AAPS Journal最新文献

Antisense oligonucleotide (ASO) therapeutics present new opportunities for treating challenging-to-treat diseases. Prediction of concentration-time course in systemic circulation and tissues within the context of large molecule physiologically based pharmacokinetic (PBPK) modelling has proven to be useful in animal-to-human extrapolation and first-in-human dose selection. A human PBPK model was developed and verified using bepirovirsen clinical data to predict plasma pharmacokinetics (PK) and tissue concentrations. Liver and kidney partition coefficient ratios from monkey studies, corrected for plasma unbound fraction in monkeys and humans, informed bepirovirsen concentration predictions in the human liver and kidney. Liver and kidney partition coefficients were calculated to be 2147 and 2822, respectively. All predicted PK parameters in healthy volunteers (except t_max) were within two-folds of observed data. Predicted vs. observed clearance (L/h), AUC_0-inf (µg.h/mL) and C_max (µg/mL) for the 300 mg single dose in healthy volunteers were 2.94, 114.43, and 10.56 vs. 2.25, 136.6, and 6.5, respectively. The majority of observed plasma concentrations for all doses were within the 5th and 95th percentiles of the predictions. The evaluated model was used to predict the impact of moderate hepatic impairment on bepirovirsen PK in virtual patients. The predicted vs. observed bepirovirsen exposure in moderate hepatic impairment was 0.9 and 0.7-fold lower, respectively, compared with healthy volunteers. The PBPK model predicted the liver and kidney tissue C_max values to be 172 and 132 µg/mL, respectively. In conclusion, a PBPK modelling approach for bepirovirsen, an ASO, is presented in this article and offers opportunities for future applications to other oligonucleotide therapeutics.

The development of generic versions of Onivyde® (irinotecan liposome injection) requires a reliable and discriminative in vitro release test (IVRT) to ensure product quality and support regulatory approval. Conventional dialysis-based IVRT often is limited in maintaining sink conditions and is affected by membrane-related variability and batch inconsistency. To overcome these challenges, we developed an IVRT using Bio-Beads SM-2 Resin (BioBeads), which rapidly adsorb released free irinotecan via hydrophobic interactions. Key parameters, including BioBeads concentration, agitation speed and angle, temperature, and formulation concentration, were systematically optimized. Identified optimized conditions were 50 mg/mL BioBeads, vertical rotation at 10 rpm, 25°C, and an Onivyde® concentration of 45 µg/mL. Under these conditions, the method achieved > 90% drug release within 24 h with minimal liposomal disruption. Among all parameters, mechanical agitation had the greatest impact on release kinetics by promoting liposomal destabilization and cholesterol depletion. Using the similarity factor (f2) as a quantitative criterion, the method demonstrated high reproducibility and effectively distinguished between non-stressed and stressed formulations. Compared to dialysis-based approaches, this method more effectively maintains sink conditions, eliminates membrane-related diffusion limitations, and simplifies sample handling by avoiding separation steps. Overall, the BioBeads-based IVRT offers a practical, robust, and sensitive platform for accelerated release testing and quality control of liposomal irinotecan, with strong potential for use in generic drug development and regulatory evaluation.

Intestinal excretion (IE), one of the under-investigated mechanisms of drug elimination, has been identified as the loci of drug-drug interactions (DDIs) within the intestinal tract. Here, we employed a modified rat in situ intestinal perfusion model to examine of the drug clearance of apixaban, talinolol, and irinotecan in the short time drug recovery study. The influence of specific efflux transporter inhibitors, including P-glycoprotein (P-gp) inhibitor elacridar, multidrug resistance-associated protein 2 (Mrp2) inhibitor MK571, and breast cancer resistance protein (Bcrp) inhibitor KO143, on IE, systemic exposure and metabolite ratio were accessed using a 2.5-h constant-rate intravenous infusion. IE plays a major role in the elimination of apixaban (36 ± 14% of the total amount eliminated estimated using the sum of biliary, renal, and intestinal excretion), but only a minor role in the excretion of talinolol (11 ± 3.9%) and irinotecan (22 ± 3.1%). Efflux transporter inhibitors of P-gp/Mrp2 significantly reduced the apixaban's intestine clearance without substantially affecting its biliary excretion or metabolite ratio, accompanied by increased systemic exposure or plasma area under the curve (AUC). However, the systemic PKs of talinolol and irinotecan were not altered, likely due to low IE. The drug's IE was temperature- and dose-dependent but not intestinal segmental-dependent. The modified perfusion model provides a robust framework for characterizing intestinal clearance and assessing transporter-mediated interactions for drugs undergoing intestinal clearance following i.v. administration. Similar to other routes, intestinal clearance can be a critical elimination pathway, and apixaban is a suitable reference "victim" drug for intestinal clearance inhibition studies.

