IVDR Class D Implementation: The Ticking Clock for High-Risk Diagnostics

In vitro diagnostics (IVDs) form the backbone of modern healthcare, guiding everything from infectious disease management to cancer treatment decisions. Under the EU’s In Vitro Diagnostic Regulation (IVDR), which came into force in May 2022, the oversight of IVDs has transformed. The new framework increased the percentage of IVDs requiring Notified Body involvement from roughly 15 percent under the old IVDD to nearly 80 percent.

Among these, Class D IVDs — the highest-risk category — face the strictest requirements. These include tests for blood-borne viruses, screening assays for the safety of the blood supply, and diagnostics for life-threatening conditions. By December 31, 2027, all Class D devices must transition to IVDR compliance. That deadline may seem distant, but considering the scale of evidence generation and Notified Body involvement required, 2025 is the critical window to act.

This blog examines IVDR Class D requirements, current regulatory expectations, common pitfalls, and what manufacturers must do now to avoid losing market access.

What Are Class D IVDs?

Class D IVDs are devices that pose the highest individual and public health risks. Examples include:

• HIV, Hepatitis B and C, and other transmissible infection tests used in blood or organ donor screening.

• High-risk assays for emerging infectious diseases such as Ebola or SARS-CoV-2.

• Diagnostics essential for ensuring the safety of the blood supply.

  
  

These products are critical to public health, which is why regulators demand rigorous validation and oversight.

IVDR Requirements for Class D Devices

Notified Body Involvement

All Class D IVDs require full review by a Notified Body. This includes assessment of technical documentation, quality management system, and performance evaluation.

EU Reference Laboratories (EURLs)

Class D IVDs also face additional oversight by EU Reference Laboratories. EURLs conduct independent verification of manufacturer claims, including performance and batch testing. This step is unique to Class D devices and adds significant complexity and time to the approval process.

Performance Evaluation

Manufacturers must provide a comprehensive performance evaluation consisting of:

• Scientific validity: Evidence that the analyte is clinically relevant.

• Analytical performance: Accuracy, precision, sensitivity, specificity, and reproducibility data.

• Clinical performance: Demonstration that the device achieves its intended purpose in clinical practice.

  
  

Post-Market Performance Follow-Up (PMPF)

Class D devices require ongoing performance follow-up to confirm safety and effectiveness. Manufacturers must design PMPF studies or use registries to collect real-world evidence.

Challenges Manufacturers Face

1. Notified Body Capacity

   As of 2025, only around a dozen Notified Bodies are designated under IVDR, and their capacity is already stretched. Engaging a Notified Body early is essential.

   
   

2. EURL Bottleneck

   EURLs must verify Class D performance claims, but as of mid-2025, only a limited number of labs are designated. Delays in EURL capacity could create bottlenecks.

   
   

3. Clinical Evidence Gaps

   Many legacy devices were approved under IVDD with limited clinical data. Under IVDR, these are insufficient. Manufacturers must generate new studies or leverage registries.

   
   

4. Complex Supply Chains

   Class D assays often rely on complex global supply chains. Traceability requirements under IVDR, including UDI and EUDAMED registration, add additional burden.

   
   

Case Examples

• Delayed Certification: A manufacturer of an HIV screening test submitted technical documentation under IVDR but lacked robust clinical performance data across diverse populations. The Notified Body requested additional studies, delaying certification and creating a risk of supply interruption.

  
  

• Proactive Success: Another firm manufacturing Hepatitis C assays anticipated IVDR requirements and began clinical performance studies in 2022. By 2024, it had submitted robust data, secured a Notified Body contract, and engaged early with an EURL. The company is on track to meet the 2027 deadline without disruption.

  
  

Practical Implementation Steps

1. Conduct a Gap Assessment

   Review existing technical files against IVDR Annex II and III requirements. Identify gaps in scientific validity, analytical performance, and clinical performance data.

   
   

2. Engage a Notified Body Early

   Secure a contract with a Notified Body as soon as possible. Capacity is limited, and waiting risks losing your place in the queue.

   
   

3. Plan for EURL Involvement

   Identify which EURLs are designated for your assays and understand their verification processes. Build time for independent batch testing into your timelines.

   
   

4. Generate Clinical Evidence

   Design and implement clinical performance studies now. Relying solely on literature or legacy data will not pass IVDR scrutiny.

   
   

5. Strengthen PMS and PMPF

   Develop proactive PMPF plans to monitor long-term performance. Use registries and real-world evidence to complement clinical trial data.

   
   

6. Update Quality Systems

   Ensure your QMS addresses IVDR-specific requirements, including performance evaluation, vigilance, and UDI assignment.

   
   

Strategic Implications for Executives

For CEOs

Class D IVD compliance is not optional. These products are critical for public health, and regulators will not compromise on safety. CEOs must allocate resources for studies and regulatory engagement to protect EU revenue.

For QA/RA Leaders

QA/RA teams must manage relationships with both Notified Bodies and EURLs. They must also ensure CERs, PERs, and PMS reports are updated continuously.

For Product Leaders

Product teams must align development plans with IVDR timelines. Clinical studies, validation, and documentation must be prioritized well before 2027.

Conclusion

Class D IVDs face the strictest requirements under IVDR. With deadlines looming in 2027, 2025 is the time to act. Manufacturers that proactively generate evidence, engage NBs and EURLs, and strengthen PMS will maintain access to the EU market. Those that delay risk losing certification for products that are essential to public health.

How PRP Compliance Can Help: We support diagnostics companies in designing performance evaluation strategies, preparing technical documentation, and engaging with NBs and EURLs. Contact PRP Compliance to ensure your Class D devices remain on the EU market beyond 2027.