Maria Malamatari

Quantitative medicine supports modern drug development and regulatory decision‐making by integrating non‐clinical and clinical data to inform dose selection, trial optimization, and extrapolation across populations and benefit–risk assessment. The Medicines and Healthcare products Regulatory Agency (MHRA) has adopted quantitative approaches across the product lifecycle within a risk‐proportionate regulatory framework. Internationally, the ICH M15 guideline provides a harmonized framework for planning, evaluation and documentation of model‐informed drug development (MIDD) evidence which is aligned with MHRA practice. This perspective describes the application of quantitative medicine to UK regulatory decision‐making using two case studies: sugemalimab (Eqjubi) in oncology and lecanemab (Leqembi) in Alzheimer's disease. The case studies are assessed using ICH M15 concepts, including context of use, model influence, and consequence of a wrong decision. For sugemalimab, quantitative pharmacokinetic modeling supported a high‐impact dosing decision with clinically meaningful consequences of a wrong decision requiring proportionate scrutiny and mitigation of uncertainty. For lecanemab, multiple quantitative models with lower individual influence supported interpretation of pharmacokinetic variability, biomarkers, and clinical outcomes within the overall benefit–risk assessment. These case studies demonstrate how quantitative models can support decisions with differential impact ranging from critical dosing decisions to interpretation of complex data. Regulatory policy that is aligned with ICH M15 can be used to support the use of quantitative medicine to link complex modeling approaches with regulatory decision‐making and enable patient access to medicines.

This report summarizes the proceedings for Day 3 of the workshop titled "Physiologically Based Biopharmaceutics Modeling (PBBM) Best Practices for Drug Product Quality: Regulatory and Industry Perspectives". This day focused on the current and future drug product quality applications of PBBM from the innovator and generic industries as well as the regulatory agencies perspectives. The presentations, which included several case studies, covered the applications of PBBM in generic drug product development, applications of virtual bioequivalence trials to support formulation bridging and the utility of absorption modeling in clinical pharmacology assessments. In addition, recent progress in the prediction of colon absorption and in vivo performance of extended-release drug products was shared. The morning session was concluded by representatives from FDA, ANVISA, MHRA, Health Canada, EMA, and PMDA giving their perspectives on the application of PBBM in regulatory submissions. The afternoon breakout sessions focused on four parallel topics: 1) PBBM in generic drug product development; 2) virtual bioequivalence trials applications; 3) safe space and extrapolation; and 4) regional absorption and modified release PBBM applications. This allowed the participants to engage in in-depth discussions of best practices as well to identify key points of consideration to allow further progress on the applications of PBBM.

Due to limited non‐clinical and clinical data, European guidance recommends to discontinue breastfeeding when taking albendazole. The aim of this study was to consider the use of PBPK modeling to support the expected exposure in breastfed infants. A fully mechanistic PBPK approach was used to provide quantitative predictions of albendazole and its main active metabolite, albendazole sulfoxide, concentrations in plasma and breast milk of lactating women. The model predicted the exposure in adults and the large food effect, however, it does not predict all the clinical data for the exposure in children. Milk/plasma ratio predictions were also largely over‐predicted for this lipophilic compound, but not for the less lipophilic metabolite. Predictions using the observed ratio and a worse‐case exposure based on C_max predictions, suggest doses to children through milk will be low. However, more clinical data are required before full exposure predictions can be made to breastfed infants.

The proceedings from the 30th August 2023 (Day 2) of the workshop "Physiologically Based Biopharmaceutics Models (PBBM) Best Practices for Drug Product Quality: Regulatory and Industry Perspectives" are provided herein. Day 2 covered PBBM case studies from six regulatory authorities which provided considerations for model verification, validation, and application based on the context of use (COU) of the model. PBBM case studies to define critical material attribute (CMA) specification settings, such as active pharmaceutical ingredient (API) particle size distributions (PSDs) were shared. PBBM case studies to define critical quality attributes (CQAs) such as the dissolution specification setting or to define the bioequivalence safe space were also discussed. Examples of PBBM using the credibility assessment framework, COU and model risk assessment, as well as scientific learnings from PBBM case studies are provided. Breakout session discussions highlighted current trends and barriers to application of PBBMs including: (a) PBBM credibility assessment framework and level of validation, (b) use of disposition parameters in PBBM and points to consider when iv data are not available, (c) conducting virtual bioequivalence trials and dealing with variability, (d) model acceptance criteria, and (e) application of PBBMs for establishing safe space and failure edges.

