Xembify: Uses, Dosage & Side Effects

What Is Xembify and What Is It Used For?

Xembify is a sterile, ready-to-use solution of human immunoglobulin G (IgG) intended for subcutaneous administration. It contains 200 mg/mL of protein, of which at least 98% is IgG. The immunoglobulins in Xembify are purified from pooled human plasma collected from thousands of healthy donors, ensuring a diverse and representative repertoire of antibodies that reflects the collective immune experience of the donor population. These antibodies work in exactly the same way as the immunoglobulins naturally produced by a healthy immune system, helping the body to recognize, bind to, and neutralize bacteria, viruses, and other pathogens.

The human immune system relies on several classes of immunoglobulins (IgG, IgA, IgM, IgD, and IgE) to defend against infections. IgG is the most abundant class, accounting for approximately 75% of total serum immunoglobulins, and plays a critical role in the secondary immune response. IgG antibodies are responsible for opsonization (marking pathogens for destruction by immune cells), complement activation (triggering a cascade of inflammatory responses), and neutralization of toxins and viruses. When a patient's immune system cannot produce adequate amounts of IgG, they become susceptible to recurrent, often severe, bacterial infections affecting the sinuses, lungs, gastrointestinal tract, and other organ systems.

The IgG subclass distribution in Xembify approximates that found in normal human serum: approximately 62% IgG1, 30% IgG2, 4.3% IgG3, and 3.2% IgG4. This balanced representation is important because each IgG subclass has distinct biological functions. IgG1 and IgG3 are particularly effective at activating complement and mediating antibody-dependent cellular cytotoxicity (ADCC), while IgG2 is crucial for responses against polysaccharide antigens (such as those on the surface of encapsulated bacteria like Streptococcus pneumoniae and Haemophilus influenzae). IgG4 plays a role in modulating immune responses and can block IgE-mediated reactions.

Approved Indications

Xembify is approved for use in adults, children, and infants (from birth to 18 years) who do not produce sufficient antibodies. The specific approved indications include:

• Primary immunodeficiency disorders (PID): These are inherited conditions in which the immune system fails to produce adequate antibodies. Examples include common variable immunodeficiency (CVID), X-linked agammaglobulinemia (Bruton's disease), severe combined immunodeficiency (SCID) with B-cell dysfunction, and other forms of congenital antibody deficiency. PID affects an estimated 1 in 1,200 to 1 in 2,000 individuals worldwide, though many cases remain undiagnosed.
• Hypogammaglobulinemia in chronic lymphocytic leukemia (CLL): Patients with CLL, a type of blood cancer characterized by overproduction of abnormal white blood cells, often develop secondary hypogammaglobulinemia (low antibody levels) as the disease progresses. This makes them highly vulnerable to recurrent bacterial infections. Xembify is indicated when prophylactic antibiotic treatment has failed to prevent these infections.
• Hypogammaglobulinemia in multiple myeloma: Multiple myeloma, a cancer of plasma cells in the bone marrow, can suppress normal immunoglobulin production. Patients with recurrent bacterial infections despite other measures may benefit from immunoglobulin replacement therapy.
• Hypogammaglobulinemia after allogeneic hematopoietic stem cell transplantation (HSCT): Patients who receive stem cells from a donor often experience prolonged periods of immune deficiency during which their new immune system is still developing. Immunoglobulin replacement can provide essential protection during this vulnerable period.

What Should You Know Before Using Xembify?

Contraindications

There are several absolute contraindications to the use of Xembify. You must not use this medicine in the following circumstances:

• Hypersensitivity: If you are allergic to human normal immunoglobulin or any of the other ingredients in Xembify (glycine, polysorbate 80, water for injections), you must not use this product.
• Severe allergic reaction to immunoglobulin: If you have previously experienced a severe allergic reaction (such as anaphylactic shock) to any human immunoglobulin product, Xembify is contraindicated.
• IgA deficiency with anti-IgA antibodies: Some patients who are deficient in IgA develop antibodies against IgA (anti-IgA antibodies). Since Xembify contains a small amount of IgA (not more than 160 micrograms per mL), these patients may experience severe allergic reactions if exposed to IgA-containing products. If you have been diagnosed with IgA deficiency, it is essential that your doctor tests for anti-IgA antibodies before prescribing Xembify.
• Wrong route of administration: Xembify must only be administered subcutaneously. It must never be injected into a blood vessel (intravenously) or into a muscle (intramuscularly).

