Multidrug resistance (MDR), which is mediated by multiple drug efflux ATP-binding cassette (ABC) transporters, is a critical issue in the treatment of acute leukemia, with permeability glycoprotein ...(P-gp), multidrug resistance-associated protein 1, and breast cancer resistance protein (i.e., ABCG2) consistently being shown to be key effectors of MDR in cell line studies. Studies have demonstrated that intrinsic MDR can arise as a result of specific gene expression profiles and that drug-induced overexpression of P-gp and other MDR proteins can result in acquired resistance, with multiple ABC transporters having been shown to be overexpressed in cell lines selected for resistance to multiple drugs used to treat acute leukemia. Furthermore, numerous anticancer drugs, including agents commonly used for the treatment of acute leukemia (e.g., doxorubicin, vincristine, mitoxantrone, and methotrexate), have been shown to be P-gp substrates or to be susceptible to efflux mediated by other MDR proteins, and multiple clinical studies have demonstrated associations between P-gp or other MDR protein expression and responses to therapy or survival rates in acute leukemia. Here we review the importance of MDR in cancer, with a focus on acute leukemia, and we highlight the need for rapid accurate assessment of MDR status for optimal treatment selection. We also address the latest research on overcoming MDR, from inhibition of P-gp and other MDR proteins through various approaches (including direct antagonism and gene silencing) to the design of novel agents or novel delivery systems for existing therapeutic agents, to evade cellular efflux.
Given the recent success of gene therapy modalities and the growing number of cell and gene-based therapies in clinical development across many different therapeutic areas, it is evident that this ...evolving field holds great promise for the unmet medical needs of patients. The recent approvals of Luxturna® and Zolgensma® prove that recombinant adeno-associated virus (rAAV)-based gene therapy is a transformative modality that enables curative treatment for genetic disorders. Over the last decade, Takeda has accumulated significant experience with rAAV-based gene therapies, especially in the early stage of development. In this review, based on the learnings from Takeda and publicly available information, we aim to provide a guiding perspective on Drug Metabolism and Pharmacokinetics (DMPK) substantial role in advancing therapeutic gene therapy modalities from nonclinical research to clinical development, in particular the characterization of gene therapy product biodistribution, elimination (shedding), immunogenicity assessment, multiple platform bioanalytical assays, and first-in-human (FIH) dose projection strategies.
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ABSTRACT
Purpose
The expression levels of several efflux drug transporters in the liver and kidney were evaluated across species to address potential roles of the transporters in species dependent ...excretion of drugs and their metabolites.
Methods
Four efflux transporters, namely MDR1/P-gp, BCRP/Bcrp, MRP2/Mrp2 and MRP3/Mrp3 in liver and kidney in three preclinical species and humans were quantified using targeted quantitative proteomics by isotope dilution nanoLC-MS/MS.
Results
In liver, the level of P-gp was highest in monkey and lowest in rat. The concentration of BCRP/Bcrp was highest in dog followed by monkey. MRP2/Mrp2 level was highest in monkey and rat, whereas MRP3/Mrp3 levels were similar in human, monkey and dog. In the kidney, the concentrations of MDR1/P-gp in human and monkey were roughly 2 to 3-fold higher than in rat and dog. In rat, BCRP/Bcrp concentrations were substantially higher than in any of the other species. MRP2/Mrp2 concentrations were similar across species, whereas expression of MRP3/Mrp3 was highest in rat.
Conclusion
Overall, the results indicated that the pattern of hepatic and renal expression of the transporters was quite species dependent. This information should be helpful in the estimation of transport mediated drug and metabolites excretion in liver and kidney across species.
This white paper provides updated International Transporter Consortium (ITC) recommendations on transporters that are important in drug development following the 3rd ITC workshop. New additions ...include prospective evaluation of organic cation transporter 1 (OCT1) and retrospective evaluation of organic anion transporting polypeptide (OATP)2B1 because of their important roles in drug absorption, disposition, and effects. For the first time, the ITC underscores the importance of transporters involved in drug‐induced vitamin deficiency (THTR2) and those involved in the disposition of biomarkers of organ function (OAT2 and bile acid transporters).
