The Role of Zytiga (abiraterone J&J) in Treatment of Men with Prostate Cancer
We see patients from all parts of New York City (Manhattan, Brooklyn, Queens, Bronx, Staten Island), Long Island, Westchester and New Jersey as well as other parts of the USA. We also see international patients from Canada, Japan, South America, Russia, Asia, Europe, Middle East, Africa, the Caribbean and other parts of the world.
Zytiga: A Game Changer in Prostate Cancer
Zytiga or abiraterone is a novel hormonal treatment for men with prostate cancer. High-quality randomized controlled studies have demonstrated that Zytiga provides improved survival in men who have failed hormonal therapy with LHRH antagonists as well as chemotherapy with docetaxel.
Evidence points that Zytiga is a much more powerful hormonal treatment than the traditional LHRH antagonists or agonists. It is fairly likely that eventually, medications such as Zytiga or Xtandi will replace LHRH antagonists and agonists as the first line treatment for high-risk prostate cancer and for PSA recurrence.
Zytiga – Mechanism of Action and Prescription Details
ZYTIGA® is a CYP17 inhibitor indicated in combination with prednisone for the treatment of patients with metastatic castration-resistant prostate cancer before or after chemotherapy with docetaxel. It inhibits 17 αhydroxylase/C17,20-lyase (CYP17). This enzyme is expressed in testicular, adrenal, and prostatic tumor tissues and is required for androgen biosynthesis.
The recommended dose of ZYTIGA® is 1,000 mg (four 250 mg tablets) administered orally once daily in combination with prednisone 5 mg BID.
Side effects versus placebo: Hypertension (1.3 vs 0.3%), Hypokalemia (5% vs 1%) and Fluid Retention (1.8 vs 0.8%), CHF (1.8 vs 0.3%) Due to Mineralocorticoid Excess, UTI 2% vs 0.5%
Studies that Support Use of Zytiga in the Treatment of Prostate Cancer
Trials excluded patients with CHF
- Must take at least 2 hours before/after food.
- Need to monitor Potassium, Calcium levels.
- Must take prednisone.
- Side effects: Hypertension, low blood potassium levels (hypokalemia), and fluid retention (edema).
Men with mCRPC who had received chemotherapy with docetaxel and who were treated with ZYTIGA® plus prednisone lived longer than men who were treated with placebo (sugar pill) plus prednisone. In the clinical trial, the median† survival for men treated with ZYTIGA® plus prednisone was 15.8 months versus 11.2 months for men treated with placebo plus prednisone.
Post-docetaxel study ECOG 0-1: OS 14 vs 10 months
Non-pretreated study ECOG 0-1: OS 35 vs 30 months. Radiographic free progression 11 vs 8 months.
Additional Studies of Abiraterone (Zytiga) Currently Underway:
Clinicaltrials.gov: higher dosing study; 250 vs 500 tablets – easier dosing; food;
- Pharmacokinetics of Abiraterone in Healthy Chinese;
- 3-arm Study of Abiraterone Acetate Alone, Abiraterone Acetate Plus Degarelix, a GnRH Antagonist, and Degarelix Alone for Patients With Prostate Cancer With a Rising PSA or a Rising PSA and Nodal Disease Following Definitive Radical Prostatectomy;
- study in diabetics;
- abiraterone plus enzalutamide;
- breast cancer
Dr. Alex Shteynshlyuger is a board-certified urologist in NYC who specializes in treating men for prostate cancer.