Xtandi

(Enzalutamide)

The active ingredient in Xtandi is enzalutamide. Enzalutamide belongs to a class of medications known as androgen receptor inhibitors, otherwise known as antiandrogens. In prostate cancer, the cancer cells that make up the tumor require androgen hormones for their growth and survival. The main androgen hormone within the body is testosterone. Enzalutamide prevents androgen hormones from reaching the tumor. As a result, this mechanism of action prevents cancer cells from growing, eventually causing them to die off. Other medications within this class include bicalutamide and darolutamide.

Depending on the treatment plan that your doctor decides on, Xtandi may be used in combination with other anti-cancer medications such as leuprolide or docetaxel for best results. Often in oncology, multiple medications and treatment options (i.e., radiotherapy, surgery) are needed to slow tumor progression and growth.

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide before using Xtandi. However, the following is a synopsis of the general guidelines for the use of Xtandi:

• Xtandi should be used exactly as prescribed. The dose you take will be decided by your doctor. As treatment progresses, they may choose to change your dose to ensure adequate tumor suppression. Certain blood work they may look at to make this decision includes the PSA or prostate-specific antigen. Elevated levels are suggestive of prostate problems.
• Xtandi is typically taken once daily with or without food. Because of their large size, Xtandi capsules and tablets could pose a choking hazard. Ensure to swallow whole with lots of water.
• If you are also receiving GnRH therapy (gonadotropin-releasing hormone therapy) and have not undergone bilateral orchiectomy (surgical castration), you should continue GnRH therapy while on Xtandi.
• Female partners of males using Xtandi and who are of childbearing potential should use an effective form of birth control or contraception while their partner is being treated and for 3 months after the last dose of Xtandi. Males must use a condom.
• If you take too much, call your healthcare provider or go to the nearest emergency room. You may have an increased risk of seizures if you take too much.
• If you experience side effects or adverse reactions that make it difficult to take Xtandi, follow up with your prescriber right away. Lapses in treatment due to intolerance can disrupt your treatment plan.
• If you miss a dose, take it as soon as you remember that day. If you have missed taking a dose for the whole day, continue with your regular dosing schedule the next day. Do not take more than the daily dose that has been prescribed to make up for a missed dose.

The most common side effects of Xtandi seen in clinical trials as compared to placebo include:

• Bone, muscle, and joint pain
• Back pain
• Headache
• Fatigue
• Hot flushes/hot flashes
• Constipation
• Loss of appetite
• Diarrhea
• High blood pressure
• Hemorrhage or uncontrolled bleeding
• Falls
• Fractures
• Dry skin

Some individuals may experience serious side effects while using Xtandi. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Seizures
• Signs of PRES (posterior reversible encephalopathy syndrome) such as seizure, sudden onset of headache that worsens with time, decreased alertness, confusion, and any vision changes.
• Signs of an allergic reaction such as hives, rash, difficulty breathing, wheezing, or swelling of the face, lips, eyes, or tongue.
• Signs of heart problems such as chest pain or discomfort, and shortness of breath.

These are not all of the possible adverse events of Xtandi. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Xtandi, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including if you have:

• Neurological problems, such as a history of seizures, brain injury, stroke, or brain tumors
• Heart problems or a history of heart disease, including ischemic heart disease
• Hypertension or high blood pressure
• Dyslipidemia or high cholesterol levels
• Swallowing problems
• Are pregnant or planning to become pregnant, or have a partner who is pregnant or planning to become pregnant
• Are breastfeeding or planning to breastfeed

There are no contraindications to using Xtandi.

Xtandi will begin to work right after the first dose. To ensure the treatment is working for you, your doctor will monitor you throughout treatment.

When Xtandi is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including but not limited to:

• Gemfibrozil
• Rifampin

Xtandi is available as 40 mg capsules and 40 mg or 80 mg tablets.

Xtandi should be stored at room temperature in a tightly closed container, away from light and moisture, and out of reach of children.

Xtandi is manufactured by the pharmaceutical company Astellas Pharma.

Yes, there is a generic available for the brand-name Xtandi.

Consult your doctor or pharmacist before starting, stopping, or changing medications while taking Xtandi.

Xtandi should not be used in pregnancy due to the risk of fetal harm and miscarriage. Talk to your doctor if you are already pregnant or if you have any plans to become pregnant. They will know or recommend what is best for you.

It is unknown if Xtandi passes into the breastmilk. Talk to your doctor if you are already breastfeeding or if you have any plans to breastfeed. They will know or recommend what is best for you.