Ixazomib, the first oral proteasome inhibitor, is approved in combination with lenalidomide and dexamethasone for the treatment of patients with multiple myeloma (MM) who have received at least one ...prior therapy. Ixazomib is a selective, potent, and reversible inhibitor of the 20S proteasome, and preferentially binds to and inhibits the β5 chymotrypsin-like proteolytic site. Ixazomib absorption is rapid, with a median time to reach maximum plasma concentration of approximately 1 h post-dose. Ixazomib pharmacokinetics (PK) are adequately described by a three-compartment model (terminal half-life of 9.5 days) with first-order linear absorption (oral bioavailability of 58%). Plasma exposures of ixazomib increase in a dose-proportional manner. A high-fat meal decreases both the rate and extent of ixazomib absorption, supporting administration on an empty stomach. Population PK analyses demonstrated that no dose adjustment is required based on age, body size/weight, race, sex, mild-to-moderate renal impairment, or mild hepatic impairment. Results from dedicated studies indicate that a reduced starting dose (from 4 to 3 mg) is appropriate for patients with severe renal impairment, end-stage renal disease requiring dialysis, or moderate-to-severe hepatic impairment. Non-cytochrome P450 (CYP)-mediated metabolism appears to be the major clearance mechanism for ixazomib. Drug–drug interaction studies have shown no meaningful effects of strong inhibitors of CYP3A on ixazomib PK; however, the strong inducer rifampin caused a clinically relevant reduction in ixazomib exposure, supporting the recommendation to avoid concomitant administration of ixazomib with strong CYP3A inducers. Exposure–response analyses of data from the phase III TOURMALINE-MM1 registrational study demonstrate a favorable benefit–risk profile for the approved dose and regimen of weekly ixazomib 4 mg on days 1, 8, and 15 of each 28-day cycle.
Drug-induced liver injury (DILI) is a severe drug adverse response, which cannot always be reliably predicted in preclinical or clinical studies. Lack of observation of DILI during preclinical and ...clinical drug development has led to DILI being a leading cause of drug withdrawal from the market. As DILI is potentially fatal, pharmaceutical companies have been developing in vitro tools to screen for potential liver injury. Screens for physicochemical properties, mitochondrial function, and transport protein inhibition have all been employed to varying degrees of success. In vitro inhibition of the bile salt export pump (BSEP) has become a major risk factor for in vivo DILI predictions, yet discrepancies exist in which methods to use and the extent to which BSEP inhibition predicts clinical DILI. The presented work focuses on optimizing DILI predictions by comparing BSEP inhibition via the membrane vesicle assay and the hepatocyte-based BSEPcyte assay, as well as dual and triple liabilities. BSEP transport inhibition of taurcholic acids and glycocholic acids were similar for up to 29 drugs tested, in both the vesicle and hepatocyte-based assays. Positive and negative DILI predictions were optimized at a 50-µM cutoff value for 50 drugs using both NIH Livertox and PharmaPendium databases. Additionally, dual inhibition of BSEP and other efflux transporters (multidrug resistance-associated protein MRP2, MRP3, or MRP4) provided no observable predictive benefit compared with BSEP inhibition alone. Eighty-five percent of drugs with high molecular weight (>600 Da), high cLogP (>3), or a daily dose >100 mg and BSEP inhibition were associated with DILI. Triple liability of BSEP inhibition, high molecular weight, and high cLogP attained a 100% positive prediction rate.
Drug metabolism and pharmacokinetics (DMPK) is an important branch of pharmaceutical sciences. The nature of ADME (absorption, distribution, metabolism, excretion) and PK (pharmacokinetics) inquiries ...during drug discovery and development has evolved in recent years from being largely descriptive to seeking a more quantitative and mechanistic understanding of the fate of drug candidates in biological systems. Tremendous progress has been made in the past decade, not only in the characterization of physiochemical properties of drugs that influence their ADME, target organ exposure, and toxicity, but also in the identification of design principles that can minimize drug-drug interaction (DDI) potentials and reduce the attritions. The importance of membrane transporters in drug disposition, efficacy, and safety, as well as the interplay with metabolic processes, has been increasingly recognized. Dramatic increases in investments on new modalities beyond traditional small and large molecule drugs, such as peptides, oligonucleotides, and antibody-drug conjugates, necessitated further innovations in bioanalytical and experimental tools for the characterization of their ADME properties. In this review, we highlight some of the most notable advances in the last decade, and provide future perspectives on potential major breakthroughs and innovations in the translation of DMPK science in various stages of drug discovery and development.
