Human Pharmacokinetic and CYP3A DDI Prediction of GDC-2394 using PBPK Modeling and Biomarker Assessment.

Physiologically-based pharmacokinetic (PBPK) modeling was used to predict the human pharmacokinetics and drug-drug interaction (DDI) of GDC-2394. PBPK models were developed using in vitro and in vivo data to reflect the oral and IV PK profiles of mouse, rat, dog and monkey. The learnings from preclinical PBPK models were applied to a human PBPK model for prospective human PK predictions. The prospective human PK predictions were within 3-fold of the clinical data from the first in human (FIH) study, which was used to optimize and validate the PBPK model and subsequently used for DDI prediction. Based on the majority of PBPK modeling scenarios using the in vitro CYP3A induction data (mRNA and activity), GDC-2394 was predicted to have no-to-weak induction potential at 900 mg BID. Calibration of the induction mRNA and activity data allowed for the convergence of DDI predictions to a narrower range. The plasma concentrations of the 4ß-hydroxycholesterol (4ß-HC) were measured in the multiple ascending dose (MAD) study to assess the hepatic CYP3A induction risk. There was no change in plasma 4ß-HC concentrations after 7 days of GDC-2394 at 900 mg BID. A dedicated DDI study found that GDC-2394 has no induction effect on midazolam in humans, which was reflected by the totality of predicted DDI scenarios. This work demonstrates the prospective utilization of PBPK for human PK and DDI prediction in early drug development of GDC-2394. PBPK modeling accompanied with CYP3A biomarkers can serve as a strategy to support clinical pharmacology development plans. Significance Statement This work presents the application of PBPK modeling for prospective human PK and DDI prediction in early drug development. The strategy taken in this report represents a framework to incorporate various approaches including calibration of in vitro induction data and consideration of CYP3A biomarkers to inform on the overall CYP3A related DDI risk of GDC-2394.

Implementation of kidney palliative care-lessons learned from the US Department of Veterans Affairs.

Advanced kidney disease is a progressive life-limiting illness associated with high symptom burden, disability, and highly intensive care near the end of life. There is growing interest in integrating palliative care principles into the care of patients with advanced kidney disease to improve care and outcomes for these patients. The United States (US) Department of Veterans Affairs (VA) has been a leader in advancing palliative care initiatives across its health system and whose experience and approach may be instructive to other health systems seeking to develop kidney palliative care (KPC) services. Herein, we review current KPC programs in the VA and highlight the different models of care that programs have been adopted and how key components of goals of care conversations and advance care planning, symptom management, multidisciplinary care, patient selection, and quality improvement have been implemented across programs. VA KPC programs have adopted "parallel", "merged", and "embedded" models of KPC that reflect the different configurations of partnerships between nephrology and palliative care providers to deliver KPC. A primary service of VA KPC programs is providing goals of care conversations and advance care planning to referred patients and systematically documenting the outcomes of these discussions in standardized note templates in the electronic medical record. Symptom management is delivered by KPC providers through regular shared or sequential visits with patients' nephrology providers and is guided by patient responses to validated symptom surveys. Programs are staffed by allied health professionals, such as chaplains, pharmacists, social workers, and dieticians, to provide whole-person care and regularly huddle with nephrology staff to reach a shared understanding of each patient's care needs and plan. KPC programs implement champions who select patients in greatest need of KPC using a combination of clinical events that trigger referral for KPC and validated mortality risk prediction scores that are automatically generated in each patient's medical record. KPC programs also routinely collect clinical, patient-reported, process, and care quality measures to assess its services. The experiences of the VA highlight novel approaches that strive to close the care gaps in meeting the KPC needs of patients with advanced kidney disease.

Trends in ototoxicity monitoring among cisplatin-treated patients with cancer.

PURPOSE: This study aims to characterize patterns in ototoxicity monitoring and identify potential barriers to audiologic follow-up. METHODS: We performed a single-institution retrospective cohort study on adult (≥ 18 years old) cancer patients treated with cisplatin from January 2014 to September 2021. Our primary outcomes were rates of baseline and post-treatment audiograms at the following time points: 3, 6, 12, and greater than 12 months. Time-to-event analyses were performed to describe additional insights to ototoxicity monitoring patterns. RESULTS: Nine hundred fifty-five patients with cancer were included for analysis. The most common primary cancer sites were head and neck (64%), followed by cervical (24%). Three hundred seventy-three patients (39%) underwent baseline audiometric assessment, 38 patients (4%) received audiologic evaluation during chemotherapy, and 346 patients (36%) obtained at least one post-treatment audiogram. Audiologic follow-up was greatest within 3 months of completing chemotherapy (26%), but this tapered dramatically to less than 10% at every other post-treatment time point. Patients with head and neck cancer achieved higher rates of audiologic follow-up at every time point than patients with non-head and neck cancer except for during treatment. CONCLUSIONS: Ototoxicity monitoring is an inconsistent practice, particularly during chemotherapy and for long-term surveillance of hearing loss. Patients with non-head and neck cancer may be at increased risk for loss of audiologic follow-up. IMPLICATIONS FOR CANCER SURVIVORS: Cisplatin ototoxicity is a common occurrence that can be effectively managed with auditory rehabilitation. Therefore, referrals to audiology and counseling on treatment-related ototoxicity are recommended throughout chemotherapy and cancer survivorship.