This Article shares the proceedings from the August 29th, 2023 (day 1) workshop "Physiologically Based Biopharmaceutics Modeling (PBBM) Best Practices for Drug Product Quality: Regulatory and Industry Perspectives". The focus of the day was on model parametrization; regulatory authorities from Canada, the USA, Sweden, Belgium, and Norway presented their views on PBBM case studies submitted by industry members of the IQ consortium. The presentations shared key questions raised by regulators during the mock exercise, regarding the PBBM input parameters and their justification. These presentations also shed light on the regulatory assessment processes, content, and format requirements for future PBBM regulatory submissions. In addition, the day 1 breakout presentations and discussions gave the opportunity to share best practices around key questions faced by scientists when parametrizing PBBMs. Key questions included measurement and integration of drug substance solubility for crystalline vs amorphous drugs; impact of excipients on apparent drug solubility/supersaturation; modeling of acid-base reactions at the surface of the dissolving drug; choice of dissolution methods according to the formulation and drug properties with a view to predict the in vivo performance; mechanistic modeling of in vitro product dissolution data to predict in vivo dissolution for various patient populations/species; best practices for characterization of drug precipitation from simple or complex formulations and integration of the data in PBBM; incorporation of drug permeability into PBBM for various routes of uptake and prediction of permeability along the GI tract.

Physiologically based biopharmaceutics modeling (PBBM) is used to elevate drug product quality by providing a more accurate and holistic understanding of how drugs interact with the human body. These models are based on the integration of physiological, pharmacological, and pharmaceutical data to simulate and predict drug behavior in vivo. Effective utilization of PBBM requires a consistent approach to model development, verification, validation, and application. Currently, only one country has a draft guidance document for PBBM, whereas other major regulatory authorities have had limited experience with the review of PBBM. To address this gap, industry submitted confidential PBBM case studies to be reviewed by the regulatory agencies; software companies committed to training. PBBM cases were independently and collaboratively discussed by regulators, and academic colleagues participated in some of the discussions. Successful bioequivalence "safe space" industry case examples are also presented. Overall, six regulatory agencies were involved in the case study exercises, including ANVISA, FDA, Health Canada, MHRA, PMDA, and EMA (experts from Belgium, Germany, Norway, Portugal, Spain, and Sweden), and we believe this is the first time such a collaboration has taken place. The outcomes were presented at this workshop, together with a participant survey on the utility and experience with PBBM submissions, to discuss the best scientific practices for developing, validating, and applying PBBMs. The PBBM case studies enabled industry to receive constructive feedback from global regulators and highlighted clear direction for future PBBM submissions for regulatory consideration.

Theophylline and aminophylline (i.e., the soluble complex of theophylline with ethylenediamine) have been used in the treatment of respiratory diseases such as asthma and chronic obstructive pulmonary disease for more than 90 years. Theophylline’s narrow therapeutic index and side effects, as well as the discovery of more potent and safer bronchodilators, made it to fall out of favour with healthcare professionals and patients. New scientific knowledge on the molecular mechanism of action of theophylline, along with increasing clinical evidence suggest that theophylline should be exploited as an anti-inflammatory agent rather than a bronchodilator. This review covers the journey of theophylline from rise to fall and back to its potential re-emergence as a combination formulation with inhaled corticosteroids in the management of chronic inflammatory lung diseases. Several approaches to formulate theophylline either as a monotherapy or as a combination therapy for delivery to the lungs are presented.

Drug delivery systems (DDS) are formulations or devices that enable the introduction of a therapeutic into the body and its delivery to its target site, potentially enhancing its efficacy and safety. Advances in formulation approaches related to the enhancement of solubility, permeability and thus bioavailability of drugs have already been successfully implemented by the pharmaceutical industry. This review highlights the importance of formulations/DDS in the clinical development and the lifecycle of drug products. Examples from already authorised drug products have been used to showcase how the development of appropriate formulations/DDS could deliver drugs to the site of action (e.g., pulmonary and nasal drug delivery) and enhance patient adherence to medication (e.g., long-acting injectables, 3D-printed tablets). Moreover, examples from authorised products have been provided to highlight how formulation can improve safety (e.g., liposomes, abuse-deterrent opioid formulations) and efficacy (e.g., albumin-based nanoparticles, permeation enhancers for oral delivery of peptides).

Nanoparticle-based therapeutics have been used in pulmonary formulations to enhance delivery of poorly water-soluble drugs, protect drugs against degradation and achieve modified release and drug targeting. This review focuses on the use of spray drying as a solidification technique to produce microparticles containing nanoparticles (i.e., nanoparticle (NP) agglomerates) with suitable properties as dry powders for inhalation. The review covers the general aspects of pulmonary drug delivery with emphasis on nanoparticle-based dry powders for inhalation and the principles of spray drying as a method for the conversion of nanosuspensions to microparticles. The production and therapeutic applications of the following types of NP agglomerates are presented: nanoporous microparticles, nanocrystalline agglomerates, lipid-based and polymeric formulations. The use of alternative spray-drying techniques, namely nano spray drying, and supercritical CO₂-assisted spray drying is also discussed as a way to produce inhalable NP agglomerates.