Abstract T002

Development and application of a validated MRD assay in Hodgkin Lymphoma

Introduction: Circulating tumor (ct)DNA sequencing in Hodgkin Lymphoma (HL) enables genotyping and minimal residual disease (MRD) assessment. However, current ctDNA MRD assays are neither validated nor optimized for HL. We designed and validated LymphoVista HL, a specialized ctDNA-based assay for HL genotyping and MRD assessment.

Methods: LymphoVista HL targets 83 kbp optimized for detecting variants of relevance and highly sensitive MRD detection in HL. First, we performed a technical validation with contrived samples to evaluate sensitivity, specificity, linearity, accuracy, limit of detection (LoD), and precision. Second, the validated assay was employed in a blinded clinical validation study using an event-enriched cohort (n=72) from the GHSG HD21 trial.

Results: We validated LymphoVista HL for variant calling and MRD detection. We achieved 91.27% sensitivity for de-novo variant identification for variants with > 0.5 % allele frequency (AF) and > 99.99% specificity. Linearity analysis showed an R-value of 0.98 confirming a linear relationship between detected AF and ground truth AF. For MRD detection, we determined a LoD of 6.54 x 10-6. Further validation results for MRD detection are shown in Table 1. The precision study revealed a repeatability of 30.33% CV even at low MRD levels and good reproducibility with a low contribution of varying reagent lots, technician, and day of assay performance to variation in results. Our clinical validation study showed the assay’s strong applicability to clinical samples. In HD21 patients treated with highly effective regimens such as eBEACOPP or BrECADD, MRD assessed after 2 chemotherapy cycles was prognostic. The assay effectively distinguished between MRD-negative patients, who had excellent outcomes, and MRD-positive patients, who had a higher relapse rate. Detailed analysis, including MRD-positivity rates, outcomes for MRD-positive and -negative patients, and correlation of MRD with positron emission tomography (PET) findings, is ongoing. Detailed results will be presented at the meeting.

Conclusion: We present LymphoVista HL, a highly accurate genotyping and MRD assay for HL based on ctDNA sequencing. Our validation study confirms the assay’s high accuracy, specificity, sensitivity, precision, and prognostic ability even in HL patients treated with highly effective regimen opening the way for MRD-guided clinical trials in HL.

Authors

Julia Mattlener, Jessica Schneider, Julia Katharina Schleifenbaum, Max Freihammer, Olivia Käsgen, Kerstin Becker, Hodgkin Lymphoma MRD Consortium, Justin Ferdinandus, Helen Kaul, Gundolf Schneider, Peter Borchmann, Jan-Michel Heger, Sven Borchmann