Fludarabine: a phase II trial in patients with previously treated low-grade lymphoma

Purine Analogue Combinations for Indolent Lymphomas

Indolent lymphomas are a group of lymphoid malignancies with differing patterns of behavior and responses to treatment. The progress in treating patients with hairy cell leukemia (HCL) using nucleoside analogues can be used as a model for other indolent B-lymphoproliferative disorders, such as follicular lymphoma. Recent advancements in therapeutic options available for these patients include combination therapy with agents that have differing mechanisms of action and non-overlapping toxicity. It has been shown that patients who are candidates for aggressive therapy might receive benefit, including disease-free survival and overall survival, from combination purine analogue therapy. Using these more aggressive therapeutic approaches earlier in the disease course and as maintenance therapy may further enhance outcomes. With the advent of these new therapies along with the molecular evaluation of these regimens, we may be nearing the time where the goal for more advanced indolent lymphoma will be to achieve a cure.

Phase II study of oral fludarabine phosphate in relapsed indolent B-Cell non-Hodgkin's lymphoma

PURPOSE

Although intravenous (IV) fludarabine phosphate is effective against indolent B-cell non-Hodgkin's lymphoma (B-NHL), IV administration for 3 to 5 consecutive days is inconvenient in an outpatient setting. To assess the efficacy and toxicity of oral fludarabine phosphate in patients with indolent B-NHL, we conducted a multicenter phase II study.

PATIENTS AND METHODS

Patients with relapsed indolent B-NHL received fludarabine phosphate tablets orally once daily on days 1 through 5 every 28 days for three to six cycles. The efficacy was separately analyzed in a mantle-cell lymphoma (MCL) cohort and indolent B-NHL except for MCL (IL) cohort. The primary end point was the overall response rate (ORR).

RESULTS

Fifty-two patients, including 46 in the IL cohort (41 with follicular lymphoma) and six in the MCL cohort, were registered, and all patients were eligible. Forty-one patients (79%) had received rituximab as prior therapy. In the IL cohort, the ORR and complete response rate were 65% (30 of 46 patients; 95% CI, 50% to 79%) and 30% (14 of 46 patients; 95% CI, 18% to 46%), respectively. One of six patients with MCL achieved a partial response. The median times to treatment failure for the 46 patients in the IL cohort and for the six patients in the MCL cohort were 8.6 and 6.1 months, respectively. Hematologic toxicities, including grade 4 neutropenia (37%), were the most frequent toxicities, and nonhematologic toxicities were mild.

CONCLUSION

Oral fludarabine phosphate is highly effective in patients with relapsed indolent B-NHL who have mostly been pretreated with rituximab and is more convenient than the IV formulation.

Radioimmunotherapy of non-Hodgkin’s lymphoma: Clinical development of the Zevalin regimen

Zevalin (ibritumomab tiuxetan; IDEC Pharmaceuticals Corporation, San Diego, CA, USA) was approved by the United States Food and Drug Administration on February 19, 2002, following 9 years of clinical development. Six clinical studies supported the Zevalin Biologics License Application. The Zevalin regimen is indicated for the treatment of patients with relapsed or refractory low-grade, follicular, or transformed B-cell non-Hodgkin's lymphoma (NHL), and for those with follicular NHL refractory to Rituxan (rituximab, MabThera; IDEC Pharmaceuticals Corporation, San Diego, CA and Genentech, South San Francisco, CA). In the year following FDA approval, approximately 1300 patients were treated in clinical trials or with the commercially available product.

Costs of drug delivery for CHOP, COP/CVP, and fludarabine: an international assessment

OBJECTIVES

The purpose of this analysis was to assess the real-life direct costs of drug delivery for frequently used chemotherapeutic regimens in patients with relapsed low-grade non-Hodgkin's lymphoma (NHL).

METHODS

This was a retrospective analysis of direct costs of drug delivery (acquisition plus administration) of relapsed low-grade NHL in 424 patients in Canada, Germany, and Italy. Results were expressed as an average treatment cost per patient for six cycles of chemotherapy. Exchange rates used were $1 (Canada)= currency 0.672, 1 DM (Germany)= currency 0.511, and 1 Lit (Italy)= currency 0.000517.

