Efficacy and Safety of Combination Androgen-Receptor Signaling Inhibitors, Denosumab, and Local Radiotherapy for Poly-Metastatic Prostate Cancer

Abstract

Background

The Treatment of Metastatic Castration-Sensitive Prostate Cancer (mCSPC) has dramatically changed over the past decade. To improve oncological outcomes, pharmacological treatments have evolved to include two-or three-drug combinations, and the efficacy of local radiation therapy (LRT) at the prostate combined with denosumab chemotherapy has been discussed.

Aims

This study aimed to provide an interim evaluation of the combination of androgen receptor signaling inhibitors denosumab, LRT, and metastasis-directed therapy (MDT) for prostate cancer with multiple bone metastases (poly-PCa).

Methods

We are currently conducting a single-arm prospective study to evaluate the combination of enzalutamide, LRT, denosumab, and MDT in terms of improving oncological outcomes in patients with poly-PCa. The primary endpoints were prostate-specific antigen (PSA)-based progression-free survival (PFS) and radiographic PFS (rPFS).

Results

Twenty patients have been enrolled in the study to date. The median follow-up period thus far is 18.0 months (interquartile range, 14.0–25.8 months). The 1-year PFS rate is 84.4% at present, and the rPFS rate is 100%. Seventeen patients (85.0%) achieved a PSA reduction of ≥ 90% versus their baseline values at enrollment, and 10 (50.0%) maintained PSA levels of < 0.2 ng/mL.

Conclusion

This treatment strategy is expected to improve the oncological outcomes of patients with poly-PCa. A more comprehensive report of this study with more patients and a longer observation period is forthcoming.