Enbrel

Common Indications

Enbrel is prescribed to help manage symptoms and slow the progression of certain autoimmune and inflammatory diseases. It is commonly used for the following conditions:

• Rheumatoid Arthritis: To reduce signs and symptoms, improve physical function, and help prevent joint damage in adults with moderate to severe active disease.
• Psoriatic Arthritis: To treat adults with active psoriatic arthritis, helping to reduce joint pain and skin symptoms.
• Ankylosing Spondylitis: To reduce symptoms in adults with this chronic inflammatory disease that primarily affects the spine.
• Plaque Psoriasis: To treat adults and children (4 years and older) with moderate to severe plaque psoriasis who are candidates for systemic therapy or phototherapy.
• Polyarticular Juvenile Idiopathic Arthritis: To treat children (2 years and older) with moderate to severe active JIA.

Healthcare providers often prescribe this medication when other treatments, such as methotrexate or other disease-modifying antirheumatic drugs (DMARDs), have not been effective enough in controlling inflammation or preventing structural damage.

Targeting Inflammation

Enbrel (etanercept) belongs to a class of medications known as tumor necrosis factor (TNF) blockers. TNF is a protein naturally produced by the body's immune system to help regulate inflammation and fight infections. However, in people with certain autoimmune diseases, the body produces too much of this protein.

How It Blocks TNF

When there is an excess of TNF, it triggers an overactive inflammatory response. This leads to the pain, stiffness, and tissue damage seen in conditions like rheumatoid arthritis, psoriatic arthritis, and plaque psoriasis. Enbrel works by mimicking a natural receptor in the body to neutralize this protein.

• Binding to TNF: The medication acts like a sponge, attaching itself to excess TNF molecules in the bloodstream.
• Preventing Receptor Attachment: By binding to these proteins, Enbrel prevents them from attaching to the actual receptors on the surface of healthy cells.
• Reducing the Signal: Because the TNF cannot attach to the cells, the signal to create inflammation is never sent.

By neutralizing this specific part of the immune system, the medication helps to decrease the underlying inflammation that causes symptoms. Because it targets a specific protein rather than the entire immune system, it is classified as a biologic therapy.

Common Side Effects

The most frequently reported side effects of Enbrel are usually mild and often improve as the body adjusts to the medication. These may include:

• Injection site reactions: Redness, itching, pain, or swelling where the needle entered the skin. These typically occur during the first month of treatment and usually resolve within three to five days.
• Infections: Upper respiratory infections, such as sinus infections, a runny nose, or the common cold.
• General symptoms: Headache, nausea, or a mild skin rash.

Serious Side Effects

Because Enbrel affects the immune system, it can lead to more severe complications. Seek medical help immediately if you experience any of the following:

• Serious infections: Fever, chills, persistent cough, or extreme fatigue. Enbrel can increase the risk of tuberculosis (TB) and infections caused by viruses, fungi, or bacteria.
• Neurological problems: Numbness, tingling, vision changes, dizziness, or weakness in the arms or legs, which may indicate conditions like multiple sclerosis or seizures.
• Blood disorders: Easy bruising, bleeding, or looking very pale, which may signal dangerously low blood cell counts.
• Heart failure: New or worsening shortness of breath, swelling of the ankles or feet, or sudden weight gain.
• Immune reactions: A lupus-like syndrome characterized by joint pain or a rash on the cheeks or arms that worsens in the sun.
• Severe allergic reactions: Hives, swelling of the face or throat, or difficulty breathing.
• Skin changes: New or worsening psoriasis, or changes in the appearance of moles which could indicate skin cancer.

Serious Infections

Enbrel affects the immune system and can decrease the body's ability to fight infections. Serious and sometimes fatal infections, including tuberculosis (TB), bacterial sepsis, and invasive fungal infections, have occurred in patients taking this medication. Treatment should not be initiated in individuals with an active infection. Patients are typically tested for TB before starting treatment and monitored for signs of infection throughout therapy.

Malignancy

Lymphoma and other malignancies, some fatal, have been reported in children and adolescent patients treated with tumor necrosis factor (TNF) blockers. There is also an increased risk of developing certain types of skin cancer. Regular monitoring for new skin lesions or changes in existing moles is often recommended.

Neurological Events

The use of TNF blockers has been linked to rare cases of new-onset or worsening central nervous system demyelinating disorders, such as multiple sclerosis and optic neuritis, as well as peripheral demyelinating polyneuropathy. Healthcare providers monitor for symptoms like numbness, vision changes, or weakness.

