Conference abstracts

2 abstracts

• Level 2prognosticASH Annual Meeting 2022

  Risk Profiling of Patients with Previously Untreated Diffuse Large B-Cell Lymphoma (DLBCL) By Measuring Circulating Tumor DNA (ctDNA): Results from the POLARIX Study

  Herrera, Alex F. · Abstract 1297 · POLARIX · paired baseline and Cycle 2 Day 1 results in 319/440 (Pola-R-CHP) and 299/439 (R-CHOP) patients

  AVENIO NHL CAPP-Seq; results as mean mutant molecules per mL

  Baseline ctDNA above the median MMPM was associated with shorter PFS and OS in both arms (Pola-R-CHP PFS HR 1.96, OS HR 2.17; R-CHOP PFS HR 1.43, OS HR 2.10). A log-fold change of at least 2.0 or undetectable ctDNA at C2D1 was reached by 66.8% and 65.6% of patients in the two arms and was prognostic (PFS HR 1.86 and 2.21). In Pola-R-CHP, a 2.5-log reduction (PFS HR 2.89) and C2D1 clearance (PFS HR 2.98, OS HR 2.74) remained prognostic independent of baseline risk factors.

• Level 3prognosticASCO Annual Meeting 2021

  Personalized, ctDNA analysis to detect minimal residual disease and identify patients at high risk of relapse with multiple myeloma.

  Dhakal, Binod · Abstract 8029 · 28 patients after upfront autologous transplant; 80 plasma timepoints; median follow-up 92.4 months; single-center retrospective

  Signatera (personalized tumor-informed mPCR-NGS), assessed about 3 months after transplant; bone-marrow comparison used multiparameter flow cytometry at 10^-4

  ctDNA was detectable in 17/24 (70.8%) before transplant, 15/28 (53.6%) at about 3 months after transplant, and 11/28 (39.2%) during later surveillance. Of 15 patients MRD-positive at 3 months, 14 (93.3%) later relapsed (HR 5.64, 95% CI 1.8-17, P=0.0003). Median PFS was 84 months if ctDNA-negative at 3 months vs 31 months if positive (P=0.003). The 3-month positive predictive value for relapse was 93.3%, higher than marrow flow cytometry (68.4%) in this series.