Abstract 340P
Background
The CHART trial has established rezvilutamide plus androgen deprivation therapy (ADT) as the standard of care for patients (pts) with high-volume, metastatic hormone-sensitive prostate cancer (mHSPC) in China; however, little is known about the outcomes of this combination in low-volume mHSPC. This study aimed to assess the effectiveness of rezvilutamide plus ADT for low-volume mHSPC in a real-world setting.
Methods
In this real-world cohort study across China, adult pts with low-volume mHSPC who had documented evidence of treatment with rezvilutamide plus ADT or were scheduled to receive this combination at the investigator’s discretion were included. The prostate-specific antigen (PSA) responses, including PSA50, PSA90 and undetectable PSA, were evaluated.
Results
From August 29, 2023 to January 25, 2024, 138 pts were included. The median age was 73 years (IQR 68-77), with 52 (37.7%) pts being ≥ 75 years. Twenty-three (16.7%) pts had an ECOG PS of ≥ 2. Median baseline PSA levels was 20.1 μg/L (IQR 2.1-60.8) and median baseline testosterone levels was 37.7 ng/dL (IQR 14.4-351.0). Sixty- three (45.7%) pts had a Gleason score of ≥ 8. Most pts (133 [96.4%]) received solely rezvilutamide plus ADT, and 14 (10.1%) had a history of ADT therapy. Median time from diagnosis to first dose of drug was 19 days (IQR 4-54). By 3 months, 128 (92.8%, 95% CI 87.1-96.5) of the 138 pts had a PSA50 response, 121 (87.7%, 95% CI 81.0-92.7) had a PSA90 response, and 78 (56.5%, 95% CI 47.8-64.9) had an undetectable PSA. By 6 months, the corresponding numbers were 27 (96.4%, 95% CI 81.7-99.9), 25 (89.3%, 95% CI 71.8-97.7) and 21 (75.0%, 95% CI 55.1-89.3) of the 28 pts, respectively. Subgroup analyses by baseline characteristics is shown in the table. Table: 340P
Subgroup analysis of efficacy by 3 months
| Characteristics | PSA50 | PSA90 | Undetectable PSA |
| Age, years, n/N (%) | |||
| < 75 | 81/86 (94.2) | 77/86 (89.5) | 53/86 (61.6) |
| ≥ 75 | 47/52 (90.4) | 44/52 (84.6) | 25/52 (48.1) |
| ECOG PS, n/N (%) | |||
| 0-1 | 103/110 (93.6) | 96/110 (87.3) | 62/110 (56.4) |
| ≥ 2 | 20/23 (87.0) | 20/23 (87.0) | 13/23 (56.5) |
| Baseline testosterone, ng/dL, n/N (%) | |||
| < 50 | 23/27 (85.2) | 21/27 (77.8) | 16/27 (59.3) |
| ≥ 50 | 19/20 (95.0) | 18/20 (90.0) | 12/20 (60.0) |
| Gleason score, n/N (%) | |||
| < 8 | 27/29 (93.1) | 25/29 (86.2) | 16/29 (55.2) |
| ≥ 8 | 59/63 (93.7) | 58/63 (92.1) | 35/63 (55.6) |
| Prior ADT therapy, n/N (%) | 13/14 (92.9) | 12/14 (85.7) | 11/14 (78.6) |
Conclusions
Rezvilutamide plus ADT yielded a promising PSA response in pts with low-volume mHSPC in a real-world setting. This study represents the first evaluation of rezvilutamide in low-volume population.
Clinical trial identification
ChiCTR2400082040.
Editorial acknowledgement
Legal entity responsible for the study
Chinese PLA General Hospital.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.