Hematologic Reactions

Rare cases of serious blood disorders, including aplastic anemia and low white blood cell or platelet counts, have been reported. Medical attention is necessary if a patient develops signs of blood issues, such as persistent fever, easy bruising, or paleness.

Heart Failure

Cases of worsening congestive heart failure or new-onset heart failure have been observed in patients taking Enbrel. Caution is used when prescribing this medication to individuals with pre-existing heart conditions, and they are monitored closely for new or worsening symptoms.

Hepatitis B Reactivation

In patients who are carriers of the hepatitis B virus, the virus may become active again during treatment with TNF blockers. Healthcare providers typically perform blood tests before and during treatment to monitor liver function and viral activity.

Vaccinations

Live vaccines should be avoided while taking Enbrel. It is recommended that all patients, especially children, receive all currently recommended immunizations before starting therapy to ensure they are protected.

Pregnancy

Information regarding the use of Enbrel during pregnancy is limited. While current evidence does not show a significantly increased risk of major birth defects, the medication does cross the placenta, especially during the third trimester. Because etanercept is an immunosuppressant, it may affect the immune system of the newborn.

If Enbrel is used during pregnancy, healthcare providers may recommend delaying certain live vaccines for the infant for several months after birth. It is important to inform the pediatrician if Enbrel was used during pregnancy to ensure a safe vaccination schedule.

Breastfeeding

Etanercept has been detected in low levels in human breast milk. It is a large protein molecule, and most experts believe that very little of the drug is absorbed by the infant because it is likely broken down in the baby's digestive system. However, the long-term effects on a nursing infant are not fully established.

Patients should discuss the benefits of breastfeeding and the clinical need for Enbrel with their doctor to determine the best course of action for both the parent and the child.

Available Forms

Enbrel is administered as a subcutaneous injection (under the skin). It is available in several different delivery formats to facilitate administration:

• Prefilled Syringes: Single-dose syringes that come ready for manual injection.
• SureClick Autoinjectors: Single-dose devices designed to automate the delivery of the medication.
• Enbrel Mini Cartridges: Single-dose cartridges designed specifically for use with the reusable AutoTouch activator device.
• Vials: Available as single-dose or multiple-dose vials. Some versions are provided as a liquid solution, while others are supplied as a lyophilized powder that must be reconstituted (mixed with a liquid) before use.

FDA Approval and Indications

Enbrel (etanercept) is approved by the U.S. Food and Drug Administration (FDA) for the treatment of several autoimmune and inflammatory conditions. These approved uses include:

• Rheumatoid arthritis
• Plaque psoriasis
• Psoriatic arthritis
• Ankylosing spondylitis
• Polyarticular juvenile idiopathic arthritis

Boxed Warning

The FDA requires a boxed warning for Enbrel, which is the most serious type of warning for a medication. This warning highlights two primary risks:

• Serious Infections: Patients taking Enbrel are at an increased risk for developing serious infections that may lead to hospitalization or death. These include tuberculosis (TB), bacterial sepsis, and invasive fungal infections.
• Malignancies: Lymphoma and other cancers, some fatal, have been reported in children and adolescent patients using tumor necrosis factor (TNF) blockers like Enbrel.

Regulatory Requirements

Due to the risk of serious infections, the FDA requires healthcare providers to test patients for latent tuberculosis before starting Enbrel treatment and to monitor them for signs of infection during therapy. Enbrel is classified as a prescription-only biological product and is not available over-the-counter.

Insurance Coverage

Most insurance plans cover Enbrel, but they often require prior authorization. This is a process where your doctor must confirm the medication is medically necessary before the insurance company will pay for it. Some insurance companies may also require step therapy, which means you must try other, often less expensive, treatments before they will approve Enbrel.

Financial Assistance

Financial assistance may be available for patients who qualify. Options often include:

• Co-pay cards: These are typically available for patients with commercial insurance to help lower the amount paid at the pharmacy.
• Patient assistance programs: These programs may provide the medication at no cost or a reduced cost for individuals who are uninsured or have limited income and meet specific eligibility criteria.

Medicare and Medicaid

For those on Medicare Part D, the cost of Enbrel can vary depending on the specific plan and the current coverage phase, such as the deductible or the coverage gap. Medicaid coverage varies by state and specific plan requirements.

Biosimilars

Biosimilar versions of etanercept are designed to be more affordable alternatives to Enbrel. While some have received FDA approval, their availability and whether they are covered by your insurance can vary. In many cases, a doctor must specifically prescribe the biosimilar for it to be dispensed, as they are not always interchangeable at the pharmacy level.