RESULTS

Direct costs of drug delivery were greater for inpatients receiving fludarabine (Canada currency 12,669; Italy currency 13,027) than for CHOP (Canada currency 7856; Germany currency 7218; Italy currency 4251) or COP/CVP (Canada currency 7360; Germany currency 8449). Treatment administration setting was a major cost driver with inpatient treatment up to 9-fold more expensive than the same regimen given to outpatients. Drug administration costs comprised the largest proportion of the total for each regimen in the inpatient setting (69-98%). Costs of drug delivery in the outpatient setting were 10% to 65% of those in the inpatient setting. Again, fludarabine was more expensive (Italy currency 8493; Canada currency 7269) than CHOP (Canada currency 4403; Germany currency 2150; Italy currency 1264) and COP/CVP (Canada currency 3009; Germany currency 867). Administration costs were 2.5- to 15-fold higher for inpatients compared to outpatients.

CONCLUSIONS

Costs of drug administration are a major driver for total direct treatment costs in the treatment of relapsed low-grade NHL and are at least as important as drug acquisition costs. Drug administration practices, in terms of inpatient or outpatient treatment, are a major factor in determining overall direct costs. Therapeutic strategies, which offer shortened treatment duration and/or a simple mode of administration, are likely to be economically attractive.

Non-Hodgkin's lymphoma: the evolving role of purine analogues

Indolent non-Hodgkin's lymphoma is the commonest form of lymphoma in the USA and Europe, with a long natural history with multiple responses and relapses. Indolent lymphomas include follicular lymphomas (the more frequent subtype), immunocytoma, and small lymphocytic lymphomas according to the Revised European-American Lymphoma classification. The tendency has been to use simple oral medication until patients have more advanced aggressive disease but new agents such as the purine analogues have led to re-evaluation of this approach. The newer purine analogues -- fludarabine, 2-chlorodeoxyadenosine (cladribine) and deoxycoformycin (pentostatin) -- are a group of potently lymphotoxic antimetabolite molecules. Their activity in the indolent non-Hodgkin's lymphomas, in particular in the follicular subtype, may be due to their unique ability as antimetabolites to inhibit resting as well as dividing cells. Within the last decade they have moved from salvage therapy to front-line studies. Further insight into the mechanism of action of the purine analogues will to lead to further advances in this group of diseases.

Immunochemotherapy in indolent non-Hodgkin's lymphoma

Non-Hodgkin's lymphomas (NHLs) comprise a diverse group of lymphatic malignancies of primarily B-cell origin, which are steadily increasing in prevalence worldwide. Of these, the indolent NHLs, although initially responsive to a variety of therapeutic regimens, have a continuous relapsing nature and are essentially incurable. Consequently, novel and innovative treatments are urgently required to prolong overall survival in patients with this disease. Rituximab, a human-mouse chimeric monoclonal antibody that mobilizes host effector mechanisms to destroy B cells expressing the CD20 antigen, has proven single-agent efficacy in NHL. There is a powerful rationale for combining rituximab with conventional chemotherapeutic agents to improve the outcome in NHL. A study evaluating the efficacy of rituximab plus cyclophosphamide/doxorubicin/vincristine/prednisone (CHOP) immunochemotherapy has been conducted in 40 patients diagnosed with indolent NHL. The overall response rate was 95% (38 of 40 patients) and 22 patients (55%) experienced a complete response. No unexpected toxicity was observed with the combination therapy. Median time to progression is not reached after 50 months of follow-up. Using a highly sensitive polymerase chain reaction technique, it was also shown that rituximab plus CHOP resulted in the elimination of bcl-2-positive lymphoma cells. A further study assessing whether or not similar efficacy can be achieved using rituximab combined with fludarabine chemotherapy has provided very encouraging early results to date, with an initial overall response rate of 93% in 30 treated patients and a complete response rate of 80%. Clearance of bcl-2-positive cells, as observed in the CHOP study, has also been achieved in these patients. The combination of rituximab with conventional chemotherapeutic agents such as CHOP appears to be a viable treatment option for indolent NHL. Ongoing and planned studies will lead to the optimal use of rituximab for the treatment of NHL.

