We  received a question from the Belgian Society of Advanced Cytometry, which is likely to be asked by many of our members; namely, what is the definition of a laboratory-developed assay and furthermore, how do we deal with the challenges presented by the new EU CE-IVD regulations.

These are questions likely to be of interest to most of ESCCA members who work in clinical laboratories, so please find our answers and thoughts on these questions here below. 

Dear colleagues,  

Thank you for your letter and for reaching out.   

To start with your specific question on the exact definition of an LDT:  As you probably know, the EU regulatory documents do not provide a precise definition. They describe them as “are manufactured and used within the same health institution. They are not marketed or transferred to other legal entities and do not bear the CE marking”.   

The statement given to you by a company sounds valid to us:  If using a CE-IVD cytometer, CE-IVD assay kit and CE-IVD software that is designed specifically for such data, and -possibly- specifically for the CE-IVD assay used, and using all these components exactly as directed by manufacturer’s instructions, then the process is not an LDT.  

Support for this can be found on various pharma and consultancy services websites, which as far as we can see, are all in line with this.

As you rightly point out, one can still ask the question: what does ‘deviate from the assay kit’ actually mean?  It is possible that individual countries’ regulatory bodies may slightly differ here – this we cannot yet know.  There is now some guidance provided by the EU, in their May 2022 document “Guidance on significant changes regarding the transitional provision under Article 110(3) of the IVDR”.  This document describes some examples of what may be changed (change of source of (identical) reagent for example) and provide a useful list of what constitutes “significant changes” that would make CE-IVD labelling void.  

“Significant change:  

• extension of the intended purpose, such as: 
• additions regarding what is detected and/or measured, such as addition of a new genotype to a human papillomavirus assay, necessitating new primers; 
• additional functions of the device, such as screening, monitoring, diagnosis; 
• for companion diagnostics: extension of the target population(s) or of the tissue type or associated medicinal products; 
• addition of specimen type(s). 
• any other major change of the intended purpose, such as:  
• change of assay type, e.g. from screening assay to confirmatory assay or from qualitative to quantitative assay;  
• change of the intended user, e.g. from professional user to lay user; 
• change of operation from automatic to manual or vice versa; 
• change of specimen type(s).” 

How can we translate this into practice?  

Based on this document and many prior discussions with IVDR compliance consultants and ESCCA colleagues, our understanding is that a ‘to the letter’ following of instructions is to be expected.  

Changing supplier of various buffers is not regarded as a significant change. Using a CE-IVD labelled kit, say B-ALL MRD, on a CSF sample, where the kit states it is validated for bone marrow and blood analysis – would render the CE labelling void  (only when run on a CSF sample). A CE-IVD kit with the intended use of detecting myeloma plasma cells at diagnosis and MRD – if used to detect plasma cell component in LPCL – would then strictly speaking be void of its CE-IVD. 

Other changes to protocols of purchased IVD assays still fall in a grey zone (also after the May 2022 doc).  A case-by-case evaluation would be required, likely.   For example: A CE-IVD kit consisting of ready-to-go FACS tubes with dried down monoclonal antibodies states in its standard operating procedure to add 50ul saline solution, wait 10 minutes, and then  add a specific amount of sample. If the lab finds that leaving out the 10 minute saline pre-incubation if fine, it does not change results (measured as fluorescence intensities or proportion of cells picked up in various gates), they may decide to save time and add saline and sample all at once.   Our interpretation is that regulatory bodies may well say that the assay is no longer CE-IVD valid. Follow-on questions arise: (1) Will all countries regulatory/assessing bodies take this approach? Maybe not all. (2) Say the laboratory prefers to save the time and so they have to validate the kit: then how extensive does that validation have to be – can it rest with the manufacture’s validation data, with a limited ‘top-up’, just showing equal results between pre-incubation versus no pre-incubation?  We suggest a shot verification is only needed, and would take support from the CLSI H62 approach for verification of IVD assays. This would to our minds be meeting ISO15189 standards, which, in turn, paves the way for compliance with regulatory standards for any in-house developed assays. In other words,   3 bases would be covered. (1) the lab is happy that they have an assay they know is good, and suits their working pattern and clinical needs (2) The regulatory body of the laboratory’s country is either going to consider the assay ass CE-IVD despite the slight alteration, and all is good,  or (3) it will consider the assay as no longer CE-IVD and therefore an in-house validated assay, in which case it would at the very least want to see validation papers that meet ISO15189 standards (which the lab then would have – the verification study according to H62 guidance for IVD assays).  Of course, the new regulatory requirements for in-house LDTs may also need further work in particular some follow-up work on assay results (this is of course where more clarity is required in general).  

