On the Slow Diffusion of Point-of-Care Systems in Therapeutic Drug Monitoring

Therapeutic drug monitoring of osimertinib in EGFR mutant non-small cell lung cancer by dried blood spot and plasma collection: A pilot study

AIMS

Therapeutic drug monitoring (TDM) has led to significant improvements in individualized medical care, although its implementation in oncology has been limited to date. Tyrosine kinase inhibitors (TKIs) are a group of therapies for which TDM has been suggested. Osimertinib is one such therapy used in the treatment of epidermal growth factor receptor (EGFR) mutation-driven lung cancer. Herein, we describe a prospective pilot study involving 21 patients on osimertinib primarily as a preliminary evaluation of drug levels in a real-world setting.

METHODS

Concentrations of the drug and its primary metabolites were measured with a validated liquid chromatography-mass spectrometry (LC-MS) assay across serial timepoints. As part of this study, inter-individual variability by dose and ethnicity as well as intra-individual variability across timepoints are explored. Furthermore, we attempted to validate dried blood spot (DBS)-based quantitation as an accurate alternative to plasma quantitation.

RESULTS

Successful quantitation of osimertinib and primary metabolites was achieved for our subjects. Compound plasma levels were highly correlated to DBS levels. There was no significant difference in concentrations with ethnicity or dosing or intra-individual variability across timepoints.

CONCLUSIONS

As such, we demonstrate that TDM for osimertinib is practical for future trials. We also validated the use of DBS as an alternative to conventional quantitation for exploration of TDM for osimertinib in larger trials and for other targeted therapies.

Advances in Psychotropic Treatment for Pregnant Women: Efficacy, Adverse Outcomes, and Therapeutic Monitoring

Advancements in psychotropic therapy for pregnant women are pivotal for addressing maternal mental health during the perinatal period. Screening for mood and anxiety symptoms during pregnancy is recommended to enable early intervention. Psychotropic medications, including antidepressants, benzodiazepines, antipsychotics, and mood stabilizers, are commonly used, but challenges remain regarding their safety and efficacy during pregnancy. Pregnancy induces significant changes in pharmacokinetics, necessitating personalized dosing strategies and careful monitoring. Real-time monitoring technologies, such as smartphone-integrated platforms and home-based monitoring, enhance accessibility and accuracy. Prospective studies and collaboration among healthcare providers are essential for evidence-based guidelines and optimal treatment strategies. Reducing stigma around mental health during pregnancy is crucial to ensure women seek help and discuss treatment options, promoting understanding and acceptance within the community.

Combination of the lateral-flow immunoassay with multicolor gold nanorod etching for the semi-quantitative detection of digoxin

We demonstrated the first ever combination of the lateral-flow immunoassay (LFA) with gold nanorod etching to achieve a multicolor readout where the changes in color hue are more easily discernible than changes in intensity of a single color.

Metabolomics for personalized medicine: the input of analytical chemistry from biomarker discovery to point-of-care tests

Metabolomics refers to the large-scale detection, quantification, and analysis of small molecules (metabolites) in biological media. Although metabolomics, alone or combined with other omics data, has already demonstrated its relevance for patient stratification in the frame of research projects and clinical studies, much remains to be done to move this approach to the clinical practice. This is especially true in the perspective of being applied to personalized/precision medicine, which aims at stratifying patients according to their risk of developing diseases, and tailoring medical treatments of patients according to individual characteristics in order to improve their efficacy and limit their toxicity. In this review article, we discuss the main challenges linked to analytical chemistry that need to be addressed to foster the implementation of metabolomics in the clinics and the use of the data produced by this approach in personalized medicine. First of all, there are already well-known issues related to untargeted metabolomics workflows at the levels of data production (lack of standardization), metabolite identification (small proportion of annotated features and identified metabolites), and data processing (from automatic detection of features to multi-omic data integration) that hamper the inter-operability and reusability of metabolomics data. Furthermore, the outputs of metabolomics workflows are complex molecular signatures of few tens of metabolites, often with small abundance variations, and obtained with expensive laboratory equipment. It is thus necessary to simplify these molecular signatures so that they can be produced and used in the field. This last point, which is still poorly addressed by the metabolomics community, may be crucial in a near future with the increased availability of molecular signatures of medical relevance and the increased societal demand for participatory medicine.

