Bendamustine plus rituximab (B-R) versus CHOP plus rituximab (CHOP-R) as first-line treatment in patients with indolent lymphomas: Nine-year updated results from the StiL NHL1 study

7501 Background: This multicenter, randomized, phase III study compared B-R and CHOP-R as first-line treatment in patients (pts) with indolent lymphomas or mantle cell lymphoma and was first published in The Lancet in 2013. The final analysis demonstrated a significantly prolonged progression-free survival (PFS) in the B-R group compared to the CHOP-R group, with a median PFS of 69.5 vs. 31.2 months, respectively. In the current analysis, we present updated results for overall survival (OS), time-to-next-treatment (TTNT), and secondary malignancies (sNPL) with a median follow-up of 113 months for patients with indolent lymphomas (excluding MCL). Methods: 447 pts with indolent lymphomas were randomized to receive B-R or CHOP-R for a maximum of 6 cycles. The primary endpoint was PFS; secondary endpoints included OS, TTNT, and sNPL. Results: Patient characteristics were well balanced between arms; median age was 64 years. The difference in OS between the two treatment arms was not statistically significant, with 60 deaths in the B-R group vs 68 deaths with CHOP-R (HR 0.82, 95% CI 0.58 – 1.15, p = 0.249). The estimated 10-year survival rates were 71% for B-R and 66% for CHOP-R. TTNT was significantly prolonged with B-R compared with CHOP-R (HR 0.52, 95% CI 0.38 – 0.69, p < 0.001). Median TTNT was not yet reached in the B-R group (95% CI 124.9 – n.y.r) vs. 56 months in the CHOP-R group (95% CI 39.1 – 82.0). Patients treated initially with B-R needed fewer second-line treatments due to disease progression compared to CHOP-R treated pts: 73 pts (34%) in the B-R group received salvage treatment compared with 106 pts (52%) in the CHOP-R group. For B-R pts, CHOP-R was used as second-line therapy 26 times (36%), whereas B-R was used for pts initially treated with CHOP-R 49 times (46%). 36 pts with sNPL were observed in the B-R group compared with 39 in the CHOP-R group, with 7 hematological malignancies in both groups to date. Conclusions: In pts with previously untreated indolent lymphomas, B-R demonstrates a PFS and TTNT benefit over CHOP-R. Clinical trial information: NCT00991211.