This review highlights some of the most notable advances in the translation of DMPK science in drug discovery and development in the last decade and predicts future breakthroughs and innovations. Display omitted
The correlation between efficacious doses in human tumor-xenograft mouse models and the human clinical doses of approved oncology agents was assessed using published preclinical data and recommended ...clinical doses. For 90 approved small molecule anti-cancer drugs, body surface area (BSA) corrected mouse efficacious doses were strongly predictive of human clinical dose ranges with 85.6% of the predictions falling within three-fold (3×) of the recommended clinical doses and 63.3% within 2×. These results suggest that BSA conversion is a useful tool for estimating human doses of small molecule oncology agents from mouse xenograft models from the early discovery stage. However, the BSA based dose conversion poorly predicts for the intravenous antibody and antibody drug conjugate anti-cancer drugs. For antibody-based drugs, five out of 30 (16.7%) predicted doses were within 3× of the recommended clinical dose. The body weight-based dose projection was modestly predictive with 66.7% of drugs predicted within 3× of the recommended clinical dose. The correlation was slightly better in ADCs (77.7% in 3×). The application and limitations of such simple dose estimation methods in the early discovery stage and in the design of clinical trials are also discussed in this retrospective analysis.
Chimeric antigen receptor (CAR) T cell therapies have revolutionized the treatment of hematologic malignancies and have potentials for solid tumor treatment. To overcome limited CAR T cell ...infiltration to solid tumors, local delivery of CAR T cells is a practical strategy that has shown promising therapeutic outcome and safety profile in the clinic. It is of great interest to understand the impact of dosing routes on CAR T cell distribution, subsequent proliferation and tumor killing in a quantitative manner to identify key factors that contribute to CAR T efficacy and safety. In this study, we established mouse minimal physiologically-based pharmacokinetic (mPBPK) models combined with pharmacodynamic (PD) components to delineate CAR T cell distribution, proliferation, tumor growth, and tumor cell killing in the cases of pleural and liver tumors. The pleural tumor model reasonably captured published CAR T cellular kinetic and tumor growth profiles in mice. The mPBPK-PD simulation of a liver tumor mouse model showed a substantial increase in initial tumor infiltration and earlier CAR T cell proliferation with local hepatic artery delivery compared to portal vein and intravenous (i.v.) injections whereas portal vein injection showed little difference from i.v. administration, suggesting the importance of having the injection site close to tumor for maximal effect of non-systemic administration. Blood flow rate in the liver tumor was found to be a sensitive parameter for cellular kinetics and efficacy, indicating a potential role of tumor vascularization in the efficacy of CAR T cell therapies.
Ectoenzyme CD38 is increased on lymphocytes in response to an antigenic challenge and it is hypothesized that targeting these activated lymphocytes could ameliorate pathologic activities in ...autoimmune diseases. The cynomolgus monkey is an appropriate model for assessing potential effects of targeting CD38 in humans because these species exhibit similar expression profiles. TAK-079 is a human monoclonal antibody (IgG
) that binds to CD38 and lyses bound cells by complement-dependent cytotoxicity and antibody-dependent cell-mediated cytotoxicity. TAK-079 binds to monkey CD38 with an affinity at EC
4.5 nM, and the potential activity of TAK-079 was investigated in a monkey collagen-induced arthritis model of autoimmune disease. Prophylactic administration of TAK-079 (3 mg/kg i.v. weekly) was well tolerated and prevented arthritis development compared with vehicle-treated control animals, which exhibited progressive disease with radiographic damage and worsening clinical scores over the study course. Therapeutic treatment of arthritic monkeys with TAK-079 (3 mg/kg i.v. weekly) was also well tolerated and reduced disease progression and symptoms. Arthritis scores and joint swelling were significantly lower than the vehicle control, accompanied by decreases in blood levels of C-reactive protein, alkaline phosphatase, and natural killer, B, and T cells. Histopathology, morphometry, and radiology revealed significantly less joint damage in animals exposed prophylactically to TAK-079 treatment compared with vehicle-treated animals and significantly less damage in animals treated therapeutically with TAK-079 or dexamethasone (0.1 mg/kg oral gavage daily), illustrating potential disease-modifying activity. In conclusion, these data indicate that depletion of CD38-expressing cells could be a therapeutic mechanism for treating autoimmune diseases. SIGNIFICANCE STATEMENT: This study demonstrates that targeting CD38-expressing leukocytes with a cytolytic antibody can ameliorate autoimmune disease in cynomolgus monkeys. The study gives a unique perspective into this therapeutic strategy because the three other anti-CD38 cytolytic antibodies in clinical development (daratumumab, isatuximab, and MOR202) cannot be tested in similar models because they do not crossreact with CD38 expressed by new world primates.
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