Warnings and Precautions

Before starting treatment with Xembify, you should discuss the following with your healthcare provider:

• Cardiovascular and thrombotic risk: Tell your doctor if you have or have had heart disease, blood vessel disease, blood clots (such as stroke, heart attack, or pulmonary embolism), thick blood (hyperviscosity), diabetes mellitus, or high blood pressure. Inform your doctor if you are taking estrogen-containing medications, including contraceptives. You may be at increased risk of developing blood clots after Xembify infusion.
• Kidney function: Xembify may cause kidney problems, including acute kidney failure. Tell your doctor if you have impaired kidney function, as this may require closer monitoring during treatment.
• Aseptic meningitis: Rarely, immunoglobulin therapy can cause aseptic meningitis (inflammation of the brain membranes not caused by bacteria). Contact your doctor if you develop severe headache, stiff neck, drowsiness, fever, extreme light sensitivity, nausea, or vomiting. These symptoms may appear hours to days after infusion.
• Blood test interference: Xembify may affect certain blood test results (serological tests). Always inform your healthcare provider that you are receiving immunoglobulin therapy before any blood tests are performed.

Risk of Infectious Disease Transmission

Xembify is manufactured from pooled human plasma. Although rigorous safety measures are taken to minimize the risk of transmitting infectious agents, the possibility cannot be entirely eliminated when using products derived from human blood or plasma. The manufacturing process includes: screening of individual donations and plasma pools for markers of viral infections (including HIV, hepatitis B, and hepatitis C); and multiple viral inactivation and removal steps that have been validated to be effective against both enveloped viruses (such as HIV, hepatitis B virus, and hepatitis C virus) and non-enveloped hepatitis A virus. These measures may have limited value against non-enveloped viruses such as parvovirus B19. However, the antibodies present in immunoglobulin products are thought to contribute to protection against hepatitis A and parvovirus B19 infections.

It is strongly recommended that the product name and batch number be recorded each time Xembify is administered, so that a link between the patient and the batch can be maintained.

Pregnancy and Breastfeeding

Xembify has not been specifically studied in pregnant or breastfeeding women. However, extensive clinical experience with immunoglobulin products over several decades suggests no harmful effects on the course of pregnancy, the fetus, or the newborn. IgG antibodies cross the placenta, particularly during the third trimester, and this natural transfer of maternal IgG is essential for protecting the newborn during the first months of life. If you are breastfeeding, the immunoglobulins in Xembify may be present in your breast milk. These antibodies may actually provide some passive protection to your infant against certain infections. Clinical experience with immunoglobulins indicates that no harmful effects on fertility are expected.

If you are pregnant, think you may be pregnant, or are planning to become pregnant, consult your doctor or pharmacist before using Xembify. Your healthcare provider will weigh the benefits of continued immunoglobulin therapy against any potential risks.

Driving and Operating Machinery

The ability to drive and operate machinery may be impaired by certain side effects associated with Xembify, such as dizziness. If you experience any adverse effects during treatment, wait until they resolve before driving or using machines. You are responsible for assessing whether you are fit to drive a motor vehicle or perform tasks that require alertness.

How Does Xembify Interact with Other Drugs?

Immunoglobulin products such as Xembify have a specific interaction profile that differs from most conventional drugs. Because immunoglobulins are proteins that are naturally present in the body and are degraded through normal catabolic pathways, they do not undergo hepatic metabolism via cytochrome P450 (CYP) enzymes and therefore do not interact with most medications through traditional pharmacokinetic mechanisms. However, there are several important considerations regarding the use of Xembify with other treatments.

Interactions with Vaccines

The most clinically significant interaction of Xembify is with live attenuated vaccines. The passively transferred antibodies in Xembify can neutralize the vaccine virus strains, thereby reducing the immune response to the vaccine and potentially rendering it ineffective. This interaction is particularly important for the following vaccines:

If you are planning to receive any vaccination, always inform your healthcare provider that you are being treated with Xembify. Your doctor will advise you on the appropriate timing of vaccinations in relation to your immunoglobulin infusions. Inactivated vaccines (such as influenza, tetanus, and COVID-19 vaccines) are generally not affected by immunoglobulin therapy and can be administered according to standard schedules, although the immune response may be slightly blunted in immunodeficient patients.

