The Foundation for the National Institutes of Health Biomarkers Consortium: Past Accomplishments and New Strategic Direction

Biomarker-guided drug development provides value for patients, payers and drug developers: lessons learned from 25 years in the biomarker industry

INTRODUCTION

There is an urgent, persistent, need for better biomarkers in clinical drug development. More informative biomarkers can increase the likelihood of drug advancement or approval, and implementing biomarkers increases the success rate in drug development. Biomarkers may guide decisions and allow resources to be directed to the projects most likely to succeed. However, biomarkers that are validated to high standards are needed, reflecting biological and pathological processes accurately. Such biomarkers are needed to develop treatments faster, and to improve and guide clinical trial design by selecting and de-selecting patients.

METHODS

In this review based on the authors' previous published experience and interaction with pharmaceutical- and biomarker stakeholders, we highlight the use and value of biomarkers in clinical development according to the BEST guidelines. We highlight the value of 3 types of biomarkers that may provide optimal value to stakeholders: diagnostic, prognostic and pharmacodynamic biomarkers.

RESULTS

A more appropriate clinical trial design, increasing the ratio between benefits and side effects, may come from a more tailored biomarker-approach identifying suitable molecular endotypes of patients to treat.

DISCUSSION

Biomarkers may guide drug developers in selecting the optimal projects to progress, when designing clinical studies and development paths. Biomarkers may aid in the diagnosis and prognostic assessment of patients and assist in matching the molecular endotype to the selected treatment, which improves the success rate of clinical development progression. The aim of this paper is to provide a comprehensive ideation framework for how to utilize biomarkers in clinical development, with a focus on utility for patients, payers and drug developers.

Evaluation of biological markers for the risk assessment of carbon black in epidemiological studies

Background/objectives

Engineered nanomaterials (ENMs) have been suggested as being capable of promoting inflammation, a key component in the pathways associated with carcinogenesis, cardiovascular disease, and other conditions. As a result, the risk assessment of biological markers as early-stage indicators has the potential to improve translation from experimental toxicologic findings to identifying evidence in human studies. The study aims to review the possible early biological changes in workers exposed to carbon black (CB), followed by an evidentiary quality evaluation to determine the predictive value of the biological markers.

Methods

We conducted a literature search to identify epidemiological studies that assessed biological markers that were involved in the inflammatory process at early stages among workers with exposure to CB. We reviewed the studies with specific reference to the study design, statistical analyses, findings, and limitations.

Results

We identified five Chinese studies that investigated the potential impact of exposure to CB on inflammatory markers, bronchial wall thickening, genomic instability, and lung function impairment in CB production workers. Of the five Chinese studies, four were cross-sectional; another study reported results at two-time points over six years of follow-up. The authors of all five studies concluded positive relationships between exposure and the inflammatory cytokine profiles. The weak to very weak correlations between biomarkers and early-stage endpoints were reported.

Conclusion

Most inflammatory markers failed to satisfy the proposed evidentiary quality criteria. The significance of the results of the reviewed studies is limited by the cross-sectional study design, inconsistency in results, uncertain clinical relevance, and high occupational exposures. Based on this review, the risk assessment relying on inflammatory markers does not seem appropriate at this time. Nevertheless, the novel research warrants further exploration in assessing exposure to ENMs and corresponding potential health risks in occupational settings.

Glycoproteomics-based liquid biopsy: translational outlook for colorectal cancer clinical management in Southeast Asia

Colorectal cancer (CRC) signifies a significant healthcare challenge in Southeast Asia. Despite advancements in screening approaches and treatment modalities, significant medical gaps remain, ranging from prevention and early diagnosis to determining targeted therapy and establishing personalized approaches to managing CRC. There is a need to expand more validated biomarkers in clinical practice. An advanced technique incorporating high-throughput mass spectrometry as a liquid biopsy to unravel a repertoire of glycoproteins and glycans would potentially drive the development of clinical tools for CRC screening, diagnosis and monitoring, and it can be further adapted to the existing standard-of-care procedure. Therefore this review offers a perspective on glycoproteomics-driven liquid biopsy and its potential integration into the clinical care of CRC in the southeast Asia region.

