CAP/CLIA accredited (US)ISO certified (EU and Asia)

CLL MRD Assay

Multiparametric Flow Cytometry

Clinical Information

Indications for Testing

Globally, the age-standardized incidence rate of chronic lymphocytic
leukemia (CLL) has increased over the past 30 years, with a higher
incidence among men and adults over 65.1,2 CLL is currently the mostprevalent type of leukemia, comprising 25% - 30% of all leukemiasin Western populations.3 While clinical remission (CR) has been thestandard goal of end-of-treatment response for decades, updated
understanding of prognosis as well as novel treatment strategies that
can achieve deeper levels of remission now necessitate newer, moresensitive, and standardized assessments of treatment response, suchas measurable (or minimal) residual disease (MRD) assessments.4,5
MRD is a highly sensitive indicator of disease burden, both during
and after therapy, and has been correlated with progression freesurvival (PFS) and overall survival (OS)6, while also serving as anindependent prognostic indicator in patients with CLL. Flow cytometry
has long been an important part of the standard of care for thediagnosis and ongoing management of many blood cancers,
including CLL. However, achieving MRD-level sensitivity for detectionof disease burden, especially with limited samples, requires newand specifically designed assays. Multiparameter flow cytometry(MFC) MRD assays are state-of-the-art and widely-used methods
for MRD detection and quantification in a variety of hematologic
malignancies, achieving high sensitivity, high specificity, short turnaround-time, and cost-effectiveness compared to some alternatives.
Our CLL MRD MFC assay is a streamlined and targeted 11-color panel
designed to characterize potential CLL cells with clear separationfrom other B-lineage cells.4,7,8 The assay is validated on bone marrowand peripheral blood samples to detect the presence or absence of
CLL MRD in patients at any stage of treatment, including targeted
immunotherapies. The technical component of the assay will beperformed in our clinical laboratories, and the interpretation will beperformed by our team of expert hematopathologists.
If available, information from diagnosis will be used to assist with theassessment, although the assay can identify aberrant cells that havediverged from normal populations without previous patient history orbaseline assessment.

Interpretation

An interpretive report will indicate
the presence/absence of CLL MRD
in relation to the assay levelof detection and clinical cut-off
value.

Identify tumor-specific immunophenotypes for post treatment
monitoring and evaluation for relapse
Stratify patient risk and streamline clinical trial enrollment
Use as a potential surrogate endpoint in clinical trials
Assess response to therapy

Biomarkers in the CLL MRD Assay
CD3

CD22CD79bCD5

CD38CD81

CD19CD40CD200

CD20CD437AAD

Key Points
Single Tube 11-Color MRD Assay
Using a standardized panel across all time points, MRD
populations can be characterized and tracked to 0.005%
sensitivity
Alignment with International Harmonized Approach7,8,10
and ERIC protocol7,8Internationally standardized testing through LabPMM
Network
Optimize shared/limited samples by co-testing with MFCand NGS
Enhanced analyses using artificial intelligence (AI) andmachine learning (ML)

TurnaroundTimeSpecimen
Requirements

ShippingConditions

24 hours

2 mL of bonemarrow in EDTA orSodium Heparin

Ambient or Cool;
Do not freeze

2-4 mL of peripheral
blood in EDTA orSodium Heparin

Sample Stability

Store specimens
at 2-8°C; must be
received by lab within
72 hours after draw

San Diego, USA | Munich, DE | Kawasaki, JP | Shanghai, CN
M-0143 Rev02 | June 2024

Gate 1a.

Gate 2b.

Gate 3c.

Gate 4d.
CLL MRD

e.

f.

g.

h.

After initial quality assessment of stable flow of acquisition, exclusion of doublets, non-viable cells, RBCs, and debris, mononuclear cells
are gated based on CD43 vs. side scatter (SSC). A cleaned singlet B-cells population is delineated (after exclusion of hematogones,
plasma cells with combination of markers such as CD5, CD3, CD81, CD40, not shown here). A combination gate (created by Boolean
logic intersecting of Gate 1, Gate 2, Gate 3 and Gate 4) populates plot h where clustered aberrant events can be gated to calculate
CLL MRD (bright pink colored population depicted here in panels a, b, c, d, e, f, g, h) within CD19 positive singlet B-cells by the aberrant
expression of CD5 and CD43, and weak expression of CD79b, CD81, CD20, CD22 and strong CD200. Alternative gating strategies will
also be concurrently assessed to evaluate for CLL populations that may lack standard biomarker expression secondary to targeted
immunotherapy. MRD is calculated as number of CLL events as a percentage of total Nucleated Cells.

References
1. Y Dong et al. Exp Hematol Oncol 9, 14 (2020). https://doi.org/10.1186/s40164-020-00170-6 2. Y Ou et al. Frontiers in Oncology https://doi.org/10.3389/fonc.2022.840616. 3. Batista, JL et al. (2017).
Pathology and Epidemiology of Cancer. Springer, Cham. https://doi.org/10.1007/978-3-319-35153-7_29 4. WG Wierda et al. Leukemia. 2021; 35: 3059–3072. https://doi.org/10.1038/s41375-021-01241-1
5. M Hallek and O Al-Sawaf. Am J Hematol. 2021; 96( 12):1679- 1705. doi:10.1002/ajh.26367 6. A Rawstron A et al. Blood. 2018;132(Suppl 1):S181. 7. AC Rawstron et al. Leukemia. 2016; Apr;30(4):929-36.
doi: 10.1038/leu.2015.313. Epub 2015 Dec 7. PMID: 26639181; PMCID: PMC4832072. 8. AC Rawstron et al. Leukemia. 2013 Jan;27(1):142-9. doi: 10.1038/leu.2012.216. Epub 2012 Jul 31. PMID: 23041722.
9. MM Sartor et al. Cytometry Part B. 2013; 84B:96–103.

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