Quantification of MRD in rituximab plus CHOP (R-CHOP) therapy in follicular lymphoma (FL): Results of a randomized trial comparing the concurrent and sequential administrations

Abstract

6704 Background: Optimal combination schedule of R-CHOP for untreated FL is still uncertain. Quantitative evaluation of MRD may suggest a correlation between the treatment schedule and its outcome. Methods: We conducted a randomized phase II study comparing 6 cycles of R-CHOP (concurrent; Arm C) and 6 cycles of CHOP followed by weekly 6 doses of rituximab (sequential; Arm S) for previously untreated, advanced-stage indolent B-cell lymphoma, mainly consisting of FL. DNA of bone marrow (BM) and peripheral blood (PB) were obtained before treatment (baseline), after 3 cycles and 6 cycles of R-CHOP/CHOP, and 4 months after R-CHOP/CHOP followed by rituximab (4 mo). Bcl-2/JH translocation was amplified and quantified by real-time PCR. Results: Sixty-five (94%) of 69 enrolled patients (pts) were diagnosed as having FL by the central pathology review. Bcl-2(MBR)/JH translocation in BM and/or PB were detectable in 27 pts (14 pts in Arm C and 13 pts in Arm S). Faster decrease in bcl-2/JH copy numbers, and thus higher clearance rate of MRD, were seen in Arm C. Bcl-2/JH copy numbers in PB at 6 cycles of Arm S were significantly higher than those of Arm C. However, the overall MRD clearance rate at 4 months were similarly high in both arms. %PFS at three years was 58.1% for Arm C and 69.7% for Arm S (P=0.322, Log-rank test). Conclusions: Both concurrent and sequential R-CHOP treatments effectively eradicated MRD in pts with untreated FL. Although the concurrent R-CHOP treatment showed faster clearance of MRD, it may not lead to the prolongation of PFS. . Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Zenyaku Kogyo Co. Ltd.