Fludarabine in alkylator-resistant follicular non-Hodgkin's lymphoma

Follicular small cell and follicular mixed small and large cell lymphoma (FL) are incurable with conventional chemotherapy, and generally follow a relapsing course, eventually becoming resistant to first-line therapy with alkylating agents. Fludarabine is a novel chemotherapeutic agent that is effective in FL, but its role in alkylator-resistant disease remains unclear. We conducted a retrospective review of all patients with alkylator-resistant FL treated with fludarabine. Patients were identified from pharmacy records and included if they fulfilled criteria for alkylator-resistant FL. Resistance was defined as failure to achieve a partial response, progression while on therapy, or relapse within six months of completing therapy. Seventeen patients met the criteria of alkylator-resistant FL and were included in the analysis. All patients received fludarabine 25 mg/m(2) for five days. A median of 2.5 courses of fludarabine was given. One patient had a complete remission and eight patients had partial remissions, for an overall response rate of 53%. Median progression-free survival was 5.4 months and median overall survival was 15.4 months for all patients. Four patients underwent subsequent autologous stem cell transplantation; all required additional salvage chemotherapy for post-fludarabine relapses. Three patients remain in remission more than 12 months post-transplantation. Fludarabine produces partial responses in patients with advanced refractory FL; however, the duration of the response limits its utility in alkylator-resistant disease.

Response criteria for NHL: importance of 'normal' lymph node size and correlations with response rates

BACKGROUND

Oncologic literature cites many different definitions of critical response measurements.

PATIENTS AND METHODS

Response criteria (RC) for non-Hodgkin's lymphoma (NHL) were developed by lymphoma experts, endorsed by international lymphoma clinicians, and applied to a 166-patient rituximab (Rituxan, MabThera) trial by a third-party, blinded panel of NHL experts (LEXCOR). Retrospectively, we analyzed this data using variations of the original RC and comparing with recently published RC.

RESULTS

The definition of a 'normal' lymph node affected the complete response (CR) rate (< or = 1.0 x 1.0 cm, 6%; < or = 1.5 x 1.5 cm, 18%; < or = 2.0 x 2.0 cm, 28%); overall response rate (ORR) was not affected. CR rates increased progressively without > or = 28 days response confirmation: 12% vs. 6% (< or = 1.0 x 1.0 cm), 26% vs. 18% (< or = 1.5 x 1.5 cm), and 36% vs. 28% (< or = 2.0 x 2.0 cm). CR rate and duration of response (DR) were unaffected when only the six largest, rather than all lesions, were measured. When the new RC were applied, CR rate (32%) was higher and DR (13.9 months) and time to progression (15.6 months) were shorter in complete responders.

CONCLUSIONS

Standard RC must be consistently and rigorously applied for accurate comparisons between studies.

Hodgkin's disease and non-Hodgkin's lymphoma

The development of new classification schemes and prognostic analyses for lymphomas has helped to identify patients at high risk for relapse who may benefit from intensification of primary therapy. Conventional salvage therapy for relapsed follicular or low-grade lymphomas now includes monoclonal antibody therapy. The combination of chemotherapy and monoclonal antibody therapy may improve outcomes for patients with advanced-stage aggressive non-Hodgkin's lymphomas. Confirmatory randomized trials are now in progress. Therapy for Hodgkin's disease continues to evolve toward the most efficacious programs, which also minimize the long-term probability of toxicity. The combination of high-dose chemotherapy and stem cell transplantation is probably the most effective therapy for patients with relapsed or refractory Hodgkin's disease.

Cost-minimization analysis of CHOP, fludarabine and rituximab for the treatment of relapsed indolent B-cell non-Hodgkin's lymphoma in the U.K

The optimal therapy for patients with relapsed indolent B-cell non-Hodgkin's lymphoma is unclear. Combination chemotherapy such as CHOP (cyclophosphamide, doxorubicin, vincristine, prednisolone) or purine analogues including fludarabine are frequently used and the anti-CD20 monoclonal antibody rituximab has recently been licensed for use. However, no comparative studies of these therapies have been reported. Since relapsed indolent B-cell NHL is generally regarded as incurable with current therapies, the place of each of these therapies is likely to be determined by their relative efficacy, toxicity and cost. We undertook a literature review and a retrospective analysis of patients receiving combination chemotherapy for relapsed indolent B-cell NHL at our institution to determine the response rates and the duration of response when treated with CHOP or fludarabine. Reported response rates and median response duration for these regimens are similar, and similar to those reported in phase II studies of rituximab. A cost minimization analysis was therefore conducted. The per patient costs for the treatment of drug-related adverse events were pound 5049 for CHOP, pound 2953 for fludarabine and pound 109 for rituximab. When costs of a full course of each treatment were compared, the costs per patient for CHOP, fludarabine and rituximab were pound 7210 (pound 5975-8445), pound 10022 (pound 8917-11126) and pound 6080 (pound 5892-6267) respectively. In this preliminary analysis, rituximab appeared to have a similar efficacy rate to CHOP and fludarabine, but had significantly fewer adverse events and a lower total cost per patient. These data require confirmation in a prospective randomized study with formal assessment of cost-effectiveness.

