Rituximab, cyclophosphamide, mitoxantrone hydrochloride liposome, vincristine, and prednisone (R-CMOP) in elderly patients with newly diagnosed diffuse large B-cell lymphoma: A multicenter, prospective study

Abstract

Abstract Backgrou nd: Anthracycline-based chemotherapy remains the standard first-line treatment for patients with diffuse large B-cell lymphoma (DLBCL). However, elderly patients are often intolerant to the cardiotoxicity associated with traditional anthracyclines. Mitoxantrone hydrochloride liposome (Lipo-MIT), a novel-generation anthracycline agent, demonstrates an improved cardiac safety profile. Therefore, we investigated the efficacy and safety of Lipo-MIT in combination with rituximab, cyclophosphamide, vincristine, and prednisone (R-CMOP) in patients aged 60 years or older with newly diagnosed DLBCL. We previously presented preliminary data from this study, which reported an objective response rate (ORR) of 100% (presented at ASH 2024, Abstract #6487). Herein, we report further efficacy and safety data from an expanded patient cohort (ChiCTR2300078813). Methods This study enrolled patients aged ≥60 years with newly diagnosed DLBCL. Eligible patients were required to have at least one evaluable or measurable lesion according to the Lugano 2014 criteria. Patients received the R-CMOP regimen every 21 days for up to 6-8 cycles. The regimen consisted of: (1) Rituximab (375 mg/m² on day 0), cyclophosphamide (750 mg/m² on day 1), Lipo-MIT (18 mg/m² on day 1), vincristine (1.4 mg/m² on day 1, maximum dose 2 mg), and prednisone (100 mg on days 1-5) for patients aged 60-80 years; (2) Rituximab (375 mg/m² on day 0), cyclophosphamide (400 mg/m² on day 1), Lipo-MIT (12 mg/m² on day 1), vincristine (1 mg on day 1), and prednisone (40 mg/m² on days 1-5) for patients aged ≥80 years. The primary endpoint was ORR. Secondary endpoints included complete response rate (CRR), progression-free survival (PFS), overall survival (OS), and safety. Results As of May 14, 2025, a total of 34 patients with newly diagnosed DLBCL were enrolled. The median age was 68.5 years (range: 60–85 years), with 13 (38.2%) males and 21 (61.8%) females. Among these patients, 20 (58.8%) were non-germinal center B-cell (non-GCB) subtype, and 12 (35.3%) were germinal center B-cell (GCB) subtype. Twenty-three patients (67.6%) were classified as stage disease Ⅲ-Ⅳ, and 22 patients (64.7%) had an International Prognostic Index (IPI) score of 3–5. Additionally, 6 patients (17.6%) presented with B symptoms at diagnosis, and 1 patient (2.9%) had central nervous system (CNS) invasion. At the time of data cutoff, 28 patients were evaluable for efficacy. The median number of treatment cycles administered was 4.5. The ORR was 92.9% (26/28), and the CRR was 57.1% (16/28). The median follow-up duration was 5.6 months (range: 0.03–25.5 months). The median PFS was 13.8 months (95% CI: 5.5–22.2). The median duration of response (DoR) was 12.5 months (95% CI: 4.0–21.0). The median overall survival (OS) was not reached. Common grade 3/4 treatment-related adverse events (TRAEs) included lymphocytopenia (67.6%), leukopenia (35.3%), neutropenia (26.5%), anemia (14.7%), and hypokalemia (20.6%). Notably, no cardiotoxicity was reported during the study period. Conclusion The R-CMOP regimen demonstrated encouraging efficacy and a manageable safety profile in patients aged 60 years or older with newly diagnosed DLBCL. Further studies with continuation of follow-up are warranted to confirm the clinical significance of the survival outcomes.