Pharmacological Models Research Articles

Abstract 17335: Novel Functional Genomic Studies in Scn1bb Variant Associated With Brugada Syndrome and the Ameliorative Effect of Acacetin

Background: Brugada syndrome (BrS) is a channelopathy associated with the development of life-threatening ventricular tachycardia and fibrillation (VT/VF). At present, pharmacological approaches to therapy are very limited. Objective: To evaluate the effect of an SCN1Bb variant and the effects of acacetin in experimental models of BrS. Methods: We evaluated the effect of acacetin in: 1) HEK293 cells expressing Kv4.3+ KChIP2 and Nav1.5+ SCN1B using patch clamp techniques (22 O C), 2) canine ventricular epicardial myocytes 3) coronary-perfused canine right (RV) preparations and 4) Langendorff-perfused canine whole-heart models of BrS in which the sodium channel blocker ajmaline or the calcium channel blocker verapamil, together with the transient outward current agonist NS5806 were used to provoke the arrhythmic phenotype. Results: Co-expression of SCN5A -WT+ KCND3-WT with KChIP2 + SCN1Bb -R214Q (variant associated with 3 cases of BrS and 1 case of sudden infant death (SIDS)), resulted in a 210% increase in total charge of the transient outward potassium current (I to ) as well as a 56.5% reduction in sodium channel current (I Na ) when compared to SCN1Bb-WT . In the absence of the mutation, acacetin inhibited I to with an IC 50 of 7.2±1.0 μM (n=3) in HEK cells, similar to the value obtained in native epicardial myocytes (6 μM). In the presence of the SCB1Bb mutant, IC 50 was dramatically reduced to 2.6±1 μM (n=5, p<0.05) Mean ±SEM. In the wedge and whole-heart models of BrS, acacetin dose-dependently reduced the epicardial action potential notch recorded from the RV or RVOT. Acacetin (5-10 μM) totally suppressed the electrocardiographic and arrhythmic manifestation of BrS, regardless of the pharmacologic model used to induce the arrhythmic phenotype. All repolarization defects were reversed, resulting in marked diminution of J waves leading to total suppression of VT/VF. Conclusions: Our findings demonstrate the ability of an SCN1Bb variant to dramatically shift the balance of current in the early phases of the RV epicardial action potential by reducing I Na as well as augmenting I to , thus predisposing to the development of the BrS phenotype. Our observations also hold promise for acacetin as a safe and effective pharmacologic treatment for BrS and some cases of SIDS.

Quantitative System Pharmacology Modeling of the Effect of Recombinant ADAMTS13 on Platelets in Patients with Congenital Thrombotic Thrombocytopenic Purpura

Background: Congenital thrombotic thrombocytopenic purpura (cTTP) is an ultra-rare, thrombotic microangiopathy due to an inherited deficiency of the von Willebrand factor (VWF)-cleaving protease, ADAMTS13.Accumulation of ultra-large VWF multimers increases blood clot formation in small blood vessels, leading to a low platelet count (thrombocytopenia). Treatment of cTTP consists of ADAMTS13 replacement with infusions of plasma-based therapies (PBT). Recombinant ADAMTS13 (rADAMTS13; Takeda Development Center Americas, Inc., Lexington, MA, USA) is in development for patients with cTTP.The ultra-rare nature of cTTP limits the sample size for a formally powered study to assess the impact of ADAMTS13 supplementation on efficacy outcome. This study was a proof-of-principle that model-based clinical trial simulations can be used to supplement clinical trial data in ultra-rare indications. Aims: To calibrate and validate a quantitative system pharmacology (QSP) model describing a mechanistic relationship between ADAMTS13, VWF and platelet numbers in patients with cTTP who received long-term prophylaxis with rADAMTS13 or PBT (fresh frozen or solvent/detergent treated plasma). In addition, to evaluate the treatment benefits of rADAMTS13 versus PBT using clinical trial simulations in virtual patients with cTTP as a supplement to the cTTP phase 3 study (NCT03393975) data. Methods: A QSP model was built using i) in vitro enzyme kinetic data and preclinical experimental data following administration of recombinant VWF and rADAMTS13 in ADAMTS13 knockout (KO) mice, and ii) data from the literature including platelet count and VWF activity from healthy human and untreated patients with cTTP. These data were used to calibrate the parameters corresponding to interactions between ADAMTS13 activity, VWF activity, and platelets. The model was validated against literature data from patients with cTTP treated with PBT and with data from a phase 2 study of patients with immune-mediated TTP treated with rADAMTS13 (NCT03922308). The model was then calibrated to longitudinal platelet data from the cTTP phase 3 study, in which patients with cTTP received prophylaxis for 6 months with PBT (exposure equivalent to ~10 IU/kg ADAMTS13 in the form of 10-20 mL/kg doses) and rADAMTS13 (40 IU/kg) either once every week (Q1W) or once every 2 weeks (Q2W) dosing intervals . The model was used to provide 1-year clinical trial simulations of isolated thrombocytopenia occurrences in a population of 1,000 virtual patients, phenotype-matched to patients in the cTTP phase 3 study. Results:Virtual clinical trial simulations using the QSP model suggested that rADAMTS13 administered over 1 year with a Q1W or Q2W schedule results in significantly fewer patients experiencing occurrences of thrombocytopenia (platelet count threshold of <150 x 10 9/L) compared to patients treated with PBT (hazard ratio [HR] relative to Q2W PBT: Q1W PBT, HR = 0.62; Q2W rADAMTS13, HR = 0.47; Q1W rADAMTS13, HR = 0.18). The treatment difference between rADAMTS13 and PBT was even more pronounced when a thrombocytopenia threshold of <100 x 10 9/L was used (Figure and Table). Simulations also predicted a prophylactic carry-over effect on platelets, with approximately 20 days taken to reach 90% of the long-term average platelet count when switching from rADAMTS13 to PBT or from PBT to rADAMTS13. A correlation analysis for a Q2W dosing of rADAMTS13 demonstrated that ADAMTS13 trough activity (C trough, Spearman ρ = 0.96) and time with ADAMTS13 activity above 10% (Spearman ρ = 0.93) showed stronger correlations with increased platelet count than the maximum plasma ADAMTS13 activity level (C max, Spearman ρ = 0.68). A correlation analysis for a Q1W dosing frequency produced similar results.Mean time above 10% ADAMTS13 activity was higher following rADAMTS13 versus PBT administration (5.2 vs 1.7 days). Conclusions: This model-based virtual clinical trial simulation predicts that dosing with rADAMTS13 would provide >50% reduction in the HR of thrombocytopenia occurrences over PBT. Patients may also have a higher level of protection for 2-3 weeks when switching from rADAMTS13 to PBT. These findings supplement the assessment of clinical benefit of rADAMTS13 in the cTTP phase 3 study and show that increased ADAMTS13 activity following rADAMTS13 administration is likely to reduce occurrences of thrombocytopenia in cTTP.

