Rituximab response in follicular lymphoma is associated with the rs20575 polymorphism in TRAILR1 extrinsic apoptosis trigger.

OBJECTIVE: Rituximab in combination with chemotherapy has been proven to increase progression-free and overall survival in follicular lymphoma (FL), but there is considerable interindividual variability in the response. Extrinsic pathway apoptosis triggered by death receptors seems to be involved in the mechanism of action of monoclonal antibodies. This study aimed to assess the association between TRAILR1/TRAIL polymorphisms (rs20575, rs20576, rs2230229, rs12488654) and rituximab response and the relationship with FASL rs763110, previously found to be associated with rituximab response. PATIENTS AND METHODS: Polymorphisms were determined in a study cohort of 125 FL patients treated with rituximab as first-line treatment and correlated with response, which was scored according to the International Working Group Consensus Revised as complete response, partial response, stable disease, and progressive disease. RESULTS: No significant association with response was found for rs20576, rs2230229, and rs12488654 polymorphisms. In contrast, rs20575 GC/GG carriers were more partial/nonresponders (88.2%) than complete responders (72.5%), showing a trend toward statistical significance (P=0.064). In a multivariable setting, we found that female sex [odds ratio=0.355, 95% confidence interval (CI): 0.137-0.922, P=0.033] and the TRAILR1 rs20575 CC genotype (odds ratio=0.162, 95% CI: 0.035-0.757, P=0.021) were independent positive predictive factors of complete clinical response to rituximab, constructing a parsimonious model with good calibration [χ of 5.719 (d.f.=6, P=0.455)] and discrimination (C-statistic=0.739, 95% CI: 0.636-0.842). CONCLUSION: After studying the pharmacogenetic role of TRAILR1/TRAIL polymorphisms in rituximab-treated FL patients, we found that the rs20575 CC genotype is an independent predictive factor of better rituximab response, indicating the possible involvement of death receptors in anti-CD20 mechanisms of action.

Long-Term Follow-Up of a Phase II Trial of Six Cycles of Dose-Dense R-CHOP-14 for First-Line Treatment of Diffuse Large B-Cell Lymphoma in Young and Elderly Patients.

BACKGROUND/AIMS: Rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) every 14 days seems to achieve better outcomes than R-CHOP every 21 days in diffuse large B-cell lymphoma (DLBCL) patients. Currently, the standard regimen is R-CHOP every 21 days. METHODS: This is a phase II clinical trial of treatment with 6 cycles of R-CHOP-14 with pegfilgrastim support in 2 populations of previously untreated DLBCL patients aged ≥65 years (n = 73) or <65 years (n = 51) with low-risk International Prognostic Index scores (0-2). RESULTS: With a median follow-up of 63.7 months, the 5-year event-free survival rate was 53.8% in patients aged ≥65 years and 71.0% in patients aged <65 years. The 5-year overall survival rate was 71.4 and 89.8%, respectively. The complete remission rate was 69.9% for older and 80.4% for younger patients. The median relative dose intensity of cytotoxic drugs was 143.2% in the elderly and 149.1% in the young patients. Febrile neutropenia was the most common grade 3-4 adverse event, being higher in elderly patients (21.3 vs. 9.3%). Eight deaths (7 in elderly patients) were considered treatment related. CONCLUSION: In conclusion, the R-CHOP-14 regimen is feasible and very active, though it is more toxic in elderly patients mainly due to an increased incidence of infections. New strategies, such as new monoclonal antibodies or new targeted therapies, are needed to improve the outcomes of DLBCL patients.