A new paper-based biosensor for therapeutic drug monitoring

Tacrolimus is one of the most effective and prevalent drugs used to combat vascularized composite allotransplantation rejection. We have fabricated a rapid and easy-to-use six-layer paper based microfluidic device using the principles of competitive immunoassays and vertical flow microfluidics for colorimetric detection of tacrolimus in a small volume of blood.

One-pot colorimetric detection of molecules based on proximity proteolysis reaction

Various types of molecules serve as biomarkers of diseases, and numerous methods have been reported to detect and quantify them. Recently, research efforts have been made to develop point-of-care (POC) tests, which contribute to early diagnoses of diseases, particularly in resource-limited settings. An assay performed in a homogeneous phase is an obvious route to develop these methods. Here, simple homogeneous methods based on proximity proteolysis reactions (PPR) are reported to detect biological molecules. A typical PPR system has been designed such that the proteolysis reaction between protease and zymogen is enhanced in the presence of a target analyte. The activated zymogen generates a color signal by hydrolyzing a chromophore. A protease and zymogen are linked to target binders using specific hybridization between complementary single-stranded DNAs, and several molecules, including proteins, antibodies, aptamers, and small molecules, are used as target binders. The developed assay methods successfully detected several kinds of analytes at subnanomolar concentrations with the one-step procedure and color signal. The modular design of the PPR-based assay will enable the development of simple POC diagnostics for various biomarkers.

Point-of-Care Drug of Abuse Testing in the Opioid Epidemic

CONTEXT.—

The United States is experiencing an opioid overdose epidemic. Point-of-care (POC) drug of abuse testing is a useful tool to combat the intensified opioid epidemic.

OBJECTIVES.—

To review commercially available POC drug of abuse testing involving opioids, to review opportunities and challenges for POC opioid testing and emerging testing methods in research literature, and finally to summarize unmet clinical needs and future development prospects.

DATA SOURCES.—

The Google search engine was used to access information for commercial opioid POC devices and the Google Scholar search engine was used to access research literature published from 2000 to 2019 for opioid POC tests.

CONCLUSIONS.—

The opioid epidemic provides unprecedented opportunities for POC drug testing, with significant clinical needs. Compared with gold standard tests, limitations for commercially available opioid POC testing include lower analytical sensitivity, lower specificity, and cross-reactivity. In response to unmet clinical needs, novel methods have emerged in research literature, such as microfluidics and miniature mass spectrometry. Future prospects include the development of quantitative POC devices and smarter and real-time drug testing.

Barriers and opportunities for the clinical implementation of therapeutic drug monitoring in oncology

There are few fields of medicine in which the individualisation of medicines is more important than in the area of oncology. Under-dosing can have significant ramifications due to the potential for therapeutic failure and cancer progression; by contrast, over-dosing may lead to severe treatment-limiting side effects, such as agranulocytosis and neutropenia. Both circumstances lead to poor patient prognosis and contribute to the high mortality rates still seen in oncology. The concept of dose individualisation tailors dosing for each individual patient to ensure optimal drug exposure and best clinical outcomes. While the value of this strategy is well recognised, it has seen little translation to clinical application. However, it is important to recognise that the clinical setting of oncology is unlike that for which therapeutic drug monitoring (TDM) is currently the cornerstone of therapy (e.g. antimicrobials). Whilst there is much to learn from these established TDM settings, the challenges presented in the treatment of cancer must be considered to ensure the implementation of TDM in clinical practice. Recent advancements in a range of scientific disciplines have the capacity to address the current system limitations and significantly enhance the use of anticancer medicines to improve patient health. This review examines opportunities presented by these innovative scientific methodologies, specifically sampling strategies, bioanalytics and dosing decision support, to enable optimal practice and facilitate the clinical implementation of TDM in oncology.