Integrated Preclinical Data Analysis of ISB 2001 Enables Optimal Starting Dose Selection for a First-in-Class Trispecific T Cell Engager Phase1 Study in Multiple Myeloma

Despite significant clinical benefit achieved by targeted immunotherapies in recent years, durable responses are still limited in multiple myeloma (MM) 1,2 potentially due to expansion of clones with low target expression 3,4,5. We have previously reported ISB 2001 as a first in class trispecific T cell engager (TCE) targeting BCMA and CD38 with a superior potency to a single Tumor Associated Antigen TCE 6,7. TCEs are often not fully cross reactive with preclinical species for conducting GLP toxicology. For TCEs, a MABEL approach is often used to derive a starting dose 9, generally requiring multiple dose escalations with low probability of patient benefit before an efficacious dose is reached. As ISB 2001 lacks cynomolgus cross reactivity, we could have used a MABEL approach to derive the starting dose. Instead, we generated datasets employing in vitro and in vivo models for ISB 2001 and teclistamab (possessing a similar mode of action). A quantitative systems pharmacology (QSP) model 8 incorporating in vitro and in vivo data was developed and used to predict clinically efficacious doses for both molecules. The QSP model demonstrated that inclusion of in vivo data was key to the best prediction of actual clinical efficacy for teclistamab. Based on this benchmarking, the ISB 2001 efficacious dose range and minimal pharmacologically active dose (MPAD) were derived. Further refinement of the starting dose was performed by introducing step-up dose administration to mitigate the risk of cytokine release syndrome and to reduce the concentration of the first administration of ISB 2001 below the threshold of cytokine release in vitro. This strategy led to the first full dose, which was approximately two-fold lower than the MPAD but 60-fold greater than the MABEL-based starting dose, and therefore significantly reduced patient exposure to sub-therapeutic doses. This approach for the selection of the starting dose for the First-in-Human clinical study was accepted by the U.S. FDA and the Human Research Ethics Committee in Australia. The utility of QSP modelling in the development of trispecific TCEs has been demonstrated before 10,11. However, to our knowledge this is the first time that a starting dose in clinical studies of a trispecific TCE, lacking species cross-reactivity and therefore a GLP toxicology preclinical package, has been derived based on integrated preclinical data analysis utilizing a QSP model. Clinical evaluation of ISB 2001 is ongoing in a phase I dose escalation and dose expansion study in subjects with relapsed/refractory MM (NCT05862012).

Dose Escalation of ISB 1342, a Novel CD38xCD3 Bispecific Antibody, in Patients with Relapsed / Refractory Multiple Myeloma (RRMM)

