Anti-Thymocyte Globulin (Rabbit)

THYMOGLOBULIN is indicated for the prophylaxis and treatment of acute rejection in adult and pediatric patients receiving a kidney transplant in conjunction with concomitant immunosuppression. THYMOGLOBULIN is an immunoglobulin G indicated for the prophylaxis and treatment of acute rejection in adult and pediatric patients receiving a kidney transplant in conjunction with concomitant immunosuppression. ( 1 )

THYMOGLOBULIN for injection: 25 mg anti-thymocyte globulin (rabbit) as a sterile lyophilized powder, in single-dose 10 mL vials for reconstitution. Single-dose 10 mL vial containing 25 mg of anti-thymocyte globulin (rabbit) lyophilized, sterile powder. ( 3 )

THYMOGLOBULIN is contraindicated in patients with history of allergy or anaphylactic reaction to rabbit proteins or to any product excipients, or who have active acute or chronic infections that contraindicate any additional immunosuppression [see Warnings and Precautions (5.2 , 5.4) and Adverse Reactions (6.2) ] . Allergy or anaphylactic reaction to rabbit proteins or to any product excipients, or active acute or chronic infections which contraindicate any additional immunosuppression ( 4 )

THYMOGLOBULIN should only be used by physicians experienced in immunosuppressant therapy in transplantation. ( 5.1 ) Hypersensitivity and infusion-related reactions: THYMOGLOBULIN infusion could result in an anaphylactic reaction. Close compliance with the recommended infusion time may reduce the incidence and severity of infusion-related reactions. ( 5.2 ) Cytopenias including anemia, neutropenia, and thrombocytopenia have occurred with THYMOGLOBULIN administration ( 6 ) and require monitoring of blood counts. Adjust dose accordingly to reverse cytopenias. Thrombotic microangiopathy (TMA) has occurred in patients treated with THYMOGLOBULIN for kidney transplantation, particularly when concomitantly administered with calcineurin inhibitors. ( 5.3 ) Infection: Infections and reactivation of infections have been reported. Monitor patients and administer anti-infective prophylaxis. ( 5.4 ) Malignancy: Incidence of malignancies may increase. ( 5.5 ) Immunization with attenuated live vaccines is not recommended for patients who have recently received THYMOGLOBULIN. ( 5.6 ) THYMOGLOBULIN may interfere with rabbit antibody–based immunoassays and with cross-match or panel-reactive antibody cytotoxicity assays. ( 5.7 )

5.1 Management of Immunosuppression To prevent over-immunosuppression, physicians may wish to decrease the dose of the maintenance immunosuppression regimen during the period of THYMOGLOBULIN use.

5.2 Hypersensitivity and Infusion-Related Reactions Severe hypersensitivity and infusion-related reactions, including fatal anaphylaxis and severe cytokine release syndrome (CRS), have been reported with the use of THYMOGLOBULIN [see Adverse Reactions (6) ] . Severe acute CRS can cause serious cardiorespiratory events and/or death. Close compliance with the recommended dosage and infusion time may reduce the incidence and severity of infusion-related reactions. Slowing the infusion rate may minimize the risk of infusion-related reactions. If a hypersensitivity or infusion-related reaction occurs, terminate the infusion immediately and provide supportive treatment according to clinical practice.

5.3 Cytopenias Cytopenias including anemia, neutropenia, and thrombocytopenia have occurred with THYMOGLOBULIN administration [see Adverse Reactions (6) ] . Monitor blood counts after THYMOGLOBULIN administration. Adjust dose accordingly to reverse cytopenias [see Dosage and Administration (2.3) ] . Thrombotic microangiopathy (TMA) has occurred in patients treated with THYMOGLOBULIN for kidney transplantation, particularly when concomitantly administered with calcineurin inhibitors.

5.4 Infection THYMOGLOBULIN is routinely used in combination with other immunosuppressive agents. Infections (bacterial, fungal, viral and protozoal), reactivation of infection (particularly cytomegalovirus [CMV]) and sepsis have been reported after THYMOGLOBULIN administration in combination with multiple immunosuppressive agents [see Adverse Reactions (6) ] . These infections can be fatal. Monitor patients carefully and administer appropriate anti-infective treatment when indicated [see Dosage and Administration (2.4) ] .

