Comparison of zuberitamab plus CHOP versus rituximab plus CHOP for the treatment of drug-naïve patients diagnosed with CD20-positive diffuse large B-cell lymphoma: a phase 3 trial

Background In patients with untreated CD20-positive diffuse large B-cell lymphoma (DLBCL), a phase 3 trial was carried out to evaluate the efficacy and safety of zuberitamab plus CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone; Hi-CHOP) versus rituximab plus CHOP (R-CHOP) treatment regimens.Methods In a 2:1 ratio, eligible patients were assigned randomly to receive treatment of six cycles of either 375 mg/m2 zuberitamab or rituximab together with conventional CHOP chemotherapy. The objective response rate (ORR) at C6D50 served as the primary endpoint, and a non-inferiority margin of 10% was established. The secondary endpoints included the complete response (CR) rate at C6D50, duration of response (DOR), progression-free survival (PFS) and event-free survival (EFS) judged by blinded-independent review committee (BIRC), overall survival (OS) and safety outcomes.Results Of the 487 randomized patients, 423 patients including 287 in the Hi-CHOP and 136 in the R-CHOP groups completed the C6D50 assessment. For the full analysis set (FAS) and per-protocol set (PPS), BIRC-assessed ORR at C6D50 for the Hi-CHOP and R-CHOP groups were 83.5% versus 81.4% and 95.3% versus 93.7%, respectively. The non-inferiority was confirmed as the lower limit of the two-sided 95% CI for the intergroup differences of −5.2% and −3.3%; both were >−10% in the FAS and PPS. The BIRC-assessed CR rate of Hi-CHOP was significantly higher in PPS (85.7% vs 77.3%, p=0.038), but comparable in FAS (75.2% vs 67.9%, p=0.092). After a median follow-up of 29.6 months, patients in the Hi-CHOP group had a slight advantage with regard to the DOR (HR 0.74, p=0.173), PFS (HR 0.67, p=0.057), EFS (HR 0.90, p=0.517) and OS (HR 0.60, p=0.059). Patients with the germinal-center B cell-like subtype who received Hi-CHOP exhibited statistically significant improvements in ORR (p=0.034) and CR rate (p=0.038) at C6D50, EFS (p=0.046) and OS (p=0.014). Treatment-emergent adverse event occurrence rates were comparable across groups (all p>0.05). Infusion-related responses occurred more often in the Hi-CHOP group (32.1% vs 19.9%, p=0.006), all of grade 1–3 severity.Conclusions Zuberitamab (375 mg/m2) plus CHOP was non-inferior to R-CHOP regarding ORR but exhibited a higher CR rate and was well tolerated in CD20-positive, previously untreated Chinese patients with DLBCL.Trial registration number Chinese Clinical Trial Registry, ChiCTR2000040602, retrospectively registered.