Introduction: ISB 1342 is a humanized CD38xCD3 bispecific T-cell engager using Ichnos proprietary Bispecific Engagement by Antibodies based on the T cell receptor (BEAT ®) platform, designed to simultaneously bind CD38 on multiple myeloma (MM) cells and CD3ε on T cells, to induce tumor killing. This mechanism of action is different from existing monospecific CD38 targeting therapies and was designed to overcome resistance to daratumumab in MM. ISB 1342 exhibits potent killing of the primary MM cells and MM cell lines with low sensitivity to daratumumab ( Pouleau B. et al. Blood 2023; 142 (3): 260-273). We report here, the updated findings from the weekly dose-escalations of intravenous (IV) and subcutaneous (SC) injections of an ongoing, single-agent phase 1 study (NCT03309111) of ISB 1342 in patients with RRMM. Methods: Adult patients with RRMM that relapsed after or were refractory to prior therapies, including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 antibody; received ISB 1342 on a weekly (QW) schedule by IV or SC injection with a priming dose on the first day in 2 parallel dose-escalation schemas. Patients had measurable disease per the International Myeloma Working Group (IMWG) criteria (2016). Dose escalation in the QW schedule began at 0.2/0.3 mg/kg priming/treatment dose and followed a “3 + 3” design. The primary study objectives are to determine the maximum tolerated dose (MTD) and select a recommended phase 2 dose (RP2D) of ISB 1342. Secondary objectives includ evaluation of anti-myeloma activity, pharmacokinetics (PK), pharmacodynamics, and immunogenicity of ISB 1342. Results: As of July 18, 2023, based on ongoing clinical database, 39 subjects had received weekly IV infusions of ISB 1342 in 8 dose-escalation groups from 0.2/0.3 mg/kg to 4.0/16.0 mg/kg as priming/treatment dose; and 7 additional subjects had received weekly SC injections at 2.0/8.0 mg/kg. Two different formulations have been tested in SC group. Median number of cycles administered was 2. The majority were male (57%) and white (74%); 13% were Black or African American. The median age was 69 years (range, 54-76) and the median time since diagnosis was 6.6 years (range, 2.8-22.2). The median number of prior anti-myeloma lines of therapy was 6 (range 1-12). Twenty-one (67%) subjects were considered to be triple-class refractory and 18 (48%) penta-drug refractory. Forty-one (89%) subjects experienced treatment-related adverse events (TRAEs) of any grade. Most TRAEs were grade 1-2, including infusion related reactions (37%), cytokine release syndrome (CRS, 34%, all grade 1or 2), anemia (24%), neutropenia (24%), and thrombocytopenia (17%). Five subjects in SC group (71% of SC) had injection site reaction, all grade 1 or 2. Grade 3 or higher TRAEs occurring in more than 5% of subjects were infusion related reaction (no grade 4), anemia (no grade 4), neutropenia, leukopenia. No Grade 5 TRAE was observed. After QW IV infusion, ISB 1342 serum concentration peaked at the end of infusion and then showed bi-exponential decline. ISB 1342 serum exposures increased in a dose linear fashion across the tested IV infusion dose range. The limited PK data after SC injection suggest slow presentation of ISB 1342 into the systemic circulation leading to lower C max and delayed T max relative to IV. Transient increases in serum cytokines were observed within 24 hours after ISB 1342 dosing, including IFNg, TNFa, IL-2, IL-6 and IL-10. Transient increases in T-cell activation were observed by flow cytometry at 24-48 hours after ISB 1342 dosing at 1.0 / 4.0 μg/kg and above, based on increased expression of CD69 on peripheral blood CD4+ and CD8+ T-cell populations (Figure 1). Comparison of the available data from subjects treated at 2 / 8 μg/kg (Cohort 109) indicated reduced T-cell activation following SC compared to IV administration of ISB 1342. The efficacy signals observed in Cohorts 108 and 109 are consistent with the estimates of the lower boundary of the predicted efficacious dose range using a quantitative systems pharmacology (QSP) model based on preclinical data. Updated clinical data, including response rates and safety data, will be present at the meeting. Conclusions: Treatment with ISB 1342 was well tolerated at higher dose levels evaluated. Observed CRS events were moderate. No increased risk of infection has been observed . Updated safety, efficacy, biomarker and PK data will be presented.

A Phase 1, First-in-Human, Dose Escalation and Dose-Expansion Study of a BCMAxCD38xCD3 Targeting Trispecific Antibody ISB 2001 in Subjects with Relapsed/Refractory Multiple Myeloma

Background Despite advances, multiple myeloma (MM) remains an incurable disease and resistance mechanisms are emerging. ISB 2001 has been designed to overcome those resistance mechanisms inherent to current MM therapies such as monoclonal antibodies (e.g. daratumumab), BCMA-targeted therapies, proteasome inhibitors(PIs), or immunomodulatory drugs(IMiDs). ISB 2001 is a first in class Trispecific T cell engager (TCE) that redirects cytotoxic T cells to BCMA and/or CD38 expressing myeloma cells. Simultaneous targeting of the two tumor associated antigens (TAA) may increase binding to tumor cells through avidity even with heterogeneous or low expression of the targeted TAA (BCMA or CD38). Therefore, it may overcome tumor escape mechanisms associated with low tumor antigenic expression inherent to current MM targeted therapies. Preclinically, ISB 2001 has demonstrated improved activity when compared to other BCMA or CD38 targeted molecules either alone or in combination across different MM models (M. Pihlgren et al., Blood. 140, 858-859 (2022), M. Pihlgren et al., Cancer Res. 83, 2970-2970 (2023)). Study design and methods This first-in-human, multicenter, open label Phase 1 study is assessing the safety, tolerability, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of ISB 2001 in relapsed/refractory multiple myeloma (RRMM) patients. This study will enroll subjects treated with prior IMiDs, PIs, and anti-CD38 therapies, or intolerant of, established therapies known to provide benefit (prior BCMA therapies, or prior transplantation and cellular therapies allowed).be conducted in two parts (Part 1: Dose escalation and Part 2: Dose expansion) (Figure 1). Criteria for enrollment in this study include patients with RRMM with measurable disease who have been treated with an anti-CD38 antibody, IMiDs, PIs either in combination or as a single agent, and /or intolerant of established therapies known to provide clinical benefit. ISB 2001 is being administered weekly by subcutaneous (SC) injection in 28-day cycles, with two step-up doses on cycle 1 day 1 (C1D1) and C1D4 before administering the full dose on C1D8. The first-in-human dose was derived by integrating both in vitro and in vivo preclinical data benchmarked to teclistamab utilizing a quantitative systems pharmacology (QSP) model guided approach. The fractionated step-up dosing before administering the full dose on C1D8 was included in every cohort preemptively to minimize the potential cytokine release syndrome (CRS) risk. The study will follow a rapid titration single patient dose escalation design until the completion of cohort 3 or until one of the safety conversion criteria are met, whichever comes first, after which the design will be converted to a conventional 3+3 dose escalation. The primary outcome measure is the number of DLTs during the first 28 days after the first study treatment (ie, Cycle 1) in each cohort. Once a potential safe and efficacious dose range is identified, the Part 2 expansion will start enrollment in two arms at two putative recommended Part 2 doses with 1:1 randomization with at least 20 patients per arm (FDA Project Optimus). The primary objective of Part 2 is to confirm safety and to select the recommended Phase 2 dose (RP2D). Secondary endpoints include PK parameters, immunogenicity incidence, ORR, CRR and DOR based on IMWG criteria. Exploratory endpoints include levels of cytokines, chemokines, sCD38, sBCMA, APRIL and BAFF in peripheral blood, immunophenotyping in peripheral blood and bone marrow, and MRD negative rate. Approximately 40 patients will be enrolled in Part 1 at sites in Australia, France and the United States. A total of approximately 40 evaluable patients will be enrolled in Part 2. The study is currently open for enrollment (Clinicaltrials.gov identifier: NCT05862012).

