Sequential therapy with fludarabine, high-dose cyclophosphamide, and rituximab in previously untreated patients with chronic lymphocytic leukemia produces high-quality responses: molecular remissions predict for durable complete responses.

PURPOSE: Modern combination strategies are active in chronic lymphocytic leukemia (CLL) but can have significant myelosuppression and immunosuppression that may require dose attenuation for safety. We explored a sequential treatment strategy to allow safe delivery of active agents at full doses. Previously, we studied sequential therapy with fludarabine followed by cyclophosphamide (F-->C). In that study, cyclophosphamide consolidation improved the frequency of complete response (CR) four-fold. Subsequently, rituximab was added to this regimen (F-->C-->R). PATIENTS AND METHODS: Thirty-six previously untreated CLL patients received therapy with fludarabine 25 mg/m(2) on days 1 through 5 every 4 weeks for six cycles, followed by consolidation with cyclophosphamide 3,000 mg/m(2) administered every 3 weeks for three cycles, followed by consolidation with weekly rituximab 375 mg/m(2) for four cycles. Evaluation for minimal residual disease included flow cytometry and a highly sensitive clonotypic polymerase chain reaction (PCR). The median age was 59 years (range, 37 to 71 years), 61% of patients had high-risk disease, and 58% had unmutated IgV(H) genes. RESULTS: There were 32 responses (89%), including 22 CRs (61%). Consolidation with cyclophosphamide improved responses in 13 patients (36%); nine patients (25%) further improved their response with rituximab. Twenty patients (56%) achieved flow cytometric CRs, and 12 patients (33%) achieved a molecular CR (PCR negative). Patients achieving molecular CRs had an excellent prognosis with a plateau in the response duration curve, and 90% remain in clinical CR at 5 years. For the entire group, 5-year survival rate is 71% compared with a rate of 48% with our prior F-->C regimen (P = .10). CONCLUSION: Sequential therapy with F-->C-->R yields improvement in quality of response, with many patients achieving a PCR-negative state.

Pentostatin, cyclophosphamide, and rituximab is an active, well-tolerated regimen for patients with previously treated chronic lymphocytic leukemia.

PURPOSE: Purine analogs and alkylators are important agents for treating chronic lymphocytic leukemia (CLL). Early studies combining fludarabine and chlorambucil were abandoned owing to increased toxicity from overlapping myelosuppression and immunosuppression. Of the purine analogs active in CLL, pentostatin appears to be the least myelosuppressive. We previously reported that pentostatin and cyclophosphamide (PC) is active and well-tolerated in patients with relapsed or refractory CLL. Subsequently, we added rituximab, and now report on this three-drug combination. PATIENTS AND METHODS: We treated 46 patients with either previously treated CLL (32 patients) or other low-grade B-cell neoplasms (14 patients). Patients received pentostatin 4 mg/m2, cyclophosphamide 600 mg/m2, and rituximab 375 mg/m2 (PCR). All drugs were administered on the same day (rituximab omitted from cycle 1), and patients received six cycles at 3-week intervals. Filgrastim, sulfamethoxazole/trimethoprim, and acyclovir were administered prophylactically. RESULTS: The median age was 62 years (range, 30 to 80 years). The median number of prior regimens was two (range, one to seven). For CLL patients, there were 24 responses (75%), including eight complete responses (25%). In fludarabine-refractory patients, 75% responded. Toxicity was acceptable, with grade 3/4 infections (including fever of unknown origin) in 28%. The regimen was well tolerated, with 72% of patients receiving the planned treatment at full dose. CONCLUSION: PCR is safe and effective in previously treated patients with CLL. In comparison with our prior two-drug regimen, we find that rituximab did not seem to add significantly to the toxicity, but did appear to confer a survival advantage. Based on these results, we are currently studying PCR as initial therapy for patients with CLL.

Rituximab and ICE as second-line therapy before autologous stem cell transplantation for relapsed or primary refractory diffuse large B-cell lymphoma.

Patients with relapsed or primary refractory diffuse large B-cell lymphoma (DLBCL) who achieve complete response (CR) before autologous stem cell transplantation (ASCT) generally have better outcomes than those who achieve only partial response (PR). We investigated whether adding rituximab to the ifosfamide-carboplatin-etoposide (ICE) chemotherapy regimen (RICE) could increase the CR rate of patients with DLBCL under consideration for ASCT. Thirty-six eligible patients were treated with RICE, and 34 received all 3 planned cycles. The CR rate was 53%, significantly better than the 27% CR rate (P =.01) achieved among 147 similar consecutive historical control patients with DLBCL treated with ICE; the PR rate was 25%. Febrile neutropenia was the most frequent grade 3 or 4 nonhematologic toxicity; it occurred in 7.5% of delivered cycles. No patient had RICE-related toxicity that precluded ASCT. The median number of CD34(+) cells per kilogram mobilized was 6.3 x 10(6). Progression-free survival rates of patients who underwent transplantation after RICE were marginally better than those of 95 consecutive historical control patients who underwent transplantation after ICE (54% vs 43% at 2 years; P =.25). RICE appears to induce very high CR rates in patients with relapsed and refractory DLBCL; however, further studies are necessary to determine whether this treatment regimen will improve outcomes after ASCT.