Circulating tumor DNA-based minimal residual disease (ctDNA-MRD) testing has emerged as a powerful prognostic tool for patients with diffuse large B-cell lymphoma (DLBCL) receiving first-line treatment, according to findings from a prospective multicenter study presented at the 2025 ASCO Annual Meeting. The research demonstrates that ctDNA-MRD status assessed by phased variant enrichment and detection sequencing (PhasED-Seq) provides superior prognostic value compared to conventional assessment methods.
Significant Survival Differences Based on MRD Status
The study revealed dramatic differences in survival outcomes based on ctDNA-MRD status at the end of treatment. Patients who were ctDNA-MRD negative (n = 126) experienced a 36-month progression-free survival (PFS) rate of 85% compared with only 15% among patients who were positive for ctDNA-MRD at the same time point (n = 34; HR, 11.03; 95% CI, 6.27-19.40; P < .0001).
Overall survival outcomes showed similarly striking differences, with 36-month rates of 92% and 41% for ctDNA-MRD negative and positive patients, respectively (HR, 7.38; 95% CI, 3.72-14.62; P < .0001).
"We prospectively validated the prognostic value of ctDNA-MRD in [patients with DLBCL treated in the frontline setting]," said Steven Wang, MD, a visiting fellow in the Department of Hematology at Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit, in The Netherlands. "We [also] demonstrated that ctDNA-MRD can detect residual disease independent of [a] PET scan."
Advanced Detection Technology
The study utilized PhasED-Seq, a baseline-informed, fixed-panel strategy with normal control sequencing to identify phased variants—multiple mutations found on the same ctDNA fragment. The technology demonstrated analytical validation with a limit of detection to 95% at 0.7 parts per million, though ultimate sensitivity is influenced by the absolute number of DNA molecules present in plasma.
At baseline, phased variants were identified in formalin-fixed paraffin-embedded (FFPE) material or pretreatment plasma and then tracked in end of treatment plasma samples. Most patients (58%) had FFPE samples while the remaining 42% had pretreatment plasma samples.
Real-World Multicenter Validation
The prospective study comprised a real-world cohort of patients with newly diagnosed DLBCL from over 50 centers in Belgium and The Netherlands. The overall cohort (n = 160) had a median age of 67 years (range, 18-88), with most patients being male (64%) and having DLBCL (89%). The majority had stage III or IV disease (79%), an International Prognostic Index (IPI) score of 0 to 2 (52%), received R-CHOP in the frontline setting (91%), and completed 6 cycles of treatment (90%).
All patients received frontline treatment with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) or DA-EPOCH-R (dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab) with curative intent.
Superior Predictive Capability for Early Relapse
The ctDNA-MRD testing demonstrated exceptional sensitivity in predicting early disease relapse. Eighty-six percent of patients who experienced disease relapse within 0 to 6 months following the end of treatment were ctDNA-MRD positive. Among patients who relapsed between 0 and 12 months or greater than 12 months, the proportions of patients who were positive for ctDNA-MRD were 80% and 22%, respectively.
Enhanced Prognostic Value Beyond PET Imaging
Even among patients with a complete molecular response (CMR) by PET scan, ctDNA-MRD status provided additional prognostic information. In patients with CMR by PET scan, the 3-year PFS rates were 89% and 36% among those who were ctDNA-MRD negative (n = 106) or positive (n = 11) at the end of treatment, respectively (HR, 6.58; 95% CI, 2.69-16.11; P < .0001).
Patients who did not achieve a CMR by PET scan displayed 3-year PFS rates of 64% and 4% in the ctDNA-MRD–negative (n = 20) and –positive (n = 23) groups, respectively (HR, 6.78; 95% CI, 2.80-16.45; P < .0001).
Risk Factor Correlations
The analysis revealed that higher Ann Arbor stage disease correlated with MRD positivity, with patients having stage III or IV disease significantly more likely to be MRD positive compared with those with stage I or II disease (P < .05). Being categorized into a higher IPI risk group was also associated with increased MRD positivity.
Comparative Prognostic Performance
Subgroup analysis demonstrated that end of treatment ctDNA-MRD was more prognostic for PFS compared with IPI score or end of treatment PET-CT scan. Patients with an IPI score of 0 to 2 experienced a higher 36-month PFS rate versus those with a score of 3 to 5 (HR, 1.61; 95% CI, 0.93-2.79; P = .086). Those with a negative PET-CT scan had a higher 36-month PFS rate versus patients with a positive scan (HR, 5.31; 95% CI, 2.87-9.82; P < .0001).
"[Findings from] our study support the integration of ctDNA-MRD by PhasED-Seq as a standard component of response evaluation in [patients with DLBCL treated in the frontline setting]," Wang concluded.
