Long-term Outcomes with HLX01 (HanliKang), a Rituximab Biosimilar, in Previously Untreated Patients with Diffuse Large B-cell Lymphoma: 5-year Follow-up Results of the Phase 3 HLX01-NHL03 Study

HLX01 (HanliKang) is a rituximab biosimilar that showed bioequivalence to reference rituximab in untreated CD20-positive diffuse large B-cell lymphoma (DLBCL) in the phase 3 HLX01-NHL03 study. Here, we report the 5-year follow-up results from the open-label extension part. Patients were randomised to either rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) or HLX01 plus CHOP (H-CHOP) every 21 days for up to six cycles. The primary efficacy endpoint was overall survival (OS), and secondary efficacy endpoint was progression-free survival (PFS). Of the 407 patients enrolled in HLX01-NHL03, 316 patients (H-CHOP = 157; R-CHOP = 159) were included in the 5-year follow-up for a median duration of 65.1 (range, 2.2-76.5) months. 96.5% of the patients had an International Prognostic Index (IPI) of 1 or 2, and 17.7% had bone marrow involvement. The 5-year OS rates were 81.0% (95% CI: 74.9-87.5%) and 75.4% (95% CI: 68.9-82.6%)( HR: 0.75, 95% CI 0.47-1.20; p = 0.23) while 5-year PFS rates were 77.7% (95% CI: 71.4-84.6%) and 73.0% (95% CI: 66.3-80.3%) (HR: 0.84, 95% CI 0.54-1.30; p = 0.43) in the H-CHOP and R-CHOP groups, respectively. Treatment outcomes did not differ between groups regardless of IPI score and were consistent with the primary analysis. H-CHOP and R-CHOP provided no significant difference in 5-year OS or PFS in previously untreated patients with low or low-intermediate risk DLBCL.