The following is a summary of “Minimal Residual Disease Status Predicts Outcome in Patients With Previously Untreated Follicular Lymphoma: A Prospective Analysis of the Phase III GALLIUM Study,” published in the December 2023 issue of Oncology by Pott, et al.
For a study, researchers sought to evaluate minimal residual/detectable disease (MRD) as a prognostic indicator in previously untreated follicular lymphoma (FL) patients from the randomized, multicenter GALLIUM trial.
Patients underwent induction with obinutuzumab (G) or rituximab (R) plus bendamustine, or cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) or cyclophosphamide, vincristine, prednisone (CVP) chemotherapy, followed by maintenance with the same antibody in responders. MRD status was evaluated at predefined time points (mid-induction [MI], end of induction [EOI], and at 4-6 monthly intervals during maintenance and follow-up). The survival analysis included patients with evaluable biomarker data at diagnosis.
MRD positivity was linked to inferior progression-free survival (PFS) at MI (hazard ratio [HR], 3.03 [95% CI, 2.07 to 4.45]; P < .0001) and EOI (HR, 2.25 [95% CI, 1.53 to 3.32]; P < .0001). MRD response was higher after G- versus R-chemotherapy at MI (94.2% vs. 88.9%; P = .013) and EOI (93.1% vs. 86.7%; P = .0077). Late responders (MI-positive/EOI-negative) had significantly poorer PFS than early responders (MI-negative/EOI-negative; HR, 3.11 [95% CI, 1.75 to 5.52]; P = .00011). The lowest MRD positivity proportion was observed in patients receiving bendamustine at MI (4.8% vs. 16.0% in those receiving CHOP; P < .0001). G seemed to compensate for less effective chemotherapy regimens, with similar MRD response rates observed across the G-chemo groups. During maintenance, more patients treated with R than with G were MRD-positive (R-CHOP, 20.7% vs. G-CHOP, 7.0%; R-CVP, 21.7% vs. G-CVP, 9.4%). Throughout maintenance, MRD positivity correlated with clinical relapse.
MRD status is indicative of outcome after induction and during maintenance, with MRD negativity being crucial for long-term disease control in FL. The higher MRD responses after G- versus R-based treatment confirm more effective tumor cell clearance.
Reference: ascopubs.org/doi/10.1200/JCO.23.00838