Abstract
BACKGROUND: The CHART study established the combination of rezvilutamide and androgen deprivation therapy (ADT) as a standard treatment for patients with high-volume metastatic hormone-sensitive prostate cancer (mHSPC). However, the therapeutic outcomes of this regimen in patients with low-volume mHSPC remain insufficiently defined. This study thus aimed to assess the real-world effectiveness of rezvilutamide combined with ADT in the treatment of low-volume mHSPC. METHODS: This multicenter, noninterventional, observational study was conducted in China and included adult patients diagnosed with low-volume mHSPC who were treated with rezvilutamide in combination with ADT as determined by the investigator. The study assessed prostate-specific antigen (PSA) responses at multiple time points (3, 6, 9, and 12 months), including a PSA decline ≥50% (PSA50), a PSA decline ≥90% (PSA90), and a PSA level <0.2 ng/mL (undetectable PSA). Subgroup analyses of PSA responses were conducted according to baseline characteristics, including age, Eastern Cooperative Oncology Group performance status (ECOG PS), and Gleason score. RESULTS: Between August 29, 2023 and December 31, 2024, a total of 257 patients were enrolled in the study. The median age was 73 years [interquartile range (IQR), 68-77 years], and the median baseline PSA level was 38 ng/mL (IQR, 7-100 ng/mL). PSA responses were observed as early as 3 months after initiating rezvilutamide treatment, with 88% [176/199; 95% exact confidence interval (CI): 83-93%] achieving PSA50, 75% (149/199; 95% exact CI: 68-81%) achieving PSA90, and 54% (108/199; 95% exact CI: 47-61%) achieving undetectable PSA levels. These responses further improved at subsequent time points (6, 9, and 12 months). By 12 months, 100% (12/12; 95% exact CI: 74-100%) achieved PSA50, 92% (11/12; 95% exact CI: 62-100%) achieved PSA90, and 83% (10/12; 95% exact CI: 52-98%) had undetectable PSA levels. CONCLUSIONS: This study is the first to evaluate the effectiveness of rezvilutamide in patients with low-volume mHSPC. In a real-world clinical setting, the combination of rezvilutamide and ADT demonstrated favorable PSA response in this patient population. These findings provide additional treatment options for patients with low-volume mHSPC and support the need for further large-scale research on rezvilutamide in this subgroup.