Global Medical Device Clinical Trials Involving Both the United States and Japan: Key Considerations for Development, Regulatory Approval, and Conduct.

As medical device development becomes increasingly global, the opportunities and potential advantages offered by international clinical trial and regulatory approval strategies are also growing. In particular, medical device clinical trials involving sites in both the United States and Japan and intended to support marketing in both countries may warrant particular consideration, given the similarities in their regulatory systems, patients and clinical practice patterns, and market sizes. Since 2003, the US-Japan Harmonization By Doing (HBD) initiative has been focused on identifying and addressing clinical and regulatory barriers to medical devices access in both countries via collaboration between governmental, academic, and industry stakeholders. Through the efforts of HBD participants, US-Japanese clinical trials have been conducted and the resulting data have supported regulatory approval for marketing in both countries. Based on these experiences, this paper outlines some of the key factors to consider when developing a global clinical trial involving US and Japanese participation. These considerations include the mechanisms for consultation with regulatory authorities on clinical trial strategies, the regulatory framework for clinical trial notification and approval, recruitment and conduct of clinical sites, and lessons learned from specific US-Japanese clinical trial experiences. The goal of this paper is to promote global access to promising medical technologies by assisting potential clinical trial sponsors in understanding when an international strategy may be appropriate and successful.

Empirical Evaluation of the Possible Contribution of Group Practice of the Transcendental Meditation and TM-Sidhi Program to Reduction in Drug-Related Mortality.

Background and Objectives: CDC data indicate that the U.S. is experiencing a sustained epidemic of drug-related mortality, with such deaths exceeding a record 100,000 in 2021, up 47% from 2019. Opioids, especially the synthetic opioid fentanyl, account for approximately 75% of this mortality. This study evaluates a proposed Consciousness-Based® approach that may possibly help reduce trends in drug-related fatalities by mitigating what WHO refers to as an "epidemic of stress" in society that helps fuel drug misuse and other negative public health trends. This approach involves providing support in public and private sector public health initiatives for individual and group practice of a subjective, evidence-based meditation procedure suitable for those of all educational, cultural, and religious backgrounds: the Transcendental Meditation® (TM®) technique and its advanced aspect, the TM-Sidhi® program. Materials and Methods: Segmented-trend regression analysis of monthly CDC data on U.S. drug-related fatality rates (dfr) from a prospective social experiment (2002-2016) was used to replicate and extend prior peer-reviewed research. Results: As hypothesized, (1) practice of the TM and TM-Sidhi program by a group of theoretically predicted size (√1% of the U.S. population) was associated with a statistically and practically significant reduction in dfr trend during the five-year "demonstration period" of the quasi-experiment; and (2) monthly dfr trend subsequently increased during the five-year follow-up period when the group fell below the required size (both p's < 0.0001). The estimated total percent decrease in dfr during the demonstration period was 35.5%, calculated relative to the baseline mean. This decline was followed by total dfr increases of 11.8% and 47.4% relative to the demonstration-period mean during the two phases of the follow-up period. Conclusion: Existing evidence warrants implementation and further evaluation of this approach in U.S. public health initiatives.

Editor's Choice - Real World Study of Mortality After the Use of Paclitaxel Coated Devices in Peripheral Vascular Intervention.

OBJECTIVE: This observational cohort study examined outcomes after peripheral vascular intervention (PVI) with paclitaxel coated devices (PCD) and non-PCD, and evaluated heterogeneity of treatment effect in populations of interest. METHODS: The study included patients undergoing percutaneous transluminal angioplasty and or stent placement between 1 October 2015 and 31 December 2018 in the Vascular Quality Initiative Registry linked to Medicare claims. It determined differences in patient mortality and ipsilateral major amputation after PVI with PCD and non-PCD using Kaplan-Meier analyses and Cox regressions with inverse probability weighting in three cohorts: (A) patients treated for femoropopliteal or infrapopliteal occlusive disease with or without any other concurrent treatment (n = 11 452); (B) those treated for isolated superficial femoral or popliteal artery disease (n = 5 519); and (C) patients with inclusion criteria designed to approximate RCT populations (n = 2 278). RESULTS: The mean age of patients was 72.3 (SD = 10.9) years, and 40.6% were female. In cohort A, patients receiving PCD had a lower mortality rate (HR 0.88, 95% CI 0.79 - 0.98) than those receiving non-PCD. There was no significant difference in mortality between groups in cohort B (HR 0.91, 95% CI 0.80 - 1.04) and cohort C (HR 1.10, 95% CI 0.84 - 1.43). Patients receiving PCD did not have a significantly elevated risk of major amputation compared with those receiving non-PCD (cohort A: HR 0.84, 95% CI 0.70 - 1.00; cohort B: HR 0.84, 95% CI 0.67 - 1.06; and cohort C: HR 1.05, 95% CI 0.51 - 2.14). CONCLUSION: No increased patient mortality or major amputation was found at three years after PVI with PCD vs. non-PCD in this large, linked registry claims study, after accounting for heterogeneity of treatment effect by population. The analysis and results from three cohorts intended to mirror the cohorts of previous studies provide robust and niche real world evidence on PCD safety and help to understand and reconcile previously discrepant findings.