Preclinical characterization of the absorption and disposition of the brain penetrant PI3K/mTOR inhibitor paxalisib and prediction of its pharmacokinetics and efficacy in human.

Glioblastoma multiforme (GBM) is the most common primary brain tumour in adults. Available treatments have not markedly improved patient survival in the last twenty years. However, genomic investigations have showed that the PI3K pathway is frequently altered in this glioma, making it a potential therapeutic target.Paxalisib is a brain penetrant PI3K/mTOR inhibitor (mouse Kp,uu 0.31) specifically developed for the treatment of GBM. We characterised the preclinical pharmacokinetics and efficacy of paxalisib and predicted its pharmacokinetics and efficacious dose in humans.Plasma protein binding of paxalisib was low, with the fraction unbound ranging from 0.25 to 0.43 across species. The hepatic clearance of paxalisib was predicted to be low in mice, rats, dogs and humans, and high in monkeys, from hepatocytes incubations. The plasma clearance was low in mice, moderate in rats and high in dogs and monkeys. Oral bioavailability ranged from 6% in monkeys to 76% in rats.The parameters estimated from the pharmacokinetic/pharmacodynamic modelling of the efficacy in the subcutaneous U87 xenograft model combined with the human pharmacokinetics profile predicted by PBPK modelling suggested that a dose of 56 mg may be efficacious in humans. Paxalisib is currently tested in Phase III clinical trials.

GTP1 metabolic stability assessment: A study of the tau PET tracer [18F]GTP1.

Tau PET imaging using the tau specific PET tracer [18F]GTP1 has been and is part of therapeutic trials in Alzheimer's disease to monitor the accumulation of tau aggregates in the brain. Herein, we examined the metabolic processes of GTP1 and assessed the influence of smoking on its metabolism through in vitro assays. The tracer metabolic profile was assessed by incubating GTP1 with human liver microsomes (HLM) and human hepatocytes. Since smoking strongly stimulates the CYP1A2 enzyme activity, we incubated GTP1 with recombinant CYP1A2 to evaluate the role of the enzyme in tracer metabolism. It was found that GTP1 could form up to eleven oxidative metabolites with higher polarity than the parent. Only a small amount (2.6 % at 60 min) of a defluorinated metabolite was detected in HLM and human hepatocytes incubations highlighting the stability of GTP1 with respect to enzymatic defluorination. Moreover, the major GTP1 metabolites were not the product of CYP1A2 activity suggesting that smoking may not impact in vivo tracer metabolism and subsequently GTP1 brain kinetics.

Filling a nick in NIK: Extending the half-life of a NIK inhibitor through structure-based drug design.

Inhibition of NF-κB inducing kinase (NIK) has been pursued as a promising therapeutic target for autoimmune disorders due to its highly regulated role in key steps of the NF-κB signaling pathway. Previously reported NIK inhibitors from our group were shown to be potent, selective, and efficacious, but had higher human dose projections than desirable for immunology indications. Herein we report the clearance-driven optimization of a NIK inhibitor guided by metabolite identification studies and structure-based drug design. This led to the identification of an azabicyclo[3.1.0]hexanone motif that attenuated in vitro and in vivo clearance while maintaining NIK potency and increasing selectivity over other kinases, resulting in a greater than ten-fold reduction in predicted human dose.

Audiologic Follow-up in Patients With Head and Neck Cancer Treated With Cisplatin and Radiation.