New Tocilizumab (TCZ) Dosing Guidance for T-Cell Engaging Bispecific Antibody-Related Cytokine Release Syndrome (CRS) in Patients (pts) with Relapsed/Refractory (R/R) B-Cell Non-Hodgkin Lymphoma (B-NHL): Insights from Pooled Clinical Trial Safety Experience and Quantitative Clinical Pharmacology (qCP) Analyses

Background: Mosunetuzumab (Mosun), approved for treatment of pts with R/R follicular lymphoma (FL) and ≥2 prior therapies, and glofitamab (Glofit), approved for treatment of pts with R/R diffuse large B-cell lymphoma, or large B-cell lymphoma arising from FL, and ≥2 prior therapies, are CD20xCD3 T-cell engaging bispecific antibodies that redirect T cells to eliminate B cells. CRS is a common on-target adverse event observed with bispecific antibodies and associated with exposure. TCZ, a humanized anti-interleukin-6 (IL-6) receptor, is often used for CRS management. TCZ dosing recommendations derived from CAR T-cell studies (Le et al. Oncologist 2018) may not be optimal for bispecific antibody-treated pts. Using TCZ clinical usage patterns in Mosun- or Glofit-treated pts with R/R B-NHL, qCP, and cytokine analyses, we explored a new TCZ dosing regimen for CRS management (for pts >30 kg body weight). Methods: Pooled safety data from seven Phase I/II studies evaluating Mosun or Glofit in pts with R/R B-NHL were analyzed. CRS was graded using ASTCT criteria (Lee et al. Biol Blood Marrow Transplant 2019). Modeling was used to predict TCZ concentrations (conc) and soluble IL-6 receptor (s-IL6R) occupancy over time, following administration of different TCZ dosing regimens in a subset of pts. Downstream cytokine pharmacodynamic responses (IL-6 and C-reactive protein [CRP]) were evaluated graphically post-TCZ dosing. Results: Data from 733 Mosun- and 772 Glofit-treated pts across different Mosun/Glofit dose levels were analyzed; of these, 232 (31.7%) and 427 (55.3%) pts, respectively, had ≥1 CRS event, and 36/232 (15.5%) and 140/427 (32.8%) pts received TCZ for CRS management. CRS events were mainly Grade 1/2 and occurred during the first treatment cycle. Most pts who received TCZ for CRS received ≤2 doses of TCZ overall (Mosun: 94.4%; Glofit: 84.2%) ( Table), and 1 dose of TCZ for the management of a single CRS event (Mosun: 91.7%; Glofit: 84.9%). CRS resolution was achieved within 3 days of TCZ administration in 75.0% and 66.9% of Mosun- and Glofit-treated pts, respectively. By then, a reduction in IL-6 and CRP levels was also observed. In a prior pharmacokinetic (PK) analysis of TCZ in pts with CAR T-cell-associated CRS, predicted TCZ conc after administration of 4 intravenous (IV) TCZ doses of 8 mg/kg every 8 hours (q8h) was generally below 649 μg/mL, the observed maximum conc in healthy volunteers and “safety threshold” used by the FDA (Le et al. Oncologist 2018). qCP analyses of TCZ PK and s-IL6R data from 67 pts who received TCZ for CRS management following treatment with Mosun or Glofit indicated that this TCZ regimen may exceed the safety threshold, in part because maximum TCZ conc is one-third lower in pts with CAR T-cell-induced CRS vs bispecific antibody-induced CRS. In addition, typical bispecific antibody regimens involve multiple doses compared with a single CAR T-cell infusion, with the potential for multiple CRS events requiring TCZ treatment; therefore, TCZ accumulation must be considered. qCP simulations predicted that for 1 x 8 mg/kg dose, median duration of >90% s-IL6R saturation was 28 (range: 14-28) days ( Table). Furthermore, simulations indicated that ≤2 consecutive TCZ doses q8h per CRS event and a maximum of 3 TCZ doses within a 6-week time period maintain the TCZ conc below the FDA safety threshold, while ensuring sustained s-IL6R occupancy ( Table). Conclusions: qCP results and clinical experience in Mosun and Glofit studies support a TCZ dosing regimen of ≤2 IV doses of 8 mg/kg per CRS event administered q8h, not exceeding a total of 3 doses within a 6-week period. Further improvement in CRS management and symptom resolution with additional TCZ doses is unlikely given the predicted duration of s-IL6R occupancy and observed rapid decline in systemic inflammatory markers post dosing. This proposed TCZ dosing regimen reflects TCZ usage patterns in clinical trials evaluating Mosun and Glofit, and is included in their Summaries of Product Characteristics. In patients with R/R B-NHL receiving bispecific antibody treatment, TCZ is generally suitable for management of acute CRS, and balances risk-benefit for potential scenarios involving multiple TCZ administrations for pts with CRS recurrence. This recommendation considers TCZ safety factors, the unique PK properties of TCZ in this setting and the expected duration of activity based on pharmacological modeling of target binding (s-IL6R occupancy).

