Impact of drug-linker on method selection for analytical characterization and purification of antibody-drug conjugates.

In addition to traditional characterisation methods of hydrophobic interaction (HIC) and reverse phase (RP) chromatography, an anion exchange chromatography (AIEX) was developed to analyse and purify antibody drug conjugates (ADCs). Since different drug antibody ratio (DAR) species may impact biological activity, therapeutic index, PK parameters or even potential immunogenicity, homogenous ADC DAR demands have been significantly increasing. To accelerate linker designs, drug screening and ADC DAR purification for in vitro and in vivo studies, we built the analytical toolbox including HIC, RP, AIEX, icIEF, SEC, and MS for downstream ADC DAR purification using HIC and AIEX. The established analytical methods can quickly assess the quality of ADC DAR profiles and provide important information to select the proper ADC DAR purification method. Since drug-linker structures can significantly affect ADC physicochemical properties, and highly impact on selections of analytical methods, we applied both HIC and AIEX characterisation and purification platforms to achieve ADC DAR homogenous. Our experiments also implied that unlike HIC, AIEX could be used to separate DAR4 positional isomers.

Construction of prediction model for fetal growth restriction during first trimester in an Asian population.

OBJECTIVE: To construct a prediction model for fetal growth restriction (FGR) during the first trimester of pregnancy and evaluate its screening performance. METHODS: This was a prospective cohort study of singleton pregnancies that underwent routine ultrasound screening at 11 to 13 + 6 weeks at the Affiliated Suzhou Hospital of Nanjing Medical University between January 2019 and April 2022. Basic clinical information, ultrasound indicators and serum biomarkers of pregnant women were collected. Fetal weight assessment was based on the fetal growth curve for the Southern Chinese population. FGR was diagnosed according to Delphi consensus criteria. Least absolute shrinkage and selection operator (lasso) regression was used to select variables for inclusion in the model. Discrimination, calibration and clinical effectiveness of the model were evaluated in training and validation cohorts. RESULTS: A total of 1188 pregnant women were included, of whom 108 had FGR. Lasso regression identified seven predictive features, including history of maternal hypertension, maternal smoking or passive smoking, gravidity, uterine artery pulsatility index, ductus venosus pulsatility index and multiples of the median values of placental growth factor and soluble fms-like tyrosine kinase-1. The nomogram prediction model constructed from these seven variables accurately predicted FGR, and the area under the receiver-operating-characteristics curve in the validation cohort was 0.82 (95% CI, 0.74-0.90). The calibration curve and Hosmer-Lemeshow test demonstrated good calibration, and the clinical decision curve and clinical impact curve supported its practical value in a clinical setting. CONCLUSION: The multi-index prediction model for FGR has good predictive value during the first trimester. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Discovery of ABBV-154, an anti-TNF Glucocorticoid Receptor Modulator Immunology Antibody-Drug Conjugate (iADC).

Stable attachment of drug-linkers to the antibody is a critical requirement, and for maleimide conjugation to cysteine, it is achieved by ring hydrolysis of the succinimide ring. During ADC profiling in our in-house property screening funnel, we discovered that the succinimide ring open form is in equilibrium with the ring closed succinimide. Bromoacetamide (BrAc) was identified as the optimal replacement, as it affords stable attachment of the drug-linker to the antibody while completely removing the undesired ring open-closed equilibrium. Additionally, BrAc also offers multiple benefits over maleimide, especially with respect to homogeneity of the ADC structure. In combination with a short, hydrophilic linker and phosphate prodrug on the payload, this afforded a stable ADC (ABBV-154) with the desired properties to enable long-term stability to facilitate subcutaneous self-administration.

Optimization of Drug-Linker to Enable Long-term Storage of Antibody-Drug Conjugate for Subcutaneous Dosing.

