A substantial amendment (SA) is a change to the conduct of the clinical trial that has a significant impact on the safety of the subjects or the scientific value of the study.
Substantial amendment
Amendments may be made to the conduct of a clinical trial. These are substantial if they are likely to have an impact on the safety of the trial subjects, on the interpretation of the scientific documents in support of the conduct of the trial, or if they are otherwise significant. It is up to the sponsor to assess the substantiality of the amendment.
SA in the European Union
The sponsor shall submit the changes, along with a rationale, to the competent authorities and/or the ethics committees and wait for their approval before they can be implemented. If the amendment concerns information that is only assessed by the competent authorities, the sponsor should notify this change to the competent authorities only. The same applies for information that is assessed by ethics committees only, typically (depending on the countries concerned) information related to a clinical site, to the Patient Information Leaflet or Informed Consent Form, or to the investigators.