Background:There is no single standard treatment (tx) modality for symptomatic chronic lymphocytic leukemia (CLL) patients (pts). Fludarabine, cyclophosphamide, and rituximab (FCR) is the prefered regimen for healthy, young pts (<65 years). However, through the disease course almost all pts in this group will relapse and may become refractory to fludarabine-containing regimens. Additionally, for older adults (>65 years) and pts with comorbidities fludarabine is not a suitable agent. Bendamustine combined with rituximab (BR) is an acceptable alternative in these patient groups.

Aim: To evaluate the efficacy and safety of BR in previously untreated or relapsed/refractory (R/R) CLL pts.

Patients and Methods: Ptswho received BR as first- or further lines of tx were enrolled in the study. Data were analysed as of August 2017. The standard dose of bendamustine was 70 mg/m2 in D1 and D2 for R/R pts and 90 mg/m2 in D1 and D2 for tx naive pts. Rituximab dose was 375 mg/m2 in the first cycle and 500 mg/m2 in consecutive cycles. Pts' demographics, disease stages, biological and cytogenetic prognostic markers, comorbidities, previous treatments, bendamustine dose, cycle durations, use of G-CSF, adverse events (AEs), tx responses and follow-up periods were noted retrospectively. Evaluation of response was established according to NCI-WG guidelines [Hallek et al, 2008]. All toxicities were assessed according to the National Cancer Institute's Common Toxicity Criteria (NCI-CTC), version 4.

Results: Nineteen ptswere enrolled in the study (Table 1). Thirteen pts were male and the median age at the time of BR treatment was 61 years (range, 41-80 years), with 9 pts (47%) older than 65 years. At the time of diagnosis, 7 pts (37%) were Rai stage IV. Del(13q), del(11q), and del(17p) were positive in 5, 1, and 2 pts, respectively. All pts had active disease as defined by the NCI-WG. Five pts received BR as first-line. Of the previously treated 14 pts, 71% had received fludarabine with either alkylating agents and/or rituximab. Median number of previous lines of tx was 2.

Among comorbidities, hypertension (32%), asthma/COPD (32%) and type 2 diabetes mellitus (3%) were the three most common.

Bendamustine dose ranged from 70 mg to 100 mg/m2. According to the physicians' decision, bendamustine was started as 70 mg in first cycle of tx and was escalated to the planned dose in all pts but three. All 6 intended courses were administered to 15 pts (79%), and in the remaining 4 pts, 3 died due to infections and one patient required early discontinuation due to prolonged neutropenia. In 8 pts (42%) tx cycle prolonged to 35 days and in 11 cases (58%) G-CSF were used during tx.

After a median follow-up of 17 months (mos), five of 19 pts (26%) had progressed at the time of analysis, and median time to next treatment (TTNT) was 12 mos (range, 5-34 mos). Treatment responses are shown in Table 2. During the follow-up 5 pts (26%) died. Two had multiple comorbidities, three received bendamustine doses ≥90 mg/m2. Deaths were due to R/R disease and/or infections. Median OS after treatment was 13 mos (range, 5-34 mos).

Overall, grade III-IV AEs occurred in 14 cases (74%): the most common toxicity was hematologic AEs (anemia in 2, neutropenia in 12, and thrombocytopenia in 2 cases), and serious infection occurred in six pts (2 bacterial pneumonia, 4 neutropenic fever). Non-hematologic toxicities were grade II rash in one, and grade II nausea in one patient.

Conclusion: BR is effective and safe in treatment naive CLL patients and shows notable activity in R/R pts. Major toxic effect are myelosuppresion and infections. Higher doses of bendamustine should be avoided in patients with comorbidities and older age.

Disclosures

No relevant conflicts of interest to declare.

Author notes

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Asterisk with author names denotes non-ASH members.

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