Substantial or non-substantial modification in clinical studies

[nocas]

Hello!

Can anyone tell me whether there is some guidance as to when to consider a modification to a clinical study protocol as substantial or non-substantial?

Thank you!

 

[FoGia]

ISO 14155 provides some guidance. I won't quote the standard here but in essence you have to look at impact of the modifications on the safety and the validity of your trial.