Samira Zeynalova

PURPOSE: To develop and validate a risk score for relapse in the CNS in patients with diffuse large B-cell lymphoma (DLBCL). PATIENTS AND METHODS: A total of 2,164 patients (18 to 80 years old) with aggressive B-cell lymphomas (80% DLBCL) treated with rituximab and CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone)-like chemotherapy, who were enrolled in studies from the German High-Grade Non-Hodgkin Lymphoma Study Group and the MabThera International Trial, were analyzed for occurrence of relapse/progression in the CNS. The resulting risk model was validated in an independent data set of 1,597 patients with DLBCL identified in the British Columbia Cancer Agency Lymphoid Cancer database. RESULTS: The risk model consists of the International Prognostic Index (IPI) factors in addition to involvement of kidneys and/or adrenal glands (CNS-IPI). In a three-risk group model, the low-risk group (46% of all patients analyzed), the intermediate-risk group (41%), and the high-risk group (12%) showed 2-year rates of CNS disease of 0.6% (CI, 0% to 1.2%), 3.4% (CI, 2.2% to 4.4%), and 10.2% (CI, 6.3% to 14.1%), respectively. Patients from the validation British Columbia Cancer Agency data set showed similar rates of CNS disease for low-risk (0.8%; CI, 0.0% to 1.6%), intermediate-risk (3.9%; CI, 2.3% to 5.5%), and high-risk (12.0%; CI, 7.9% to 16.1%) groups. CONCLUSION: The CNS-IPI is a robust, highly reproducible tool that can be used to estimate the risk of CNS relapse/progression in patients with DLBCL treated with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy. Close to 90% of patients with DLBCL belong to the low- and intermediate-risk groups and have a CNS relapse risk < 5%; they may be spared any diagnostic and therapeutic intervention. In contrast, those in the high-risk group have a > 10% risk of CNS relapse and should be considered for CNS-directed investigations and prophylactic interventions.

One thousand two hundred twenty-two patients treated in the Rituximab with CHOP over age 60 years (RICOVER-60) trial were examined for central nervous system (CNS) disease developing during first-line therapy or after a complete or partial remission had been achieved. Patients received 6 or 8 courses of CHOP (cyclophosphamide, adriamycin, vincristine, prednisone) administered every 2 weeks (CHOP-14) with or without rituximab. CNS prophylaxis for patients with involvement of bone marrow, testes, upper neck, or head consisted of intrathecal (i.th.) methotrexate (days 1 and 5 of first 2 courses). Fifty-eight cases of lymphoma in the CNS were observed (36/609 patients in the CHOP-14 and 22/608 patients in the arituximab-CHOP-14 [R-CHOP-14] arm). The estimated 2-year incidence of CNS disease was 6.9% (confidence interval [CI] 4.5; 9.3) after CHOP-14 and 4.1% (CI 2.3; 5.9) after R-CHOP-14. R-CHOP reduced the relative risk for CNS disease to 0.58 (95% CI 0.3; 1.0, P = .046). Cox regression analysis identified "involvement of more than 1 extranodal site" and "B-symptoms" as significant risk factors for CNS disease. Patients treated with R-CHOP-14 did not show any benefit from i.th. methotrexate. We conclude that elderly patients with aggressive CD20-positive lymphoma show a significantly lower incidence of CNS disease if treated with R-CHOP-14 instead of CHOP-14. Intrathecal methotrexate has no role in preventing CNS disease for patients treated with combined immunochemotherapy (R-CHOP-14)--with the possible exception of patients with testicular involvement.

Pharmacokinetics of 8 doses of rituximab (375 mg/m(2)) given in combination with 2-week cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone/prednisolone (CHOP-14) was determined by ELISA in 20 elderly patients with diffuse large B-cell lymphoma (DLBCL) 10 minutes before and after each infusion and 1 week and 1, 2, 3, 6, and 9 months after the last infusion. Population pharmacokinetic modeling was performed with nonlinear mixed-effect modeling software (NONMEM VI). Concentration-time data were fitted into an open 2-compartment model and total clearance, central compartment volume, intercompartment clearance, and volume of distribution at steady-state (Vd(ss)) were investigated. Total clearance was 9.43 mL/h and Vd(ss) was 9.61 l. Rituximab clearance was reduced (8.21 mL/h vs 12.68 mL/h; P = .003) and elimination half-life was prolonged in women compared with men (t(1/2β) = 30.7 vs 24.7 days; P = .003). Body weight also affected Vd(ss) (0.1 l increase of Vd(ss) per kilogram above median of 75 kg). A sex-dependent effect and the higher weight of males contribute to their faster rituximab clearance, which might explain why elderly males benefit less from the addition of rituximab to CHOP than females. This trial was registered on www.clinicaltrials.gov as numbers NCT00052936, EU-20243 (RICOVER-60 Trial), EU-20534, and NCT00726700 (Pegfilgrastim Trial).