Fludarabine, cyclophosphamide, and dexamethasone (FluCyD) combination is effective in pretreated low-grade non-Hodgkin's lymphoma

PURPOSE

Fludarabine phosphate is effective as a single agent in low-grade non-Hodgkin's lymphoma (NHL). Combined with other antineoplastic agents it enhances the antitumor effect. Our aim was to define the therapeutic efficacy and toxicity of a combination of fludarabine, cyclophosphamide and dexamethasone (FluCyD) in patients with advanced low-grade lymphoma.

PATIENTS AND METHODS

Twenty-five adults with pretreated advanced-stage low-grade NHL were treated with three-day courses of fludarabine 25 mg/m2/day, cyclophosphamide 350 mg/m2/day, and dexamethasone 20 mg/day, every four weeks for a maximum of six courses.

RESULTS

Of the 25 patients, 18 (72%) responded, 8 (32%) achieving CR and 10 (40%) PR. Seven were failures. The median follow-up was 21 months (5-26). Eight CR patients remain in CR after 5-21 months. Of 10 PR patients, 3 are in continuous PR without further treatment after 12, 17 and 18 months. Myelosuppression was the most prevalent toxic effect. Although severe granulocytopenia (granulocyte count nadir < 500/microliter) and thrombocytopenia (platelet count nadir < 50,000/microliter) occurred in only 10% and 16% of courses, respectively, slow granulocyte or platelet count recovery caused delay of 40% of the courses. Nine patients (36%) required discontinuation of therapy because of persistent granulocytopenia and/or thrombocytopenia: three after one course, three after 2-4 courses, and three after five courses. Thirteen infectious episodes in 11 patients complicated 11% of courses. Two of 10 patients monitored for the circulating EBV load showed increased viral load. One of these developed aggressive lymphoma. CD4+ lymphocytes declined from a pre-therapy median value of 425/microliter to 141/microliter post-treatment (P = 0.001). Non-hematologic toxicities were rare and mild.

CONCLUSIONS

The combination of fludarabine with cyclophosphamide and dexamethasone is effective in pretreated advanced-stage low-grade NHL. It may broaden the range of therapeutic options in the salvage treatment of these patients. The main toxicity of this combination is prolonged myelosuppression that may cause treatment delay or withdrawal. The benefit of adding granulocyte colony-stimulating factor, particularly in patients with poor marrow reserve, needs to be investigated.

Treatment of indolent lymphoma with fludarabine/mitoxantrone combination: a phase II trial

In an effort to reduce the risk of opportunistic infections, 25 patients with advanced indolent lymphoma (age range: 30-77 years) were treated, using a combination of fludarabine and mitoxantrone, without corticosteroids. Fludarabine was given at 25 mg/m2 for three daily doses, and mitoxantrone at 10 mg/m2. Cycles were repeated every four weeks for up to maximum response, and for no more than six months. Eight patients had follicular lymphoma, and 11 had CLL/SLL. Objective response was observed in 11 of 12 previously untreated patients, including five complete remissions, and in 10 of 13 previously treated patients, including three complete remissions. Only two relapsed patients failed to respond, whereas two patients were not evaluable. Hence, the overall response rate based on the intention-to-treat analysis was 84 per cent (95 per cent CI: 70-98 per cent). The median survival has not been reached after a 22-month follow-up. Median time to progression was 15 months. One patient on corticosteroids developed pneumocystis carinii pneumonia, and an elderly patient succumbed to neutropenic sepsis. Apart from granulocytopenia, the treatment was well tolerated. Omission of corticosteroids reduces the risk of opportunistic infections, while the activity of the combination against indolent lymphoma and CLL is maintained.

