ESMO Congress 2023 | OncologyPRO

Abstract 1788P

Background

CHART trial has demonstrated the survival benefit of rezvilutamide plus androgen deprivation therapy (ADT) over bicalutamide plus ADT in treating patients with high-volume, metastatic hormone-sensitive prostate cancer (mHSPC). This post-hoc analysis aimed to evaluate the association between achievement of deep PSA decline with survival outcomes in patients with high-volume mHSPC in the CHART trial.

Methods

Patients with high-volume mHSPC were randomly assigned (1:1) to receive ADT plus either rezvilutamide or bicalutamide. PSA kinetics and the association between deep PSA decline (≤0.2 ng/ml) and radiographic progression-free survival (rPFS) and overall survival (OS) in two groups were evaluated.

Results

A total of 654 patients were included in the analysis, with 326 patients in the rezvilutamide plus ADT group, and 328 patients in the bicalutamide plus ADT group. The median PSA nadir levels were 0.02 ng/ml, and 0.68 ng/ml in two groups, respectively. At 6-month, 170 (52.15%) and 90 (27.44%) patients achieved a deep PSA decline, respectively. With a median follow-up of 29.3 months, patients who achieved a deep PSA decline at 6-month had longer rPFS (HR=0.359, 95%CI 0.238, 0.543, P<0.001) and OS (HR=0.339, 95%CI 0.212, 0.540, P<0.001) than those who did not achieve it in the rezvilutamide plus ADT group. Significantly, rezvilutamide plus ADT was found to significantly prolong rPFS compared to bicalutamide plus ADT, regardless of whether patients achieved deep PSA decline at 6-month (HR=0.462, 95%CI 0.283, 0.754, P=0.002) or not (HR=0.587, 95%CI 0.428, 0.804, P<0.001). Table: 1788P

PSA kinetics in CHART trial

Variables	Rezvilutamide plus ADT (n=326)	Bicalutamide plus ADT (n=328)
PSA baseline (ng/ml), median (Q1, Q3)	78.79 (12.82, 314.80)	51.32 (8.08, 236.63)
PSA nadir (ng/ml), median (Q1, Q3)	0.02 (0.00, 0.41)	0.68 (0.08, 3.16)
Time to PSA nadir, day, median (Q1, Q3)	308.0 (169.0, 634.8)	167.0 (85.0, 281.0)
PSA nadir ≤0.2 ng/ml, n (%)	224 (68.7)	109 (33.2)
Time to PSA ≤0.2 ng/ml, day, median (Q1, Q3)	392.0 (222.3, 671.0)	238.0 (141.0, 393.0)
PSA ≤0.2 ng/ml at 3-month, n (%)	125 (38.34)	58 (17.68)
PSA ≤0.2 ng/ml at 6-month, n (%)	170 (52.15)	90 (27.44)
PSA ≤0.2 ng/ml at 12-month, n (%)	201 (61.66)	108 (32.93)

Conclusions

Rezvilutamide plus ADT resulted in a deep PSA decline, which was associated with improved long-term survival in patients with high-volume mHSPC.

Clinical trial identification

NCT03520478.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Jiangsu Hengrui Pharmaceuticals Co., Ltd.

Disclosure

J. Lian, Q. Shi: Financial Interests, Personal, Full or part-time Employment: Jiangsu Hengrui Pharmaceuticals. All other authors have declared no conflicts of interest.