What is it? Why is it important?

A Suspected Unexpected Serious Adverse Reaction (SUSAR) is a SAE that is:

  • Suspected to be related to the product under investigation (IMP)
  • Unexpected, as the event has not yet been described in terms of its nature, intensity or frequency (e.g. based on the RSI: IB for non-licensed IMPs, product information for licensed MPs)


SUSARs are subject to expedited reporting, meaning that the event must be reported within a given timeframe.


A SUSAR in a double-blind study might require unblinding in order to establish a potential relationship with the product under investigation (IMP).


In order to prevent participants from being disqualified from the study, unblinding procedures must prevent the disclosure of the study’s treatment allocation (e.g. SP-INV, study staff). In order to treat participants with a SUSAR, the Site-INV must know the treatment allocation (e.g. treatment group or placebo)

What do I need to do?

As a Site-INV:

  • Report all SAEs to the SP-INV within 24 hours of awareness
  • If a SAE qualifies as a SUSAR, the SP-INV will require additional details needed to complete the SUSAR reporting form (CIOMS)


As a SP-INV:

  • Assess SAE expectedness based on the RSI
  • For SAEs that qualify as SUSARs, fill in the CIOMS form (e.g. based on reports provided by the Site-INV)
  • Report SUSARs occurred at Swiss study site to Swissmedic within:
    • 7 days, for fatal events
    • 15 days, for all other cases
  • Report to:


For category A studies, report all SUSARs to Swissmedic within 15 days (e.g. through the Pharmacovigilance (PV) drug safety department, or the PV unit at your hospital).


Do not delay expedited reporting due to the lack of required information (e.g. Site-INV to SP-INV, SP-INV to PV). Applicable follow-up reports can be forwarded as they become available.


In multi-centre Swiss studies:

  • The coordinating Site-INV might also take on SUSAR reporting responsibilities to participating local EC(s)
  • A list of all SUSARs that have occurred at all study sites (including international sites) are summarised in the annual safety report


SUSARs documentation and reporting is mandatory during the course of a study. The defined reporting period for a particular study is documented in the study protocol (e.g. please refer to the protocol for the definition of your study reporting period). Usually it is mandatory once the participant has signed the ICF until:

  • Study termination (e.g. last study participant at last study visit), or
  • The end of some predefined safety follow-up period (e.g. as defined in the study protocol)


Where can I get help?

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

External Links

Swissethics – see in particular

  • Templates and checklists / Notification
    • SAE medicinal product

Swissmedic – see in particular

  • Information sheets
    • BW101_20_002e_MB Safety of Medicines
    • BW101_10_003e_AA Instruction for reporting during the course of a study
    • BM101_10_002e_MB FAQ on clinical trials with medicinal products
  • Human medicine
    • Clinical trials on medicinal products
    • Safety measures in clinical trials


ICH GCP E6(R2) – see in particular guidelines

  • 4.11 Safety reporting
  • 6.8 Safety assessment

Swiss Law

ClinO – see in particular article

  • Art. 41 Documentation and reporting of SUSAR


  • BASEC - Business Administration System for Ethics Committees
  • CIOMS - The Council for International Organizations of Medical Sciences
  • ClinO - Clinical Trials Ordinance
  • CTU – Clinical Trials Unit
  • EC – Ethics Committee
  • FAQ – Frequently Asked Questions
  • IB – Investigator’s Brochure
  • ICF – Informed Consent Form
  • ICH GCP – International Council for Harmonisation - Good Clinical Practice
  • IMP – Investigation medicinal Product
  • PV - Pharmacovigilance
  • RSI - Reference Safety Information
  • SAE – Serious Adverse Event
  • Site-INV – Site Investigator
  • SP-INV – Sponsor Investigator
  • SUSAR – Suspected Unexpected Serious Adverse Reaction
Conduct ↦ Safety ↦ Medicinal Product Safety Reporting ↦ Suspected Unexpected Serious Adverse Reaction

Provides some background knowledge and basic definitions

Basic Protocol
Basic Statistics
Basic Monitoring
Basic Drug or Device

Starts with a study idea

Ends after having assessed and evaluated study feasibility

Concept Protocol
Concept Statistics
Concept Drug or Device

Starts with confidence that the study is feasible

Ends after having received ethics and regulatory approval

Development Protocol
Development Statistics
Development Drug or Device

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

Starts with participant recruitment

Ends after the last participant has completed the last study visit

Conduct Protocol
Conduct Statistics
Conduct Drug or Device

Starts with last study visit completed

Ends after study publication and archiving

Completion Protocol
Completion Statistics
Completion Drug or Device
Current Path (click to copy): Conduct ↦ Safety ↦ Medicinal Product Safety Reporting ↦ Suspected Unexpected Serious Adverse Reaction

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