Liquid chromatography-mass spectrometry (LC-MS) is the standard instrumental procedure for quantitating nitrosamine drug substance-related impurities (NDSRIs) due to its superior specificity and sensitivity. Electrospray (ESI) is the most used ionization source in LC-MS. However, analytes can undergo fragmentation directly within the ESI source before reaching the collision cell. This phenomenon is known as in source fragmentation (ISF). To our knowledge, the impact of ISF on analytical procedure performance for NDSRI measurements has not been explored. Thus, here, we present a case study on an NDSRI (nitroso-bumetanide) to illustrate how efforts can be taken during analytical procedure development to minimize ISF while still achieving the analytical target profile (ATP) measurement goals. In addition, we share some thoughts about incorporating risk assessment and leveraging prior knowledge for analytical procedure development for NDSRI LC-MS technology-based testing purposes.

In February of 2024, the Product Quality Research Institute held a virtual workshop entitled "Model-Informed Drug Development (MIDD) Approaches in Pediatric Formulation Development." The workshop covered a range of topics related to pediatric formulation development and testing, including dissolution testing and applications to modeling drug absorption in developing pediatric patients. Workshop speakers reviewed the progress that has been made to advance our understanding of ontogeny related processes that drive interactions with product formulations and inform pediatric product development. They discussed recently constructed pediatric biorelevant models that provide more realistic information about drug dissolution in pediatric patients and their use in physiologically based models to produce data for regulatory submissions. Despite the progress, opportunities remain to expand the fund of knowledge on pediatric absorptive processes that will support the development of pediatric-friendly drug formulations.

Olink Target 48 Cytokine (Thermo Fisher Scientific) is a biomarker panel and assay kit frequently used to characterize the pharmacodynamic effects of novel therapeutics and predict treatment outcomes. We have assessed assay performance across four commercial laboratories to determine the consistency of results. Overall reliability of individual biomarkers and the performance of controls were also assessed, and data were used for an exploratory assessment of differential biomarker expression in patients with head and neck cancer or lung cancer, relative to healthy donors. Reproducibility between operators was found to be good for three of the four laboratories, although the median coefficient of variation between operators for laboratory 4 was above the threshold of acceptability (30%) in the first half of the study. Performance across serial dilutions was also good for all laboratories except laboratory 2. Overall, data were statistically concordant for all laboratories except laboratory 4. Olink sample and calibrator controls performed well, and 43 of the 45 biomarkers in the panel were found to have good or moderate reliability. In total, 21 biomarkers were found to be upregulated or downregulated in patients with cancer relative to healthy donors. This comprehensive evaluation supports the use of Olink Target 48 Cytokine for use in biomarker studies and clinical applications, and highlights the need for standardization in sample handling and assay execution across providers.

We developed a novel cassette-dosing pharmacokinetic (PK) evaluation method that combines antibody engineering with multiplex liquid chromatography-tandem mass spectrometry (LC-MS/MS). The antibody was engineered by introducing alanine mutations or insertions into the GPSVFPLAPSSK sequence on the CH1 domain of IgG1, thereby enabling clear differentiation and simultaneous measurement of multiple antibodies recognizing the same antigen. Twelve antibodies, one unmodified and eleven modified, were selected for this study and evaluated for assay performance and PK. The method was validated with intra-day and inter-day assay data, which demonstrated accuracy ranging from 70.3% to 128.4% and precision (%CV) less than or equal to 28.7% for all antibodies. The mouse PK profiles of modified antibodies after intravenous administration were comparable to that of the unmodified antibody, with no statistical differences in key PK parameters (t_1/2, C₀, AUC_last, and V_ss). These results indicate that the modifications had no substantial impact on PK profiles. Furthermore, cassette-dosing PK results were also consistent with those of single-dosing PK studies for six antibodies, indicating that there were no drug-drug interactions among antibodies. This method enables the efficient selection of lead/clinical candidates and the prediction of human PK for IgG1-type antibodies, which are the most widely used subtype in antibody therapeutics. Consequently, this novel approach complies with the 3Rs principle (Reduction, Refinement, and Replacement) in animal research and can substantially reduce costs in antibody drug development.