Biomarkers in osteoarthritis: current status and outlook - the FNIH Biomarkers Consortium PROGRESS OA study

Currently, no disease-modifying therapies are approved for osteoarthritis (OA) use. One obstacle to trial success in this field has been our existing endpoints' limited validity and responsiveness. To overcome this impasse, the Foundation for the NIH OA Biomarkers Consortium is focused on investigating biomarkers for a prognostic context of use for subsequent qualification through regulatory agencies. This narrative review describes this activity and the work underway, focusing on the PROGRESS OA study.

Clinical Utility of Fluid Biomarker in Depressive Disorder

Major depressive disorders are ranked as the single largest contributor to non-fatal health loss and biomarkers could largely improve our routine clinical activity by predicting disease course and guiding treatment. However there is still a dearth of valid biomarkers in the field of psychiatry. The initial assumption that a single biomarker can capture the myriad of complex processes proved to be naive. The purpose of this paper is to critically review the field and to illustrate the possible practical application for routine clinical care. Biomarkers derived from DNA analysis are the ones that have received the most attention. Other potential candidates include circulating transcription products, proteins, and inflammatory markers. DNA polygenic risk scores proved to be useful in other fields of medicine and preliminary results suggest that they could be useful both as risk and diagnostic biomarkers also in depression and for the choice of treatment. A number of other possible fluid biomarkers are currently under investigation for diagnosis, outcome prediction, staging, and stratification of interventions, however research is still needed before they can be used for routine clinical care. When available, clinicians may be able to receive a lab report with detailed information about disease risk, outcome prediction, and specific indications about preferred treatments.

The Pivotal Role of Quantum Dots-Based Biomarkers Integrated with Ultra-Sensitive Probes for Multiplex Detection of Human Viral Infections

The spread of viral diseases has caused global concern in recent years. Detecting viral infections has become challenging in medical research due to their high infectivity and mutation. A rapid and accurate detection method in biomedical and healthcare segments is essential for the effective treatment of pathogenic viruses and early detection of these viruses. Biosensors are used worldwide to detect viral infections associated with the molecular detection of biomarkers. Thus, detecting viruses based on quantum dots biomarkers is inexpensive and has great potential. To detect the ultrasensitive biomarkers of viral infections, QDs appear to be a promising option as biological probes, while physiological components have been used directly to detect multiple biomarkers simultaneously. The simultaneous measurement of numerous clinical parameters of the same sample volume is possible through multiplex detection of human viral infections, which reduces the time and cost required to record any data point. The purpose of this paper is to review recent studies on the effectiveness of the quantum dot as a detection tool for human pandemic viruses. In this review study, different types of quantum dots and their valuable properties in the structure of biomarkers were investigated. Finally, a vision for recent advances in quantum dot-based biomarkers was presented, whereby they can be integrated into super-sensitive probes for the multiplex detection of human viral infections.

Exercise and Nutrition Strategies for Combating Sarcopenia and Type 2 Diabetes Mellitus in Older Adults

Medical and technology development have drastically the improved quality of life and, consequently, life expectancy. Nevertheless, the more people who enter the third-age, the more geriatric syndromes expand in the elderly. Sarcopenia and Type 2 diabetes mellitus (T2DM) are common diseases among the elderly and the literature has extensively studied these two diseases separately. Recent evidence, however, revealed that there is a bidirectional relationship between sarcopenia and T2DM. The aims of the present review were: (1) to present diet and exercise interventions for the management of sarcopenia and T2DM and (2) identify which diet and exercise interventions can be used simultaneously in order to effectively deal with these two disorders. Exercise and a balanced diet are used as effective countermeasures for combating sarcopenia and T2DM in older adults based on their bidirectional relationship. Lifestyle changes such as exercise and a balanced diet seem to play an important role in the remission of the diseases. Results showed that chronic exercise can help towards glycemic regulation as well as decrease the incidence rate of muscle degradation, while diet interventions which focus on protein or amino acids seem to successfully treat both disorders. Despite the fact that there are limited studies that deal with both disorders, it seems that a combined exercise regime (aerobic and resistance) along with protein intake > 1gr/kg/d is the safest strategy to follow in order to manage sarcopenia and T2DM concurrently.