5.5 Malignancy Malignancies with fatal outcomes have been reported in patients treated with THYMOGLOBULIN [see Adverse Reactions (6) ]. Use of immunosuppressive agents, including THYMOGLOBULIN, may increase the risk of malignancies, including lymphoma or lymphoproliferative disorders.

5.6 Immunizations The safety of immunization with attenuated live vaccines following THYMOGLOBULIN therapy has not been studied; therefore, immunization with attenuated live vaccines is not recommended for patients who have recently received THYMOGLOBULIN.

5.7 Laboratory Tests THYMOGLOBULIN may interfere with rabbit antibody–based immunoassays and with cross-match or panel-reactive antibody cytotoxicity assays. THYMOGLOBULIN has not been shown to interfere with any routine clinical laboratory tests that do not use immunoglobulins.

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. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Genzyme Corporation at 1-800-633-1610 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. 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, and low counts of platelets and white blood cells. Prophylaxis of Acute Rejection The safety of THYMOGLOBULIN compared to Active Comparator for the prophylaxis of acute rejection in patients receiving a kidney transplant were evaluated in a randomized, open-label, international, multicenter trial in patients receiving solitary kidneys from deceased donors (n=278; Study 1). Table 1: Adverse Reactions Adverse reactions are treatment emergent adverse events (TEAE) reported as related to the study agent in at least 1 patient. and Laboratory Abnormalities Reported More Frequently (incidence Number (percentage) is shown regardless of causal relationship. >5%) Following THYMOGLOBULIN versus Active Comparator basiliximab Adverse Reaction [n (%) ] THYMOGLOBULIN (N=141) Active Comparator (N=137) Urinary tract infection 55 (39%) 36 (26%) Pyrexia 39 (28%) 25 (18%) Headache 26 (18%) 17 (12%) Hyperlipidemia 21 (15%) 9 (7%) Anxiety 20 (14%) 12 (9%) Chills 13 (9%) 5 (4%) Laboratory Abnormalities Hyperkalemia: blood potassium ≥5.5 mmol/L; Leukopenia: WBC <3000 cells/mm 3 . Thrombocytopenia: platelet count <75,000 cells/mm 3 . Hyperkalemia 81 (57%) 70 (51%) Leukopenia 89 (63%) 20 (15%) Thrombocytopenia 23 (16%) 7 (5%) Malignancies Six patients in the THYMOGLOBULIN group developed malignancies (Epstein-Barr virus-induced lymphoma of the cavum, Epstein-Barr virus-positive large B-cell lung lymphoma, Epstein-Barr virus-induced lymphoma of the brain, squamous cell carcinoma, renal cancer, and recurrent basal cell carcinoma). In the Active Comparator group, 1 patient developed renal cancer. Infections Infections occurred in 76% of THYMOGLOBULIN-treated patients (severe in 23%), and in 63% of Active Comparator-treated patients (severe in 15%). Infections occurring in ≥5% of the patients in either treatment group during the 12-month follow-up are summarized in Table 2. Urinary tract infection was the most frequent type of infection, and was reported as severe in 9% of THYMOGLOBULIN-treated patients and in 2% of Active Comparator-treated patients. CMV infections were reported more frequently in the Active Comparator group, with an incidence of 6% (severe in 1%) in THYMOGLOBULIN-treated patients and of 18% (severe in 7%) in Active Comparator-treated patients. Patients who were CMV-positive at the time of transplant, as well as CMV-negative recipients of transplants from CMV-positive donors, were required to receive antiviral prophylaxis for 3 months after transplant. Table 2: Infections Reported in ≥5% of Study Patients Infection THYMOGLOBULIN All (N=141) THYMOGLOBULIN Severe/Unknown (N=141) Active Comparator basiliximab All (N=137) Active Comparator Severe/Unknown (N=137) Urinary tract infections Urinary tract infection group includes: Urinary tract infections, Urinary tract infection fungal, Urinary tract infection bacterial, Bacterial pyelonephritis, Urosepsis. 