A mean-field description for the expansion kinetics of activated T cell populations.

When lymphocytes encounter their cognate antigen, they become activated and undergo a limited number of cell divisions during which they differentiate into memory or effector cells or die. While the dynamics of individual cells are often heterogeneous, the expansion kinetics at the population level are highly reproducible, suggesting a mean-field description. To generate a finite division destiny, we consider two scenarios: Cells stop dividing after a certain number of iterations or their death rate increases with each cell division. The dynamics of the combined system can be mapped to a partial differential equation, and for a suitable choice of the activation rate, we obtain simple analytical solutions for the total cell number and the mean number of divisions per cell which can well describe the signal-dependent T cell expansion kinetics from in vitro experiments. Interestingly, only the division cessation mechanism yields an expression for the division destiny that does not contradict experiments. We show that the generation-dependent decrease of the division rate in individual cells leads to a time-dependent decrease at the population level which is consistent with a "time-to-die" control mechanism for the division destiny as suggested previously. We also derive mean-field equations for the total cell number which provide a basis for implementing T cell expansion kinetics into quantitative systems pharmacology models for immuno-oncology and CAR-T cell therapies.

Experimental Models of Mitochondrial Dysfunction Disorders in the Pathogenesis of CNS Diseases on Zebrafish

Mitochondrial dysfunctions are associated with the pathogenesis of various brain disorders, including Alzheimer’s, Parkinson’s, Huntington’s, amyotrophic lateral sclerosis, Leigh syndrome and autism spectrum disorder. For the study of mitochondrial dysfunction and the development and testing of new therapeutic strategies, in vivo studies with zebrafish (Danio rerio) are of particular interest, due to their biological characteristics, practicality in laboratory maintenance, and high throughput. Here, we discuss genetic and pharmacological models of common mitochondrial dysfunctions and related neurological disorders in rodents and zebrafish, focusing of the growing utility of these fish in modeling mitochondrial pathogenesis of various CNS diseases.

Passive Immunotherapies Targeting Amyloid-β in Alzheimer's Disease: A Quantitative Systems Pharmacology Perspective.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by amyloid-β (Aβ) protein accumulation in the brain. Passive immunotherapies using monoclonal antibodies for targeting Aβ have shown promise for AD treatment. Indeed, recent US FDA approval of aducanumab and lecanemab, alongside positive donanemab Phase III results demonstrated clinical efficacy after decades of failed clinical trials for AD. However, the pharmacological basis distinguishing clinically effective from ineffective therapies remains unclear, impeding development of potent therapeutics. This study aimed to provide a quantitative perspective for effectively targeting Aβ with antibodies. We first reviewed the contradicting results associated with amyloid hypothesis and the pharmacological basis of Aβ immunotherapy. Subsequently, we developed a quantitative systems pharmacology (QSP) model that describes the non-linear progression of Aβ pathology and the pharmacologic actions of the Aβ-targeting antibodies. Using the QSP model, we analyzed various scenarios for effective passive immunotherapy for AD. The model revealed that binding exclusively to the Aβ monomer has minimal effect on Aβ aggregation and plaque reduction, therefore antibody affinity towards Aβ monomer is unwanted, as it could become a distractive mechanism for plaque reduction. Neither early intervention, high brain penetration, nor increased dose alone could yield significant improvement of clinical efficacy for antibodies targeting solely monomers. Antibodies that bind all Aβ species but lack effector function exhibited moderate effects in plaque reduction. Our model highlights the importance of binding aggregate Aβ species and incorporating effector functions for efficient and early plaque reduction, guiding the development of more effective therapies for this devastating disease. Significance Statement Despite previous unsuccessful attempts spanning several decades, passive immunotherapies utilizing monoclonal antibodies for targeting amyloid-beta (Aβ) have demonstrated promise with two recent FDA approvals. However, the pharmacological basis that differentiates clinically effective therapies from ineffective ones remains elusive. Our study offers a Quantitative Systems Pharmacology (QSP) perspective, emphasizing the significance of selectively targeting specific Aβ species and importance of antibody effector functions. This perspective sheds light on the development of more effective therapies for this devastating disease.

