Imaging Prostate Cancer: Clinical Utility of Prostate-Specific Membrane Antigen.

PURPOSE: Our goal was to review the pathway and pertinent materials leading to approval of prostate-specific membrane antigen (PSMA) scanning by the U.S. Food and Drug Administration (FDA). MATERIALS AND METHODS: Beginning with the pivotal trials and working backward, we summarize the evolution of PSMA scanning, beginning with the discovery of the molecule, the mechanism of action to identify prostate cancer, the route to the present-day test and some of the major publications leading to each step of the sequence. From the thousands of PSMA articles listed on PubMed®, the present review is focused on the 4 large U.S. trials incorporating university studies of the gallium-68 compound and commercial studies of the fluorine-18 compound. The review further focuses on the role of PSMA scanning for both initial staging of prostate cancer and diagnosis of recurrent prostate cancer. RESULTS: PSMA is a transmembrane-bound glycoprotein which is overexpressed by 100-1,000-fold in prostate cancer cells. Preclinical PSMA studies at Cornell and Johns Hopkins in the 1990s were followed by early human studies in Germany in the early 2010s, then pivotal clinical trials at University of California, Los Angeles and University of California, San Francisco, leading to the first FDA approval in December 2020 (68Ga-PSMA-11). In January 2021, a commercially available product (18F-DCFPyL) was approved on the basis of multisite registration trials (CONDOR and OSPREY). Sensitivity and specificity of PSMA scanning exceeds that of any other imaging method currently available for initial staging of prostate cancer and diagnosis of recurrent disease. The accuracy of PSMA scanning is attributed to the great image contrast (high signal-to-noise ratio), a property deriving from the high PSMA tracer uptake by prostate cancer cells. That property can be estimated quantitatively by a metric, the standardized uptake value. A follow-on PSMA compound, the theranostic lutetium-177, is currently pending FDA approval for treatment of metastases. CONCLUSIONS: PSMA scanning is a disruptive technology that promises to transform the way prostate cancer is initially staged, recurrence is diagnosed and some advanced cases are treated.

AI-based smartphone apps for risk assessment of skin cancer need more evaluation and better regulation.

Smartphone applications ("apps") with artificial intelligence (AI) algorithms are increasingly used in healthcare. Widespread adoption of these apps must be supported by a robust evidence-base and app manufacturers' claims appropriately regulated. Current CE marking assessment processes inadequately protect the public against the risks created by using smartphone diagnostic apps.

Understanding, Verifying, and Implementing Emergency Use Authorization Molecular Diagnostics for the Detection of SARS-CoV-2 RNA.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has brought a new wave of challenges to health care, particularly in the area of rapid diagnostic test development and implementation. The diagnosis of acute coronavirus disease 2019 (COVID-19) is critically dependent on the detection of SARS-CoV-2 RNA from clinical specimens (e.g., nasopharyngeal swabs). While laboratory-developed testing for SARS-CoV-2 is an essential component of diagnostic testing for this virus, the majority of clinical microbiology laboratories are dependent on commercially available SARS-CoV-2 molecular assays. In contrast to assays approved or cleared by the U.S. Food and Drug Administration (FDA) for in vitro diagnostic use, assays for the detection of SARS-CoV-2 nucleic acids have emergency use authorization (EUA) from the FDA. Outside of highly specialized academic and commercial laboratory settings, clinical microbiology laboratories are likely unfamiliar with the EUA classification, and thus, assay verification can be daunting. Further compounding anxiety for laboratories are major issues with the supply chain that are dramatically affecting the availability of test reagents and requiring laboratories to implement multiple commercial EUA tests. Here, we describe guidance for the verification of assays with EUA for the detection of SARS-CoV-2 nucleic acid from clinical specimens.

Caution Is Required When Using Non-Food and Drug Administration-Cleared Assays to Diagnose Sexually Transmitted Infections in Children.

Nucleic acid amplification testing is the gold-standard for Chlamydia trachomatis and Neisseria gonorrhoeae testing in adults. We present 3 pediatric cases in which testing resulted in probable false-positive results. Clinicians should avoid tests without clearance from a regulatory agency and should maintain consistent communication with laboratories.

Expert Recommendations on Frequency of Utilization of Common Laboratory Tests in Medical Inpatients: a Canadian Consensus Study.

