What are the outcomes of sipuleucel-T treatment for patients with metastatic castration-resistant prostate cancer?

This study evaluated the safety and effectiveness of sipuleucel-T (Provenge) treatment in patients with metastatic castration-resistant prostate cancer (mCRPC). The authors found that the average survival after sipuleucel-T treatment was 30.7 months and that 13.7% of patients experienced side effects.

Castration-resistant prostate cancer is resistant to hormone therapy. This type of cancer can become metastatic, meaning that it spreads to other parts of the body. One of the symptoms of prostate cancer is high levels of prostate-specific antigen (PSA) in the blood. As the disease gets worse, PSA levels rise. 

Because it is resistant to hormone therapy, patients with mCRPC need other treatment options. These may include chemotherapy, radiation therapy, or biological therapy. Sipuleucel-T treatment is a biological therapy that uses the patient’s immune system to fight cancer cells. Previous studies showed that this treatment is effective for other types of prostate cancer. The long-term outcomes of sipuleucel-T therapy for patients with mCRPC are unclear.

This study had 1902 patients with mCRPC. Patients received 1 to 3 infusions of sipuleucel-T treatment. The average follow-up was 46.6 months.

Overall, the average survival of patients after sipuleucel-T treatment was 30.7 months. During follow-up, the overall mortality rate was 66%. The main cause of mortality was disease progression (76.8%).

Patient survival was analyzed based on different characteristics of patients and prostate cancer.  Patients with a lower PSA level had a 1.22 times higher chance of a more favorable survival.  Patients below the age of 72 had a 1.3 times higher chance of a more favorable survival than those over 72.  Patients who had previously received certain chemotherapy drugs had more than a 1.5 times higher chance of a more favorable survival than those that did not.

78% of patients received other treatments after sipuleucel-T. 54.5% received abiraterone (Zytiga), 43.7% received enzalutamide (Xtandi) and 38.9% received docetaxel (Taxotere).

Overall, 260 patients (13.7%) experienced side effects after sipuleucel-T treatment. The most common side effects were the growth of cancer (28 patients), brain-related effects (16 patients) and chills (13 patients). 54 patients (2.8%) experienced heart-related side effects. Serious side effects were reported in 9.2% of patients.

This study found that sipuleucel-T treatment was well-tolerated and associated with a survival of 30.7 months for patients with mCRPC. The authors suggest that 

The manufacturer of sipuleucel-T, Dendreon, funded this study. This study did not compare sipuleucel-T to any other treatments. Patients in this study also had different treatment histories.

Talk to your doctor about your treatment options.