What is it? Why is it important?

Swissmedic and EC must initially approve an amendment prior to its implementation.

Exceptions are:

  • Safety amendments, where measures must be implemented with the aim to protect the safety of study participants
  • Non-substantial amendments

The approval process is identical to an initial submission, such as:

  • Question / answer sessions between EC/Swissmedic and SP-INV
  • Comparable response timelines
  • The issue of official decision letters by EC/Swissmedic

An EC/Swissmedic decision letter either states that:

  • The amendment is approved and can be implemented
  • The amendment can only be approved under the condition that certain required adaptations are made
  • The amendment is rejected and cannot be implemented


Response timelines for substantial amendments include for:

  • ClinO studies:
    • 30 days for EC
    • 30 days for Swissmedic
    • 30 days for FOPH
  • ClinO-MD studies:
    • 30 days for EC
    • 38 days for Swissmedic, which can be extended by 7 days
  • HRO projects:
    • 30 days for EC

What do I need to do?

As a SP-INV consider EC / Swissmedic processing timelines, and:

  • Plan your amendment accordingly
  • Prepare for potential question/answer sessions

Once EC/RA approved:

  • Implement the amendment
  • Inform concerned study sites and respective Site-INVs
  • Ensure outdated documents are replaced by amended ones:
    • Archive outdated documents, and ensure they are clearly identified as such (e.g. date of archiving)
    • Preserve outdated electronic documents in read-only format. This guarantees that changes between documents remain traceable
  • Train staff on the amendment and ensure the amendment is correctly implemented


For Swissmedic approved studies:

  • An amendment that entails a change in the SP-INV requires that a corresponding approval must be received at least 30 days prior the take-over
  • Upon EC/RA approval, train study staff on documents and procedures affected by the amendment

Where can I get help?

Your local CTU can support you with experienced staff regarding this topic

Swiss Law

FEDLEX – laws are available online under numbers

  • 810.305 ClinO
  • 810.306 ClinO-MD
  • 810.301 HRO

ClinO – see in particular articles

  • Art. 29 Changes IMP and other studies to EC
  • Art. 34 Changes IMP studies to Swissmedic
  • Art. 55-56 Changes transplant studies

ClinO-MD – see in particular articles

  • Art. 15 Amendments to EC
  • Art. 20 Amendments to Swissmedic

HRO – see in particular article and annex

  • Art. 18 Changes
  • Annex 2 EC submission
  • ClinO – Clinical Trials Ordinance
  • ClinO-MD – Ordinance on Clinical Trials with Medical Devices
  • CTU – Clinical Trials Unit
  • EC – Ethics Committee
  • EC/RA – Ethics Committee / Regulatory Authorities
  • FEDLEX – Publication Platform for Federal Laws
  • FOPH – Federal Office of Public Health
  • HRO - Human Research Ordinance
  • IMP – Investigational Medicinal Product
  • Site-INV – Site Investigator
  • SP-INV – Sponsor Investigator
Conduct ↦ Ethics and Laws ↦ Amendment ↦ Approval

Provides some background knowledge and basic definitions

Basic Protocol
Basic Statistics
Basic Monitoring
Basic Drug or Device
Basic Biobanking

Starts with a study idea

Ends after having assessed and evaluated study feasibility

Concept Protocol
Concept Statistics
Concept Drug or Device
Concept Biobanking

Starts with confidence that the study is feasible

Ends after having received ethics and regulatory approval

Development Protocol
Development Statistics
Development Drug or Device
Development Biobanking

Starts with ethics and regulatory approval

Ends after successful study initiation

Set-Up Protocol
Set-Up Ethics and Laws
Set-Up Statistics
Set-Up Quality and Risk
Set-Up Drug or Device
Set-Up Biobanking

Starts with participant recruitment

Ends after the last participant has completed the last study visit

Conduct Protocol
Conduct Statistics
Conduct Drug or Device
Conduct Biobanking

Starts with last study visit completed

Ends after study publication and archiving

Completion Protocol
Completion Statistics
Completion Drug or Device
Completion Biobanking
Current Path (click to copy): Conduct ↦ Ethics and Laws ↦ Amendment ↦ Approval

Please note: the Easy-GCS tool is currently under construction.