OBJECTIVES: Evaluate factors associated with adherence to ototoxicity monitoring among patients with head and neck cancer treated with cisplatin and radiation therapy at a tertiary care center. METHODS: We performed a single-institution retrospective cohort study on adults with head and neck cancer treated with cisplatin and radiation therapy who participated in an ototoxicity monitoring program. The primary outcomes were rates of post-treatment audiograms at the following time points: one, three, six, 12, and greater than 12 months. Multivariable logistic regression was performed to identify risk factors associated with complete loss of follow-up after pre-treatment evaluation. RESULTS: Two hundred ninety-four head and neck cancer patients were analyzed. Overall, 220 (74.8%) patients had at least one post-treatment audiogram; 58 (20.0%) patients had more than one audiogram. The time point with the highest follow-up rate was at 3 months (n = 170, 57.8%); rates at the remaining times ranged from 7.1% to 14.3%. When controlling for covariates, patients without insurance and those with stage IV cancers were associated with complete loss of audiologic follow-up (aOR = 7.18, 95% CI = 2.75-19.90; aOR = 1.96, 95% CI = 1.02-3.77, respectively). Among 156 patients recommended for a hearing aid, only 39 (24.8%) patients received one. CONCLUSIONS: Head and neck cancer patients enrolled in an ototoxicity monitoring program demonstrate moderately high follow-up rates for at least one post-treatment audiogram. However, follow-up tapers dramatically after 6 months, and overall hearing aid utilization is low. Further research is needed to understand barriers to long-term audiologic follow-up and hearing aid utilization to decrease untreated hearing loss in cancer survivorship. LEVEL OF EVIDENCE: Level 3 Laryngoscope, 133:3161-3168, 2023.

Value Placed on Comfort vs Life Prolongation Among Patients Treated With Maintenance Dialysis.

Importance: Patients receiving maintenance dialysis experience intensive patterns of end-of-life care that might not be consistent with their values. Objective: To evaluate the association of patients' health care values with engagement in advance care planning and end-of-life care. Design, Setting, and Participants: Survey study of patients who received maintenance dialysis between 2015 and 2018 at dialysis centers in the greater metropolitan areas of Seattle, Washington, and Nashville, Tennessee, with longitudinal follow-up of decedents. Logistic regression models were used to estimate probabilities. Data analysis was conducted between May and October 2022. Exposures: A survey question about the value that the participant would place on longevity-focused vs comfort-focused care if they were to become seriously ill. Main Outcomes and Measures: Self-reported engagement in advance care planning and care received near the end of life through 2020 using linked kidney registry data and Medicare claims. Results: Of 933 patients (mean [SD] age, 62.6 [14.0] years; 525 male patients [56.3%]; 254 [27.2%] identified as Black) who responded to the question about values and could be linked to registry data (65.2% response rate [933 of 1431 eligible patients]), 452 (48.4%) indicated that they would value comfort-focused care, 179 (19.2%) that they would value longevity-focused care, and 302 (32.4%) that they were unsure about the intensity of care they would value. Many had not completed an advance directive (estimated probability, 47.5% [95% CI, 42.9%-52.1%] of those who would value comfort-focused care vs 28.1% [95% CI, 24.0%-32.3%] of those who would value longevity-focused care or were unsure; P < .001), had not discussed hospice (estimated probability, 28.6% [95% CI, 24.6%-32.9%] comfort focused vs 18.2% [95% CI, 14.7%-21.7%] longevity focused or unsure; P < .001), or had not discussed stopping dialysis (estimated probability, 33.3% [95% CI, 29.0%-37.7%] comfort focused vs 21.9% [95% CI, 18.2%-25.8%] longevity focused or unsure; P < .001). Most respondents wanted to receive cardiopulmonary resuscitation (estimated probability, 78.0% [95% CI, 74.2%-81.7%] comfort focused vs 93.9% [95% CI, 91.4%-96.1%] longevity focused or unsure; P < .001) and mechanical ventilation (estimated probability, 52.0% [95% CI, 47.4%-56.6%] comfort focused vs 77.9% [95% CI, 74.0%-81.7%] longevity focused or unsure; P < .001). Among decedents, the percentages of participants who received an intensive procedure during the final month of life (estimated probability, 23.5% [95% CI, 16.5%-31.0%] comfort focused vs 26.1% [95% CI, 18.0%-34.5%] longevity focused or unsure; P = .64), discontinued dialysis (estimated probability, 38.3% [95% CI, 32.0%-44.8%] comfort focused vs 30.2% [95% CI, 23.0%-37.8%] longevity focused or unsure; P = .09), and enrolled in hospice (estimated probability, 32.2% [95% CI, 25.7%-38.7%] comfort focused vs 23.3% [95% CI, 16.4%-30.5%] longevity focused or unsure; P = .07) were not statistically different. Conclusions and Relevance: This survey study found that there appeared to be a disconnect between patients' expressed values, which were largely comfort focused, and their engagement in advance care planning and end-of-life care, which reflected a focus on longevity. These findings suggest important opportunities to improve the quality of care for patients receiving dialysis.