Other Medication Considerations

Xembify should always be administered separately and must not be mixed with other medicinal products. No clinically significant pharmacokinetic interactions with conventional medications have been identified. However, the following general precautions apply:

• Anticoagulants and antiplatelet agents: While no direct interaction has been documented, patients receiving these medications alongside Xembify should be monitored, as immunoglobulin products carry a theoretical risk of thromboembolic events.
• Nephrotoxic agents: Concurrent use of medications that can affect kidney function may increase the risk of renal adverse events when used with immunoglobulin products. Adequate hydration and monitoring of kidney function are recommended.
• Serological testing: The passively transferred antibodies in Xembify may cause false-positive results in certain serological tests (e.g., Coombs test, tests for specific infectious agents). Always inform your laboratory that you are receiving immunoglobulin therapy.

What Is the Correct Dosage of Xembify?

Xembify must always be used exactly as prescribed by your doctor. Treatment is typically initiated by a physician or nurse experienced in the management of immunodeficiency disorders. Once you have received comprehensive training on the infusion technique, equipment use, aseptic procedures, recognition of serious adverse reactions, and record-keeping, you may self-administer Xembify at home.

Adults

The dose and dosing schedule for Xembify are individualized for each patient. Your doctor will calculate the appropriate dose based on your body weight, any previous immunoglobulin therapy you may have received, and your clinical response (particularly serum IgG trough levels and infection frequency). The general dosing parameters for adults are as follows:

For the first two infusions, the rate should start at 10 mL per hour per infusion site. If well tolerated, the rate may be increased every 10 minutes up to a maximum of 25 mL per hour per site for adults. After two well-tolerated infusion sessions, the rate can be gradually increased to 35 mL per hour per site, as directed by your doctor.

Children and Infants

The dosing for children and adolescents (0–18 years) is the same as for adults, as the dose is calculated based on body weight. The maximum infusion rate for children and adolescents is 20 mL per hour per infusion site during the initial escalation phase. In infants and small children, the infusion site may need to be changed more frequently, approximately every 5 to 15 mL, to ensure comfort and adequate absorption. Your pediatric immunologist will determine the optimal dosing regimen for your child.

Elderly Patients

The dosing for elderly patients (65 years and older) does not differ from that for younger adults, as the dose is individualized based on body weight and clinical response. Elderly patients may have additional comorbidities that warrant closer monitoring during treatment, particularly regarding cardiovascular and renal function.

Infusion Technique

Xembify is administered via slow subcutaneous infusion into the fatty tissue beneath the skin using an infusion pump. The key steps for home administration include:

1. Preparation: Allow the solution to reach room temperature (20–37 °C) before use. This may take 60 minutes or longer. Do not heat or microwave.
2. Inspection: Verify that the solution is clear to slightly opalescent and colorless or slightly yellow to light brown. Do not use if cloudy, discolored, or if particles are present.
3. Aseptic technique: Clean the workspace, wash hands thoroughly, and wipe the vial stopper with an alcohol swab. Draw the solution into a syringe using sterile technique.
4. Site selection: Choose appropriate infusion sites (abdomen, thighs, upper arms, or sides of hips). Clean sites with alcohol and allow to dry for at least 30 seconds. Rotate sites between infusions.
5. Infusion: Insert the needle at a 90-degree angle into the subcutaneous tissue. Verify correct placement (aspirate to check for blood), then begin infusion at the prescribed rate.
6. Record-keeping: Document the date, time, dose, batch number, infusion sites, and any adverse effects in your treatment diary. Bring this record to all doctor appointments.

Missed Dose

If you miss a scheduled dose of Xembify, do not take a double dose to compensate. Contact your doctor for instructions on when to administer the missed dose and how to resume your regular dosing schedule.

Overdose

If you have used more Xembify than prescribed, or if a child has accidentally received the medication, contact your doctor, hospital, or poison control center immediately for risk assessment and advice. Symptoms of overdose may relate to fluid overload and hyperviscosity, particularly in elderly patients or those with impaired cardiac or renal function.