Best practices for the development and fit-for-purpose validation of biomarker methods: a conference report

This conference report summarized a full-day workshop, “best practices for the development and fit-for-purpose validation of biomarker methods,” which was held prior to the American Association of Pharmaceutical Scientists (AAPS) PharmSci360 Congress, San Antonio, TX, November 2019. The purpose of the workshop was to bring together thought leaders in biomarker assay development in order to identify which assay parameters and key statistical measures need to be considered when developing a biomarker assay. A diverse group of more than 40 scientists participated in the workshop. The workshop and subsequent working dinner stimulated robust discussion. While a consensus on best practices was not achieved, some common themes and major points to consider for biomarker assay development have been identified and agreed on. The focus of this conference report is to summarize the presentations and discussions which occurred at the workshop. Biomarker assay validation is a complex and an evolving area with discussions ongoing.

Creation of a collection of blood samples of patients with multiple myeloma

Aim. To create a collection of samples of blood components of patients with multiple myeloma for potential fundamental and applied biomedical research.

Material and methods. The material was collected according to the developed algorithm, including the collection of clinical information, biological material, sample preparation, quality control and storage in the biobank of the National Medical Research Center of Oncology.

Results. As of August 2021, the cryostorage of the National Medical Research Center of Oncology biobank contains a collection of 175 samples of blood serum, plasma and mononuclear cell fraction of patients with multiple myeloma. Samples were obtained from 32 patients of both sexes, the mean age of which was 59,5±1,65 years. To create an electronic catalog, personal, clinical and laboratory data about patients were collected, after which each sample was assigned its own unique identification number. Written informed consent was obtained from all patients for the storage of their biomaterial in a biobank with possible subsequent use for scientific purposes. Freezing of the obtained samples was carried out in accordance with low-temperature storage protocol. The electronic catalog contains a wide range of systematized clinical and laboratory information on samples.

Conclusion. The collection of multiple myeloma samples is a unique resource for potential research on its pathophysiology, the development of diagnostic biomarkers, and the search for targeted agents.

Human disease biomarker panels through systems biology

As more uses for biomarkers are sought after for an increasing number of disease targets, single-target biomarkers are slowly giving way for biomarker panels. These panels incorporate various sources of biomolecular and clinical data to guarantee a higher robustness and power of separation for a clinical test. Multifactorial diseases such as psychiatric disorders show great potential for clinical use, assisting medical professionals during the analysis of risk and predisposition, disease diagnosis and prognosis, and treatment applicability and efficacy. More specific tests are also being developed to assist in ruling out, distinguishing between, and confirming suspicions of multifactorial diseases, as well as to predict which therapy option may be the best option for a given patient's biochemical profile. As more complex datasets are entering the field, involving multi-omic approaches, systems biology has stepped in to facilitate the discovery and validation steps during biomarker panel generation. Filtering biomolecules and clinical data, pre-validating and cross-validating potential biomarkers, generating final biomarker panels, and testing the robustness and applicability of those panels are all beginning to rely on machine learning and systems biology and research in this area will only benefit from advances in these approaches.

Imaging and Biochemical Markers for Osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis in adults that affects more than 500 million people globally [...].

The Yin and the Yang of Transformative Research During the COVID-19 Pandemic-A Perspective

The COVID-19 pandemic has highlighted the necessity for scientists from diverse disciplines to collaboratively mitigate the singular calamity facing humanity this century. The ability of researchers to combine exponential advances in technology and scientific acumen has resulted in landmark discoveries in pediatric research and is surmounting the COVID-19 challenge. Several of these discoveries exist in a realm of research that is not classically "basic" or "clinical." Translational research characterizes this domain partially, but does not fully capture the integrated research approaches that have spurred these discoveries. Herein, we share our perspective on the common themes underpinning the basic and clinical research. We also highlight major differences in the scope, emphasis, approach, and limitations of basic and clinical research that impede multi-disciplinary approaches that facilitate truly transformative research. These differences in research thinking and methodology are ingrained during training wherein the limitations of the chosen discipline, and strengths of alternate disciplines are not adequately explored. Insular approaches are particularly limited in impacting complex diseases pathophysiology in the era of precision medicine. We propose that integration of -omics technologies, systems biology, adaptive clinical trial designs, humanized animal models, and precision pre-clinical model systems must be incorporated into research training of future scientists. Several initiatives from the NIH and other institutions are facilitating such broad-based "research without frontiers" training that paves the way for seamless, multi-disciplinary, research. Such efforts become "transformative" when scientific challenges are tackled in partnership with a willingness to share ideas, tackle challenges, and develop tools/models from the very beginning.

