Comparative study for the IMI2-NeuroDeRisk project on microelectrode arrays to derisk drug-induced seizure liability.

Introduction: In the framework of the IMI2-NeuroDeRisk consortium, three in vitro electrophysiology assays were compared to improve preclinical prediction of seizure-inducing liabilities.
Methods: Two cell models, primary rat cortical neurons and human induced pluripotent stem cell (hiPSC)-derived glutamatergic neurons co-cultured with hiPSC-derived astrocytes were tested on two different microelectrode array (MEA) platforms, Maestro Pro (Axion Biosystems) and Multiwell-MEA-System (Multi Channel Systems), in three separate laboratories. Pentylenetetrazole (PTZ) and/or picrotoxin (PTX) were included in each plate as positive (n = 3-6 wells) and ≤0.2% DMSO was used as negative controls (n = 3-12 wells). In general, concentrations in a range of 0.1-30 μM were tested, anchored, when possible, on clinically relevant exposures (unbound C _max ) were tested. Activity thresholds for drug-induced changes were set at 20%. To evaluate sensitivity, specificity and predictivity of the cell models, seizurogenic responses were defined as changes in 4 or more endpoints. Concentration dependence trends were also considered.
Results: Neuronal activity of 33 compounds categorized as positive tool drugs, seizure-positive or seizure-negative compounds was evaluated. Acute drug effects (<60 min) were compared to baseline recordings. Time points < 15 min exhibited stronger, less variable responses to many of the test agents. For many compounds a reduction and cessation of neuronal activity was detected at higher test concentrations. There was not a single pattern of seizurogenic activity detected, even among tool compounds, likely due to different mechanisms of actions and/or off-target profiles. A post-hoc analysis focusing on changes indicative of neuronal excitation is presented.
Conclusion: All cell models showed good sensitivity, ranging from 70 to 86%. Specificity ranged from 40 to 70%. Compared to more conventional measurements of evoked activity in hippocampal slices, these plate-based models provide higher throughput and the potential to study subacute responses. Yet, they may be limited by the random, spontaneous nature of their network activity.
Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest. All co-authors are employed by pharmaceuticals or biotechnology companies interested in developing novel in vitro assays to improve human health and in assessing methodological improvements to this end, without bias. This research was conducted in the context of the IMI2: NeuroDeRisk non-competitive industry-academic consortium funded by the European Medicines Agency. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.
(Copyright © 2023 Merck Sharp & Dohme LLC., a subsidiary of Merck & Co., Inc., Rahway, NJ, USA, The Author(s). Published by Elsevier Inc. All rights reserved.)