Phase I and pharmacokinetic study of oral fludarabine phosphate in relapsed indolent B-cell non-Hodgkin's lymphoma

Development of fludarabine formulations in the treatment of chronic lymphocytic leukemia

Fludarabine is an antineoplastic agent used in the treatment of hematological malignancies, particularly chronic lymphocytic leukemia (CLL) and indolent B-cell lymphoma. Because of its immunosuppressive effects, fludarabine has been added to reduced intensity conditioning regimens. The oral formulation of fludarabine has become widely available. Pharmacokinetic studies have shown that an oral dose of 40 mg/m²/d would provide systemic drug exposure similar to the standard intravenous (IV) dose of 25 mg/m²/d. The oral dose can be taken once daily without any dietary restrictions. Dose adjustments are mandatory in patients with renal impairment to avoid increased toxicity. Several noncomparative trials in previously untreated and treated patients with CLL have shown that treatment with the oral formulation demonstrates similar efficacy compared to historical control groups treated with the IV formulation. The tolerability profile of oral fludarabine seems similar to that of the IV formulation. Myelosuppression and infectious complications are the most frequently reported adverse events. Gastrointestinal toxicity is more frequent with the oral formulation, but is usually of mild or moderate severity. Although oral fludarabine makes treatment more convenient, health care workers must be aware of the compliance behavior of each patient.

Combination therapy with rituximab and intravenous or oral fludarabine in the first-line, systemic treatment of patients with extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue type

BACKGROUND

Currently, there are no consensus guidelines regarding the best therapeutic option for patients with extranodal marginal zone lymphomas of the mucosa-associated lymphoid tissue (MALT) type.

METHODS

Patients with systemically untreated or de novo extranodal MALT lymphoma received rituximab 375 mg/m(2) intravenously on Day 1 and fludarabine 25 mg/m(2) intravenously on Days 1 through 5 (Days 1-3 in patients aged >70 years) every 4 weeks, for 4 to 6 cycles. After the first cycle, oral fludarabine could be given orally at 40 mg/m(2) on the same schedule. After 3 cycles, a workup was done. Patients who achieved a complete remission (CR) received an additional cycle, and patients who achieved a partial remission (PR) received a total of 6 cycles.

RESULTS

Twenty-two patients were studied, including 12 patients with gastric lymphoma and 10 patients with extragastric MALT lymphoma. Six patients (27%) had stage IV disease. In total, 101 cycles were administered (median, 4 cycles per patients). After the third cycle, 13 patients (62%) achieved a CR, and 8 patients (38%) achieved a PR. Primary extragastric disease was an adverse factor to achieve CR after 3 cycles of chemotherapy (hazard ratio, 23.3; 95% confidence interval, 2.0-273.3). At the end of treatment, the overall response rate was 100%, and 90% of patients achieved a CR. The progression-free survival rate at 2 years in patients with gastric and extragastric MALT lymphoma was 100% and 89%, respectively. Toxicities were mild and mainly were hematologic.

CONCLUSIONS

Combination therapy with rituximab and fludarabine is a very active treatment with favorable safety profile as first-line systemic treatment for patients with extranodal MALT lymphoma.

Reduced-intensity conditioning allogeneic hematopoietic cell transplantation using oral fludarabine as part of the conditioning regimen

BACKGROUND

In 2003, oral fludarabine was introduced for the treatment of patients with hematologic malignancies as an alternative to its intravenous (i.v.) formulation. In an attempt to simplify the management of patients undergoing reduced intensity allogeneic hematopoietic transplantation, we have incorporated oral fludarabine in the conditioning regimen.

METHODS

We present a non-randomized retrospective analysis of 37 patients conditioned with oral fludarabine compared with 144 patients conditioned with the i.v. formulation. In addition to fludarabine, the conditioning regimens also included melphalan or busulfan depending on the underlying disease. Donors were HLA-matched siblings in 75% of cases and unrelated donors in the remaining 25%.

RESULTS

Eight patients (22%) receiving oral fludarabine were switched to the i.v. route because of gastrointestinal toxicity (three patients), patient preference (two patients) and physician preference (three patients). There were no statistical differences in terms of hospital admission (P=0.16), time to neutrophil engraftment (P=0.35), time to platelet engraftment (P=0.38), acute graft versus host disease rate (P=0.71) and non-relapse mortality at days +30 (P=1.0) and +100 (P=0.43).

DISCUSSION

This preliminary analysis confirms that oral fludarabine can replace its i.v. formulation as part of reduced-intensity conditioning regimens with no deleterious effect on any of the early transplantation outcomes. In addition, oral fludarabine can be more convenient for patients and caregivers, facilitating its implementation.

Phase II study of oral fludarabine in combination with rituximab for relapsed indolent B-cell non-Hodgkin lymphoma

Oral fludarabine is more convenient than intravenous fludarabine in an outpatient setting. To assess the efficacy and toxicity of oral fludarabine in combination with rituximab in patients with relapsed indolent B-cell non-Hodgkin lymphoma (B-NHL), we conducted a multicenter phase II study. Patients with relapsed indolent B-NHL with two or fewer prior regimens and up to 16 doses of rituximab were eligible. Patients received 375 mg/m(2) rituximab on day 1, and 40 mg/m(2) oral fludarabine once daily on days 1 through 5 every 28 days for up to six cycles. The primary endpoint was the overall response rate. Forty-one patients were enrolled, including 38 (93%) with follicular lymphoma. Thirty-four patients (83%) had received rituximab as prior therapy. Twenty-seven patients (66%) completed the planned six cycles. Dose reduction of oral fludarabine was required in 17 patients (41%). The overall response rate was 76% (31 of 41 patients; 95% confidence interval, 60-88%) with a complete response rate of 68% (28 of 41 patients; 95% confidence interval, 52-82%). Median progression-free survival for the 41 patients was 19.7 months (95% confidence interval, 12.3-26.5 months). Hematological toxicities, including grade 4 neutropenia (68%), were the most frequent toxicities. Non-hematological toxicities were mild, except for one patient who died of Pneumocystis jiroveci pneumonia 4 months after the protocol treatment. In conclusion, oral fludarabine in combination with rituximab is a highly effective and convenient therapy for patients with relapsed indolent B-NHL who have mostly been pretreated with rituximab.

Fludarabine in the treatment of chronic lymphocytic leukemia: a review

Fludarabine (FAMP) is the most effective and most extensively studied purine analog in indolent B-cell malignancies. Its use is indicated for first-and second-line treatment of B-cell chronic lymphocytic leukemia (B-CLL). FAMP as a single agent has produced superior response rates and progression-free survival than standard therapy with chlorambucil and alkylator-based regimen. Efficacy of FAMP may be increased by combining this purine analog with other chemotherapeutic and non-chemotherapeutic agents. FAMP and cyclophosphamide combination (FC) has shown promising results with higher overall response and complete response rates than FAMP in monotherapy, although no difference has been detected in survival. Quality of response and eradication of minimal residual disease (MRD) have been reported to be associated with prolonged survival. Eradication of MRD has been achieved by combining FC with mitoxantrone or monoclonal antibody including alemtuzumab or rituximab or both. FAMP has been widely used in non-myeloablative conditioning regimens, often combined with a variety of other cytotoxic agents, with the aim of inducing enough immunosuppression to allow successful engraftment and to exert some pretransplant anti-tumor activity. The current paper provides an overview of use of FAMP as a single agent or as a cornerstone of different therapeutic strategies for treatment of B-CLL patients.