“It’s Just a Lab Test”… Until It Isn’t. What the MHRA webinar on IVDs really means for QA leaders and sponsors
We joined the MHRA webinar expecting a technical update on clinical trials involving in vitro diagnostic devices.
What many people really want to know, though, is simpler:
When does a lab test become an IVD in regulatory terms?
Does this affect routine safety bloods?
What about biomarkers?
And if a laboratory has developed its own method, where does that leave us?
For QA leaders and sponsors, the practical implications matter more than the submission mechanics.
What follows is not a rehash of the checklist. It is an attempt to translate what this means for trial governance in the real world.
A working definition that actually helps
The MHRA described IVDs in trials as devices that analyse human samples to determine a physiological or pathological state, or to monitor safety and efficacy, particularly where the result is actionable within the trial.
That sounds broad. It is.
A more usable rule of thumb is this:
If the result of a test changes what you do in the trial, treat it as part of the IVD component.
That includes tests used to:
decide eligibility
stratify patients
guide treatment decisions
monitor response or safety
define endpoints
The important shift is not definitional. It is conceptual.
The regulator sees one integrated study. If the diagnostic influences trial conduct, it belongs inside the same governance lens as the investigational medicinal product.
What about routine safety labs?
This is where confusion often starts.
Routine safety bloods analysed in an accredited NHS laboratory may not automatically trigger an “IVD submission issue”. But if those results are used within the trial to make decisions, for example:
dose adjustments
stopping rules
participant continuation
safety endpoint assessment
then they are no longer just routine clinical care. They are functioning as part of the trial’s decision-making framework.
For QA leaders, this is less about new paperwork and more about traceability.
Can you clearly articulate:
which tests are routine care
which tests influence trial decisions
how governance differs between the two
If that boundary is blurred, it will likely surface under inspection-style questioning.
Biomarkers: where the spotlight is brightest
Biomarkers are perhaps the clearest example of the shift.
If a biomarker result determines eligibility, assigns a participant to a treatment arm, or contributes to efficacy analysis, the regulator is interested in the analytical performance of that test.
Sensitivity.
Specificity.
Precision.
Accuracy.
Sample stability.
The science of the biomarker is only part of the story. The reliability of the test that measures it becomes equally important.
For sponsors, this means biomarker strategy is not purely scientific. It is regulatory and governance-driven as well.
For QA, it means asking uncomfortable but necessary questions early:
Is the performance evidence proportionate to the role the biomarker plays?
Is that evidence documented and reviewable?
Is responsibility for oversight clearly defined?
If those questions are only asked during CTA assembly, the system is reacting rather than operating.
In-house or bespoke assays: where does that leave you?
The webinar acknowledged that many trials use assays developed specifically for the study and that these may never be UKCA or CE marked.
The absence of a mark does not make this impossible. It changes the burden.
Where a device is unmarked or bespoke, the expectation shifts towards documented analytical performance evidence. The regulator is looking for defensibility rather than certification.
For QA leaders, this is a governance issue.
Who reviewed the performance data?
On what basis was the assay deemed fit for purpose?
How is ongoing performance monitored?
If the only answer is “the lab says it works”, that may not be enough.
This month’s inspection readiness theme is relevant here. You do not want to discover, during questioning, that the scientific confidence in a method has never been translated into documented regulatory confidence.
The post-IVDR environment: what has really changed?
For readers trying to orient themselves, the difference between the old IVDD world and the current IVDR-influenced environment can feel abstract.
At a high level, the shift has been towards:
stronger, more explicit evidence expectations
clearer classification frameworks
greater scrutiny of performance data
closer integration between devices and the clinical contexts in which they are used
Northern Ireland aligns with the EU IVDR framework. Great Britain operates under its own regime, with MHRA guidance shaping clinical trial expectations.
For multinational sponsors, this makes early design decisions more important. The regulatory pathway cannot be an afterthought once sites are selected.
For QA leaders, it reinforces a simple point: diagnostic governance is no longer peripheral. It is structurally linked to trial approval and oversight.
What is still unclear?
It would be misleading to suggest that every boundary is perfectly defined.
There remain grey areas that organisations must navigate thoughtfully:
The precise boundary between routine care testing and trial-relevant testing. The same assay may fall on different sides depending on how results are used.
The degree of proportionality expected for staff competence evidence in different settings.
Practical interpretation of health institution exemption scenarios in complex academic or NHS contexts.
These are not reasons for alarm. They are reasons for early discussion.
Inspection findings often arise not from regulatory change itself, but from assumptions left unchallenged.
A practical reflection for QA leaders
If you wanted to sanity-check your current or upcoming trial, three questions may help:
Which tests in this protocol influence trial decisions?
Where is the analytical performance evidence for those tests held and reviewed?
Is oversight of those tests clearly integrated into the trial governance structure?
If the answers require multiple hurried conversations across silos, that is useful information.
If the answers are clear, documented and calmly explainable, you are closer to genuine readiness.
The MHRA webinar was presented as a technical session about IVD components in clinical trials.
What it really signalled was something broader.
Diagnostics are no longer background infrastructure. They are visible, governed elements of the trial system.
For QA leaders and sponsors, that is less about additional burden and more about integration.
And integration, done early, is far easier than reconstruction under pressure.
PS – Staying Informed Without Attending Everything
We attend sessions like this so our clients do not have to, translating regulatory updates into practical implications for trial design and governance.
We are developing a regulatory insight and interpretation service for organisations that want early visibility of developments and clear, practical analysis of what actually changes in practice.
This is entirely optional. If you would simply like to be kept informed as this develops, you can register your interest on our “find out more” page. We will share occasional briefings and early details as the model takes shape.
