Enzalutamide (Xtandi) is an advanced prostate cancer drug taken alone or combined with androgen deprivation therapy (ADT) to treat metastatic prostate cancer. It works by blocking the androgen receptor signaling, which is implicated in prostate cancer growth, and is indicated for patients with hormone sensitive, non-metastatic, and hormone resistant forms of metastatic prostate cancer.
What is the benefit of taking this medicine?
Enzalutamide not only extends overall survival but also improves progression-free survival and quality of life by delaying disease progression and complications.
- Significant improvement in survival in hormone sensitive disease: ARCHES data pending
- 27 – 37% improvement in survival in hormone resistant disease (AFFIRM & PROSPER)
Dosing
Oral: 160 mg once daily (4 pills daily).
Administration
Oral: Administer at the same time each day, either with or without food. Swallow capsules whole; do not chew, dissolve, or open the capsules.
Side Effects
Based on clinical trial data from PROSPER, AFFIRM, and PREVAIL:
Missed Dose
If you miss a dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up. If you miss more than one dose, talk to your doctor right away.
Reproductive Considerations
Male patients with female partners of reproductive potential should use effective contraception during treatment and for 3 months after the last enzalutamide dose.
Monitoring
- Complete blood count and CMP (baseline, every 6 months).
- PSA every 3 months or as clinically indicated.
- Monitor for signs/symptoms of ischemic heart disease, posterior reversible encephalopathy syndrome, and seizure; evaluate fall and fracture risk.
Mechanism of Action
Enzalutamide is a pure androgen receptor signaling inhibitor. It inhibits androgen receptor nuclear translocation, DNA binding, and coactivator mobilization, leading to cellular apoptosis and decreased prostate tumor volume.
In layman’s terms: This medication is an anti-androgen (anti-testosterone). When testosterone binds to an androgen receptor, it causes the tumor cells to grow. You are taking this medication to block the effects of testosterone by slowing down the growth and spread of prostate cancer. As a result, the prostate tumor may stop growing, and the cancer cells die.
Storage
Store in a tightly closed container at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Other Considerations
Be sure to let your other prescribers know that you are taking this medication. This drug may interact with other drugs prescribed; you may be at higher risk for hypertension; your cholesterol levels may change, and routine lab results may come back irregular.
Notify MD of any new or worrisome side effects.
