Perspectives on the evaluation and adoption of complex in vitro models in drug development: Workshop with the FDA and the pharmaceutical industry (IQ MPS Affiliate).

Complex in vitro models (CIVM) offer the potential to improve pharmaceutical clinical drug attrition due to safety and/ or efficacy concerns. For this technology to have an impact, the establishment of robust characterization and qualifi­cation plans constructed around specific contexts of use (COU) is required. This article covers the output from a workshop between the Food and Drug Administration (FDA) and Innovation and Quality Microphysiological Systems (IQ MPS) Affiliate. The intent of the workshop was to understand how CIVM technologies are currently being applied by pharma­ceutical companies during drug development and are being tested at the FDA through various case studies in order to identify hurdles (real or perceived) to the adoption of microphysiological systems (MPS) technologies, and to address evaluation/qualification pathways for these technologies. Output from the workshop includes the alignment on a working definition of MPS, a detailed description of the eleven CIVM case studies presented at the workshop, in-depth analysis, and key take aways from breakout sessions on ADME (absorption, distribution, metabolism, and excretion), pharmacology, and safety that covered topics such as qualification and performance criteria, species differences and concordance, and how industry can overcome barriers to regulatory submission of CIVM data. In conclusion, IQ MPS Affiliate and FDA scientists were able to build a general consensus on the need for animal CIVMs for preclinical species to better determine species concordance. Furthermore, there was acceptance that CIVM technologies for use in ADME, pharmacology and safety assessment will require qualification, which will vary depending on the specific COU.

Liver microphysiological systems development guidelines for safety risk assessment in the pharmaceutical industry.

The liver is critical to consider during drug development because of its central role in the handling of xenobiotics, a process which often leads to localized and/or downstream tissue injury. Our ability to predict human clinical safety outcomes with animal testing is limited due to species differences in drug metabolism and disposition, while traditional human in vitro liver models often lack the necessary in vivo physiological fidelity. To address this, increasing numbers of liver microphysiological systems (MPS) are being developed, however the inconsistency in their optimization and characterization often leads to models that do not possess critical levels of baseline performance that is required for many pharmaceutical industry applications. Herein we provide a guidance on best approaches to benchmark liver MPS based on 3 stages of characterization that includes key performance metrics and a 20 compound safety test set. Additionally, we give an overview of frequently used liver injury safety assays, describe the ideal MPS model, and provide a perspective on currently best suited MPS contexts of use. This pharmaceutical industry guidance has been written to help MPS developers and end users identify what could be the most valuable models for safety risk assessment.

A robust in vitro screening assay to identify NF-kappaB inhibitors for inflammatory muscle diseases.

Specific therapies are not available for inflammatory muscle diseases. We and others have shown that the pro-inflammatory NF-kappaB pathway is highly activated in these conditions. Since NF-kappaB is an important therapeutic target, we decided to utilize an in vitro screening assay to identify potential inhibitors that block TNF-alpha induced NF-kappaB activation in a C2C12 muscle line stably expressing an NF-kappaB luciferase reporter gene. Upon evaluation of multiple anti-inflammatory agents in undifferentiated myoblasts as well as differentiated myotubes , we found different levels of inhibition depending on the state of differentiation. Interestingly, we found that some drugs that are known to inhibit NF-kappaB in immune cells were not effective in muscle cells. Drug toxicity was assessed for using an MTT cell viability assay, and the validity of the luciferase assay was verified by immunostaining for NF-kappaB nuclear translocation in myoblasts. In conclusion, we have determined the optimal assay conditions for detecting potentially valuable NF-kappaB inhibitors for the first time in a muscle cell line that may have significant therapeutic potential for inflammatory muscle diseases.