Is it really worth changing something so small in a purchased kit?!  This is a very good reason for clinical flow cytometry labs to work together with manufactures, to ensure that their CE-IVD labelled kits are as useful as possible for us.  

 Another scenario could be that the CE-IVD labelled kit’s instructions are not too precise. For example, the sample volume to use might be arbitrary. It may not relate to the cell count of the sample, and some work may be required by the lab to find out optimal sample cell concentration/volume to add per tube.  Our understanding is that this forms part of the verification process that labs are always required carrying out when employing a CE-IVD kit/equipment/software/system. (Again, here we can have useful support from H62 on IVD assay verification). 

The scenario of purchasing 2, or 3, or 14 separate monoclonal antibodies, each individually CE-IVD labelled, mix then into a cocktail, label a sample and diagnose CLL (using  CE-IVD cytometer and software) is unlikely to be considered a CE-IVD assay by any regulatory or accreditation bodies we are familiar with.  The reagents would clearly be used outside the scope for which they were CE-IVD labelled.  

Just  to mention, there is a paper by Spitzenberger et al that we found quite useful, you have probably seen it, if not, it looked at definitions of LDTs in various countries (also outside the EU) and produced 4 main scenarios describing LDTs, summarised in their Figure 2 (Spitzenberger et al. Laboratory-Developed Tests: Design of a Regulatory Strategy in Compliance with the International State-of-the-Art and the Regulation (EU) 2017/746 (EU IVDR [In Vitro Diagnostic Medical Device Regulation]). Therapeutic innovation & regulatory science, 2022, 56.1: 47-64.):  

The EU may still provide further guidance on LDTs; we note the current status for section 9 in the document Update - Joint implementation and preparedness plan for Regulation (EU) 2017/746 on in vitro diagnostic medical devices (IVDR) (europa.eu) : 

The timelines for the gradual implementation of the new regulations that you mention correlates with what we know and what is published on the EU websites.  We have included a summary of the time lines at the end of this letter.  

It is likely that most routine clinical FC laboratories will keep using LDTs for the foreseeable future. It is in the nature of our work.  For this reason, support and guidelines for how to validate FC assays would be helpful for us all, as well as clear directives on which risk class various flow assays would be placed in (A, B, C or D, see figure below, borrowed from Lubbers et al. The new EU regulation on in vitro diagnostic medical devices: implications and preparatory actions for diagnostic laboratories. Hemasphere, 2021, 5.5.). Our understanding is that the majority of flow assays are likely t be deemed ‘cancer tests’ and will be placed in C.  

You other specific question was ‘how do you deal with these challenges’. Well, key here is to prepare as much as possible.  A central aspect of the regulations is adherence to the ISO 15189 standards.  There are areas in the standards that could benefit from collaboration/working groups to establish acceptable approaches. Ranging from narrow subjects, specific paragraphs, to the central question of how to validate LDT assays. Here, the standards do not provide great detail. General aspects apply and the CLSI document H62 is now published and provide support. However, like most clinical cytometrists, we too feel that more granularity would be helpful. ESCCA is working on this and will present and discuss guidelines for flow assay validation in September at the Belfast ESCCA conference. Additionally, a focus group/s for certain (trickier) aspects of the 15189 standards are starting up, and we very much welcome participation by interested members. 

General time line for implementation of new EU regulations: 

IVDD tests with certificates issued from 25.5.2017 to 26.5.2022 will be valid according risk category as follows: 

26 May 2025 (class D), 26 May 2026 (class C), 26 May 2027 (class B), 26 May 2027 (class A) and can be used in line with IVDR 

All other tests (including the described scenarios with CE IVD, non CE-IVD, mixture of CE-IVD and non CE-IVD reagents and software) should be in line with the IVDR requirements for LDTs 

IVDR requirements for LDTs valid from 26.5.2022 

• No transfer of devices /use within one entity
• No commercial scale 

IVDR requirements for LDTs postponed to 26.5.2024 

•  info to authorities
• compliance with QMS/ISO 15189 (scientific, analytical and clinical performance)
• justification of use
• extra requirements for “class D” 
• Post market surveillance 

IVDR requirements for LDTs postponed to 2028 

•  need do prove absence of commercially available alternative 

Briefly, if no CE-IVD tests with prolonged validation are used, each laboratory has 2 years to validate their own LDTs and provide compliance with quality and risk management and/or ISO 15189 norm.  