What Are the Side Effects of Xembify?

Like all medicines, Xembify can cause side effects, although not everyone who uses it will experience them. The safety profile of Xembify has been established through clinical trials and post-marketing surveillance. Overall, subcutaneous immunoglobulin administration is generally well tolerated, with most adverse reactions being mild and localized to the infusion site. Local infusion site reactions tend to decrease in frequency and severity with continued treatment as the body adjusts to the subcutaneous infusion.

In rare cases, human normal immunoglobulins can cause a sudden drop in blood pressure and, in isolated instances, anaphylactic shock, even in patients who have tolerated previous administrations without any adverse effects. Signs of these serious allergic reactions include dizziness or fainting, skin rash and itching, swelling of the mouth or throat, difficulty breathing, wheezing, abnormal heart rhythm, chest pain, and blue discoloration of the lips, fingers, or toes. If you experience any of these symptoms during an infusion, stop the infusion immediately and seek emergency medical care.

Chills, dizziness, vomiting, low blood pressure, and moderate lower back pain have also been reported occasionally during or shortly after immunoglobulin infusions. If you notice any side effects, whether listed here or not, inform your healthcare provider. Reporting suspected adverse reactions after the medicine has been authorized is important for the ongoing monitoring of the benefit-risk balance of the medicine.

How Should You Store Xembify?

Proper storage of Xembify is essential to maintain the integrity and effectiveness of the immunoglobulin solution. The following storage guidelines should be followed carefully:

• Refrigerated storage: Store Xembify in a refrigerator at 2 °C to 8 °C (36 °F to 46 °F).
• Room temperature storage: Xembify may be stored at temperatures not exceeding 25 °C (77 °F) for up to 6 months before the expiration date. When removing the product from the refrigerator, write the discard date (whichever comes first: 6 months from the current date or the printed expiration date) on the carton.
• No re-refrigeration: Once the product has been stored at room temperature, it must not be returned to the refrigerator.
• Do not freeze: Freezing will damage the immunoglobulin proteins and render the product unusable.
• Protect from light: Keep the vials in the outer carton to protect from light.
• Prompt use after preparation: Administer Xembify as soon as possible after transferring it from the vial to a syringe.
• Expiration date: Do not use Xembify after the expiration date printed on the label and carton.
• Visual inspection: Do not use if the solution is discolored, cloudy, contains deposits, or has been frozen.

Keep Xembify out of the sight and reach of children. Dispose of unused solution and used equipment (needles, syringes, tubing) in an appropriate sharps disposal container according to local regulations. Do not dispose of medicines via wastewater or household waste. Ask your pharmacist how to dispose of medicines that are no longer needed. These measures help protect the environment.

What Does Xembify Contain?

Understanding the composition of Xembify is important for patients and healthcare providers to ensure safe and effective use. The active substance and excipients are described below.

Active Substance

The active substance is human normal immunoglobulin for subcutaneous use (SCIg). Each milliliter contains 200 mg of protein, of which at least 98% is immunoglobulin G (IgG). The IgG subclass composition closely mirrors that of normal human serum:

Xembify also contains a small amount of IgA (not more than 160 micrograms per mL). This is clinically relevant for patients with IgA deficiency who may have developed anti-IgA antibodies, as exposure to even small amounts of IgA could trigger a severe allergic reaction.

Excipients (Inactive Ingredients)

The other ingredients in Xembify are:

• Glycine (E640): An amino acid used as a stabilizer to maintain protein structure and prevent aggregation during storage.
• Polysorbate 80 (E433): A non-ionic surfactant used to prevent protein aggregation and maintain solution stability.
• Water for injections: The solvent in which the active and inactive ingredients are dissolved.

Available Pack Sizes

Xembify is supplied as a clear to slightly opalescent, colorless or slightly yellow to light brown solution in clear glass vials with a stopper, aluminum seal, and plastic cap. The following pack sizes are available:

• 1 g / 5 mL (1 or 10 vials per carton)
• 2 g / 10 mL (1, 10, or 20 vials per carton)
• 4 g / 20 mL (1 or 20 vials per carton)
• 10 g / 50 mL (1 or 10 vials per carton)

Not all pack sizes may be marketed in all countries. Each carton contains the vial(s) of Xembify and a patient information leaflet.