On-Site Therapeutic Drug Monitoring

Recent technological advances have stimulated efforts to bring personalized medicine into practice. Yet, traditional application fields like therapeutic drug monitoring (TDM) have remained rather under-appreciated. Owing to clear dose-response relationships, TDM could improve patient outcomes and reduce healthcare costs. While chromatography-based routine practices are restricted due to high costs and turnaround times, biosensors overcome these limitations by offering on-site analysis. Nevertheless, sensor-based approaches have yet to break through for clinical TDM applications, due to the gap between scientific and clinical communities. We provide a critical overview of current TDM practices, followed by a TDM guideline to establish a common ground across disciplines. Finally, we discuss how the translation of sensor systems for TDM can be facilitated, by highlighting the challenges and opportunities.

The Steps to Therapeutic Drug Monitoring: A Structured Approach Illustrated With Imatinib

Pharmacometric methods have hugely benefited from progress in analytical and computer sciences during the past decades, and play nowadays a central role in the clinical development of new medicinal drugs. It is time that these methods translate into patient care through therapeutic drug monitoring (TDM), due to become a mainstay of precision medicine no less than genomic approaches to control variability in drug response and improve the efficacy and safety of treatments. In this review, we make the case for structuring TDM development along five generic questions: 1) Is the concerned drug a candidate to TDM? 2) What is the normal range for the drug's concentration? 3) What is the therapeutic target for the drug's concentration? 4) How to adjust the dosage of the drug to drive concentrations close to target? 5) Does evidence support the usefulness of TDM for this drug? We exemplify this approach through an overview of our development of the TDM of imatinib, the very first targeted anticancer agent. We express our position that a similar story shall apply to other drugs in this class, as well as to a wide range of treatments critical for the control of various life-threatening conditions. Despite hurdles that still jeopardize progress in TDM, there is no doubt that upcoming technological advances will shape and foster many innovative therapeutic monitoring methods.

Seconds-resolved pharmacokinetic measurements of the chemotherapeutic irinotecan in situ in the living body

The ability to measure drugs in the body rapidly and in real time would advance both our understanding of pharmacokinetics and our ability to optimally dose and deliver pharmacological therapies. To this end, we are developing electrochemical aptamer-based (E-AB) sensors, a seconds-resolved platform technology that, as critical for performing measurements in vivo, is reagentless, reversible, and selective enough to work when placed directly in bodily fluids. Here we describe the development of an E-AB sensor against irinotecan, a member of the camptothecin family of cancer chemotherapeutics, and its adaptation to in vivo sensing. To achieve this we first re-engineered (via truncation) a previously reported DNA aptamer against the camptothecins to support high-gain E-AB signaling. We then co-deposited the modified aptamer with an unstructured, redox-reporter-modified DNA sequence whose output was independent of target concentration, rendering the sensor's signal gain a sufficiently strong function of square-wave frequency to support kinetic-differential-measurement drift correction. The resultant, 200 μm-diameter, 3 mm-long sensor achieves 20 s-resolved, multi-hour measurements of plasma irinotecan when emplaced in the jugular veins of live rats, thus providing an unprecedentedly high-precision view into the pharmacokinetics of this class of chemotherapeutics.

Saliva as a Future Field in Psoriasis Research

Psoriasis is a skin inflammatory disease characterized by an increased body of comorbidities, including parodontopathy. Despite the visibility of skin lesions, prognostic biomarkers, related to disease monitoring and therapeutic effectiveness, are still missing. Although several markers have been studied, none of them has been identified as an independent prognostic factor. This concise review aims to summarize the current knowledge and results in saliva research applied to psoriasis. Combination of different markers could improve the prognostic prediction in patients with psoriasis. Future studies are needed to implement research on salivary biomarkers and their prognostic/therapeutic effects in the management of patients with psoriasis.

