Xtandi

Prostate Cancer Treatment

Xtandi is used to treat several specific types of prostate cancer, depending on whether the cancer has spread and how it responds to other hormone treatments. It is commonly prescribed for:

• Castration-resistant prostate cancer (CRPC): This includes cancer that has spread to other parts of the body (metastatic) as well as cancer that has not spread (non-metastatic), but which no longer responds to medical or surgical treatments that lower testosterone.
• Metastatic castration-sensitive prostate cancer (mCSPC): This refers to prostate cancer that has spread to other parts of the body but still responds to treatments that lower testosterone levels.
• Non-metastatic castration-sensitive prostate cancer (nmCSPC): Xtandi is used for patients who have a high risk of biochemical recurrence. This is often indicated by rising prostate-specific antigen (PSA) levels after previous treatments such as surgery or radiation, even if the cancer cannot yet be seen on imaging tests.

This medication is often used in combination with other therapies, such as gonadotropin-releasing hormone (GnRH) therapy, or after a surgical procedure to lower testosterone levels.

How Xtandi Works

Prostate cancer cells often depend on male hormones, known as androgens (such as testosterone), to grow and multiply. Xtandi works by interfering with the way these hormones interact with cancer cells.

Blocking Hormone Signals

Xtandi is designed to stop androgens from fueling the growth of the cancer. It does this through several specific actions:

• Blocking receptors: It prevents androgens from attaching to receptors on the surface of prostate cancer cells.
• Stopping movement: It prevents the androgen receptors from moving into the nucleus (the control center) of the cell.
• Preventing DNA binding: It stops the receptors from binding with the cell's DNA, which is a necessary step for the cell to receive instructions to grow and divide.

By disrupting these processes, Xtandi helps slow the progression of the disease and may lead to the shrinking of tumors. Because it targets the hormone signaling pathway rather than killing cells directly like traditional chemotherapy, it is considered a targeted hormone therapy.

Common Side Effects

The most frequently reported side effects of Xtandi include:

• Fatigue or physical weakness
• Hot flashes
• Back, joint, or muscle pain
• Headache
• High blood pressure
• Diarrhea or constipation
• Decreased appetite and weight loss
• Dizziness
• Swelling of the hands, arms, legs, or feet

Serious Side Effects

Contact a healthcare provider immediately if you experience any of the following serious symptoms:

• Seizures: A risk of seizures exists while taking this medication.
• Posterior Reversible Encephalopathy Syndrome (PRES): A brain condition characterized by sudden severe headache, confusion, seizures, or vision changes.
• Heart Problems: Including chest pain, shortness of breath, or signs of a heart attack.
• Falls and Fractures: An increased risk of falling which may lead to broken bones.
• Severe Allergic Reactions: Such as swelling of the face, lips, or tongue, or a severe rash.
• Infections: Including fever or respiratory issues.
• Blood in the urine: Or other significant changes in urination patterns.

Seizure Risk

Seizures have been reported in people using Xtandi. The risk may be increased in individuals with certain underlying conditions, such as a history of seizures, recent stroke, brain injury, or brain tumors. Certain other medications may also increase this risk.

Posterior Reversible Encephalopathy Syndrome (PRES)

PRES is a rare but serious brain condition that can occur during treatment. Symptoms often include sudden headaches, confusion, seizures, or vision loss. If PRES is suspected, the medication is usually discontinued.

Heart Problems

Treatment may increase the risk of ischemic heart disease, which includes heart attacks and blockages in the arteries. Monitoring for symptoms like chest pain or shortness of breath is common, especially for those with existing heart disease or risk factors such as high blood pressure.

Falls and Fractures

There is an increased risk of falls and bone fractures associated with this medication. These events can happen regardless of whether a person feels dizzy or loses consciousness. Bone density and fall risk are typically monitored by healthcare providers.

Reproductive Risks

Xtandi can cause harm to a developing fetus. Men with female partners of reproductive potential are advised to use effective contraception during treatment and for three months after the last dose. If a partner is pregnant, a condom should be used during sexual activity.

Pregnancy Risks

Xtandi is not approved for use in women. Based on its mechanism of action and findings from animal studies, this medication can cause fetal harm, including birth defects or pregnancy loss, if a woman is exposed to it while pregnant.

Precautions for Men

Because Xtandi may be present in semen, men taking this medication must follow specific safety guidelines if they have female partners who are pregnant or may become pregnant:

• Contraception: Men with female partners of reproductive potential should use effective birth control during treatment and for 3 months after the final dose.
• Pregnant Partners: Men should use a condom during sexual activity if their partner is pregnant to prevent the partner from being exposed to the medication through semen.
• Sperm Donation: Men should not donate sperm while taking Xtandi and for 3 months after stopping the medication.

Breastfeeding

There is no data regarding the presence of Xtandi in human milk or its effects on a breastfed child, as the drug is not indicated for use in females. Individuals should discuss any concerns regarding medication exposure with their healthcare provider.

Available Forms

Xtandi is available as a medication to be taken by mouth. It comes in two different solid forms:

• Oral tablets
• Oral capsules

Both the tablets and capsules are intended to be swallowed whole. They should not be chewed, crushed, or dissolved before taking.

FDA Approval Status

Xtandi was first approved by the U.S. Food and Drug Administration (FDA) in August 2012. Since its initial authorization, the FDA has expanded its approved uses to include a broader range of prostate cancer conditions based on clinical trial evidence.

Approved Indications

The FDA has approved Xtandi for the treatment of adult patients with the following conditions:

• Castration-Resistant Prostate Cancer (CRPC): This includes both metastatic disease (cancer that has spread) and non-metastatic disease.
• Metastatic Castration-Sensitive Prostate Cancer (mCSPC): For patients whose cancer still responds to testosterone-lowering treatments but has spread to other parts of the body.
• Non-Metastatic Castration-Sensitive Prostate Cancer (nmCSPC): Specifically for patients with high-risk biochemical recurrence (BCR).

Regulatory Monitoring and Safety

The FDA monitors the ongoing safety of Xtandi through the FDA Adverse Event Reporting System (FAERS). In 2020, the FDA identified potential signals of serious risks, such as ischemic heart disease, which are evaluated to determine if changes to the drug's labeling are necessary. Currently, Xtandi does not require a Risk Evaluation and Mitigation Strategy (REMS) program or a Boxed Warning.

Insurance and Out-of-Pocket Costs

The price of Xtandi is primarily influenced by your health insurance plan. Most Medicare Part D and private insurance plans cover the medication, but the specific out-of-pocket costs, such as copayments or coinsurance, depend on the plan's formulary. Because Xtandi is a specialized oncology medication, it is typically dispensed through specialty pharmacies rather than standard retail locations.

Financial Assistance Options

Several programs may be available to help manage the cost of treatment:

• Manufacturer Support: The drug manufacturer often provides patient assistance programs or copay savings cards for eligible patients with commercial insurance to help reduce monthly expenses.
• Patient Assistance Programs: For individuals who are uninsured or underinsured, there may be programs that provide the medication at a lower cost or for free based on financial need and clinical eligibility.
• Independent Foundations: Some non-profit organizations offer grants to help patients cover the costs of cancer medications and related expenses.

Patients are encouraged to contact their insurance provider or the manufacturer's support services to obtain a specific cost estimate and explore available financial aid options.