Study Comparing BEBT-908 Combined With R to SOC for the Treatment of Relapsed/Refractory Diffuse Large B-Cell Lymphoma

The study will recruit 416 subjects, who will be randomly assigned in a 1:1 ratio to either the experimental group (BEBT-908 combined with R) or the control group \[investigator-selected standard chemotherapy regimen (R-GemOx or R-ICE)\]. Approximately 208 subjects will be enrolled in the experimental group, and approximately 208 in the control group. The treatment cycle is 21 days, with a total of 8 treatment cycles. The experimental group will receive BEBT-908 + R treatment from cycles 1 to 8; participants who do not appear progressive disease (PD) after cycle 8 may continue to receive BEBT-908 and/or R treatment, entering a maintenance phase of up to 24 months. The control group will receive the investigator-selected SOC (i.e., R-GemOx or R-ICE) treatment from cycles 1 to 8, and will not receive further study medication after cycle 8. Each subject's study process includes three phases: screening, treatment, and post-treatment follow-up. The screening phase can last up to 21 days. During the treatment phase, tumor assessments will be conducted every 6 weeks (±7 days) within the first 8 treatment cycles, and every 9 weeks (±7 days) after cycle 8.After the end of treatment, safety follow-up will be conducted on day 28 (+7 days) after the last dose, efficacy follow-up will be conducted every 9 weeks (±7 days), and survival follow-up will be conducted every 3 months (±2 weeks).