BACKGROUND: Repetitive inpatient laboratory testing in the face of clinical stability is a marker of low-value care. However, for commonly encountered clinical scenarios on medical units, there are no guidelines defining appropriate use criteria for laboratory tests. OBJECTIVE: This study seeks to establish consensus-based recommendations for the utilization of common laboratory tests in medical inpatients. DESIGN: This study uses a modified Delphi method. Participants completed two rounds of an online survey to determine appropriate testing frequencies for selected laboratory tests in commonly encountered clinical scenarios. Consensus was defined as agreement by at least 80% of participants. PARTICIPANTS: Participants were 36 experts in internal medicine across Canada defined as internists in independent practice for ≥ 5 years with experience in medical education, quality improvement, or both. Experts represented 8 of the 10 Canadian provinces and 13 of 17 academic institutions. MAIN MEASURES: Laboratory tests and clinical scenarios included were those that were considered common on medical units. The final survey contained a total of 45 clinical scenarios looking at the utilization of six laboratory tests (complete blood count, electrolytes, creatinine, urea, international normalized ratio, and partial thromboplastin time). The possible frequency choices were every 2-4 h, 6-8 h, twice a day, daily, every 2-3 days, weekly, or none unless there was specific diagnostic suspicion. These scenarios were reviewed by two internists with training in quality improvement and survey methods. KEY RESULTS: Of the 45 initial clinical scenarios included, we reached consensus on 17 scenarios. We reached weak consensus on an additional 19 scenarios by combining two adjacent frequency categories. CONCLUSIONS: A Canadian expert panel of internists has provided frequency recommendations on the utilization of six common laboratory tests in medical inpatients. These recommendations need validation in prospective studies to assess whether restrictive versus liberal laboratory test ordering impacts patient outcomes.

The Manufacturers' Perspective on World Health Organization Prequalification of In Vitro Diagnostics.

In vitro diagnostic devices (IVDs) help clinicians determine specific conditions, monitor therapeutic efficacy, and prevent drug resistance development. While stringent regulatory authorities (SRAs) regulate IVDs in most high-income countries, regulatory authorities in many low- and middle-income countries (LMICs) are nonexistent or do not enforce rigorous standards. In 2010, the World Health Organization established its Prequalification of In Vitro Diagnostics (PQDx) program to ensure "access to safe, appropriate and affordable" IVDs, especially in LMICs with little or no domestic regulatory frameworks, thereby reaching underserved populations. However, challenges in PQDx policies and procedures include an overloaded pipeline, timelines not publicly available, confusion about which products PQDx focuses on, perceived burden for documenting changes to prequalified products, overlap with SRA approvals, and uncertainty around long-term financing. PQDx can maximize its impact by considering the perspective of IVD manufacturers; similarly, IVD manufacturers should exercise adequate quality control over their submissions and associated processes.

Rapid Antigen Tests for Influenza: Rationale and Significance of the FDA Reclassification.

Rapid antigen tests for influenza, here referred to as rapid influenza diagnostic tests (RIDTs), have been widely used for the diagnosis of influenza since their introduction in the 1990s due to their ease of use, rapid results, and suitability for point of care (POC) testing. However, issues related to the diagnostic sensitivity of these assays have been known for decades, and these issues gained greater attention following reports of their poor performance during the 2009 influenza A(H1N1) pandemic. In turn, significant concerns arose about the consequences of false-negative results, which could pose significant risks to both individual patient care and to public health efforts. In response to these concerns, the FDA convened an advisory panel in June 2013 to discuss options to improve the regulation of the performance of RIDTs. A proposed order was published on 22 May 2014, and the final order published on 12 January 2017, reclassifying RIDTs from class I to class II medical devices, with additional requirements to comply with four new special controls. This reclassification is a landmark achievement in the regulation of diagnostic devices for infectious diseases and has important consequences for the future of diagnostic influenza testing with commercial tests, warranting the prompt attention of clinical laboratories, health care systems, and health care providers.

Molecular approaches for HPV genotyping and HPV-DNA physical status.

Persistent infection with high-risk human papillomavirus (HPV) genotypes is the leading cause of cervical cancer development. To this end several studies have focused on designing molecular assays for HPV genotyping, which are considered as the gold standard for the early diagnosis of HPV infection. Moreover, the tendency of HPV DNA to be integrated into the host chromosome is a determining event for cervical oncogenesis. Thus, the establishment of molecular techniques was promoted in order to investigate the physical status of the HPV DNA and the locus of viral insertion into the host chromosome. The molecular approaches that have been developed recently facilitate the collection of a wide spectrum of valuable information specific to each individual patient and therefore can significantly contribute to the establishment of a personalised prognosis, diagnosis and treatment of HPV-positive patients. The present review focuses on state of the art molecular assays for HPV detection and genotyping for intra-lesion analyses, it examines molecular approaches for the determination of HPV-DNA physical status and it discusses the criteria for selecting the most appropriate regions of viral DNA to be incorporated in HPV genotyping and in the determination of HPV-DNA physical status.

Statistical innovations in the medical device world sparked by the FDA.

