--- title: "The Contract Clause Your Combined CDx Study Site Agreement Is Probably Missing" description: "Discover why combined CDx site agreements need explicit IVDR monitoring and audit rights for test sites and sample collection sites." url: https://qbdgroup.com/en/blog/cdx-site-agreement-ivdr-monitoring type: "Blog post" language: en published: 2026-09-02 author: "Kirsten Van Garsse" category: "Regulatory Affairs" publisher: "QbD Group" citation: "QbD Group, \"The Contract Clause Your Combined CDx Study Site Agreement Is Probably Missing\", https://qbdgroup.com/en/blog/cdx-site-agreement-ivdr-monitoring" --- # The Contract Clause Your Combined CDx Study Site Agreement Is Probably Missing > Discover why combined CDx site agreements need explicit IVDR monitoring and audit rights for test sites and sample collection sites. There is a category of problem in combined CDx programmes that does not appear on risk registers, does not come up in governance meetings, and is not caught by submission reviews. It only surfaces when a Competent Authority reviewer looks at the performance study data and asks: **Who monitored the sites that generated it?** In many combined CDx programmes, the honest answer is: nobody, specifically. And often for two completely different reasons, at two completely different kinds of site. ## In This Blog Post - Why laboratories may unknowingly operate as regulated test sites - Why sample collection sites can fall between pharma and diagnostic monitoring - What these monitoring gaps mean for CDx evidence - Which IVDR-specific rights combined-study site agreements should define - What an integrated monitoring model looks like in practice ## Reason One: Nobody Told the Lab It Was a Regulated Test Site Pharma brings in a CRO to manage clinical site monitoring. The CRO has a monitoring plan, trained monitors, and a well-established process for GCP compliance. That plan covers the clinical sites where patients are enrolled and treated. It does not necessarily cover the labs. The diagnostic partner has field application scientists and commercial support staff who visit those labs. They help with instrument setup, reagent supply, and technical troubleshooting. They are excellent at their jobs. But they do not necessarily have a monitoring mandate for a regulated performance study, nor are they necessarily operating under a monitoring plan that has been reviewed against IVDR requirements. The labs themselves are running the biomarker assay as a service to the clinical trial. They understand that they are part of the programme. What they often do not understand is that, under the IVDR, they may also be acting as test sites for a regulated performance study. Their results are not simply service outputs. They are regulated evidence, submitted to Competent Authorities to support CE marking and subject to IVDR oversight requirements, whether or not the lab''s own service agreement says so. ## Reason Two: Nobody Double-Checked the Sample Collection Site This is the quieter version of the same problem. And in QbD''s experience, it is at least as common. Sample collection sites, where the patient''s specimen is actually drawn, are frequently the very same clinical sites already running the drug trial. That overlap is exactly why they get missed. The diagnostic partner assumes pharma''s CRO already has the site covered because it is being monitored for the drug trial. Pharma''s CRO assumes the diagnostic partner is handling anything IVD-specific because the sample is "the diagnostic partner''s business". Both assumptions are reasonable. **Neither is checked.** The site ends up monitored for GCP, but not specifically for: - pre-analytical sample handling - chain of custody - performance-study-specific consent Yet these are precisely the parts of the visit that matter for the CDx evidence. ## The Consequences Are Not Theoretical Monitoring findings at test sites and sample collection sites may not be reconciled with findings at clinical sites more broadly because they are tracked in separate systems, by separate teams, with no joint review process. That creates blind spots. A data quality issue could involve: - a reagent lot change - an instrument calibration gap - a specimen handling deviation - incomplete documentation - a performance-study-specific protocol deviation Any one of these issues may not surface until the performance data is reviewed during submission preparation. At that point, it may be too late to repeat the assay. And too late to close the audit trail gap. Sites that have never been told about their regulated status may also be poorly prepared for an audit. When an audit is triggered following a Competent Authority query, the site can find itself unprepared, with incomplete records and little time to take corrective action. The resulting pressure does not remain confined to the diagnostic workstream. It can compress submission timelines for both pharma and IVD simultaneously. ## The Clause That Is Usually Missing This is where the site agreement should be doing more work than it usually does. Most combined-study site agreements are written for the drug trial and then quietly assumed to "cover" the diagnostic component too. They rarely state explicitly who has the right to monitor and audit the site specifically for **IVDR purposes**, as distinct from GCP purposes. And they rarely say anything at all about the sample collection activity taking place at that same site. A site agreement built for a combined study should establish, in terms specific enough to survive a Competent Authority query: 1. **Who holds IVDR-specific monitoring and audit rights at the site**, whether pharma''s CRO, the diagnostic sponsor, or a named delegate. 2. **That those rights explicitly extend to sample collection and handling activities**, not only to drug-trial procedures. 3. **What happens when a finding at the site has implications for the other organisation''s regulatory file**, including how that finding is communicated and escalated. Without that clause, both organisations are relying on an assumption instead of a right. **Assumptions are exactly what do not survive contact with a reviewer''s question.** ## What Good CDx Site Monitoring Looks Like Good combined-study monitoring starts by treating the diagnostic component as part of the monitoring strategy from the beginning, rather than adding it once the performance study is already underway. Study site monitoring, for test sites and sample collection sites alike, is integrated into the overall clinical monitoring plan from the start of the programme. There is: - a named monitoring owner - a defined scope covering the relevant GCP and IVDR requirements at each site - a monitoring frequency reflecting the criticality of the data to the CDx claim - a clear process for escalating findings across organisations and regulatory workstreams Monitoring findings from every relevant site type are reviewed in the same forum, by the same joint governance team, against a single integrated finding log. When a finding at a test site has implications for the pharma submission, pharma RA knows about it. When a change at a sample collection site affects the biomarker assay protocol, the diagnostic partner''s RA team is in the room. And the site agreement says so. **Explicitly, before the study starts, in a clause both organisations can point to when a reviewer asks who is responsible.** --- Source: https://qbdgroup.com/en/blog/cdx-site-agreement-ivdr-monitoring — © QbD Group. Quote freely with attribution and a link back.