Liquid biopsy enters the clinic - implementation issues and future challenges

Historically, studies of disseminated tumour cells in bone marrow and circulating tumour cells in peripheral blood have provided crucial insights into cancer biology and the metastatic process. More recently, advances in the detection and characterization of circulating tumour DNA (ctDNA) have finally enabled the introduction of liquid biopsy assays into clinical practice. The FDA has already approved several single-gene assays and, more recently, multigene assays to detect genetic alterations in plasma cell-free DNA (cfDNA) for use as companion diagnostics matched to specific molecularly targeted therapies for cancer. These approvals mark a tipping point for the widespread use of liquid biopsy in the clinic, and mostly in patients with advanced-stage cancer. The next frontier for the clinical application of liquid biopsy is likely to be the systemic treatment of patients with 'ctDNA relapse', a term we introduce for ctDNA detection prior to imaging-detected relapse after curative-intent therapy for early stage disease. Cancer screening and diagnosis are other potential future applications. In this Perspective, we discuss key issues and gaps in technology, clinical trial methodologies and logistics for the eventual integration of liquid biopsy into the clinical workflow.

Improving cardiotoxicity prediction in cancer treatment: integration of conventional circulating biomarkers and novel exploratory tools

Early detection strategies and improvements in cancer treatment have dramatically reduced the cancer mortality rate in the United States (US). However, cardiovascular (CV) side effects of cancer therapy are frequent among the 17 million cancer survivors in the US today, and cardiovascular disease (CVD) has become the second leading cause of morbidity and mortality among cancer survivors. Circulating biomarkers are ideal for detecting and monitoring CV side effects of cancer therapy. Here, we summarize the current state of clinical studies on conventional serum and plasma CVD biomarkers to detect and prevent cardiac injury during cancer treatment. We also review how novel exploratory tools such as genetic testing, human stem cell-derived cardiomyocytes, Omics technologies, and artificial intelligence can elucidate underlying molecular and genetic mechanisms of CV injury and to improve predicting cancer therapy-related cardiotoxicity (CTRC). Current regulatory requirements for biomarker qualifications are also addressed. We present generally applicable lessons learned from published studies, particularly on how to improve reproducibility. The combination of conventional circulating biomarkers and novel exploratory tools will pave the way for precision medicine and improve the clinical practice of prediction, detection, and management of CTRC.

Detection of disease-associated microRNAs - application for autism spectrum disorders

Autism spectrum disorders (ASD) diagnostic procedure still lacks a uniform biological marker. This review gathers the information on microRNAs (miRNAs) specifically as a possible source of biomarkers of ASD. Extracellular vesicles, and their subset of exosomes, are believed to be a tool of cell-to-cell communication, and they are increasingly considered to be carriers of such a marker. The interest in studying miRNAs in extracellular vesicles grows in all fields of study and therefore should not be omitted in the field of neurodevelopmental disorders. The summary of miRNAs associated with brain cells and ASD either studied directly in the tissue or biofluids are gathered in this review. The heterogeneity in findings from different studies points out the fact that unified methods should be established, beginning with the determination of the accurate patient and control groups, through to sample collection, processing, and storage conditions. This review, based on the available literature, proposes the standardized approach to obtain the results that would not be affected by technical factors. Nowadays, the method of high-throughput sequencing seems to be the most optimal to analyze miRNAs. This should be followed by the uniformed bioinformatics procedure to avoid misvalidation. At the end, the proper validation of the obtained results is needed. With such an approach as is described in this review, it would be possible to obtain a reliable biomarker that would characterize the presence of ASD.

Fit-for-Purpose Biometric Monitoring Technologies: Leveraging the Laboratory Biomarker Experience

