Can You Combine Provenge with Zytiga?

A clinical trial is studying whether combining Provenge with Zytiga for men with metastatic castrate-resistant prostate cancer leads to meaningful outcomes. In this particular study, scientists are examining whether there is a benefit in how well Provenge (sipuleucel-T) works when Zytiga (abiraterone acetate) is given at the same time or if it is better delaying treatment with Zytiga until after completion of Provenge. Both drugs are used in men men who have castrate-resistant prostate cancer and not responded to or had cancer progression on other treatments.

Oncology practice often combines multiple therapies with a different mechanism of action. The idea is to attack the cancer from more than one avenue to hopefully lead to an improved outcome. Because Provenge and Zytiga each has a different mechanism of action, there is interest in combining the two agents.

What is Provenge?

Provenge is an immune therapy that stimulates your own immune system to fight the prostate cancer. With Provenge, immune cells are taken from you in a very similar fashion as a blood transfusion and then undergo a special treatment. The treated immune cells are then reinfused. The infusion stimulates your immune system to find and attack prostate cancer cells in your body.

The infusion is generally well tolerated. Common side effects include:

  • Muscle aches
  • Joint pain
  • Fatigue
  • Fever
  • Chills
  • Headache
  • Nausea

In a clinical trial of men who had not previously received chemotherapy and were generally asymptomatic, survival was improved by approximately 4 months. Additionally, more men treated with Provenge treatment group were alive 3 years after starting therapy compared to those not treated with Provenge. Risk of death in the Provenge treatment group was 22% less than in the nontreatment group.

What is Zytiga?

This anti-androgen therapy is unique in that it is administered as a pill. In obtaining approval by the FDA, Zytiga was shown to be clinically useful and improve overall survival in metastatic castrate resistant prostate cancer in patients previously treated with docetaxel (Taxotere).

Zytiga is taken in combination with a steroid. Common side effects include:

  • Joint swelling
  • Muscle pain
  • Diarrhea
  • Cough
  • Urinary tract infections

Combining Provenge with Zytiga

If you think that you might be a candidate or would like to consider combining Provenge with Zytiga, you need to have a discussion with your doctor. Some insurance companies tightly regulate the use of both Provenge and Zytiga—especially since this is still considered an experimental combination treatment. Your insurance company may require your doctor to follow a certain pathway or order in which cancer drugs are used.

Read more in our Prostate Cancer Health Center.

References

American Cancer Society. Prostate Cancer.

Concurrent versus sequential treatment with sipuleucel-T and abiraterone in men with metastatic castrate resistant prostate cancer (mCRPC). Clinical Trials.gov

Patel JC et al. Emerging molecularly targeted therapies in castration refractory prostate cancer. Prostate Cancer vol. 2013:981684