Xembify

Primary Humoral Immunodeficiency

Xembify is specifically indicated for the treatment of primary humoral immunodeficiency (PI). This is a group of conditions where the immune system is missing or not working correctly, making it difficult for the body to protect itself against germs.

Specific types of PI that may be treated with this medication include:

• Congenital agammaglobulinemia
• Common variable immunodeficiency (CVID)
• Wiskott-Aldrich syndrome
• Severe combined immunodeficiencies (SCID)

Purpose of Treatment

People with PI often have low levels of antibodies, which are proteins the immune system uses to neutralize bacteria and viruses. Xembify contains immunoglobulin G (IgG) collected from human plasma. When administered, it helps boost the patient's antibody levels to a more normal range, providing protection against various infections.

This medication is intended for subcutaneous (under the skin) administration and is used as a long-term replacement therapy for patients who cannot produce enough of their own antibodies.

How Xembify Works

Xembify is a type of medicine called immune globulin. It contains a concentrated amount of immunoglobulin G (IgG), which are antibodies naturally found in human blood. These antibodies are a critical part of the immune system and help the body recognize and neutralize bacteria, viruses, and other foreign substances.

In people with primary humoral immunodeficiency (PI), the body does not produce enough of these antibodies or the antibodies it does produce do not work correctly. This leaves the person more vulnerable to frequent and severe infections.

When Xembify is injected under the skin, it enters the bloodstream and provides the missing IgG. This replacement therapy helps to:

• Restore antibody levels to a more normal range.
• Improve the body's ability to defend itself against various pathogens.
• Reduce the frequency and severity of infections.

Because the body naturally uses up these antibodies over time, regular treatments are necessary to maintain protective levels in the blood.

Common Side Effects

The most common side effects of Xembify are local reactions at the site of infusion. These typically include:

• Redness, swelling, or itching
• Pain or tenderness
• Bruising or firm lumps

Other common symptoms reported by patients include cough, diarrhea, headache, nausea, fatigue, and joint or back pain.

Serious Side Effects

Contact a healthcare provider immediately if you experience signs of a serious reaction. These may include:

• Allergic Reactions: Symptoms such as hives, dizziness, or swelling of the face, lips, or tongue.
• Blood Clots: Signs include sudden shortness of breath, chest pain, or pain and swelling in a limb.
• Kidney Problems: Symptoms include decreased urination or swelling in the legs and feet.
• Aseptic Meningitis: A condition involving a severe headache, stiff neck, fever, and sensitivity to light.
• Lung Complications: Severe breathing problems that may occur within hours of an infusion.
• Hemolysis: The breakdown of red blood cells, which can cause fatigue, dark urine, or yellowing of the skin.

Boxed Warning: Thrombosis

Blood clots (thrombosis) may occur with immune globulin products, including Xembify. Risk factors include advanced age, prolonged immobilization, hypercoagulable conditions, a history of venous or arterial thrombosis, use of estrogens, indwelling central vascular catheters, and cardiovascular risk factors. Thrombosis may occur even in the absence of known risk factors. For patients at risk, Xembify should be administered at the minimum dose and infusion rate practicable.

Hypersensitivity and Allergic Reactions

Severe hypersensitivity reactions, including anaphylaxis, can occur. Xembify is contraindicated in individuals who have a history of anaphylactic or severe systemic reactions to human immune globulin. It is also contraindicated in patients with selective immunoglobulin A (IgA) deficiency who have antibodies against IgA and a history of hypersensitivity, as they are at higher risk for severe reactions.

Kidney Dysfunction

Acute renal failure, acute tubular necrosis, and death have been reported with the use of immune globulin products. While these complications are often associated with products containing sucrose, Xembify does not contain sucrose. However, monitoring of kidney function and urine output is still necessary, particularly for patients at increased risk of renal failure.

