Real-life disease monitoring in follicular lymphoma patients using liquid biopsy ultra-deep sequencing and PET/CT

Abstract

In the present study, we screened 84 Follicular Lymphoma patients for somatic mutations suitable as liquid biopsy MRD biomarkers using a targeted next-generation sequencing (NGS) panel. We found trackable mutations in 95% of the lymph node samples and 80% of the liquid biopsy baseline samples.Then, we use an ultra-deep sequencing approach with 2 • 10 − 4 sensitivity (LiqBio-MRD) to track those mutations on 156 follow-up liquid biopsy samples from 55 treated patients. Positive LiqBio-MRD correlated with a higher risk of progression both at the interim evaluation (HR 13.0, 95% CI 2.70-63.4, p < 0.001) and at the end of treatment (EOT, HR 14.3, 95% CI 4.4-46.4, p < 0.001). Similar results were observed by PET/CT Deauville score, with a median PFS of 19 months vs. NR (p < 0.001) at the interim and 13 months vs. NR (p < 0.001) at EOT. LiqBio-MRD and PET/CT combined identi ed the patients that progressed in less than two years with 89% sensitivity and 100% speci city. Our results demonstrate that LiqBio-MRD is a robust and non-invasive approach, complementary to metabolic imaging, for identifying FL patients at high risk of failure during the treatment and should be considered in future responseadapted clinical trials.

Personalized monitoring of circulating tumor DNA with a specific signature of trackable mutations after chimeric antigen receptor T-cell therapy in follicular lymphoma patients

“…FFPE lymph node genomic DNA (gDNA) was extracted and quantified as previously described ( 24 ). For circulating-free DNA (cfDNA) extraction, 10 to 20 mL of peripheral blood (PB) was collected in EDTA tubes and processed in less than four hours at the H12O.…”

“…The plasma was separated with two centrifugation steps at 1600 × g and 4500 × g, and stored at −80°C until further use. Purification, quantification and quality control (fragment size and gDNA contamination assessment) of cfDNA were performed as previously described ( 24 ).…”

“…Nevertheless, current studies confirming this data are missing in FL. Recently, our group demonstrated that circulating tumor DNA (ctDNA) is an emerging biomarker able to risk stratify and assess treatment response in FL patients treated with first-line immuno-chemotherapy ( 24 ). In DLBCL, Quin Deng et al.…”

Genomic landscape of follicular lymphoma across a wide spectrum of clinical behaviors

“…The study of circulating tumor DNA might be an interesting development aiming to capture a pooled representation of the genetic landscape of a tumor. 54 Selected genes with a relevant role in immune biology (IRF8, PLCG2, CD79B, PIM1 and MCL1), were more thoroughly investigated in order to understand the molecular consequences of the mutations identified in our FL cohort (Figure 4F). CD79B mutations have been previously reported in FL.…”

“…It should also be recalled that temporal spatial heterogeneity is a well‐recognized phenomenon in FL and therefore the genetic findings originated from a single biopsy site can drastically differ from those from a different area or clinical timepoint. The study of circulating tumor DNA might be an interesting development aiming to capture a pooled representation of the genetic landscape of a tumor 54 …”