Reference
Glossary
Common terms, A to Z.
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- 3Rs
- Replace, reduce and refine the use of animals in research and testing.
A
- ADMET
- Absorption, distribution, metabolism, excretion and toxicity of a compound.
- Adverse outcome pathway (AOP)
- A structured chain of events from a molecular initiating event to an adverse outcome. Used to organize evidence from NAMs.
C
- C-Path NAMs-DC
- Critical Path Institute's precompetitive coalition of NAM developers, launched in May 2026 to align on validation and qualification.
- Complement-ARIE
- NIH Common Fund program to develop, validate and standardize NAMs. First awards in March 2026.
- Context of use (COU)
- The specific question, setting and decision a method is meant to support. Regulatory acceptance is tied to it.
D
- DART
- Developmental and reproductive toxicity.
- Defined approach
- A fixed combination of data sources and a set interpretation procedure that yields a prediction, used in OECD guidelines such as skin sensitization.
- DILI
- Drug-induced liver injury, a leading cause of clinical failures and market withdrawals.
- Drug Development Tool (DDT)
- A method FDA can qualify for a context of use so sponsors can rely on it without re-justifying it each time.
E
- EURL ECVAM
- The EU reference laboratory for alternatives to animal testing, at the Joint Research Centre.
F
- FDA Modernization Act 2.0
- US law (December 2022) that removed the statutory animal-testing requirement for new drugs.
- FDA Modernization Act 3.0
- Bill directing FDA to update its regulations to match the 2022 law. Passed both chambers as different bills; final Senate action pending as of October 2026.
- FIFRA
- The US federal pesticide law, administered by EPA.
I
- In chemico
- Cell-free chemical reactivity assays.
- In silico
- Computational methods, from QSAR and read-across to PBPK, QSP and machine learning.
- iPSC
- Induced pluripotent stem cells: reprogrammed adult cells that can be turned into many human cell types.
- IQ MPS Affiliate
- Pharma industry group within the IQ Consortium that works on MPS adoption, benchmarking and regulatory engagement.
- ISTAND
- FDA's Innovative Science and Technology Approaches for New Drugs, a qualification route for novel drug development tools. Permanent since 2026.
M
- Microphysiological system (MPS)
- An engineered in vitro system that recreates tissue or organ function, often with fluid flow.
- MIDD
- Model-informed drug development: using models such as PBPK and QSP to inform development decisions.
N
- NAMs
- New approach methodologies: non-animal or animal-sparing methods to assess safety, efficacy and pharmacokinetics.
- NHP
- Nonhuman primate.
- NICEATM
- US interagency center for evaluating alternative test methods. Now a division of NIH ORIVA.
O
- OECD Test Guideline
- An internationally agreed test method that supports mutual acceptance of data across member countries.
- Organ-on-chip
- A microfluidic device that cultures human cells under flow to mimic organ-level function.
- Organoid
- A self-organizing 3D tissue grown from stem cells that reproduces features of an organ.
- ORIVA
- NIH Office of Research Innovation, Validation, and Application, formally launched in June 2026.
P
- PBPK
- Physiologically based pharmacokinetic modeling, which predicts drug concentrations in organs over time.
Q
- QSAR
- Quantitative structure-activity relationship: predicting activity or toxicity from chemical structure.
- QSP
- Quantitative systems pharmacology: mechanistic models that link drug action to clinical effect.
- Qualification
- A regulator's formal conclusion that a tool is fit for a stated context of use.
R
- REACH
- The EU regulation covering registration, evaluation, authorization and restriction of chemicals.
- Read-across
- Predicting a chemical's properties from data on structurally or biologically similar chemicals.
S
- Spheroid
- A simple 3D cell aggregate, often used for liver and tumor models.
T
- TSCA
- US Toxic Substances Control Act. Since 2016 it requires EPA to promote alternatives to vertebrate animal testing.
U
- UKCVAM
- The planned UK Centre for the Validation of Alternative Methods.
V
- Validation
- Evidence that a method is reliable and relevant for a defined purpose.
- VQN
- The Complement-ARIE validation and qualification network, organized with FNIH.
W
- Weight of evidence (WoE)
- Combining several data sources to reach a safety conclusion instead of relying on a single test.