The world of medical devices while highly diverse is extremely innovative, and this facilitates the adoption of innovative statistical techniques. Statisticians in the Center for Devices and Radiological Health (CDRH) at the Food and Drug Administration (FDA) have provided leadership in implementing statistical innovations. The innovations discussed include: the incorporation of Bayesian methods in clinical trials, adaptive designs, the use and development of propensity score methodology in the design and analysis of non-randomized observational studies, the use of tipping-point analysis for missing data, techniques for diagnostic test evaluation, bridging studies for companion diagnostic tests, quantitative benefit-risk decisions, and patient preference studies.

Regulatory In Vitro Diagnostics Landscape in Africa: Update on Regional Activities.

Improved diagnostic tests for tuberculosis case detection are urgently needed that are affordable, robust, and easy to use so that they can be implemented widely. The mandate of national regulatory authorities is to ensure the safety and effectiveness of diagnostics, protecting the population against unsafe products while expediting access to beneficial new devices. However, regulatory approval processes in the developing world are often complex, lengthy, and not transparent. Recent progress in building regulatory capacity using harmonized approaches will reduce duplication in clinical performance studies and manufacturing audits, facilitate information sharing through trust and mutual confidence building, and ultimately improve efficiency. These savings can be passed onto the consumers in the form of more affordable pricing and allowing new high-quality tests for tuberculosis to be introduced more quickly and without delay.

Early Biomarkers and Regulatory Innovation in Multidrug-Resistant Tuberculosis.

Biomarkers play an essential role in accelerating drug development. Sputum culture conversion using solid medium is the best-characterized tuberculosis biomarker, having been examined at the patient and trial levels in studies with thousands of subjects, and having recently been validated using data from 3 unsuccessful phase 3 trials. We presently are poised at the threshold of regulatory innovation for antibacterials to treat drug-resistant infections, in which Special Medical Use authorization restricted to patients with limited options could be based on the results of small clinical trials. Patients worldwide would be well served by licensing of new regimens for multidrug-resistant tuberculosis based on biomarker evidence commensurate with the urgency of the current global crisis.

An overview of recommendations and translational milestones for genomic tests in cancer.

PURPOSE: To understand the translational trajectory of genomic tests in cancer screening, diagnosis, prognosis, and treatment, we reviewed tests that have been assessed by recommendation and guideline developers. METHODS: For each test, we marked translational milestones by determining when the genomic association with cancer was first discovered and studied in patients, and when a health application for a specified clinical use was successfully demonstrated and approved or cleared by the US Food and Drug Administration. To identify recommendations and guidelines, we reviewed the websites of cancer, genomic, and general guideline developers and professional organizations. We searched the in vitro diagnostics database of the US Food and Drug Administration for information, and we searched PubMed for translational milestones. Milestones were examined against type of recommendation, Food and Drug Administration approval or clearance, disease rarity, and test purpose. RESULTS: Of the 45 tests we identified, 9 received strong recommendations for their usage in clinical settings, 14 received positive but moderate recommendations, and 22 were not currently recommended. For 18 tests, two or more different sources had issued recommendations, with 67% concordance. Only five tests had Food and Drug Administration approval, and an additional five had clearance. The median time from discovery to recommendation statement was 14.7 years. CONCLUSION: In general, there were no associations found between translational trajectory and recommendation category.Genet Med 17 6, 431-440.

Diagnostic test allergens used for in vivo diagnosis of allergic diseases are at risk: a European Perspective.

In the European Union (EU), allergens used for diagnostic tests (TAs) are defined as medicinal products and have to be registered by national authorities. The current situation is not homogeneous. Existing authorizations need to be kept in the market in some EU states, while others need complete new authorizations requiring clinical trials, quality assurance methods, stability studies, and periodic safety update reports. Allergen manufacturers argue that offering a comprehensive panel of TAs may be economically disastrous. Expenses for initiation and maintenance of TA authorizations far exceed their related revenues and manufacturers may be forced to significantly limit their allergen portfolios. The availability of a wide range of high-quality TAs is very important for in vivo diagnoses of IgE-mediated allergies. Increased regulatory demands induce costs that need to be covered by public health organizations or reimbursed by health insurance companies.

Concerns regarding a new culture method for Borrelia burgdorferi not approved for the diagnosis of Lyme disease.

In 2005, CDC and the Food and Drug Administration (FDA) issued a warning regarding the use of Lyme disease tests whose accuracy and clinical usefulness have not been adequately established. Often these are laboratory-developed tests (also known as "home brew" tests) that are manufactured and used within a single laboratory and have not been cleared or approved by FDA. Recently, CDC has received inquiries regarding a laboratory-developed test that uses a novel culture method to identify Borrelia burgdorferi, the spirochete that causes Lyme disease. Patient specimens reportedly are incubated using a two-step pre-enrichment process, followed by immunostaining with or without polymerase chain reaction (PCR) analysis. Specimens that test positive by immunostaining or PCR are deemed "culture positive". Published methods and results for this laboratory-developed test have been reviewed by CDC. The review raised serious concerns about false-positive results caused by laboratory contamination and the potential for misdiagnosis.