Biometric monitoring technologies (BioMeTs) are becoming increasingly common to aid data collection in clinical trials and practice. The state of BioMeTs, and associated digitally measured biomarkers, is highly reminiscent of the field of laboratory biomarkers 2 decades ago. In this review, we have summarized and leveraged historical perspectives, and lessons learned from laboratory biomarkers as they apply to BioMeTs. Both categories share common features, including goals and roles in biomedical research, definitions, and many elements of the biomarker qualification framework. They can also be classified based on the underlying technology, each with distinct features and performance characteristics, which require bench and human experimentation testing phases. In contrast to laboratory biomarkers, digitally measured biomarkers require prospective data collection for purposes of analytical validation in human subjects, lack well‐established and widely accepted performance characteristics, require human factor testing, and, for many applications, access to raw (sample‐level) data. Novel methods to handle large volumes of data, as well as security and data rights requirements add to the complexity of this emerging field. Our review highlights the need for a common framework with appropriate vocabulary and standardized approaches to evaluate digitally measured biomarkers, including defining performance characteristics and acceptance criteria. Additionally, the need for human factor testing drives early patient engagement during technology development. Finally, use of BioMeTs requires a relatively high degree of technology literacy among both study participants and healthcare professionals. Transparency of data generation and the need for novel analytical and statistical tools creates opportunities for precompetitive collaborations.

Defining the Path Forward for Biomarkers to Address Unmet Needs in Inflammatory Bowel Diseases

Despite major advances in the inflammatory bowel diseases field, biomarkers to enable personalized and effective management are inadequate. Disease course and treatment response are highly variable, with some patients experiencing mild disease progression, whereas other patients experience severe or complicated disease. Periodic endoscopy is performed to assess disease activity; as a result, it takes months to ascertain whether a treatment is having a positive impact on disease progression. Minimally invasive biomarkers for prognosis of disease course, prediction of treatment response, monitoring of disease activity, and accurate diagnosis based on improved disease phenotyping and classification could improve outcomes and accelerate the development of novel therapeutics. Rapidly developing technologies have great potential in this regard; however, the discovery, validation, and qualification of biomarkers will require partnerships including academia, industry, funders, and regulators. The Crohn's & Colitis Foundation launched the IBD Biomarker Summit to bring together key stakeholders to identify and prioritize critical unmet needs; prioritize promising technologies and consortium approaches to address these needs; and propose harmonization approaches to improve comparability of data across studies. Here, we summarize the outcomes of the 2018 and 2019 meetings, including consensus-based unmet needs in the clinical and drug development context. We highlight ongoing consortium efforts and promising technologies with the potential to address these needs in the near term. Finally, we summarize actionable recommendations for harmonization, including data collection tools for improved consistency in disease phenotyping; standardization of informed consenting; and development of guidelines for sample management and assay validation. Taken together, these outcomes demonstrate that there is an exceptional alignment of priorities across stakeholders for a coordinated effort to address unmet needs of patients with inflammatory bowel diseases through biomarker science.

Novel Approaches for Assessing Circadian Rhythmicity in Humans: A Review

The temporal organization of molecular and physiological processes is driven by environmental and behavioral cycles as well as by self-sustained molecular circadian oscillators. Quantification of phase, amplitude, period, and disruption of circadian oscillators is essential for understanding their contribution to sleep-wake disorders, social jet lag, interindividual differences in entrainment, and the development of chrono-therapeutics. Traditionally, assessment of the human circadian system, and the output of the SCN in particular, has required collection of long time series of univariate markers such as melatonin or core body temperature. Data were collected in specialized laboratory protocols designed to control for environmental and behavioral influences on rhythmicity. These protocols are time-consuming, expensive, and not practical for assessing circadian status in patients or in participants in epidemiologic studies. Novel approaches for assessment of circadian parameters of the SCN or peripheral oscillators have been developed. They are based on machine learning or mathematical model-informed analyses of features extracted from 1 or a few samples of high-dimensional data, such as transcriptomes, metabolomes, long-term simultaneous recording of activity, light exposure, skin temperature, and heart rate or in vitro approaches. Here, we review whether these approaches successfully quantify parameters of central and peripheral circadian oscillators as indexed by gold standard markers. Although several approaches perform well under entrained conditions when sleep occurs at night, the methods either perform worse in other conditions such as shift work or they have not been assessed under any conditions other than entrainment and thus we do not yet know how robust they are. Novel approaches for the assessment of circadian parameters hold promise for circadian medicine, chrono-therapeutics, and chrono-epidemiology. There remains a need to validate these approaches against gold standard markers, in individuals of all sexes and ages, in patient populations, and, in particular, under conditions in which behavioral cycles are displaced.

Osteoarthritis year in review 2019: biomarkers (biochemical markers)

OBJECTIVE

To provide an insightful summary of studies on biochemical markers for osteoarthritis (OA).

