Darolutamide in Combination with Radium-223 Exhibits Synergistic Antitumor Efficacy in LNCaP Prostate Cancer Models

Area of Science:

• Oncology
• Radiotherapy
• Pharmacology

Background:

• Prostate cancer frequently progresses to castration-resistant prostate cancer (CRPC), a largely incurable stage.
• Current treatments for CRPC are limited, necessitating novel therapeutic approaches.
• Androgen receptor (AR) signaling is a key driver in prostate cancer progression.

Purpose of the Study:

• To evaluate the combined efficacy of darolutamide, an AR inhibitor, and radium-223, an alpha-emitting therapeutic agent.
• To investigate the synergistic antitumor effects of this combination in preclinical models of bone-metastatic CRPC.
• To explore the underlying mechanisms of action for the combination therapy.

Main Methods:

• In vitro studies assessing the effects of darolutamide and radium-223 on prostate cancer cells.
• In vivo evaluation using an intratibial LNCaP xenograft model in mice, mimicking bone metastasis.
• Gene set enrichment analysis to identify molecular pathways affected by the treatment.
• Histopathological analysis of bone tissue to assess tumor-induced changes and treatment effects.

Main Results:

• Darolutamide and radium-223 demonstrated synergistic antitumor efficacy both in vitro and in vivo.
• The combination treatment downregulated genes involved in DNA damage response (DDR) signaling.
• Pathological bone remodeling, including osteoblast and osteoclast activity and abnormal bone formation, was reduced.
• Darolutamide did not impede the uptake of radium-223 into bone tissue.

Conclusions:

• The combination of darolutamide and radium-223 exhibits significant synergistic antitumor activity against CRPC bone metastases.
• This combination therapy effectively mitigates tumor-induced bone pathology.
• These findings support further clinical investigation of darolutamide plus radium-223 for treating CRPC with bone metastasis.