The Predictive Value of Non-Clinical Testing

Maximum Duration of Clinical Trial

Recommended Minimum Duration of Repeated-Dose Toxicity Studies to Support Clinical Trials

Rodents

Non-rodents

Up to 2 weeks

2 weeks^a

2 weeks^a

Between 2 weeks and 6 months

Same as clinical trial^b

Same as clinical trial^b

Longer than 6 months

6 months^b,c

9 months^b,c,d

^a In the United States, extended single-dose toxicity studies can replace two week studies to support single-dose human trials.

^b In some circumstances, clinical trials longer than three months can start, if data are available from a 3-months rodent and a 3-months non-rodent study. On a case-by-case basis, this extension can be supported by chronic, in-life and necropsy data.

^c There can be cases where children are the primary population, and where existing animal studies have identified developmental concerns. In these cases, it can be appropriate to do long-term toxicity testing in juvenile animals.

^d In the  EU, studies in non-rodents for six months are considered acceptable. However, where studies with a longer duration have been conducted, it is not appropriate to conduct an additional study of six months.

Duration of Indicated Treatment

Rodent

Non-Rodent

Up to 2 weeks

1 month

1 month

More than 2 weeks to 1 month

3 months

3 months

More than 1 month to 3 months

6 months

6 months

More than 3 months

6 months^a

9 months^a,b

^a There can be cases where children are the primary population, and where existing animal studies have identified developmental concerns. In these cases, it can be appropriate to do long-term toxicity testing in juvenile animals ^b In the EU, studies in non-rodents for six months are considered acceptable. However, where studies with a longer duration have been conducted, it is not appropriate to conduct an additional study of six months.