Real-world retrospective study of prostate-specific antigen and safety assessment with darolutamide plus androgen deprivation therapy for metastasis hormone-sensitive prostate cancer.

Background: ARASENS has demonstrated the efficacy and safety for darolutamide (DARO) with androgen deprivation therapy (ADT) plus docetaxel in metastasis hormone-sensitive prostate cancer (mHSPC). There is a lack of reports for DARO with ADT in mHSPC though the regimen is used in clinical from time to time. Moreover, recent studies have supported the importance of early and rapid prostate-specific antigen (PSA) reduction, which correlates with reduced disease progression and improved survival in patients with mHSPC. This study aims to evaluate PSA reduction as a primary endpoint for DARO with ADT in the treatment of mHSPC and to evaluate the real-world short-term PSA control of DARO with ADT from two leading medical centers in China.

Methods: We retrospectively reviewed the clinical records of patients with mHSPC receiving ADT and DARO (600 mg, b.i.d.). The collection of data spanned from March 1, 2022, to July 31, 2023. The main observation indicators were PSA level and drug-related adverse events (AE) after medication. PSA levels were closely monitored prior to treatment initiation and at 2-week intervals, as well as at 1, 3, and 6 months after the initiation of treatment. We also conducted an analysis to determine the proportion of patients achieving a PSA reduction of 50% or more (PSA50) and 90% or more (PSA90) as well as the percentage of patients with a notable decrease in PSA level to 0.2 ng/mL and PSA nadir of ≤0.02 ng/mL.

Results: Fifty-one patients were included in the study, with a median age of 73 years. At diagnosis of HSPC, the majority of patients had a Gleason score ≥8 (n=40, 78.40%) and a median baseline PSA level of 88 ng/mL. Approximately 45.1% (n=23) of patients had a Charlson Comorbidity Index over 1 and were receiving one or more nontumor-related treatments. The median follow-up time was 9.3 months (range, 1.16-15.8 months). The median reductions in PSA levels compared to baseline were 84.37%, 91.48%, 94.67% and 99.81% at 2 weeks, 1 month, 3 months and 6 months after administration of DARO with ADT, respectively. The median time to PSA50, PSA90, significant PSA reduction (PSA <0.2 ng/mL), and PSA nadir (PSA <0.02 ng/mL) was 0.97, 1.27, 1.98, and 2.08 months, respectively. AE mainly included fatigue (two patients) and arm pain (one patient), all of which were grade I or II AE. No grade III or AE were observed.

Conclusions: For treating prostate cancer, DARO with ADT has good early efficacy, demonstrating prompt and substantial control of PSA levels, with a favorable safety profile.