ORLANDO, Fla.—An ongoing evaluation has shown comparable rates of secondary myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML) and other secondary neoplasia (sNPL) among 3 treatment regimens: bendamustine plus rituximab (B-R); cyclophosphamide, doxorubicin, vincristine, prednisone plus rituximab (CHOP-R); and fludarabine-rituximab (F-R). These results, combined with data from other studies showing improved efficacy with B-R vs CHOP-R or F-R, confirm the value of B-R as a treatment option in patients with follicular, indolent, or mantle cell lymphoma.

Consideration of potential therapy-related sequelae, such as sNPL, is particularly important now that long-term survival among patients with low grade/indolent non-Hodgkin’s lymphoma (iNHL) is increasingly common, Mathias J. Rummel, MD, PhD, Justus-Liebig-Universität Giessen, Giessen, Germany, and colleagues stated in a poster presentation during the 52nd American Society of Hematology Meeting and Exposition. However, no data have been reported concerning such complications with the B-R regimen in this population.

The investigators obtained data from 2 randomized studies. The Study Group Indolent Lymphomas, (StiL) Germany, NHL-1 study compared bendamustine 90 mg/m² days 1 and 2 plus rituximab 375 mg/m² day 1 (every 28 days) with CHOP-R (every 21 days) as first-line therapy in 513 patients (260 B-R, 253 CHOP-R). Median age was 64 years (range, 31–83 years). StiL-study NHL-2 compared B-R with fludarabine 25 mg/m² days 1–3 plus rituximab 375 mg/m² day 1 (every 28 days) in 184 patients with relapsed disease (96 B-R, 88 F-R) who had received a median of 1 prior therapy (range, 1–7). Median age was 68 years (range, 38–87 years).

As of May 2010, median observation time was 35 months for patients in the NHL-1 study and 33 months for NHL-2. The majority of patients in both studies received 6 cycles of therapy. In NHL-1, 16 patients (6.2%) developed sNPL after B-R as first-line treatment compared with 19 (7.5%) after CHOP-R. Most (87.5%) were solid tumors: after B-R, 4 gastrointestinal, 4 urothelium, 2 prostate, 2 squamous epithelium, 1 bronchial, and 1 adrenal; and, after CHOP-R, 6 gastrointestinal, 5 prostate, 3 bronchial, 2 breast, 1 melanoma, 1 urothelium, and 1 endocrinal pancreas.

Rate of secondary hematological neoplasias did not differ between arms: after B-R, 1 MDS and 1 T-cell lymphoma occurred and, after CHOP-R, 1 AML and 1 Hodgkin’s lymphoma. Median time from treatment initiation to diagnosis of a sNPL was 18.5 months for patients in the B-R arm and 14 months for the CHOP-R arm. After completing study therapy and prior to a diagnosis of sNPL, 5 patients receiving B-R and 2, CHOP-R, received additional chemotherapy.

In the NHL-2 study, 6 patients (6.3%) developed sNPL after B-R as relapse therapy vs 9 (11%) after F-R. Of these, 3 patients in the B-R group and 2 patients in the F-R group developed a secondary hematological neoplasia (2 MDS, 1 Hodgkin’s lymphoma after B-R; 2 AML/MDS after F-R). Solid tumors were observed in 3 patients following B-R (2 urothelium, 1 squamous epithelium), and in 8 following F-R (3 squamous epithelium, 2 bronchial, 1 gastrointestinal, 1 urothelium, 1 anal). Median time from initiation of study therapy to diagnosis of sNPL was 33 months for the B-R group and 24.5 months for the F-R group.

Longer-term  follow-up will provide important additional information on the rate of sNPL after B-R vs other anti-lymphoma regimens, they concluded.