To facilitate subcutaneous dosing, biotherapeutics need to exhibit properties that enable high-concentration formulation and long-term stability in the formulation buffer. For antibody-drug conjugates (ADCs), the introduction of drug-linkers can lead to increased hydrophobicity and higher levels of aggregation, which are both detrimental to the properties required for subcutaneous dosing. Herein we show how the physicochemical properties of ADCs could be controlled through the drug-linker chemistry in combination with prodrug chemistry of the payload, and how optimization of these combinations could afford ADCs with significantly improved solution stability. Key to achieving this optimization is the use of an accelerated stress test performed in a minimal formulation buffer.

Artificial intelligence-supported applications in head and neck cancer radiotherapy treatment planning and dose optimisation.

INTRODUCTION: The aim of this review is to describe how various AI-supported applications are used in head and neck cancer radiotherapy treatment planning, and the impact on dose management in regards to target volume and nearby organs at risk (OARs). METHODS: Literature searches were conducted in databases and publisher portals Pubmed, Science Direct, CINAHL, Ovid, and ProQuest to peer reviewed studies published between 2015 and 2021. RESULTS: Out of 464 potential ones, ten articles covering the topic were selected. The benefit of using deep learning-based methods to automatically segment OARs is that it makes the process more efficient producing clinically acceptable OAR doses. In some cases automated treatment planning systems can outperform traditional systems in dose prediction. CONCLUSIONS: Based on the selected articles, in general AI-based systems produced time savings. Also, AI-based solutions perform at the same level or better than traditional planning systems considering auto-segmentation, treatment planning and dose prediction. However, their clinical implementation into routine standard of care should be carefully validated IMPLICATIONS TO PRACTICE: AI has a primary benefit in reducing treatment planning time and improving plan quality allowing dose reduction to the OARs thereby enhancing patients' quality of life. It has a secondary benefit of reducing radiation therapists' time spent annotating thereby saving their time for e.g. patient encounters.

Discovery of ABBV-3373, an Anti-TNF Glucocorticoid Receptor Modulator Immunology Antibody Drug Conjugate.

Using a convergent synthetic route to enable multiple points of diversity, a series of glucocorticoid receptor modulators (GRM) were profiled for potency, selectivity, and drug-like properties in vitro. Despite covering a large range of diversity, profiling the nonconjugated small molecule was suboptimal and they were conjugated to a mouse antitumor necrosis factor (TNF) antibody using the MP-Ala-Ala linker. Screening of the resulting antibody drug conjugates (ADCs) provided a better assessment of efficacy and physical properties, reinforcing the need to conduct structure-activity relationship studies on the complete ADC. DAR4 ADCs were screened in an acute mouse contact hypersensitivity model measuring biomarkers to ensure a sufficient therapeutic window. In a chronic mouse arthritis model, mouse anti-TNF GRM ADCs were efficacious after a single dose of 10 mg/kg i.p. for over 30 days. Data on the unconjugated payloads and mouse surrogate anti-TNF ADCs identified payload 17 which was conjugated to a human anti-TNF antibody and advanced to the clinic as ABBV-3373.

High-throughput approaches to functional characterization of genetic variation in yeast.

Expansion of sequencing efforts to include thousands of genomes is providing a fundamental resource for determining the genetic diversity that exists in a population. Now, high-throughput approaches are necessary to begin to understand the role these genotypic changes play in affecting phenotypic variation. Saccharomyces cerevisiae maintains its position as an excellent model system to determine the function of unknown variants with its exceptional genetic diversity, phenotypic diversity, and reliable genetic manipulation tools. Here, we review strategies and techniques developed in yeast that scale classic approaches of assessing variant function. These approaches improve our ability to better map quantitative trait loci at a higher resolution, even for rare variants, and are already providing greater insight into the role that different types of mutations play in phenotypic variation and evolution not just in yeast but across taxa.

Effect of Social Determinants of Health on Uncontrolled Human Immunodeficiency Virus (HIV) Infection Among Persons With HIV in San Francisco, California.