Navigating the Regulatory Pathway for Medical Devices-a Conversation with the FDA, Clinicians, Researchers, and Industry Experts.

Successful translation of new and innovative medical products from concept to clinical use is a complex endeavor that requires understanding and overcoming a variety of challenges. In particular, regulatory pathways and processes are often unfamiliar to academic researchers and start-ups, and even larger companies. Growing evidence suggests that the successful translation of ideas to products requires collaboration and cooperation between clinicians, researchers, industry, and regulators. A multi-stakeholder group developed this review to enhance regulatory knowledge and thereby improve translational success for medical devices. Communication between and among stakeholders is identified as a critical factor. Current regulatory programs and processes to facilitate communication and translation of innovative devices are described and discussed. Case studies are used to highlight the importance of flexibility when considering evidence requirements. We provide a review of emerging strategies, opportunities, and best practices to increase the regulatory knowledge base and facilitate medical device translation by all stakeholders. Clinicians, regulators, industry, and researchers require regulatory knowledge and collaboration for successful translation of innovative medical devices.

Japan-USA Orbital Atherectomy for Calcific Coronary Lesions: COAST Study, a Harmonization by Doing Proof-of-Concept: The Japanese and US Regulatory Perspective.

Regulatory approval processes for medical devices in Japan and the United States of America (US) often require similar clinical trials to establish safety and effectiveness. The Harmonization by Doing (HBD) program provides a collaborative environment for communication between regulators, academics and industry, facilitating the design and conduct of US/Japanese clinical trials supporting approval in both countries.

Electrophysiology devices and the regulatory approval process within the U.S. FDA and abroad.

Almost all electrophysiology (EP) devices need to obtain premarket approval before they can be commercially sold and available for use in the community. The US Food and Drug Administration (FDA) has different paths to market approval depending on the intended use and the associated risks of the device. The European Union and Japan have device approval processes that have many similarities as well as differences to the US regulatory system. This paper describes some of the history and background of the US device approval process with an emphasis on EP devices. It provides an overview of the different regulatory pathways in the USA that are currently being utilized and contrasts them to the procedures often used in the European Union and in Japan. It also touches on the impact of the twenty-first Century Cures Act and how the balance between premarket and postmarket regulatory oversight is continually being examined and refined.

Decision analysis of retrievable inferior vena cava filters in patients without pulmonary embolism.

BACKGROUND: Retrievable filters are increasingly implanted for prophylaxis in patients without pulmonary embolism (PE) but who may be at transient risk. These devices are often not removed after the risk of PE has diminished. This study employs decision analysis to weigh the risks and benefits of retrievable filter use as a function of the filter's time in situ. METHODS: Medical literature on patients with inferior vena cava (IVC) filters and a transient risk of PE were reviewed. Weights reflecting relative severity were assigned to each adverse event. The risk score was defined as weight × occurrence rate and combines the frequency and severity for each type of adverse event. The value function in the decision model combines the following risks: (1) risk in situ; (2) risk of removal, and (3) relative risk without filters. A decreasing net risk score represents a net expected benefit, and an increasing net risk score indicates the expected harm outweighs the expected benefit. RESULTS: The net risk score reaches its minimum between day 29 and 54 postimplantation. This is consistent with an increasing net risk associated with continued use of retrievable IVC filters in patients with transient, reversible risk of PE. The results were insensitive to reasonable variations in the assessed weights and adverse event occurrence rates. CONCLUSIONS: For patients with retrievable IVC filters in whom the transient risk of PE has passed, quantitative decision analysis suggests the benefit/risk profile begins to favor filter removal between 29 and 54 days after implantation.

FDA perspective on objective performance goals and clinical trial design for evaluating catheter-based treatment of critical limb ischemia.

The article by Conte et al.(1) on behalf of the Society for Vascular Surgery (SVS) in this issue of the Journal of Vascular Surgery provides guidelines for improving the consistency and interpretability of clinical trials intended to evaluate treatment options for patients with critical limb ischemia (CLI). This article identifies a number of key challenges with conducting and comparing CLI trials, including the wide spectrum of clinical presentations that CLI encompasses, the use of disparate eligibility criteria and endpoint measurements, and logistical and economic considerations that can limit study initiation and completion. The authors propose definitions for a number of performance goals derived from historical surgical literature as a means of reducing the negative impact of these factors. The current editorial reviews aspects of this proposal from the perspective of the authors in terms of their understanding of the statutory obligations of the U.S. Food and Drug Administration (FDA) to regulate the marketing of cardiovascular devices based on valid scientific evidence.