Decision-making about dialysis: Beyond just dialysis or death.

Nearly half of the persons receiving dialysis in the United States are aged 65 years or older. Kidney failure occurs most frequently in older adults, and typically triggers a discussion regarding dialysis treatment. In this Special Article, we describe the journey of Mr. Howard Russell, an older adult who experienced kidney failure and underwent dialysis. Using the experience of Mr. Russell, we illustrate the complexity of dialysis decision-making, including how disease trajectory and health policy can potentially impede older adults from achieving "what matters." Our intent is to provide guidance regarding these barriers and support to clinicians who are sharing similar journeys with older adults making decisions about dialysis. Based on Mr. Russell's journey, we suggest that when discussing dialysis with an older adult, four points be considered: (1) recognize if dialysis is needed long-term; (2) understand what matters for the older adult; (3) sync the treatment plan when what matters changes; and (4) set up with resources for kidney failure, which is limited but evolving.

Residue-Level Characterization of Antibody Binding Epitopes Using Carbene Chemical Footprinting.

Characterization of antibody binding epitopes is an important factor in therapeutic drug discovery, as the binding site determines and drives antibody pharmacology and pharmacokinetics. Here, we present a novel application of carbene chemical footprinting with mass spectrometry for identification of antibody binding epitopes at the single-residue level. Two different photoactivated diazirine reagents provide complementary labeling information allowing structural refinement of the antibody binding interface. We applied this technique to map the epitopes of multiple MICA and CTLA-4 antibodies and validated the findings with X-ray crystallography and yeast surface display epitope mapping. The characterized epitopes were used to understand biolayer interferometry-derived competitive binding results at the structural level. We show that carbene footprinting provides fast and high-resolution epitope information critical in the antibody selection process and enables mechanistic understanding of function to accelerate the drug discovery process.

A Patient Decision Aid About Conservative Kidney Management in Advanced Kidney Disease: A Randomized Pilot Trial.

RATIONALE & OBJECTIVE: Available decision aids for patients about treatment of advanced chronic kidney disease (CKD) often lack information on conservative kidney management (CKM). We assessed the feasibility and acceptability of a decision aid on CKM among patients with advanced CKD and their family members. STUDY DESIGN: Randomized pilot trial. SETTING & PARTICIPANTS: Patients aged≥75 years with stage 4 or 5 CKD and their family members at 4 medical centers in the greater Seattle area between August 2020 and December 2021. INTERVENTIONS: Usual care with or without a decision aid on CKM. OUTCOME: Acceptability was assessed by attrition rates between the initial study visit (T1) and the 3-month follow-up evaluation (T3). The primary outcome and measure of feasibility was the proportion of participants who discussed CKM with a health care provider between T1 and T3. RESULTS: We randomized 92 patients of whom 86 (55.8% male; age 82±6 years; 82.6% White) completed T1-42 in the usual care arm and 44 in the usual care plus decision aid arm-and 56 family members of whom 53 (18.9% male; age 71±11 years; 86.8% White) completed T1-20 in usual care arm and 33 in the usual care plus decisions aid arm. The attrition rates were 21% versus 21% (P=1.0) for patients, and 10% versus 18% (P=0.46) for family members in the usual care versus usual care plus decisions aid arms. Receipt of the decision aid significantly increased discussion of CKM with a health care provider for patients (26.4% vs 3.0%, P=0.007) and family members (26.9% vs 0, P=0.02). LIMITATIONS: Possible limited generalizability because participants were a relatively homogenous group. The decision aid focuses on CKM and may be less applicable to those with limited knowledge of kidney replacement therapies. CONCLUSIONS: A CKM decision aid was feasible and acceptable, and increased discussion of this treatment option with health care providers. This aid may serve as a useful adjunct to the currently available educational tools on treatments for advanced CKD. FUNDING: Grant from a not-for-profit entity (National Palliative Care Research Center). TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT04919941.

Spleen tyrosine kinase inhibition restores myeloid homeostasis in COVID-19.

Spleen tyrosine kinase (SYK) is a previously unidentified therapeutic target that inhibits neutrophil and macrophage activation in coronavirus disease 2019 (COVID-19). Fostamatinib, a SYK inhibitor, was studied in a phase 2 placebo-controlled randomized clinical trial and was associated with improvements in many secondary end points related to efficacy. Here, we used a multiomic approach to evaluate cellular and soluble immune mediator responses of patients enrolled in this trial. We demonstrated that SYK inhibition was associated with reduced neutrophil activation, increased circulation of mature neutrophils (CD10+CD33-), and decreased circulation of low-density granulocytes and polymorphonuclear myeloid-derived suppressor cells (HLA-DR-CD33+CD11b-). SYK inhibition was also associated with normalization of transcriptional activity in circulating monocytes relative to healthy controls, an increase in frequency of circulating nonclassical and HLA-DRhi classical monocyte populations, and restoration of interferon responses. Together, these data suggest that SYK inhibition may mitigate proinflammatory myeloid cellular and soluble mediator responses thought to contribute to immunopathogenesis of severe COVID-19.

