Xtandi (enzalutamide)
Astellas / Pfizer · Androgen Receptor Inhibitor
What is Xtandi? Xtandi (enzalutamide) is an androgen receptor inhibitor by Astellas/Pfizer approved for castration-resistant prostate cancer (CRPC) and metastatic castration-sensitive prostate cancer (mCSPC), used with or without androgen deprivation therapy.
About Xtandi
| Brand Name | Xtandi |
| Generic / INN | enzalutamide |
| Drug Class | Androgen Receptor Inhibitor |
| Manufacturer | Astellas / Pfizer |
| Administration | Oral capsule or tablet |
| FDA Approval | 2012 |
FDA-Approved Uses for Xtandi
Indications are based on FDA approval. Your healthcare provider determines appropriate use based on your specific diagnosis, stage, biomarker status, and overall clinical picture.
- Metastatic castration-resistant prostate cancer (mCRPC)
- Non-metastatic castration-resistant prostate cancer (nmCRPC)
- Metastatic castration-sensitive prostate cancer (mCSPC) — with androgen deprivation therapy
How Does Xtandi Work?
Enzalutamide competitively inhibits the androgen receptor (AR) — blocking testosterone and DHT binding, inhibiting AR nuclear translocation, and preventing AR-DNA binding and gene transcription. Unlike first-generation antiandrogens (bicalutamide), enzalutamide has no agonist activity and effectively blocks AR signaling even in cells overexpressing AR.
Dosage & Administration
160 mg (four 40 mg capsules) orally once daily, with or without food. Dose reductions for toxicity. Avoid strong CYP3A4/CYP2C8 inhibitors and strong inducers (significantly alters enzalutamide exposure).
Dosing is individualized by the prescribing clinician. Never adjust your dose without consulting your healthcare provider. This information is educational only and does not replace the official prescribing information.
Warnings, Precautions & Side Effects
General Warning
Seizures — contraindicated in patients with seizure disorder or risk factors without careful consideration. Posterior reversible encephalopathy syndrome (PRES). Ischemic heart disease. Falls and fractures. Hypertension. Embryo-fetal toxicity.
- Seizures
- PRES
- Ischemic cardiovascular events
- Falls and fractures
- Embryo-fetal toxicity
Common Side Effects
- Fatigue
- Hot flush
- Hypertension
- Headache
- Falls
- Arthralgia
- Nausea
- Diarrhea
- Weight loss
- Cognitive effects
This is not a complete list. Always report new or worsening symptoms to your healthcare provider promptly.
Storage & Handling
Store at room temperature 25°C (77°F). Keep in original container.
BiologicHealthPlus provides temperature-monitored cold-chain specialty delivery for medications requiring refrigeration. Never use a medication if its storage conditions have been compromised.
Insurance Coverage, Prior Authorization & Patient Assistance
🛡️ Commercial Insurance
Xtandi is covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage tier and cost-sharing vary by plan.
✅ Prior Authorization
Prior authorization is required by virtually all insurance plans for Xtandi. BiologicHealthPlus handles the complete prior authorization process at no cost to patients or providers.
🏥 Medicare Coverage
Medicare Part D covers this oral specialty medication. Medicaid coverage varies by state.
🆓 Patient Assistance
Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. Contact BiologicHealthPlus for a confidential eligibility review.
Prior Authorization Patient Assistance Insurance & Savings Medication Costs
Frequently Asked Questions — Xtandi
Xtandi is a second-generation androgen receptor inhibitor approved for castration-resistant and castration-sensitive prostate cancer. Unlike older antiandrogens, it has no agonist activity and blocks multiple steps of AR signaling.
Both are AR inhibitors approved for similar prostate cancer settings. Key differences include chemical structure, CNS penetration, seizure risk, and drug interaction profiles. Clinical selection depends on individual patient factors and prior therapy.
Seizures have been reported with enzalutamide. Use with extreme caution in patients with a history of seizure, brain injury, or conditions predisposing to seizure.
Xtandi is covered by commercial insurance and Medicare Part D with prior authorization for approved prostate cancer indications.
Related Medications & Conditions
Related Medications
Erleada (apalutamide) · Nubeqa (darolutamide) · Abiraterone Acetate · Akeega (niraparib + abiraterone)
Related Conditions
Metastatic castration-resistant prostate cancer (mCRPC) · Non-metastatic CRPC (nmCRPC) · Castration-sensitive prostate cancer (mCSPC)