In younger patients with mantle cell lymphoma (MCL), pre-transplant MRD status in both bone marrow and peripheral blood can be an early predictor of progression-free survival (PFS) and overall survival (OS) following autologous hematopoietic cell transplant (AHCT), according to a study presented at the 62nd American Society of Hematology Annual Meeting & Exposition.
A team of researchers led by Mary Callanan, PhD, of the University Hospital F. Mitterrand and Inserm UMR in France, conducted an analysis in 220 minimal residual disease (MRD)-evaluable patients to examine MRD response rates and their impact on prognosis at the pre-AHCT induction phase.
In a separate analysis, the investigators assessed the prognostic value of combining molecular MRD and positron emission tomography (PET) for outcome prediction in both the pre- and post-AHCT settings. Patients in this study were younger than 66 years and were previously untreated. All patients received four courses of R-DHAP (rituximab, dexamethasone, cytarabine, and cisplatin) followed by AHCT.
In the 195 MRD-evaluable patients who completed R-DHAP induction therapy, MRD negativity was found in 77% of peripheral blood and 64% of bone marrow samples. The MRD status prior to AHCT was significantly predictive of PFS and OS (P<0.0001), including for peripheral blood samples (P=0.0295) and bone marrow samples (P=0.0407).
After AHCT, MRD-negative status was found in 94% of peripheral blood and 81% of bone marrow samples. The MRD status in peripheral blood and bone marrow samples was also predictive of PFS (P=0.0452 and P=0.0261, respectively).
Rituximab maintenance improved PFS and OS in patients who were MRD-negative prior to (peripheral blood [P=0.0260]; bone marrow [P=0.0405]) or after AHCT (peripheral blood [P=0.001]; bone marrow [P=0.007]). The combination of PET and MRD status also improved prediction of PFS in both the pre- (peripheral blood [P< 0.0001]; bone marrow [P=0.0028]) and post-AHCT setting (peripheral blood [P<0.0001]; bone marrow [P=0.0082]).
“Early sequential MRD monitoring at the pre-AHCT treatment phase and directly post-AHCT thus offers strong potential for early clinical outcome prediction, as a surrogate clinical endpoint, and for MRD-guided, risk-adapted treatment in MCL,” the researchers concluded.