The Use of Metabolomics and Inflammatory Mediator Profiling Provides a Novel Approach to Identifying Pediatric Appendicitis in the Emergency Department

Multiplexed profiling approaches including various ‘omics’ platforms are becoming a new standard of biomarker development for disease diagnosis and prognosis. The present study applied an integrated metabolomics and cytokine profiling approach as a potential aid to the identification of pediatric appendicitis. Metabolic analysis using serum (n = 121) and urine (n = 102) samples, and cytokine analysis using plasma (n = 121) samples from children presenting to the Emergency Department with abdominal pain were performed. Comparisons between children with appendicitis vs. non-appendicitis abdominal pain, and with perforated vs. non-perforated appendicitis were made using multivariate statistics. Serum and urine biomarker patterns were statistically significantly different between groups. The combined serum metabolomics and inflammatory mediator model revealed clear separation between appendicitis and non-appendicitis abdominal pain (AUROC: 0.92 ± 0.03) as well as for perforated and non-perforated appendicitis (AUROC: 0.88 ± 0.05). Urine metabolic analysis also demonstrated distinction between the groups appendicitis and non-appendicitis abdominal pain (AUROC: 0.85 ± 0.04), and perforated and non-perforated appendicitis (AUROC: 0.98 ± 0.02). In children presenting to the Emergency Department with abdominal pain, metabolomics and inflammatory mediator profiling are capable of distinguishing children with appendicitis from those without. The approach also differentiates between severities of disease. These results provide an important first step towards a potential aid for improving appendicitis identification.

Point-of-care testing (POCT) and evidence-based laboratory medicine (EBLM) - does it leverage any advantage in clinical decision making?

Point-of-care testing (POCT) is the analysis of patient specimens outside the clinical laboratory, near or at the site of patient care, usually performed by clinical staff without laboratory training, although it also encompasses patient self-monitoring. It is able to provide a rapid result near the patient and which can be acted upon immediately. The key driver is the concept that clinical decision making may be delayed when samples are sent to the clinical laboratory. Balanced against this are considerations of increased costs for purchase and maintenance of equipment, staff training, connectivity to the laboratory information system (LIS), quality control (QC) and external quality assurance (EQA) procedures, all required for accreditation under ISO 22870. The justification for POCT depends upon being able to demonstrate that a more timely result (shorter turnaround times (TATs)) is able to leverage a clinically important advantage in decision making compared with the central laboratory (CL). In the four decades since POCT was adapted for the self-monitoring of blood glucose levels by subjects with diabetes, numerous new POCT methodologies have become available, enabling the clinician to receive results and initiate treatment more rapidly. However, these instruments are often operated by staff not trained in laboratory medicine and hence are prone to errors in the analytical phase (as opposed to laboratory testing where the analytical phase has the least errors). In some environments, particularly remote rural settings, the CL may be at a considerable distance and timely availability of cardiac troponins and other analytes can triage referrals to the main centers, thus avoiding expensive unnecessary patient transportation costs. However, in the Emergency Department, availability of more rapid results with POCT does not always translate into shorter stays due to other barriers to implementation of care. In this review, we apply the principles of evidence-based laboratory medicine (EBLM) looking for high quality systematic reviews and meta-analyses, ideally underpinned by randomized controlled trials (RCTs), looking for evidence of whether POCT confers any advantage in clinical decision making in different scenarios.

Bioluminescent Antibodies for Point-of-Care Diagnostics

We introduce a general method to transform antibodies into ratiometric, bioluminescent sensor proteins for the no‐wash quantification of analytes. Our approach is based on the genetic fusion of antibody fragments to NanoLuc luciferase and SNAP‐tag, the latter being labeled with a synthetic fluorescent competitor of the antigen. Binding of the antigen, here synthetic drugs, by the sensor displaces the tethered fluorescent competitor from the antibody and disrupts bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. The semisynthetic sensors display a tunable response range (submicromolar to submillimolar) and large dynamic range (ΔR_max>500 %), and they permit the quantification of analytes through spotting of the samples onto paper followed by analysis with a digital camera.

[Hot rods in the ICU : What is the antibiotic mileage of your renal replacement therapy?]