Background: In 2010-2014, the San Francisco Department of Public Health (SFDPH) established programs to rapidly link people with human immunodeficiency virus (PWH) to care and offer antiretroviral therapy (ART) at human immunodeficiency virus (HIV) diagnosis. Such programs reduced the number of PWH out of care or with detectable HIV viral load (ie, uncontrolled HIV infection). We investigated the role of social determinants of health (SDH) on uncontrolled HIV. Methods: Cross-sectional data from adult PWH diagnosed and reported to the SFDPH as of December 31, 2019, prescribed ART, and with confirmed San Francisco residency during 2017-2019 were analyzed in conjunction with SDH metrics derived from the American Community Survey 2015-2019. We focused on 5 census tract-level SDH metrics: percentage of residents below the federal poverty level, with less than a high school diploma, or uninsured; median household income; and Gini index. We compared uncontrolled HIV prevalence odds ratios (PORs) across quartiles of each metric independently using logistic regression models. Results: The analysis included 7486 PWH (6889 controlled HIV; 597 uncontrolled HIV). Unadjusted PORs of uncontrolled HIV rose with increasingly marginalized quartiles, compared to the least marginalized quartile for each metric. Adjusting for demographics and transmission category, the POR for uncontrolled HIV for PWH in the most marginalized quartile remained significant across metrics for poverty (POR = 2.0; confidence interval [CI] = 1.5-2.6), education (POR = 2.4; CI = 1.8-3.2), insurance (POR = 1.8; CI = 1.3-2.5), income (POR = 1.8; CI = 1.4-2.3), and income inequality (POR = 1.5; CI = 1.1-2.0). Conclusions: Beyond demographics, SDH differentially affected the ability of PWH to control HIV. Despite established care programs, PWH experiencing socioeconomic marginalization require additional support to achieve health outcome goals.

EGR2-related mixed demyelinating and axonal Charcot-Marie-Tooth disease: An electrodiagnostic, nerve imaging, and histological study.

BACKGROUND AND AIMS: The early growth response 2 gene (EGR2) mutations are associated with a group of hereditary neuropathy, including axonal neuropathy and hypomyelinating neuropathy or Charcot-Marie-Tooth disease (CMT) type 1D. We aim to perform an electrodiagnostic, nerve imaging, and histological study of EGR2-associated neuropathy. MATERIALS AND METHODS: We performed a retrospective analysis of two patients with EGR2-related neurology at our hospital. The neuropathy was confirmed by the nerve conduction study. Nerve imaging and sural biopsies were performed in two patients. RESULTS: Two unrelated boys exhibited early-onset length-dependent neuropathy. Next generation sequencing identified EGR2 gene with previously described E412K mutation in the third zine finger domain in patient 1 and a previously undescribed variant D355N mutation in the first zinc finger domain in patient 2. The magnetic resonance imaging of the lumbosacral plexus showed no abnormalities in patient 1 and thickened lumbosacral plexuses in patient 2. Electrophysiology and nerve biopsies showed a prominent axonal neuropathy, accompanied with demyelinating involvement. CONCLUSION: Therefore, it seemed that the EGR2 mutations could cause not only the known demyelinating type and axonal type but also mixed-type CMT. Our findings expanded the phenotypic heterogeneities of EGR2-associated neuropathy.

PacRAT: a program to improve barcode-variant mapping from PacBio long reads using multiple sequence alignment.

SUMMARY: Use of PacBio sequencing for characterizing barcoded libraries of genetic variants is on the rise. However, current approaches in resolving PacBio sequencing artifacts can result in a high number of incorrectly identified or unusable reads. Here, we developed a PacBio Read Alignment Tool (PacRAT) that improves the accuracy of barcode-variant mapping through several steps of read alignment and consensus calling. To quantify the performance of our approach, we simulated PacBio reads from eight variant libraries of various lengths and showed that PacRAT improves the accuracy in pairing barcodes and variants across these libraries. Analysis of real (non-simulated) libraries also showed an increase in the number of reads that can be used for downstream analyses when using PacRAT. AVAILABILITY AND IMPLEMENTATION: PacRAT is written in Python and is freely available (https://github.com/dunhamlab/PacRAT). SUPPLEMENTARY INFORMATION: Supplemental data are available at Bioinformatics online.

Design and Development of Glucocorticoid Receptor Modulators as Immunology Antibody-Drug Conjugate Payloads.