IDEC-C2B8 (Rituximab) Anti-CD20 Monoclonal Antibody Therapy in Patients With Relapsed Low-Grade Non-Hodgkin's Lymphoma

IDEC-C2B8 is a chimeric monoclonal antibody (MoAb) directed against the B-cell–specific antigen CD20 expressed on non-Hodgkin's lymphomas (NHL). The MoAb mediates complement and antibody-dependent cell-mediated cytotoxicity and has direct antiproliferative effects against malignant B-cell lines in vitro. Phase I trials of single doses up to 500 mg/m2 and 4 weekly doses of 375 mg/m2 showed clinical responses with no dose-limiting toxicity. We conducted a phase II, multicenter study evaluating four weekly infusions of 375 mg/m2 IDEC-C2B8 in patients with relapsed low-grade or follicular NHL (Working Formulation groups A-D). Patients were monitored for adverse events, antibody pharmacokinetics, and clinical response. Thirty-seven patients with a median age of 58 years (range, 29 to 81 years) were treated. All patients had relapsed after chemotherapy (median of 2 prior regimens) and 54% had failed aggressive chemotherapy. Infusional side effects (grade 1-2) consisting of mild fever, chills, respiratory symptoms, and occasionally hypotension were observed mostly with the initial antibody infusion and were rare with subsequent doses. Peripheral blood B-cell depletion occurred rapidly, with recovery beginning 6 months posttreatment. There were no significant changes in mean IgG levels and infections were not increased over what would be expected in this population. Clinical remissions were observed in 17 patients (3 complete remissions and 14 partial remissions), yielding an intent to treat response rate of 46%. The onset of these tumor responses was as soon as 1 month posttreatment and reached a maximum by 4 months posttreatment. In the 17 responders, the median time to progression was 10.2 months (5 patients exceeding 20 months). Likelihood of tumor response was associated with a follicular histology, with the ability to sustain a high serum level of antibody after the first infusion, and with a longer duration of remission to prior chemotherapy. One patient developed a detectable but not quantifiable immune response to the antibody that had no clinical significance. IDEC-C2B8 in a dose of 375 mg/m2 weekly for 4 weeks has antitumor activity in patients with relapsed low-grade or follicular NHL. Results with this brief, outpatient treatment compare favorably with results with standard chemotherapy, and IDEC-C2B8 has a better safety profile. Further studies evaluating IDEC-C2B8 in other types of lymphoma either alone or combined with chemotherapy are warranted.

IDEC-C2B8 (Rituximab) Anti-CD20 Monoclonal Antibody Therapy in Patients With Relapsed Low-Grade Non-Hodgkin's Lymphoma

IDEC-C2B8 is a chimeric monoclonal antibody (MoAb) directed against the B-cell–specific antigen CD20 expressed on non-Hodgkin's lymphomas (NHL). The MoAb mediates complement and antibody-dependent cell-mediated cytotoxicity and has direct antiproliferative effects against malignant B-cell lines in vitro. Phase I trials of single doses up to 500 mg/m2 and 4 weekly doses of 375 mg/m2 showed clinical responses with no dose-limiting toxicity. We conducted a phase II, multicenter study evaluating four weekly infusions of 375 mg/m2 IDEC-C2B8 in patients with relapsed low-grade or follicular NHL (Working Formulation groups A-D). Patients were monitored for adverse events, antibody pharmacokinetics, and clinical response. Thirty-seven patients with a median age of 58 years (range, 29 to 81 years) were treated. All patients had relapsed after chemotherapy (median of 2 prior regimens) and 54% had failed aggressive chemotherapy. Infusional side effects (grade 1-2) consisting of mild fever, chills, respiratory symptoms, and occasionally hypotension were observed mostly with the initial antibody infusion and were rare with subsequent doses. Peripheral blood B-cell depletion occurred rapidly, with recovery beginning 6 months posttreatment. There were no significant changes in mean IgG levels and infections were not increased over what would be expected in this population. Clinical remissions were observed in 17 patients (3 complete remissions and 14 partial remissions), yielding an intent to treat response rate of 46%. The onset of these tumor responses was as soon as 1 month posttreatment and reached a maximum by 4 months posttreatment. In the 17 responders, the median time to progression was 10.2 months (5 patients exceeding 20 months). Likelihood of tumor response was associated with a follicular histology, with the ability to sustain a high serum level of antibody after the first infusion, and with a longer duration of remission to prior chemotherapy. One patient developed a detectable but not quantifiable immune response to the antibody that had no clinical significance. IDEC-C2B8 in a dose of 375 mg/m2 weekly for 4 weeks has antitumor activity in patients with relapsed low-grade or follicular NHL. Results with this brief, outpatient treatment compare favorably with results with standard chemotherapy, and IDEC-C2B8 has a better safety profile. Further studies evaluating IDEC-C2B8 in other types of lymphoma either alone or combined with chemotherapy are warranted.