Genomic and Reverse Translational Analysis Discloses a Role for Small GTPase RhoA Signaling in the Pathogenesis of Schizophrenia: Rho-Kinase as a Novel Drug Target.

Schizophrenia is one of the most serious psychiatric disorders and is characterized by reductions in both brain volume and spine density in the frontal cortex. RhoA belongs to the RAS homolog (Rho) family and plays critical roles in neuronal development and structural plasticity via Rho-kinase. RhoA activity is regulated by GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs). Several variants in GAPs and GEFs associated with RhoA have been reported to be significantly associated with schizophrenia. Moreover, several mouse models carrying schizophrenia-associated gene variants involved in RhoA/Rho-kinase signaling have been developed. In this review, we summarize clinical evidence showing that variants in genes regulating RhoA activity are associated with schizophrenia. In the last half of the review, we discuss preclinical evidence indicating that RhoA/Rho-kinase is a potential therapeutic target of schizophrenia. In particular, Rho-kinase inhibitors exhibit anti-psychotic-like effects not only in Arhgap10 S490P/NHEJ mice, but also in pharmacologic models of schizophrenia (methamphetamine- and MK-801-treated mice). Accordingly, we propose that Rho-kinase inhibitors may have antipsychotic effects and reduce cognitive deficits in schizophrenia despite the presence or absence of genetic variants in small GTPase signaling pathways.

Deep reinforcement learning-based control of chemo-drug dose in cancer treatment

Background and objectiveAdvancement in the treatment of cancer, as a leading cause of death worldwide, has promoted several research activities in various related fields. The development of effective treatment regimens with optimal drug dose administration using a mathematical modeling framework has received extensive research attention during the last decades. However, most of the control techniques presented for cancer chemotherapy are mainly model-based approaches. The available model-free techniques based on Reinforcement Learning (RL), commonly discretize the problem states and variables, which other than demanding expert supervision, cannot model the real-world conditions accurately. The more recent Deep Reinforcement Learning (DRL) methods, which enable modeling the problem in its original continuous space, are rarely applied in cancer chemotherapy. MethodsIn this paper, we propose an effective and robust DRL-based, model-free method for the closed-loop control of cancer chemotherapy drug dosing. A nonlinear pharmacological cancer model is used for simulating the patient and capturing the cancer dynamics. In contrast to previous work, the state variables and control action are modeled in their original infinite spaces to avoid expert-guided discretization and provide a more realistic solution. The DRL network is trained to automatically adjust the drug dose based on the monitored states of the patient. The proposed method provides an adaptive control technique to respond to the special conditions and diagnosis measurements of different categories of patients. Results and conclusionsThe performance of the proposed DRL-based controller is evaluated by numerical analysis of different diverse simulated patients. Comparison to the state-of-the-art RL-based method, which uses discretized state and action spaces, shows the superiority of the approach in the process and duration of cancer chemotherapy treatment. In the majority of the studied cases, the proposed model decreases the medication period and the total amount of administrated drug, while increasing the rate of reduction in tumor cells.

Changes in cardiac-driven perivascular fluid movement around the MCA in a pharmacological model of acute hypertension detected with non-invasive MRI

Perivascular spaces mediate a complex interaction between cerebrospinal fluid and brain tissue that may be an important pathway for solute waste clearance. Their structural or functional derangement may contribute to the development of age-related neurogenerative conditions. Here, we employed a non-invasive low b-value diffusion-weighted ECG-gated MRI method to capture perivascular fluid movement around the middle cerebral artery of the anaesthetised rat brain. Using this method, we show that such MRI estimates of perivascular fluid movement directionality are highly sensitive to the cardiac cycle. We then show that these measures of fluid movement directionality are decreased in the angiotensin-II pharmacological model of acute hypertension, with an associated dampening of vessel pulsatility. This translational MRI method may, therefore, be useful to monitor derangement of perivascular fluid movement associated with cardiovascular pathologies, such as hypertension, in order to further our understanding of perivascular function in neurology.

Fluoroethylnormemantine (FENM) shows synergistic protection in combination with a sigma-1 receptor agonist in a mouse model of Alzheimer's disease

Fluoroethylnormemantine (FENM) is a Memantine derivative with anti-amnesic and neuroprotective activities showed in the Aβ25-35 pharmacological mouse model of Alzheimer's disease (AD). As AD is a complex multi-factorial neurodegenerative pathology, combination therapies relying on drugs acting through different pathways, have been suggested to more adequately address neuroprotection. As several agonists of the sigma-1 receptor (S1R), an intracellular chaperone, are presently in phase 2 or 3 clinical trials in neurodegenetrative diseases including AD, we examined the potentialities of S1R drug-based combinations with FENM, or Memantine. Aβ25-35-treated mice were treated with S1R agonists (PRE-084, Igmesine, Cutamesine) and/or FENM, or Memantine, during 7 days after intracerebroventricular administration of oligomerized Aβ25-35. Mice were then tested for spatial short-term memory on day 8 and non-spatial long-term memory on days 9–10, using the spontaneous alternation or passive avoidance tests, respectively. The FENM or Memantine combination with Donepezil, that non-selectively inhibits acetylcholinesterase and activates S1R, was also tested. The efficacy of combinations using maximal non-active or minimal active doses of S1R agonist or FENM was analyzed using calculations of the combination index, based on simple isobologram representation. Data showed that most of the FENM-based combinations led to synergistic protection against Aβ25-35-induced learning deficits, for both long- and short-term memory responses, with a higher efficiency on the latter. Memantine led to synergistic combination in short-term memory but poorly in long-term memory responses, with either PRE-084 or Donepezil. These study showed that drug combinations based on FENM and S1R agonists may lead to highly effective and synergistic protection in AD, particularly on short-term memory.