Glucocorticoid receptor modulators (GRM) are the first-line treatment for many immune diseases, but unwanted side effects restrict chronic dosing. However, targeted delivery of a GRM payload via an immunology antibody-drug conjugate (iADC) may deliver significant efficacy at doses that do not lead to unwanted side effects. We initiated our α-TNF-GRM ADC project focusing on identifying the optimal payload and a linker that afforded stable attachment to both the payload and antibody, resulting in the identification of the synthetically accessible maleimide-Gly-Ala-Ala linker. DAR 4 purified ADCs were shown to be more efficacious in a mouse contact hypersensitivity model than the parent α-TNF antibody. Analysis of P1NP and corticosterone biomarkers showed there was a sufficient therapeutic window between efficacy and unwanted effects. In a chronic mouse arthritis model, α-TNF-GRM ADCs were more efficacious than both the parent α-TNF mAb and an isotype control bearing the same GRM payload.

Preclinical Safety and Efficacy Assessments for Novel Femtosecond Lasers in Corneal Refractive Surgery.

Preclinical safety requirements and test methods have been standardized over time to guide medical device developers in the path needed to manufacture safe devices and achieve regulatory approval. Today, femtosecond lasers are commonly used in cataract and refractive surgeries. Currently, an industry standard to guide developers in preclinical testing of ophthalmic lasers does not exist. Consequently, the data presented in regulatory submissions may vary between manufacturers, making the regulatory review process more ambiguous. Here, the authors present a comprehensive discussion of preclinical test methods applied to the evaluation of an ophthalmic laser. We include in vitro and ex vivo models, as well as an in vivo rabbit model subject to corneal refractive treatments, for consideration in a preclinical safety evaluation plan. Scientific rationale to support the ocular endpoints of evaluation in the rabbit model to demonstrate safety is also presented and discussed.

Building resilience in US military families: why it matters.

Service members and their families have endured significant stressors over the past 19 years in support of the nation's engagement in the wars in Iraq and Afghanistan. 'Resilience' is the term most commonly used to describe the military spouse and military-connected child. However, due to a paucity of research on military families, little is known about the impact of spousal/parental military service on the military family. The ability of the healthcare provider is critical to ensuring the success of the military spouse and military-connected child. Providers can support the physical and psychological health needs of military families through (1) identification of military family members in clinical practice and (2) providing culturally competent care that correlates the unique lifestyle and physical and psychological health exposures associated with spousal/parental military service. Historically, in the United States, there has been a proud legacy of generational military service in families-upwards of 80% of new recruits have a family member who has served in the military. The leading factor associated with retention of the service member on Active Duty or in the Reserve or National Guard is the satisfaction of the at-home spouse. Disenfranchising the military spouse and lack of services and support for military-connected children could create a gap in meeting recruitment goals creating a threat to national security in the United States.

Worldwide Variations in Methodology and Reporting of Early Childhood Caries: A Scoping Review.

Purpose: The purpose of this study was to identify the variations in the definition, diagnostic criteria, and clinical study methods regarding early childhood caries (ECC) in preschool children or children younger than six years old. Methods: This is a scoping review of ECC studies published from January 1999 to December 2019. Extracted information from 256 studies included the year of publication, country/city of the studied population, nomenclature used, diagnostic criteria, and case definition. Results: The number of published studies was greatest in the past five years. Thirteen different methods for diagnosis of ECC were identified, with World Health Organization criteria being the most frequently used. The nomenclature "dental caries in primary teeth" remained the most popular terminology to describe caries in preschool children, followed by ECC. The threshold for determining caries ranged from visual observation of dental caries to a full range of clinical and radiographic findings. Conclusions: There is a wide variation in diagnostic criteria and case definitions of early childhood caries. Global consensus would advance the understanding, epidemiology, burden, and management of ECC.

Development of a Citywide Rapid Antiretroviral Therapy Initiative in San Francisco.

