Re-Treatment with Rituximab Plus Chemotherapy in Patients with Aggressive Lymphoma Treated Previously with CHOP or CHOP-Like Combinations Plus Rituximab.

Introduction. CHOP plus Rituximab has become the standard treatment for patients with aggressive B-cell lymphoma - particularly DLBCL -, after having shown a better response rate and event free survival over CHOP. However, a number of patients are resistant or relapse (R/R) after a good response. The aim of this study is to assess the efficacy of different Rituximab-containing regimens as salvage therapy in refractory/relapsed (R/R) patients with aggressive lymphoma who had been treated with R-CHOP or R-CHOP-like regimens as first-line therapy.

Patients and Methods. Thirty-six consecutive patients (34 evaluable for response) from the the same institution were reviewed. Twenty-five patients had diffuse large B-cell lymphoma, 4 mantle-cell lymphoma, and 7 Grade 3b follicular lymphoma. Patients received R-CHOP (n=21), DA-R-EPOCH (n=12) orR-Hyper-CVAD (n=3) as first-line therapy. The following salvage regimens were used in this study: R-ESHAP (n=1), R-ICE (n=10), R-TT (n=4), R-GemOx (n=13), Rituximab monotherapy (n=7), and R-MC (n=1). The first three of these regimens were considered ‘aggressive’ (AG) and the three remaining regimens were considered ‘less aggressive’ (LAG).

Results. Median patient age was 59.6 years (range: 31–84 years). The overall response rate (ORR) was 53% (38% complete response [CR]; 15% partial response {PR]. CR directly correlated with IPI score at relapse or therapy failure. ORR was similar in both types of regimen, however the response quality (determined as % CR) was 45% with the LAG regimen and 22% with the AG regimen.With a median follow-up of 29 months the overall survival (OS) was 53% and the event free survival (EFS) was 22%. EFS correlated inversely with IPI at relapse or therapy failure (P=0.015) and directly with response to salvage therapy (P=0.0002). in addition, EFS was slightly higher in patients treated with LAG regimen (42% vs 20%); however this was not statistically significant.

Conclusion. Some authors have hypothesised that ORR appears to decrease when patients who had previously received Rituximab + chemotherapy for first-line therapy were treated with Rituximab + chemotherapy as salvage therapy at relapse. However, our data indicate that responses to Rituximab + chemotherapy continue to occur in these patients. In addition, ‘aggressive’ salvage regimens do not achieve better responses. Large, prospective studies are requires in order to verify the findings of this study.