EILCP

Inter-Laboratory Comparison Programme (EILCP) is free for all ESCCA members, and  offers interesting haemato-oncology cases for us to analyse and then compare our results with the expert laboratory who contributed the files, and with all other EILCP members (it is anonymous of course!) Cases span all our workload, Diagnosis, AML MRD, ALL MRD, T-ALL MRD, CLL MRD, HCL MRD and high resolution PNH. It is a great  scheme for both personal trianing and to provide evidence of flow data sharing, assisting us in ISO15189 compliance.

The application form can be downloaded from the EICLP page in the membership section.

9TH PRAGUE SCHOOL ON FLOW CYTOMETRY - VIRTUAL

24-27 October 2022

The flyer, topic overview and full programme for the 9th Virtual Prague School on Flow Cytometry is now available on the Meetings page!

EXTENDED deadline for application: 31 July 2022! 

All interested clinical cytometrists from Ukraine are welcome to attend the course as our guests, free of charge.

New European Union In Vitro Diagnostics Regulations (EU IVDR)

Many of our members have asked questions around working under the planned new EU IVDR. The time-line for these regulations to come into play has changed, creating extended valuable time to prepare for them.

Clinical flow cytometry laboratories provide a multitude of diagnostic and prognostic tests. These may be available commercially or developed in-house (referred to in the EU IVDR as ‘devices manufactured and used only within health institutions’).

We recognise the importance of working together with industry to support development of high quality CE-IVD assays suitable for use in routine laboratories. Additionally, we acknowledge that it is necessary that our laboratories provide in-house assays as part of our service since we work in a constantly evolving field, and thus require the capacity to provide cutting edge service to our users. Application of in-house assays requires robust validation procedures and compliance with ISO-15189:2012 accreditation.

Therefore, ESCCA welcomes working with industry with a view to increasing the availability of commercial IVDR assays for use in routine practice. Also, we aim to work towards supporting individual members and laboratories by providing guidance related to assay validation and ISO 15189 accreditation. To this end, we look forward to working within ESCCA, as well as with our affiliated societies, to aid development of consensus guidelines.

8th Prague school on flow cytometry

The flyer and programme of this interactive course on advanced applications in hematology-oncology and imunology are now available for download at the Eduction page.

ESCCA Virtual Conference: Post-conference webinar by Cytognos

Dissecting the heterogeneity of Common Variable Immunodeficiencies

Speakers: Martín Pérez Andrés, PhD. Professor of immunology, University of Salamanca.
The webinar will be hold in English and Spanish and feature 15 min live Q&A.

Key learning points:

• Flow cytometry methods for deep immune profiling.
• B-cell and T-cell defects in CVID patients.
• Correlation of the immune phenotype with the clinical manifestations of CVID.

English Session

Wednesday, 29 September, 2021 at 17:00 CEST (45 min)

Register here

Tuesday, 28 September, 2021 at 17:00 CEST (45 min)

Register here

Any question about this webinar, please contact Cytognos directly: info@cytognos.com 

ESCCA Virtual Conference: Post-conference webinar by BD

Title: The value of automating flow cytometry reagent cocktailing
Date: Monday, 27 September, 2021 at 17:00 CET (60 mins)
Speakers:
By Lori Apoll, Clinical Sales Consultant , BD.
Hosted by Kate Easten, Clinical Product Manager, BD, the webinar will feature a live Q&A with Dr. Tim Farren, Head of Immunophenotyping at Barts Health NHS Trust, London, UK, who will share his experience.

Click here for more information and to register!

The ACS runs educational Roadshows each year. ACS Roadshows provide an intensive one day course on important subjects  in cytometry, presented by international and local speakers. The 2021 ACS Roadshow takes place virtually on 10 August. Participation is free. For more information and to register, see https://cytometry.org.au/upcoming-events/srl-roadshow/

During the Covid-19 outbreak many meetings have either been cancelled or postponed and the need for educational content is greater than ever. Also the ESCCA Conference in Vilnius, initially scheduled in September 2020, had to be postponed to April 2021.

Therefore, ESCCA has made some of the educational presentations of the 2019 Conference in Bergen publicly available. These can be downloaded in the Education section/ESCCA publications.

CCEN offers a link to some of the Educational Resources  made available for free access by ICCS.
Access via https://www.cytoed.org//web/index.php under the E-learning tab and "what's new".