INTRODUCTION: Ending the HIV epidemic in the U.S. holds rapid antiretroviral therapy as a key strategy to improve the health of those with HIV and to decrease transmission. In 2015, Getting to Zero San Francisco, a multisector consortium, expanded rapid antiretroviral therapy citywide. METHODS: A Getting to Zero San Francisco Rapid ART Program Initiative for HIV Diagnoses Committee (academic, community, service delivery, health department partners) designed the program, protocol, dissemination plan, and monitoring strategy. Newly diagnosed patients were linked to an HIV medical home or Rapid ART Program Initiative for HIV Diagnoses initiation hub to best deliver rapid antiretroviral therapy across a diverse patient mix, with a goal of ≤5 working days from diagnosis to care and ≤1 day from care to antiretroviral therapy. Stakeholders were trained on rapid antiretroviral therapy via Getting to Zero San Francisco meetings, in-services, public health detailing, and peer-to-peer recruiting, prioritizing HIV clinics serving patients of color, Latinx ethnicity, youth, and the uninsured or publicly insured. Rapid ART Program Initiative for HIV Diagnoses-specific metrics were derived from surveillance data; stratified by sex/gender, age, race/ethnicity, and housing status; and presented at public meetings. Data were analyzed between January and April 2021. RESULTS: From 2014 to 2018, median time from diagnosis to care decreased 71% (7 to 2 days), care to antiretroviral therapy decreased from 19 to 0 days, and diagnosis to virologic suppression decreased 51% (94 to 46 days). Improvements occurred regardless of age, race/ethnicity, sex/gender, exposure, or housing status. CONCLUSIONS: During a citywide initiative to optimize antiretroviral therapy initiation, time from HIV diagnosis to care, antiretroviral therapy, and virologic suppression decreased across all affected groups to varying degrees. The Rapid ART Program Initiative for HIV Diagnoses Committee continues to address challenges to retention and expand implementation.

False-negative real-time polymerase chain reaction tests in COVID-19 patients: an epidemiological analysis of 302 patients.

OBJECTIVES: Patients who arrive at the emergency department (ED) with COVID-19, who test negative at the first real-time polymerase chain reaction (RT-PCR), represent a clinical challenge. This study aimed to evaluate if the clinical manifestation at presentation, the laboratory and imaging results, and the prognosis of COVID-19 differ in patients who tested negative at the first RT-PCR compared with those who tested positive and also to evaluate if comorbid conditions patient-related or the period of arrival are associated with negative testing. STUDY DESIGN: We retrospectively collected clinical data of patients who accessed the ED from March 1 to May 15, 2020. METHODS: We compared clinical variables, comorbid conditions, and clinical outcomes in the two groups by univariate analysis and logistic regression. RESULTS: Patients who tested negative at the first RT-PCR showed a higher prevalence of cardiopathy, immunosuppression, and diabetes, as well as a higher leukocyte and lower lymphocyte counts compared with patients who tested positive. A bilateral interstitial syndrome and a typical pattern at computed tomography scan were prevalent in the test-negative group. Test-negative patients were more likely to be admitted to the hospital but less likely to need admission in a high level of care ward. The false-negative rate increased from March to May. CONCLUSION: False-negative RT-PCR COVID-19 patients present a similar spectrum of symptoms compared with positive cohort, but more comorbidities. Imaging helps to identify them. True positives had a higher risk of serious complications.

The structure of the bacterial DNA segregation ATPase filament reveals the conformational plasticity of ParA upon DNA binding.

The efficient segregation of replicated genetic material is an essential step for cell division. Bacterial cells use several evolutionarily-distinct genome segregation systems, the most common of which is the type I Par system. It consists of an adapter protein, ParB, that binds to the DNA cargo via interaction with the parS DNA sequence; and an ATPase, ParA, that binds nonspecific DNA and mediates cargo transport. However, the molecular details of how this system functions are not well understood. Here, we report the cryo-EM structure of the Vibrio cholerae ParA2 filament bound to DNA, as well as the crystal structures of this protein in various nucleotide states. These structures show that ParA forms a left-handed filament on DNA, stabilized by nucleotide binding, and that ParA undergoes profound structural rearrangements upon DNA binding and filament assembly. Collectively, our data suggest the structural basis for ParA's cooperative binding to DNA and the formation of high ParA density regions on the nucleoid.