The mechanism of action by which polyclonal antilymphocyte preparations suppress immune responses is not fully understood. Possible mechanisms by which Anti-Thymocyte Globulin may induce immunosuppression in vivo include: T-cell clearance from the circulation and modulation of T-cell activation, homing, and cytotoxic activities. Anti-Thymocyte Globulin includes antibodies against T-cell markers such as CD2, CD3, CD4, CD8, CD11a, CD18, CD25, CD44, CD45, HLA-DR, HLA Class I heavy chains, and ß2 micro-globulin. In vitro, Anti-Thymocyte Globulin (concentrations >0.1 mg/mL) mediates T-cell suppressive effects via inhibition of proliferative responses to several mitogens. In patients, T-cell depletion is usually observed within a day after initiating Anti-Thymocyte Globulin therapy. Anti-Thymocyte Globulin has not been shown to be effective for treating antibody-mediated (humoral) rejections.

Single-use 10 ml vial containing 25 mg of anti-thymocyte globulin (rabbit) lyophilized, sterile powder.

Anti-Thymocyte Globulin is an immunoglobulin G indicated for the prophylaxis and treatment of acute rejection in patients receiving a kidney transplant. Use in conjunction with concomitant immunosuppression.

The first dose should be infused over at least 6 hours; doses on subsequent days should be infused over at least 4 hours.

Premedication with corticosteroids, acetaminophen, and/or an antihistamine prior to each infusion is recommended.

The Anti-Thymocyte Globulin dose should be reduced by one half if the white blood cell (WBC) count is between 2,000 and 3,000 cells/mm3 or if the platelet count is between 50,000 and 75,000 cells/mm3. Stopping Anti-Thymocyte Globulin treatment should be considered if the WBC count falls below 2,000 cells/mm3 or if the platelet count falls below 50,000 cells/mm3

• Prophylaxis of acute rejection: 1.5 mg/kg of body weight administered daily for 4 to 7 days
• Treatment of acute rejection: 1.5 mg/kg of body weight administered daily for 7 to 14 days

Allergy or anaphylactic reaction to rabbit proteins or to any product excipients, or active acute or chronic infections which contraindicate any additional immunosuppression

The most common adverse reactions and laboratory abnormalities (incidence>5% higher than comparator) are urinary tract infection, abdominal pain, hypertension, nausea, shortness of breath, fever, headache, anxiety, chills, increased potassium levels in the blood, low counts of platelets and white blood cells

Pregnancy & Lactation

Animal reproduction studies have not been conducted with Anti-Thymocyte Globulin. It is also not known whether Anti-Thymocyte Globulin can cause fetal harm. Anti-Thymocyte Globulin should be given to a pregnant woman only if the benefit outweighs the risk.

Anti-Thymocyte Globulin has not been studied in nursing women. It is not known whether this drug is excreted in human milk. Because other immunoglobulins are excreted in human milk, breastfeeding should be discontinued during Anti-Thymocyte Globulin therapy.

Precautions & Warnings

Anti-Thymocyte Globulin should only be used by physicians experienced in immunosuppressant therapy in transplantation.

Immune-mediated reactions: Anti-Thymocyte Globulin infusion could result in an anaphylactic reaction.

Infusion-associated reactions: Close compliance with the recommended infusion time may reduce the incidence and severity of infusion-associated reactions.

Hematologic effects: low counts of platelets and white blood cells have been identified and are reversible following dose adjustments. Monitor total white blood cell and platelet counts.

Infection: Infections and reactivation of infections have been reported. Monitor patients and administer anti-infective prophylaxis.

Malignancy: Incidence of malignancies may increase.

Immunization with attenuated live vaccines is not recommended for patients who have recently received THYMOGLOBULIN. THYMOGLOBULIN may interfere with rabbit antibody–based immunoassays and with cross-match or panel-reactive antibody cytotoxicity assays.

Use in Special Populations

Pediatric Use: The safety and effectiveness of Anti-Thymocyte Globulin in pediatric patients have not been established in controlled trials. However, based on limited European studies and U.S. compassionate use, the dose, efficacy, and adverse reaction profile are not thought to be different than for adults.