Using Human-Centered Design Principles to Create a Decision Aid on Conservative Kidney Management for Advanced Kidney Disease.

Background: Most patients are unaware of approaches to treating advanced chronic kidney disease (CKD) other than dialysis. Methods: We developed a dedicated decision aid on conservative kidney management using human-centered design principles in three phases: (1) discovery: engagement of informants to understand their needs and preferences; (2) design: multiple rapid cycles of ideation, prototyping, and testing of a decision aid with a small group of informants; and (3) implementation: testing the decision aid in real-world settings with attention to how the decision aid can be further refined. Informants included a national patient advisory committee on kidney diseases, 50 patients with stage 4 or 5 CKD and 35 of their family members, and 16 clinicians recruited from the greater Seattle area between June 2019 and September 2021. Results: Findings from the discovery phase informed an initial prototype of the decision aid, which included five sections: a description of kidney disease and its signs and symptoms, an overview of conservative kidney management and the kinds of supports provided, self-reflection exercises to elicit patients' values and goals, the pros and cons of conservative kidney management, and the option of changing one's mind about conservative kidney management. The prototype underwent several rounds of iteration during its design phase, which resulted in the addition of an introductory section describing the intended audience and more detailed information in other sections. Findings from its implementation phase led to the addition of examples of common questions that patients and family members had about conservative kidney management and a final section on other related educational resources. Conclusions: Human-centered design principles supported a systematic and collaborative approach between researchers, patients, family members, and clinicians for developing a decision aid on conservative kidney management.

Isotretinoin and its Metabolites Alter mRNA of Multiple Enzyme and Transporter Genes In Vitro, but Downregulation of Organic Anion Transporting Polypeptide Does Not Translate to the Clinic.

Isotretinoin [13-cis-retinoic acid (13cisRA)] is widely used for the treatment of neuroblastoma and acne. It acts via regulating gene transcription through binding to retinoic acid receptors. Yet, the potential for isotretinoin to cause transcriptionally mediated drug-drug interactions (DDIs) has not been fully explored. We hypothesized that isotretinoin and its active metabolites all-trans-retinoic acid (atRA) and 4-oxo-13cisRA would alter the transcription of enzymes and transporters in the human liver via binding to nuclear receptors. The goal of this study was to define the DDI potential of isotretinoin and its metabolites resulting from transcriptional regulation of cytochrome P450 and transporter mRNAs. In human hepatocytes (n = 3), 13cisRA, atRA, and 4-oxo-13cisRA decreased OATP1B1, CYP1A2, CYP2C9, and CYP2D6 mRNA and increased CYP2B6 and CYP3A4 mRNA in a concentration-dependent manner. The EC50 values for OATP1B1 mRNA downregulation ranged from 2 to 110 nM, with maximum effect (Emax ) ranging from 0.17- to 0.54-fold. Based on the EC50 and Emax values and the known circulating concentrations of 13cisRA and its metabolites after isotretinoin dosing, a 55% decrease in OATP1B1 activity was predicted in vivo. In vivo DDI potential was evaluated clinically in participants dosed with isotretinoin for up to 32 weeks using coproporphyrin-I (CP-I) as an OATP1B1 biomarker. CP-I steady-state serum concentrations were unaltered following 2, 8, or 16 weeks of isotretinoin treatment. These data show that isotretinoin and its metabolites alter transcription of multiple enzymes and transporters in vitro, but translation of these changes to in vivo drug-drug interactions requires clinical evaluation for each enzyme. SIGNIFICANCE STATEMENT: Isotretinoin and its metabolites alter the mRNA expression of multiple cytochrome P450s (CYPs) and transporters in human hepatocytes, suggesting that isotretinoin may cause clinically significant drug-drug interactions (DDIs). Despite the observed changes in organic anion transporting polypeptide 1B1 (OATP1B1) mRNA in human hepatocytes, no clinical DDI was observed when measuring a biomarker, coproporphyrin-I. Further work is needed to determine whether these findings can be extrapolated to a lack of a DDI with CYP1A2, CYP2B6, and CYP2C9 substrates.