A Two-Way Proposal for the Determination of Bioequivalence for Narrow Therapeutic Index Drugs in the European Union.

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.

Evaluation of a Proposed Approach for the Determination of the Bioequivalence Acceptance Range for Narrow Therapeutic Index Drugs in the European Union.

Bioequivalence (BE) of products containing narrow therapeutic index (NTI) drugs in the European Union is currently established by demonstrating that the 90% confidence interval for the ratio of the population geometric means of the test compared to the reference product's AUC, and in certain cases Cmax, is included within the tighter acceptance range of 90.00−111.11%. An alternative criterion, consisting of narrowed limits based on the within-subject variability of the reference product, was recently proposed. Its performance for a three-period partial replicate design was tested by simulation in terms of power to show BE, type I error (T1E) and sample size requirements. A new condition, a constraint on the test-to-reference geometric mean ratio (cGMR) to be contained within the range of 90.00−111.11%, was also tested. The probability of showing BE when the products differ more than 10% was increased, but only if the reference product's within-subject variability was moderate-to-high. The inclusion of the additional cGMR limited this. An increase in the T1E (<7%) was observed. The inclusion of the additional cGMR did not change the highest inflation of the T1E. Finally, a significant sample size reduction was observed and the inclusion of the cGMR usually did not increase the required sample size.

A Proposed Approach for the Determination of the Bioequivalence Acceptance Range for Narrow Therapeutic Index Drugs in the European Union.

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%.

Towards a better use of scientific advice for developers of advanced therapies.

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.

In vitro evaluation of 225 Ac-DOTA-substance P for targeted alpha therapy of glioblastoma multiforme.

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 225 Ac was developed and binding affinity properties were determined. The effects of 225 Ac-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. 225 Ac-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 225 Ac-DOTA-SP is a promising compound for treatment of GBM.

Nonclinical data supporting orphan medicinal product designations: lessons from rare neurological conditions.

Here, we provide an in-depth literature and experience-based review of nonclinical models and data used to support orphan medicinal product designations (OMPDs) in rare neurodegenerative conditions. The Committee for Orphan Medicinal Products (COMP) of the European Medicines Agency updates its assessment processes based on scientific progress and aims to provide transparent criteria required in support of OMPDs. Thus, we also provide an updated analysis of existing nonclinical models in selected conditions and identify key features of nonclinical studies that are crucial for the support of OMPDs. This could not only inform future drug development in rare neurological conditions, but also indicate areas where the use of nonclinical models can be made more efficient.

Promoting Safe Early Clinical Research of Novel Drug Candidates: A European Union Regulatory Perspective.

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.

Impact analysis of ICH S9 on non-clinical development of anticancer drugs.

Cancer presents a major healthcare challenge worldwide, with several millions new cases a year, and represents a therapeutic area with a high need for new drugs. To respond to this, the parties of the International Conference for Harmonization agreed in 2007 to develop a guideline on nonclinical requirements for oncology therapeutics' development (ICH S9), which came into effect in early 2010. This guideline includes recommendations to facilitate and accelerate the development and marketing of cancer therapeutic agents for serious and life threatening malignancies and aims to address this need through a refinement and a reduction in the use of experimental animals, following the 3Rs principles. To assess the impact of ICH S9 on drug development and reduction of animal use, we performed an analysis of Marketing Authorization Applications at the European Medicines Agency relevant to the period in which the development of the guideline was approaching the final steps and its early implementation period. From the analysis performed, a consistent trend towards a decrease in the average number of non-clinical studies performed (-40.7%) and number of animals used per development program (-58.1%) for new chemical entities has been detected, highlighting increasing compliance by companies to the recommendations of ICH S9.

Critical review on the Environmental Risk Assessment of medicinal products for human use in the centralised procedure.

In this article we analyse the Environmental Risk Assessment (ERA) of 59 medicinal products for human use authorised in the EU through the centralised procedure between 2011 and 2012, to establish whether company submissions are compliant with the European Medicines Agency (EMA) guideline and complete in terms of data and study reports provided. The most frequent questions raised by EU regulatory authorities are described, together with an evaluation of the presence and quality of ERA-related information in published regulatory assessment documents. The results of this review show recent improvement in ERA-related data presented in regulatory assessment documents available to the public while also highlighting a need to develop further guidance on environmental issues in order to assist applicants improve their ERA dossiers and overcome current shortcomings.