Antithymocyte immunoglobulin (rabbit) Advanced Drug Monograph

Antithymocyte Immunoglobulin (Rabbit) Report

Name: Antithymocyte immunoglobulin (rabbit) Name (English): Antithymocyte immunoglobulin (rabbit) DrugBank ID: DB00098 Type: Biotech CAS Number: 308067-60-9

Summary: Antithymocyte immunoglobulin (rabbit), also known as rabbit anti-thymocyte globulin (rATG) or Thymoglobulin, is a purified polyclonal antibody obtained from rabbits immunized with human thymocytes. It is an immunosuppressive medication used to prevent and treat acute rejection in kidney transplant patients. rATG works by depleting T-lymphocytes, which are key mediators of transplant rejection, through complement-mediated cytotoxicity and apoptosis.

Pharmacology:

• Mechanism of Action: rATG binds to various cell surface antigens on T-lymphocytes, leading to their depletion. This reduces the host immune response against the transplanted organ.
• Indication: Prophylaxis and treatment of acute rejection in kidney transplant recipients. Off-label uses include treatment of acute graft-versus-host disease (GVHD), severe aplastic anemia, and as part of conditioning regimens for stem cell transplantation.
• Pharmacokinetics: T-cell depletion is usually observed within one day of initiating therapy. The half-life is reported to be 2-3 days and may increase with multiple doses. rATG is likely removed by opsonization via the reticuloendothelial system or by the production of human anti-rabbit antibodies.

Adverse Reactions: Common adverse reactions include fever, chills, leukopenia, thrombocytopenia, infections (including urinary tract infections), hypertension, nausea, headache, and anxiety. Serious immune-mediated reactions such as anaphylaxis and cytokine release syndrome can occur.

Drug Interactions: rATG can increase the immunosuppressive effects and the risk of infection when used with other immunosuppressants like canakinumab and rilonacept.

Contraindications: rATG is contraindicated in patients with a history of allergy or anaphylaxis to rabbit proteins or any of the product's excipients, and in patients with active acute or chronic infections that contraindicate further immunosuppression.

Warnings and Precautions: rATG should only be administered by physicians experienced in immunosuppressive therapy. Patients should be closely monitored for infusion-related reactions, hematologic effects, and signs of infection or malignancy. Vaccination with live attenuated vaccines is not recommended following rATG therapy.

Dosage and Administration: Dosage varies depending on the indication and patient weight. It is administered intravenously, typically over 4-6 hours, in a hospital setting under strict medical supervision. Pre-medication with antipyretics, antihistamines, and corticosteroids may be used to reduce infusion reactions.

Clinical Trials: rATG has been investigated in various clinical trials for indications beyond kidney transplantation, including treatment of aplastic anemia and type 1 diabetes mellitus, and prevention of graft-versus-host disease in stem cell transplantation.

Note: This report provides a comprehensive overview based on available information. For detailed and specific information, consult the official product labeling and healthcare professionals.