DESIGN

Two investigators systematically searched the electronic PubMed database for clinical studies into soluble biochemical markers for OA in humans that were published between 01-03-2018 and 01-03-2019. Data from selected publications were systematically extracted and tabulated and were summarized in a narrative review.

RESULTS

Out of 1,279 publications, 124 fulfilled all selection criteria and were selected for data extraction. The majority were around knee OA, cross-sectional in design, relatively small, and/or focused on one or a few biochemical markers. Among the intervention studies, relatively many were on non-pharmacological interventions, used clinical outcomes and/or were rather short. Some leads that were provided by this year's studies pertained to less conventional inflammatory mediators, oxidative stress, acidosis, angiogenesis and/or autoantibody formation.

CONCLUSIONS

This year's biochemical marker studies did provide potential leads for therapeutic targets or other biochemical marker applications that require robust and strategic follow-up research to be validated.

Metabolomic and Lipidomic Biomarkers for Premalignant Liver Disease Diagnosis and Therapy

In recent years, there has been a plethora of attempts to discover biomarkers that are more reliable than α-fetoprotein for the early prediction and prognosis of hepatocellular carcinoma (HCC). Efforts have involved such fields as genomics, transcriptomics, epigenetics, microRNA, exosomes, proteomics, glycoproteomics, and metabolomics. HCC arises against a background of inflammation, steatosis, and cirrhosis, due mainly to hepatic insults caused by alcohol abuse, hepatitis B and C virus infection, adiposity, and diabetes. Metabolomics offers an opportunity, without recourse to liver biopsy, to discover biomarkers for premalignant liver disease, thereby alerting the potential of impending HCC. We have reviewed metabolomic studies in alcoholic liver disease (ALD), cholestasis, fibrosis, cirrhosis, nonalcoholic fatty liver (NAFL), and nonalcoholic steatohepatitis (NASH). Specificity was our major criterion in proposing clinical evaluation of indole-3-lactic acid, phenyllactic acid, N-lauroylglycine, decatrienoate, N-acetyltaurine for ALD, urinary sulfated bile acids for cholestasis, cervonoyl ethanolamide for fibrosis, 16α-hydroxyestrone for cirrhosis, and the pattern of acyl carnitines for NAFL and NASH. These examples derive from a large body of published metabolomic observations in various liver diseases in adults, adolescents, and children, together with animal models. Many other options have been tabulated. Metabolomic biomarkers for premalignant liver disease may help reduce the incidence of HCC.

Regulation and Innovation: Role of Regulatory Science in Facilitating Pharmaceutical Innovation

Regulatory science is defined as science and research intended to inform decision making in a regulatory framework. This issue of Clinical Pharmacology & Therapeutics and the papers herein deal with the expansive topic of regulatory science and its role in fostering innovation and accelerating access to medicines. Regulatory health authorities, industry, and multiple stakeholders have a shared objective in advancing regulatory science to keep up with the ever-increasing pace of biomedical science.

Regulatory and Developmental Aspects of Biomarkers in the Treatment of Ocular Surface Disease

The ideal biomarker would be a simple laboratory or clinical evaluation before treatment, which would predict subsequent therapeutic response. This might include selection of which patients might respond to that treatment. While other disciplines such as neurology and oncology have biomarkers, ophthalmology is limited to one-elevated intraocular pressure as a surrogate for progressive glaucomatous field loss. US law in 2016 required the Food and Drug Administration (FDA) to set up a system to qualify biomarkers. The system now exists-with most validated or pending biomarkers limited to safety and infection. The American Academy of Ophthalmology selected dry eye disease as one of three diseases in which to standardize outcomes in ophthalmology research. There have been a number of biomarkers proposed for evaluating ocular surface disease and its treatment. None currently meets the scientific or regulatory basis for being a valid biomarker-however, additional research may result in validity. Given the FDA's scientific basis, it is unlikely that an unproven biomarker could be used for regulatory approval, even for a "SubPart H" conditional new drug application. Elsewhere in ophthalmology, we know that even patients who share the same disease gene or mutation may differ substantially in penetrance and clinical expression. Thus, it is not unexpected that ocular surface disease, a heterogeneous disease with a variable presentation of signs and symptoms, has yet to have validated biomarkers that reach the level of evidence that allows their use for diagnosis, prognosis, therapy, and for making decisions in drug development.