjects fulfilled genetic testing criteria. Removing the genetic criterion caused loss of diagnosis in 18 (4%) patients (11/216 [5%] probands, 7/186 [4%] relatives), and delay of diagnosis ≥30 days in 22 (5%) patients (21/216 [10%] probands, 1/186 [0.5%] relative). A first malignant VA occurred in no patients who lost diagnosis and in 3 patients (3/216 [1%] probands and no relatives) during their diagnosis delay, none fatal. Time to event analysis showed no significant difference in time from diagnosis to malignant VA between pathogenic variant carriers and non-carriers. CONCLUSION: Disregarding the genetic criterion of the TFC caused loss or delay of diagnosis in 10% (n=40/402) of ARVC patients. Malignant VA occurred in 1% (n=3/402) of cases with lost or delayed diagnosis, none fatal

Reducing contamination risk in cluster-randomized infectious disease-intervention trials

Background: Infectious disease interventions are increasingly tested using cluster-randomized trials (CRTs). These trial settings tend to involve a set of sampling units, such as villages, whose geographic arrangement may present a contamination risk in treatment exposure. The most widely used approach for reducing contamination in these settings is the so-called fried-egg design, which excludes the outer portion of all available clusters from the primary trial analysis. However, the fried-egg design ignores potential intra-cluster spatial heterogeneity and makes the outcome measure inherently less precise. Whereas the fried-egg design may be appropriate in specific settings, alternative methods to optimize the design of CRTs in other settings are lacking. Methods: We present a novel approach for CRT design that either fully includes or fully excludes available clusters in a defined study region, recognizing the potential for intra-cluster spatial heterogeneity. The approach includes an algorithm that allows investigators to identify the maximum number of clusters that could be included for a defined study region and maintain randomness in both the selection of included clusters and the allocation of clusters to either the treatment group or control group. The approach was applied to the design of a CRT testing the effectiveness of malaria vector-control interventions in southern Malawi. Conclusions: Those planning CRTs to evaluate interventions should consider the approach presented here during trial design. The approach provides a novel framework for reducing the risk of contamination among the CRT randomization units in settings where investigators determine the reduction of contamination risk as a high priority and where intra-cluster spatial heterogeneity is likely. By maintaining randomness in the allocation of clusters to either the treatment group or control group, the approach also permits a randomization-valid test of the primary trial hypothesis

Drug Registries and Approval of Drugs:Promises, Placebo, or a Real Success?

Purpose: As part of the approval process, regulatory authorities often require postauthorization studies that involve patient registries; it is unknown, however, whether such registry studies are adequately completed. We investigated whether registry studies for new drugs were performed as agreed at time of approval. Methods: This study reviewed protocols and follow-up reports for 73 registry studies that were proposed for 43 drugs approved by the Committee for Medicinal Products for Human Use in Europe in the period 2007 to 2010. Results: The data lock point of January 1, 2016, was taken to allow a 5-year follow-up period for each drug after approval. At that time, 2 studies (3%) in registries had been finalized, 19 registries (26%) had not enrolled any patients, and 52 studies (71%) were ongoing. The median enrollment was 31% (interquartile range [IQR], 6-104) of the required number of patients for 41 registry studies that had a predefined sample size, 30% (IQR, 2-101) for nonimposed registries, and 61% (IQR, 18-144) for imposed registries. (C) 2018 The Authors. Published by Elsevier HS Journals, Inc

Registries supporting new drug applications

Purpose: Knowledge of the benefits and risks of new drugs is incomplete at the time of marketing approval. Registries offer the possibility for additional, post-approval, data collection. For all new drugs, which were approved in the European Union between 2007 and 2010, we reviewed the frequency, the type, and the reason for requiring a registry. Methods: The European Public Assessment Reports, published on the website of the European Medicine Agency, were reviewed for drugs approved by the Committee for Medicinal Products for Human Use. We searched for key characteristics of these drugs, including therapeutic area (ATC1 level), level of innovation (the score is an algorithm based on availability of treatment and therapeutic effect), and procedural characteristics. In addition, we identified if these registries were defined by disease (disease registry) or exposure to a single drug (drug registry). Results: Out of 116 new drugs approved in the predefined period, for 43 (37%), 1 to 6 registry studies were identified, with a total of 73 registries. Of these 46 were disease registries and 27 (single) drug registries. For 9 drugs, the registry was a specific obligation imposed by the regulators. The level of innovation and the orphan status of the drugs were determinants positively predicting post-approval registries (OR 10.3 [95% CI 1.0-103.9] and OR 2.8 [95% CI 1.0-7.5], respectively). Conclusions: The majority of registries required by regulators are existing disease registries. Registries are an important and frequently used tool for post-approval data collection for orphan and innovative drugs

Chondrodysplasia, enchondromas and a chest deformity causing severe pulmonary morbidity in a boy with a PTHLH duplication:A case report

Parathyroid hormone-like hormone (PTHLH) plays an important role in bone formation. Several skeletal dysplasias have been described that are associated with disruption of PTHLH functioning. Here we report on a new patient with a 898 Kb duplication on chromosome 12p11.22 including the PTHLH gene. The boy has multiple skeletal abnormalities including chondrodysplasia, lesions radiographically resembling enchondromas and posterior rib deformities leading to a severe chest deformity. Severe pulmonary symptoms were thought to be caused by limited mobility and secondary sputum evacuation problems due to the chest deformity. Imaging studies during follow-up revealed progression of the number of skeletal lesions over time. This case extends the phenotypic spectrum associated with copy number variation of PTHLH