Does sipuleucel-T improve the survival of men with advanced prostate cancer treated with androgen receptor-targeting drugs?

This study evaluated the effectiveness of adding sipuleucel-T (Provenge) androgen receptor-targeting agents (ARTAs) such as abiraterone acetate (AA; Zytiga) and enzalutamide (Xtandi) in men with metastatic castration-resistant prostate cancer (mCRPC). The data showed that those receiving both sipuleucel-T and ARTAs were more likely to have longer survival compared to ARTAs alone.

Prostate cancer (PC) is one of the most common cancers affecting men. Treatment of PC depends on the stage of the cancer and can include a combination of surgery, radiation, hormone therapy, and chemotherapy. Many PCs are initially treated with surgery or radiation therapy. Hormone treatment may also be added, such as androgen receptor-targeting agents (ARTAs). ARTAs block the effects of androgens such as testosterone (the male sex hormone that helps prostate cancer grow and spread) on prostate cancer cells. Metastatic castration-resistant prostate cancer (mCRPC) is an advanced form of PC that spreads to other parts of the body and no longer responds to hormone therapy. This means that the cancer can continue to spread and grow.

Immunotherapy has recently been used for the treatment of advanced PC. Sipuleucel-T is the first immunotherapy approved for the treatment of advanced PC. It works by activating the immune system and helps it target and destroy prostate cancer cells. Combining both sipuleucel-T and ARTAs as a treatment for mCRPC has been shown to improve patient outcomes. However, the effectiveness of this combination in real-world patients is still unknown. 

This study included 5415 patients with mCRPC. 773 patients (group 1) were treated with both sipuleucel-T and ARTAs (most commonly enzalutamide. 4642 patients group 1) were treated with ARTAs alone (most commonly AA). Patients were followed up for at least 36 months. 

The average overall survival (OS) for group 1 was 30.4 months compared to 14.3 months for group 2. Patients in the combination group had a 28.3% lower risk of mortality compared to ARTAs alone.  

This study showed that the combination of sipuleucel-T and ARTAs improved the survival of patients with mCRPC compared to ARTAs alone in real-world practice. 

This study was based on medical records. The study groups were not equal and information might have been missing. Further studies are needed to confirm these results. Dendreon, the manufacturer of sipuleucel-T, funded this study.