Risk categories A, B and C under ClinO
Swiss clinical trials are sorted into risk categories A, B and C, with the hazard potential rising from A to C. The category decides which authorisations you need: category A needs the ethics committee alone, categories B and C need the committee plus Swissmedic. Categorise before you build the dossier.
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Why categorisation comes first
The category drives three things at once: which bodies authorise the trial, how deep the review goes, and how much safety reporting and monitoring the sponsor owes. Get it wrong and you do not merely amend the file, you resubmit it.
Category A
Category A covers trials with an authorised medicinal product used within the terms of its Swiss authorisation, so within the approved indication, dose and route. The risk beyond routine care is limited, and the competent cantonal ethics committee is the only authorising body. Most investigator-initiated comparisons of established therapies land here.
Category B
Category B covers trials with an authorised product used outside the terms of its authorisation, and trials with an unauthorised product whose safety profile is already acceptably characterised. Both the ethics committee and Swissmedic authorise. In practice this is the largest category for industry-sponsored trials of products already in clinical development.
Category C
Category C covers trials with a higher hazard potential: gene therapy and products containing genetically modified organisms, and unauthorised products with a limited safety database. The ethics committee and Swissmedic both authorise, and the Swissmedic review is the most thorough, with close attention to manufacturing, preclinical data and the risk management measures at the site.
| Category | What it covers | Who authorises | Safety reporting | Monitoring |
|---|---|---|---|---|
| A | Authorised product, used within its authorisation | Ethics committee | SUSARs to the committee, annual safety report | Risk based, usually lighter |
| B | Authorised product off-label, or unauthorised product with an acceptable profile | Ethics committee and Swissmedic | SUSARs to Swissmedic and the committee, annual safety report | Risk based, documented monitoring plan |
| C | Higher hazard potential, e.g. gene therapy, limited safety database | Ethics committee and Swissmedic | SUSARs to Swissmedic and the committee, annual safety report, closer oversight | Intensive, often with a safety committee |
Device trials under ClinO-MD
Clinical trials with medical devices follow their own ordinance and their own categorisation. Broadly, a trial with a device that carries a conformity assessment and is used within its intended purpose sits at the lower end and needs the ethics committee, while a trial with a device that has no conformity assessment, or that is used outside its intended purpose, moves up and brings Swissmedic in. The safety reporting follows the device vigilance logic, so serious incidents rather than adverse drug reactions.
How to categorise a protocol
Work through the questions in this order. Each answer either settles the category or moves you to the next question, and the decision belongs in writing in the trial master file, with the reasoning.
- Is the intervention a medicinal product, a medical device or something else? That picks the ordinance.
- Is the product authorised in Switzerland? If not, you are in category B or C.
- If it is authorised, is it used strictly within the authorised indication, dose and route? If yes, category A.
- If it is used off-label, category B, unless the hazard potential pushes it higher.
- For an unauthorised product, how well is the safety profile characterised? A thin database, gene therapy or GMOs point to category C.
- Record the decision and the reasoning, and confirm it in pre-submission advice where anything is borderline.
A wrong category costs weeks, not days
If you file a category B trial as category A, the committee will not simply reclassify and continue. The dossier is missing the Swissmedic application and the documents that go with it, so you resubmit and start the review over. When a protocol sits near a boundary, ask before you file.
Frequently asked questions
Who decides the category, the sponsor or the authority?
The sponsor categorises the trial and justifies it in the application. The ethics committee and Swissmedic verify that categorisation and can correct it, which is why pre-submission advice is worth having when the case is not clear.
Does off-label use always mean category B?
Off-label use of an authorised product points to category B, but a higher hazard potential can move a trial to category C. What matters is the risk to participants, not the label status alone.
Does a placebo arm change the category?
Not by itself. What matters is the intervention under study and the risk it carries for participants. A placebo arm does affect the ethics committee's risk-benefit assessment and the justification you have to give.
Can the category change during a trial?
Yes, if the protocol is amended substantially, for example by adding an off-label arm or a new dose level. That is a substantial amendment and may bring Swissmedic in where it was not involved before.
Where are the categories defined?
In the Clinical Trials Ordinance (ClinO, SR 810.305) for medicinal products and in ClinO-MD for medical devices. Both build on the Human Research Act as the framework.
Do you need an RPPV in Switzerland?
We act as the qualified person responsible for pharmacovigilance, run case processing and write the PSURs for your Swiss authorisations.