Artificial Intelligence for Quantitative Modeling in Drug Discovery and Development: An Innovation and Quality Consortium Perspective on Use Cases and Best Practices.

Recent breakthroughs in artificial intelligence (AI) and machine learning (ML) have ushered in a new era of possibilities across various scientific domains. One area where these advancements hold significant promise is model-informed drug discovery and development (MID3). To foster a wider adoption and acceptance of these advanced algorithms, the Innovation and Quality (IQ) Consortium initiated the AI/ML working group in 2021 with the aim of promoting their acceptance among the broader scientific community as well as by regulatory agencies. By drawing insights from workshops organized by the working group and attended by key stakeholders across the biopharma industry, academia, and regulatory agencies, this white paper provides a perspective from the IQ Consortium. The range of applications covered in this white paper encompass the following thematic topics: (i) AI/ML-enabled Analytics for Pharmacometrics and Quantitative Systems Pharmacology (QSP) Workflows; (ii) Explainable Artificial Intelligence and its Applications in Disease Progression Modeling; (iii) Natural Language Processing (NLP) in Quantitative Pharmacology Modeling; and (iv) AI/ML Utilization in Drug Discovery. Additionally, the paper offers a set of best practices to ensure an effective and responsible use of AI, including considering the context of use, explainability and generalizability of models, and having human-in-the-loop. We believe that embracing the transformative power of AI in quantitative modeling while adopting a set of good practices can unlock new opportunities for innovation, increase efficiency, and ultimately bring benefits to patients.

Towards a platform quantitative systems pharmacology (QSP) model for preclinical to clinical translation of antibody drug conjugates (ADCs)

A next generation multiscale quantitative systems pharmacology (QSP) model for antibody drug conjugates (ADCs) is presented, for preclinical to clinical translation of ADC efficacy. Two HER2 ADCs (trastuzumab-DM1 and trastuzumab-DXd) were used for model development, calibration, and validation. The model integrates drug specific experimental data including in vitro cellular disposition data, pharmacokinetic (PK) and tumor growth inhibition (TGI) data for T-DM1 and T-DXd, as well as system specific data such as properties of HER2, tumor growth rates, and volumes. The model incorporates mechanistic detail at the intracellular level, to account for different mechanisms of ADC processing and payload release. It describes the disposition of the ADC, antibody, and payload inside and outside of the tumor, including binding to off-tumor, on-target sinks. The resulting multiscale PK model predicts plasma and tumor concentrations of ADC and payload. Tumor payload concentrations predicted by the model were linked to a TGI model and used to describe responses following ADC administration to xenograft mice. The model was translated to humans and virtual clinical trial simulations were performed that successfully predicted progression free survival response for T-DM1 and T-DXd for the treatment of HER2+ metastatic breast cancer, including differential efficacy based upon HER2 expression status. In conclusion, the presented model is a step toward a platform QSP model and strategy for ADCs, integrating multiple types of data and knowledge to predict ADC efficacy. The model has potential application to facilitate ADC design, lead candidate selection, and clinical dosing schedule optimization.

41P Evaluation of ARX517: A next-generation anti-PSMA antibody drug conjugate for prostate cancer treatment, in preclinical enzalutamide-resistant and enzalutamide-sensitive pharmacology models and in toxicology models

41P Evaluation of ARX517: A next-generation anti-PSMA antibody drug conjugate for prostate cancer treatment, in preclinical enzalutamide-resistant and enzalutamide-sensitive pharmacology models and in toxicology models

Effect of Flax seed oil and Ashwagandharishta on various behavioral and pharmacological models of depression in Swiss albino mice

Abstract Background: Linum usitatissimum Linn., commonly known as flax seed or linseed, is known to be the richest plant source of alpha linoleic acid, an omega 3 fatty acid, whereas Ashwagandharishta, an Ayurvedic classical formulation, is the treatment remedy for Apasmara (epilepsy), Murchha (syncope), and Unmada (psychosis). Aim: The aim of the present study is to evaluate the antidepressant effect of flax seed oil and Ashwagandharishta on various behavioral and pharmacological models of depression. Materials and methods: The healthy Swiss albino mice were randomly divided into five groups: (i) Normal control i.e., water control, (ii) vehicle control - Milk control (7.4 mL/kg), (iii) flax seed oil with milk (2.6 mL/kg), (iv) Ashwagandharishta (6.5 mL/kg), and (v) flax seed oil with milk followed by Ashwagandharishta (2.6 mL/kg + 7.4 mL/kg+ 6.5 mL/kg). The antidepressant effect was evaluated using behavioral despair test, anti-reserpine test, and L-DOPA potentiation test. Results: Flax seed oil, when administered with milk as the vehicle was found to be an excellent antidepressant in behavioral model of depression [P < 0.001 [vs. control]; P < 0.05 [vs. milk]] as well as against reserpine-induced depression (P < 0.05). However, it failed to exert a similar effect in the L-DOPA potentiation test. Whereas Ashwagandharishta showed moderate antidepressant activity in behavior despair test (P < 0.05) as well as against reserpine-induced depression (P < 0.01) and failed to exert L-DOPA potentiating effect. Conclusion: Flax seed oil and Ashwagandharishta exhibit a significant antidepressant effect in various behavioral and pharmacological models of depression in Swiss albino mice.

