Zytiga vs Xtandi
The two leading oral therapies for advanced prostate cancer — one shuts down androgen production, the other blocks the receptor androgens act on.
At a glance
Key differences
- Different classes. Zytiga is a CYP17 inhibitor; Xtandi is an androgen receptor inhibitor. They act on different targets in the body.
- How they are taken. Both are given by the oral route.
- Time on the market. Zytiga was first approved by the FDA in 2011, Xtandi in 2012.
- Who markets them. Zytiga is marketed by Janssen (Johnson & Johnson); Xtandi by Astellas.
What each one treats
ZYTIGA is indicated in combination with prednisone for the treatment of patients with Metastatic castration-resistant prostate cancer (CRPC) Metastatic high-risk castration-sensitive prostate cancer (CSPC) ZYTIGA is a CYP17 inhibitor indicated in combination with prednisone for the treatment of patients with metastatic castration-resistant prostate cancer (CRPC). ( 1 ) metastatic high-risk castration-sensitive prostate cancer (CSPC). ( 1 )
XTANDI ® is indicated for the treatment of patients with: • castration-resistant prostate cancer (CRPC) • metastatic castration-sensitive prostate cancer (mCSPC) • non‑metastatic castration‑sensitive prostate cancer (nmCSPC) with biochemical recurrence at high risk for metastasis (high-risk BCR) XTANDI is an androgen receptor inhibitor indicated for the treatment of patients with: • castration-resistant prostate cancer. ( 1 ) • metastatic castration-sensitive prostate cancer. ( 1 ) • non‑metastatic castration‑sensitive prostate cancer with biochemical recurrence at high risk for metastasis. ( 1 )
How each one works
12.1 Mechanism of Action Abiraterone acetate (ZYTIGA) is converted in vivo to abiraterone, an androgen biosynthesis inhibitor, that inhibits 17 α-hydroxylase/C17,20-lyase (CYP17). This enzyme is expressed in testicular, adrenal, and prostatic tumor tissues and is required for androgen biosynthesis. CYP17 catalyzes two sequential reactions: 1) the conversion of pregnenolone and progesterone to their 17α-hydroxy derivatives by 17α-hydroxylase activity and 2) the subsequent formation of dehydroepiandrosterone (DHEA) and androstenedione, respectively, by C17, 20 lyase activity. DHEA and androstenedione are androgens and are precursors of testosterone. Inhibition of CYP17 by abiraterone can also…
12.1 Mechanism of Action Enzalutamide is an androgen receptor inhibitor that acts on different steps in the androgen receptor signaling pathway. Enzalutamide has been shown to competitively inhibit androgen binding to androgen receptors; and consequently, inhibits nuclear translocation of androgen receptors and their interaction with DNA. A major metabolite, N‑desmethyl enzalutamide, exhibited similar in vitro activity to enzalutamide. Enzalutamide decreased proliferation and induced cell death of prostate cancer cells in vitro , and decreased tumor volume in a mouse prostate cancer xenograft model.
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How this page is built
The facts on this page are pulled directly from official U.S. FDA datasets — they are not written from memory. Each field below names the dataset it came from, so you can check it yourself.
- FDA Drug Label (openFDA) ↗ Indications, mechanism of action and pharmacologic class
- Drugs@FDA ↗ First FDA approval date and the company holding the application
- FDA Drug Shortage Database ↗ Current US supply / shortage status
Plain-English summaries and drug-class explainers are written and reviewed by Sreepriya Prasannan (MSc Digital Transformation of Life Sciences (Innopharma Education / Griffith College); MSc & BSc Botany). Data is retrieved automatically from the sources above and cross-checked with AI-assisted verification (Anthropic's Claude) — brand and generic names are matched against the exact FDA product record so that a combination product or a different formulation cannot be mistaken for the drug on this page. An editor reviews the result before publication. We describe this in full in our editorial standards and corrections policy. The FDA data on this page was last retrieved on 8 Oct 2026. How every register is built: methodology · fixes we have made: corrections log.