How dysregulated colonic crypt dynamics cause stem cell overpopulation and initiate colon cancer.

Based on investigation of the earliest colonic tissue alteration in familial adenomatous polyposis (FAP) patients, we present the hypothesis that initiation of colorectal cancer by adenomatous polyposis coli (APC) mutation is mediated by dysregulation of two cellular mechanisms. One involves differentiation, which normally decreases the proportion (proliferative fraction) of colonic crypt cells that can proliferate; the other is a cell cycle mechanism that simultaneously increases the probability that proliferative cells are in S phase. In normal crypts, stem cells (SC) at the crypt bottom generate rapidly proliferating cells, which undergo differentiation while migrating up the crypt. Our modeling of normal crypts suggests that these transitions are mediated by mechanisms that regulate proliferative fraction and S-phase probability. In FAP crypts, the population of rapidly proliferating cells is shifted upwards, as indicated by the labeling index (LI; i.e., crypt distribution of cells in S phase). Our analysis of FAP indicates that these transitions are delayed because the proliferative fraction and S-phase probability change more slowly as a function of crypt level. This leads to expansion of the proliferative cell population, including a subpopulation that has a low frequency of S-phase cells. We previously reported that crypt SC overpopulation explains the LI shift. Here, we determine that SCs (or cells having high stemness) are proliferative cells with a low probability of being in S phase. Thus, dysregulation of mechanisms that control proliferative fraction and S-phase probability explains how APC mutations induce SC overpopulation at the crypt bottom, shift the rapidly proliferating cell population upwards, and initiate colon tumorigenesis.

Stretch increases alveolar epithelial permeability to uncharged micromolecules.

We measured stretch-induced changes in transepithelial permeability in vitro to uncharged tracers 1.5-5.5 A in radius to identify a critical stretch threshold associated with failure of the alveolar epithelial transport barrier. Cultured alveolar epithelial cells were subjected to a uniform cyclic (0.25 Hz) biaxial 12, 25, or 37% change in surface area (DeltaSA) for 1 h. Additional cells served as unstretched controls. Only 37% DeltaSA (100% total lung capacity) produced a significant increase in transepithelial tracer permeability, with the largest increases for bigger tracers. Using the permeability data, we modeled the epithelial permeability in each group as a population of small pores punctuated by occasional large pores. After 37% DeltaSA, increases in paracellular transport were correlated with increases in the radii of both pore populations. Inhibition of protein kinase C and tyrosine kinase activity during stretch did not affect the permeability of stretched cells. In contrast, chelating intracellular calcium and/or stabilizing F-actin during 37% DeltaSA stretch reduced but did not eliminate the stretch-induced increase in paracellular permeability. These results provide the first in vitro evidence that large magnitudes of stretch increase paracellular transport of micromolecules across the alveolar epithelium, partially mediated by intracellular signaling pathways. Our monolayer data are supported by whole lung permeability results, which also show an increase in alveolar permeability at high inflation volumes (20 ml/kg) at the same rate for both healthy and septic lungs.

Measurement of stretch-induced loss of alveolar epithelial barrier integrity with a novel in vitro method.

Mechanical ventilation with high tidal volumes has been shown to contribute to the formation or worsening of interstitial and alveolar edema. Previously we showed that application of large biaxial deformations in vitro perturbs the concentration and distribution of functional tight junction proteins in alveolar epithelial cells. Using a novel method, we determined that applied epithelial strain increases paracellular permeability in a dose- and rate-dependent manner. Primary rat alveolar epithelial cells were subjected to 12%, 25%, or 37% change in surface area (Delta SA) cyclic equibiaxial stretch for 1 h. Cells were also stretched noncyclically at 25% Delta SA for 1 h. During the experimental period, a fluorescently tagged ouabain derivative was added to the apical fluid. Evidence of binding indicated functional failure of the paracellular transport barrier. The percentage of field area stained was quantified from microscopic images. There was no significant evidence of basolateral fluorescent staining at 12% Delta SA or at 25% Delta SA applied cyclically or statically. However, cyclic stretch at 37% Delta SA resulted in significantly more staining than in unstretched cells (P < 0.0001) or those stretched at either 12% (P < 0.0001) or 25% cyclic (P < 0.0005) or static (P < 0.05) Delta SA. These results suggest that large cyclic tidal volumes may increase paracellular permeability, potentially resulting in alveolar flooding.