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In the European Union, bioequivalence (BE) for narrow therapeutic index (NTI) drugs is currently demonstrated when the 90% confidence interval for the ratio of the population geometric means of the test and reference products for AUC, and in some cases for Cmax, falls within the acceptance range of 90.00% to 111.11%. However, meeting this requirement results in an increased difficulty of demonstrating BE and a need for clinical trials with larger subject sample sizes, especially for medium-to-high variability drugs. To address this challenge, a scaled average BE based on the reference product within-subject variability for narrowing the acceptance range of NTI drugs was recently proposed. However, this approach showed increased type I error (T1E), especially close to the cut-off point between the unscaled and scaled portions of the method. Based on simulations, this limitation can be overcome by predefining the protocol the path to be followed: either the fixed 90.00–111.11% acceptance range approach or the previously proposed scaled average BE approach with a slight adjustment of the one-sided significance level α to 0.042 for a 2 × 3 × 3 partial replicate design and without a lower cut-off point. This results in a mixed approach allowing to reduce the sample size whilst not inflating the T1E. [ABSTRACT FROM AUTHOR]

Keywords: 3Rs; carcinogenicity; human pharmaceuticals; ICHS1; regulatory assessment; weight of evidence EN 3Rs carcinogenicity human pharmaceuticals ICHS1 regulatory assessment weight of evidence 2341 2348 8 07/21/23 20230801 NES 230801 INTRODUCTION The global regulatory requirements for the assessment of the carcinogenic potential of pharmaceuticals provided for the conduct of long-term carcinogenicity studies in two rodent species, usually the rat and the mouse. The EU Safety Working Party represented the European Union (EU) in this respect on the first ICH meeting in Brussels in 1991.[2] Carcinogenicity testing was introduced as a requirement for pharmaceuticals between 1950 and 1970, and the introduction of "Good Laboratory Practice" by the Organization for Economic Cooperation and Development (OECD) in 1979 has led to standardization of the study design. Given the their extensive use of animals as well as the costs of these studies, it is in keeping with the mission of International Council on Harmonization of Technical Requirements of Pharmaceuticals for Human Use (ICH) to examine whether this practice requiring long-term carcinogenicity studies in two species could be reduced without compromising human safety. [Extracted from the article]

The current regulatory criterion for bioequivalence of narrow therapeutic index (NTI) drugs in the European Union requires that the 90% confidence interval for the ratio of the population geometric means of the test product compared with the reference for area under the plasma concentration‐time curve (AUC), and in certain cases maximum plasma drug concentration (Cmax), to be included within the tighter acceptance range of 90.00–111.11%. As a consequence, sponsors need to recruit a higher number of subjects to demonstrate bioequivalence and this may be seen as increasing the burden for the development of generics. This "one‐size‐fits‐all" criterion is particularly questionable when the within‐subject variability of the reference product is moderate to high. As an alternative, we propose a further refined statistical approach where the acceptance range is narrowed based on the within‐subject variability of the reference product of the NTI drug, similar to the one used for widening the standard 80.00–125.00% acceptance range for highly variable drugs. The 80.00–125.00% acceptance range is narrowed, only if the within‐subject variability is lower than 30%, down to the current NTI acceptance range of 90.00–111.11% when the within‐subject variability is 13.93% or lower. Examples within the current European Medicines Agency list of NTI drugs show a considerable reduction in required sample size for drugs like tacrolimus and colchicine, where the predicted within‐subject variability is 20–30%. In these cases, this approach is less sample size demanding without any expected increase in the therapeutic risks, since patients treated with reference products with moderate to high within‐subject variability are frequently exposed to bioavailability differences larger than 10%. [ABSTRACT FROM AUTHOR]

Scientific advice (SA) is an important tool offered by regulators to help developers generate robust evidence on a medicine's benefits and risks. Drawing on accumulated experience and looking at the SA provided by the European Medicines Agency in 2018 to advanced therapy medicinal products originally developed by public bodies, we discuss most commonly raised issues and the complexity and timings of the questions posed. Earlier and more frequent SA could help advanced therapy medicinal product developers to pre‐empt delays at the marketing authorisation stage. Carefully addressing quality and nonclinical issues before entering the pivotal phase of development will clear the path for a smooth clinical development and successful marketing authorisation. [ABSTRACT FROM AUTHOR]

Glioblastoma multiforme (GBM) is the most malignant form of brain tumors with dismal prognosis despite treatment by surgery combined with radiotherapy and chemotherapy. The neuropeptide Substance P (SP) is the physiological ligand of the neurokinin‐1 receptor, which is highly expressed in glioblastoma cells. Thus, SP represents a potential ligand for targeted alpha therapy. In this study, a protocol for the synthesis of SP labeled with the alpha emitter 225Ac was developed and binding affinity properties were determined. The effects of 225Ac‐DOTA‐SP were investigated on human glioblastoma cell lines (T98G, U87MG, U138MG) as well as GBM stem cells. A significant dose‐dependent reduction in cell viability was detected up to 6 days after treatment. Also, colony‐forming capacity was inhibited at the lower doses tested. In comparison, treatment with the conventional agent temozolomide showed higher cell viability and colony‐forming capacity. 225Ac‐DOTA‐SP treatment caused induction of late apoptosis pathways. Cells were arrested to G2/M‐phase upon treatment. Increasing doses and treatment time caused additional S‐phase arrest. Similar results were obtained using human glioblastoma stem cells, known to show radioresistance. Our data suggest that 225Ac‐DOTA‐SP is a promising compound for treatment of GBM. [ABSTRACT FROM AUTHOR]

The European Medicines Agency (EMA) revises its guideline on minimizing risk in first‐in‐human trials to reflect changing practice and in light of a recent tragic incident. [ABSTRACT FROM AUTHOR]