Table 3.

The guidelines for the assessment of pharmacology and toxicology for ACI in the EU, US and Japan.

Name of guidelines	Type of assessment	Animal model	Duration post treatment	Content of assessment
Guideline on human cell-based medicinal products, EU, 2007 and Reflection paper on in-vitro cultured chondrocyte containing products for cartilage repair of the knee, EU, 2010	Pharmacodynamics	•Goat, sheep, horse and other appropriate animal (mini pig, cow etc.) •The number of animals in studies should allow for robust analysis	•Long enough (Not specified)	•Initial proof of study with in vitro cell culture •First in vivo proof of study, (small animal study, large animal number) •Pivotal non-clinical study (large animal) Ex) Proof of regeneration and repair
	Biodistribution/Pharmacokinetics	•Relevant animal model (Consideration that product is not sufficiently physically retained)	N.D.	•To demonstrate the cell alteration due to the factors in the new environment
	Mechanical property	N.D.	•Long enough (Not specified)	•The long pivotal study should include testing for biomechanical property
	Validation of clinical evaluation	N.D.	•Long enough (Not specified)	•Validation of MRI method as structural endpoint, Proof of regeneration and repair
	Local/Systemic Toxicology	•Relevant animal model	•Much longer than standard toxicity study.	•To demonstrate the interaction with surrounding normal tissue •The study may be combined with efficacy study. Ex) Single and repeated toxicity and Local Tolerance, etc.
	Tumorigenicity	N.D.	N.D.	•To perform with cells that are at the limit of routine cell culture or even beyond that limit. •Tissues found to contain applied cells or expressed products during the biodistribution studies should also be analyzed with special emphasis during tumorigenicity studies.
	Genotoxicity	N.D.	N.D.	•Genotoxicity should be evaluated only in the case in which a product directly influences DNA or other chromosomal material.
Guidance for FDA Reviewers and Sponsors Content and Review of Chemistry, Manufacturing, and Control (CMC) Information for Human Somatic Cell Therapy Investigational New Drug Applications (INDs), US, 2008 and Guidance for Industry Preparation of IDEs and INDs for Products Intended to Repair or Replace Knee Cartilage, US, 2011	Pharmacodynamics	•Large animal (Goat, Sheep and Horse) •The number of studies •Appropriate number is relevant structural and biological characteristics of the product	•Minimum of one year	•Biological response To demonstrate that a product's components have the potential to contribute to the clinical efficacy •Durability To evaluate the ability of resistance of wear, degradation, withstand physiological relevant loads over time, etc. •Dose response To assess the dose response with cell number, material constituent etc. as anatomic and biomechanical considerations
	Biodistribution/Pharmacokinetics	N.D.	N.D.	•Lesion size and location To assess the mimicking what will be studied clinically
	Mechanical property	N.D.	N.D.	•To assess the withstand static/dynamic loading, method of fixation,
	Validation of clinical evaluation	N.D.	N.D.	•To reduce the number of animal sacrifices at each time point, it may be appropriate to provide interim validate the MRI or arthroscopic assessment.
	Local/Systemic Toxicology	N.D.	N.D.	•Local: interaction and degradation •Systemic: Migration
	Tumorigenicity	N.D.	N.D.	•Potential for tumorigenicity or inappropriate differentiation of cellular products exists within or outside of the articular space.
The evaluation index of medical device in next generation (Evaluation index about regeneration of articular cartilage), Japan, 2010 and Ensuring the safety and quality of human autologous cell-based or tissue-based pharmaceutical or medical device, Japan, 2012	Local/Systemic Toxicology	N.D.	N.D.	•Local: interaction and degradation Systemic: Migration
	Tumorigenicity	N.D.	N.D.	•Potential for tumorigenicity or inappropriate differentiation of cellular products exists within or outside of the articular space.
	Mechanical property	N.D.	N.D.	•To test the viscoelastic property, compatibility of load bearing, sliding property
	Local/Systemic Toxicology	N.D.	N.D.	•Local: To demonstrate the interaction with surrounding normal tissue, no undesirable transformation of the cell •Systemic: To assess the degradation, reabsorption and potential of ectopic tissue formation
	Tumorigenicity	•Knock-out animal (Injection)The model without chromosomal aberration is favorable (Karyotype)	N.D.	•To test the incidence of tumor and hypertrophy (Karyotype analysis, Injection, Soft-agar analysis)
	Immunogenicity	N.D.	N.D.	•To assess the undesirable immunoreaction caused by product or expression of cytokine

N.D.: not described.

US, the United States; EU, the European Union; ACI, Autologous Chondrocyte Implantation; MRI, Magnetic resonance imaging; ICRS, International Cartilage Repair Society.