Assessment of product immunogenicity in clinical trials via characterization of the anti-drug antibody (ADA) response to the drug, is an important component of biological license applications (BLA). The clinical pharmacology review of immunogenicity focuses on the impact of ADA on pharmacokinetics (PK) based on data from three analysis datasets: Analysis Dataset (AD) for Subject Level data (ADSL), AD for Pharmacokinetic Concentrations (ADPC), and AD for Immunogenicity Specimens (ADIS). These datasets are derived from tabulation datasets that conform with the Clinical Data Interchange Standards Consortium (CDISC) Study Data Tabulation Model (SDTM) as requested by FDA and follow the CDISC Analysis Data Model (ADaM). Because no guidance is available on how to derive the ADIS dataset from the SDTM IS domain, BLAs submitted to the Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER) vary in the completeness and quality of their ADIS datasets. This challenge has been addressed by information requests that can extend time of the clinical pharmacology review of immunogenicity. We analyzed the availability and content of ADIS, ADPC, and ADSL datasets in 48 BLAs submitted to CDER between 2019 and 2022. 75% of BLAs had at least one type of dataset issue. 50% of all BLAs had data reporting issues specifically (data format issues and/or missing data), 17% had data structure issues (where immunogenicity data were not reported in the dataset where the reviewer expected it, and/or a dataset does not follow the ADaM basic data structure), and 8% had more than one type of dataset issue. Our findings suggest that the publication of clinical trial dataset specifications to support the clinical pharmacology review of immunogenicity data could improve the efficiency of the regulatory review of CDER BLAs.

Immunogenicity of monoclonal antibodies (mAbs) and other biotherapeutics remains a significant clinical challenge. The resulting anti-drug antibodies (ADAs) can neutralize the drug, accelerate its clearance, diminish efficacy, and potentially trigger hypersensitivity reactions via the formation of immune complexes (ICs). Current pharmacokinetic (PK) and ADA assays typically measure the drug or ADAs but provide limited information on IC structure, concentration, and duration of exposure in humans. While rat studies suggest larger ICs are rapidly cleared, human dynamics are less understood. This study investigated IC formation and clearance in patients enrolled in a terminated Phase 1 clinical trial of TYRP1-TCB, a novel T-cell engager. Analysis of patient samples revealed that six patients, treated with 0.4 mg every three weeks, developed ADAs, resulting in IC formation. These complexes were evaluated using size exclusion chromatography (SEC) and enzyme-linked immunosorbent assay (ELISA). ICs of diverse sizes were detected, with larger ICs cleared faster than smaller ones. These findings highlighted the need for appropriate PK assays in clinical studies. Total drug PK assays alone may overestimate drug exposure during an immune response, as they do not distinguish between binding competent and ADA-bound drug. In contrast, active drug assays do not give any information on circulating drug that can no longer bind to the target. Neither approach gives information on circulating ICs, which may represent the majority of the drug administered following a strong ADA response. This study underscores the importance of understanding ADA and IC dynamics for ensuring the safe and effective use of biotherapeutics.

Oxybutynin (OXB), an antimuscarinic agent used to treat overactive bladder, is available as oral tablets, transdermal patches, and transdermal gels. In a recent clinical study involving the transdermal products, ~ 15-fold higher OXB exposures were observed during and following occlusion (i.e., creating a significant barrier to transepidermal water loss) potentially elevating the risk of adverse events. To better understand and predict these occlusion effects, a transdermal in vitro-in vivo correlation (IVIVC) model was developed. In vitro OXB permeation from a transdermal gel was characterized based on in vitro permeation tests using excised human skin without occlusion or with occlusion application from 7 to 10 h. OXB disposition was characterized by using digitized data from literature following intravenous administration. In vivo OXB absorption was characterized by using deconvolution techniques on data from a clinical study under similar occlusion conditions. In vitro and in vivo flux and occlusion-related parameters were correlated in an IVIVC model. While the in vitro flux showed a mean lag time of 3.5 h (21% variability), in vivo flux had no lag. The skin exit rate constant was similar in vitro (0.17 h^-1, 61% variability) and in vivo (0.16 h^-1, 79% variability). In vivo occlusion effects increased on average by 18-fold and 30-fold during occlusion and after occlusion removal, respectively. The IVIVC model predictions adequately described the observed data with precisely estimated parameters. This work establishes a new framework for developing transdermal IVIVCs and demonstrates the feasibility of predicting in vivo OXB concentrations while accounting for occlusion effects.