Aseptic Meningitis Syndrome

Aseptic meningitis syndrome (AMS) has been reported with immune globulin treatments. This non-infectious inflammation of the brain lining typically begins within several hours to two days after treatment. Symptoms may include severe headache, neck stiffness, fever, nausea, and sensitivity to light. AMS usually resolves within several days after treatment is discontinued.

Other Serious Precautions

• Hemolysis: Xembify may contain blood group antibodies that can act as hemolysins and induce the breakdown of red blood cells (hemolysis).
• Transfusion-Related Acute Lung Injury (TRALI): Some patients may experience noncardiogenic pulmonary edema, a condition where fluid builds up in the lungs. This is characterized by severe respiratory distress and low oxygen levels.
• Infectious Agents: Because Xembify is made from human plasma, it may carry a risk of transmitting infectious agents, such as viruses and the agent of Creutzfeldt-Jakob disease.
• Interference with Laboratory Tests: The temporary rise of various antibodies in the blood following an infusion may lead to false-positive results in serological tests.

Pregnancy

It is not known whether Xembify can cause harm to an unborn baby or affect a woman's ability to conceive. There have been no clinical studies conducted in pregnant women, and animal reproduction studies have not been performed with this medication.

Healthcare providers generally only prescribe Xembify during pregnancy if there is a clear medical necessity. If you are pregnant or planning to become pregnant, consult your doctor to discuss the potential risks and benefits of treatment.

Breastfeeding

There is no specific information available on whether Xembify passes into breast milk, how it affects a nursing infant, or its impact on milk production. It is known that maternal antibodies are naturally present in human milk.

The decision to breastfeed while using Xembify should be made in consultation with a healthcare provider. They will help weigh the developmental and health benefits of breastfeeding against the mother's clinical need for the medication and any potential risks to the infant.

Dosage Forms

Xembify is available as a sterile, preservative-free liquid solution. It is intended for subcutaneous administration only. The medication is supplied in single-dose vials.

FDA Approval and Indications

The U.S. Food and Drug Administration (FDA) approved Xembify (immune globulin subcutaneous (human) 20%) in July 2019. It is indicated for the treatment of primary humoral immunodeficiency (PI) in adults and pediatric patients 2 years of age and older.

Boxed Warning

Xembify carries a boxed warning regarding the risk of thrombosis (blood clots). Thrombosis may occur with immune globulin products, including Xembify, regardless of the route of administration. Risk factors for developing blood clots include:

• Advanced age
• Prolonged immobilization
• Hypercoagulable conditions
• History of venous or arterial thrombosis
• Use of estrogens
• Indwelling central vascular catheters
• Hyperviscosity (thickened blood)
• Cardiovascular risk factors

For patients at risk of thrombosis, healthcare providers are advised to administer Xembify at the minimum dose and infusion rate practicable. Patients should be adequately hydrated before administration and monitored for signs and symptoms of thrombosis. Those at risk for hyperviscosity should be assessed for blood viscosity.

Factors Influencing Cost

The total price of Xembify treatment is largely determined by the amount of medication prescribed. Dosage is calculated based on the patient's body weight and their previous intravenous or subcutaneous immune globulin dose. Because Xembify is administered frequently—ranging from daily to weekly—the cumulative volume of the drug used significantly impacts the overall cost.

Insurance and Prior Authorization

As a specialty biologic product, Xembify is typically covered under most insurance plans for the treatment of primary humoral immunodeficiency. However, insurance companies often require prior authorization. This process involves a healthcare provider submitting documentation to prove medical necessity before the insurer agrees to cover the cost of the drug.

Specialty Pharmacy and Distribution

Xembify is generally not available at standard retail pharmacies. It is distributed through specialty pharmacies that handle biologics and provide the necessary supplies for subcutaneous administration. Out-of-pocket costs, such as co-payments or co-insurance, may vary depending on whether the insurance plan processes the claim under medical or pharmacy benefits.

Financial Assistance

Patients may have access to financial support programs to help manage the costs of Xembify. These programs are often provided by the manufacturer and may include co-pay assistance for patients with commercial insurance or patient assistance programs for those who are uninsured or underinsured.