We would neither be disappointed nor upset if the gas mileage on the sticker of a car didn't match our personal, real-life fuel consumption. Depending on our daily route to work, our style of accelerating and the number of passengers in our carpool, the gas mileage will vary. As soon as the falcon wing door of our car is closed and entrance to the ICU is granted, we tend to forget all of this, even though another hot rod is waiting there for us. Renal replacement therapy is like a car; it fulfills goals, such as the removal of uremic toxins and accumulated fluids, but it also "consumes" (removes) antibiotics. Unlike catecholamines, where we have the mean arterial pressure on our ICU dashboard, we do not have a gauge to measure antibiotic "consumption", i.e. elimination by renal replacement therapy. This manuscript describes the principles and basic knowledge to improve dosing of antibiotics in critically ill patients undergoing renal replacement therapy. As in modern cars, we briefly touch on hybrid therapies combining renal replacement therapy with extracorporeal lung support or adsorbent technologies that remove cytokines or bacteria. Further, the importance of considering body size and body composition is addressed, especially for choosing the right initial dose of antibiotics. Lastly we point out the dire need to increase the availability of timely and affordable therapeutic drug monitoring on the most commonly used antiinfectives, ideally using point-of-care devices at the bedside.

Potential of Surface Enhanced Raman Spectroscopy (SERS) in Therapeutic Drug Monitoring (TDM). A Critical Review

Surface-Enhanced Raman Spectroscopy (SERS) is a label-free technique that enables quick monitoring of substances at low concentrations in biological matrices. These advantages make it an attractive tool for the development of point-of-care tests suitable for Therapeutic Drug Monitoring (TDM) of drugs with a narrow therapeutic window, such as chemotherapeutic drugs, immunosuppressants, and various anticonvulsants. In this article, the current applications of SERS in the field of TDM for cancer therapy are discussed in detail and illustrated according to the different strategies and substrates. In particular, future perspectives are provided and special concerns regarding the standardization of self-assembly methods and nanofabrication procedures, quality assurance, and technology readiness are critically evaluated.

Integrating Cell Phone Imaging with Magnetic Levitation (i-LEV) for Label-Free Blood Analysis at the Point-of-Living

There is an emerging need for portable, robust, inexpensive, and easy-to-use disease diagnosis and prognosis monitoring platforms to share health information at the point-of-living, including clinical and home settings. Recent advances in digital health technologies have improved early diagnosis, drug treatment, and personalized medicine. Smartphones with high-resolution cameras and high data processing power enable intriguing biomedical applications when integrated with diagnostic devices. Further, these devices have immense potential to contribute to public health in resource-limited settings where there is a particular need for portable, rapid, label-free, easy-to-use, and affordable biomedical devices to diagnose and continuously monitor patients for precision medicine, especially those suffering from rare diseases, such as sickle cell anemia, thalassemia, and chronic fatigue syndrome. Here, a magnetic levitation-based diagnosis system is presented in which different cell types (i.e., white and red blood cells) are levitated in a magnetic gradient and separated due to their unique densities. Moreover, an easy-to-use, smartphone incorporated levitation system for cell analysis is introduced. Using our portable imaging magnetic levitation (i-LEV) system, it is shown that white and red blood cells can be identified and cell numbers can be quantified without using any labels. In addition, cells levitated in i-LEV can be distinguished at single-cell resolution, potentially enabling diagnosis and monitoring, as well as clinical and research applications.

Nanosensors for early cancer detection and for therapeutic drug monitoring

The use of nanotechnology for drug delivery in cancer therapy has raised high expectations. Additionally, the use of nanomaterials in sensors to extract and detect tumor specific biomarkers, circulating tumor cells, or extracellular vesicles shed by the tumor holds the promise to detect cancer much earlier and hence improve long-term survival of the patients. Moreover, the monitoring of the anticancer drug concentration, which has a narrow therapeutic window, will allow for a personalized dosing of the drug and will lead to improved therapeutic outcome and life quality of the patient. This review will provide an overview on the use of nanosensors for the early diagnosis of cancer and for the therapeutic drug monitoring, giving some examples. We envision nanosensors to make significant improvements in the cancer management as easy-to-use point-of-care devices for a broad population of users.