Patients With DLBCL See No Additional Gains With Maintenance Rituximab After CHOP

A recent study found that rituximab maintenance therapy provides no additional benefit for patients with diffuse large B‐cell lymphoma (DLBCL) who are in complete remission (CR) after receiving rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy.

The randomized phase 3 trial from the Netherlands assessed whether intensification of rituximab during the first 4 cycles of CHOP can improve outcomes, compared with standard R‐CHOP. It was previously shown that intensification of rituximab was not more effective than standard CHOP, showing same CR‐rates and progression free survival (PFS) after induction.

This study looked at the second randomization for rituximab maintenance therapy. Patients in CR after induction treatment were randomized between rituximab maintenance and observation. According to the trial registry, the patient population included previously untreated patients aged 66 to 80 years with stage 2 to stage 4 DLBCL and CD20-positive B cells.

Researchers randomized patients between 24 months of rituximab maintenance at a dose of 375 mg/m² intravenously every 8 weeks (n = 199 ) or observation (n = 199). Computerized tomography scans were performed at 6, 12, 18 and 24 months in both arms.

The primary endpoint was disease-free survival (DFS) from maintenance randomization; secondary endpoints were overall survival (OS) and adverse events (AEs).

The majority of patients (54%) had a high‐intermediate or high age-adjusted International Prognostic Index (aaIPI) score. Nearly half were male with a median age of 65 years (range 31‐80); 48% were 66 years or older.

After a median follow‐up of 79.9 months (maximum 125.7 months), the 5‐year DFS rate was 79% for rituximab maintenance versus 74% for observation.

This difference was not statistically significant, with a hazard ratio of 0.83 (95% confidence interval 0.57‐1.19, P = .31, adjusted for age and aa‐IPI).

The secondary endpoint of OS was also not significantly different (85% versus 83% at 5 years).

In addition, no clinical subgroup benefited from rituximab maintenance.

Toxicity was mild; grade 3 and 4 AEs were reported in 17% and 6% of patients, respectively. Infection was the most frequent AE; neutropenia was seen in 1% (grade 3) and 3% (grade 4) of patients.

Reference

Lugtenburg P, de Nully Brown P, van der Holt B, et al. Rituximab maintenance for patients with diffuse large B‐cell lymphoma in first complete remission: results from a randomized Hovon‐Nordic lymphoma group phase III study. Presented at: 15th International Conference on Malignant Lymphoma Palazzo dei Congressi, June 18-22, 2019; Lugano, Switzerland. Abstract 043.