Human retinal ganglion cell neurons generated by synchronous BMP inhibition and transcription factor mediated reprogramming

In optic neuropathies, including glaucoma, retinal ganglion cells (RGCs) die. Cell transplantation and endogenous regeneration offer strategies for retinal repair, however, developmental programs required for this to succeed are incompletely understood. To address this, we explored cellular reprogramming with transcription factor (TF) regulators of RGC development which were integrated into human pluripotent stem cells (PSCs) as inducible gene cassettes. When the pioneer factor NEUROG2 was combined with RGC-expressed TFs (ATOH7, ISL1, and POU4F2) some conversion was observed and when pre-patterned by BMP inhibition, RGC-like induced neurons (RGC-iNs) were generated with high efficiency in just under a week. These exhibited transcriptional profiles that were reminiscent of RGCs and exhibited electrophysiological properties, including AMPA-mediated synaptic transmission. Additionally, we demonstrated that small molecule inhibitors of DLK/LZK and GCK-IV can block neuronal death in two pharmacological axon injury models. Combining developmental patterning with RGC-specific TFs thus provided valuable insight into strategies for cell replacement and neuroprotection.

In-silico Assessment of Potent Immunomodulators from Pimpinella anisum and its Antioxidant Potential

New targets, effective substances, and safety in pharmacological models are highlighted by recent drug development. The study’s primary goal is to use an in-silico technique to determine the immunomodulatory potential of phytoconstituents from Pimpinella anisum. Several computer aided tool were utilized for in-silico. autodock vina is major free tool utilized to examine a drug discovery strategy based on the atomic-level screening of small compounds and proteins and protein-ligand interactions. Basic docking phases include ligand position, orientation, and binding affinities. The current methodology includes ligand choice, protein prep, target, ligand optimisation, target active binding site analysis, and binding affinity. SwissADME was used to assess the pharmacokinetic parameters, and Lipinski’s “rules” were used to assess drug similarity. In the current research paper six ligands such as P-anisaldehyde, trans-anethole, cis-anethole, estragole, and linalool were dock against two proteins 1M48 and 1P9M. Molecular docking studies suggest strong binding affinity between -6.9 to -4.2 in case on 1M48 and -6.2 to -4.7 in case of 1P9M. Further antioxidant potential of P. anisum using several solvents was determined. In-vitro antioxidant study and in-silico screening suggested that P. anisum ethanolic extract can be contributed in immunomodulation

A quantitative systems pharmacology model for certolizumab pegol treatment in moderate-to-severe psoriasis.

Psoriasis is a chronic immune-mediated inflammatory systemic disease with skin manifestations characterized by erythematous, scaly, itchy and/or painful plaques resulting from hyperproliferation of keratinocytes. Certolizumab pegol [CZP], a PEGylated antigen binding fragment of a humanized monoclonal antibody against TNF-alpha, is approved for the treatment of moderate-to-severe plaque psoriasis. Patients with psoriasis present clinical and molecular variability, affecting response to treatment. Herein, we utilized an in silico approach to model the effects of CZP in a virtual population (vPop) with moderate-to-severe psoriasis. Our proof-of-concept study aims to assess the performance of our model in generating a vPop and defining CZP response variability based on patient profiles. We built a quantitative systems pharmacology (QSP) model of a clinical trial-like vPop with moderate-to-severe psoriasis treated with two dosing schemes of CZP (200 mg and 400 mg, both every two weeks for 16 weeks, starting with a loading dose of CZP 400 mg at weeks 0, 2, and 4). We applied different modelling approaches: (i) an algorithm to generate vPop according to reference population values and comorbidity frequencies in real-world populations; (ii) physiologically based pharmacokinetic (PBPK) models of CZP dosing schemes in each virtual patient; and (iii) systems biology-based models of the mechanism of action (MoA) of the drug. The combination of our different modelling approaches yielded a vPop distribution and a PBPK model that aligned with existing literature. Our systems biology and QSP models reproduced known biological and clinical activity, presenting outcomes correlating with clinical efficacy measures. We identified distinct clusters of virtual patients based on their psoriasis-related protein predicted activity when treated with CZP, which could help unravel differences in drug efficacy in diverse subpopulations. Moreover, our models revealed clusters of MoA solutions irrespective of the dosing regimen employed. Our study provided patient specific QSP models that reproduced clinical and molecular efficacy features, supporting the use of computational methods as modelling strategy to explore drug response variability. This might shed light on the differences in drug efficacy in diverse subpopulations, especially useful in complex diseases such as psoriasis, through the generation of mechanistically based hypotheses.