59 (42%) 12 (9%) 39 (29%) 3 (2%) Sepsis Sepsis group includes: Sepsis, Escherichia sepsis, Staphylococcal bacteremia. 9 (6%) 5 (4%) 1 (1%) 1 (1%) Lower respiratory tract and lung infections Lower respiratory tract and lung infections group includes: Lower respiratory tract and lung infections, and Pneumonia pseudomonal. 18 (13%) 2 (1%) 16 (12%) 4 (3%) Upper respiratory tract infection 15 (11%) 0 15 (11%) 1 (1%) Nasopharyngitis 7 (5%) 0 9 (7%) 0 Cytomegaloviral infections The collective term "cytomegaloviral infections" includes CMV duodenitis, CMV gastritis, CMV hepatitis, CMV infection, and CMV viremia. 8 (6%) 2 (1%) 21 (18%) 7 (7%) Herpes zoster 7 (5%) 0 2 (2%) 1 (1%) Oral candidiasis 8 (6%) 0 11 (8%) 0 Adverse Drug Reactions Occurring within 24 Hours and Infusion-Related Reactions Adverse reactions occurring during or within 24 hours of infusion in >5% of patients in the THYMOGLOBULIN group are summarized in Table 3. Table 3: Adverse Drug Reactions Adverse reactions that occurred during or within 24 hours of an infusion, and where the incidence was higher in the THYMOGLOBULIN group. Occurring within 24 Hours of Infusion and with >5% Incidence in Patients who Received THYMOGLOBULIN Primary System Organ Class n (%) THYMOGLOBULIN (N=141) Active Comparator basiliximab (N=137) Constipation 47 (33%) 23 (17%) Anemia 35 (25%) 19 (14%) Hyperkalemia 33 (23%) 18 (13%) Hypertension 25 (18%) 19 (14%) Leukopenia and White blood cell count decreased 29 (21%) 0 Pyrexia 18 (13%) 3 (2%) Vomiting 17 (12%) 14 (10%) Thrombocytopenia 13 (9%) 1 (1%) Abdominal pain 11 (8%) 6 (4%) Anxiety 10 (7%) 2 (2%) Hyperphosphatemia 10 (7%) 2 (2%) Tachycardia 10 (7%) 5 (4%) Acidosis 9 (6%) 8 (6%) Diarrhea 9 (6%) 1 (1%) Hypokalemia 9 (6%) 4 (3%) Infusion-related reactions Adverse reactions that occurred within 24 hours after the completion of the THYMOGLOBULIN administration and are considered as possible infusion related reactions (IARs) include the following: anxiety, confusional state, agitation, restlessness, headache, lethargy, dizziness, decreased sensitivity, fast heart rate, myocardial infarction, elevated blood pressure, decreased blood pressure, cough, throat irritation, reduced oxygen supply to tissues, shortness of breath, pulmonary edema, pain in mouth and throat, diarrhea, upper abdominal pain, abdominal tenderness, abdominal discomfort, nausea, pruritus, rash, joint pain, fever, chills, lack of energy, localized edema, malaise, and chest pain. Serum sickness was reported in 6 of 405 patients enrolled across completed studies where patients had been treated with THYMOGLOBULIN for the prophylaxis of acute rejection in patients receiving a kidney transplant. Anaphylactic shock was reported in 2 of 405 patients enrolled across completed studies. Treatment of acute rejection In the US Phase 3 randomized controlled clinical trial (n=163; Study 3) comparing the efficacy and safety of THYMOGLOBULIN and Active Comparator in the treatment of acute rejection in kidney transplant patients, adverse reactions occurring at least 5% more frequently in the THYMOGLOBULIN group than in the Active Comparator group are shown in Table 4. Malignancies were reported in 3 patients who received THYMOGLOBULIN and in 3 patients who received Active Comparator during the one-year follow-up period. These included two cases of post-transplant lymphoproliferative disease (PTLD) in the THYMOGLOBULIN group and two cases of PTLD in the Active Comparator group. Table 4: Adverse Reactions Treatment-emergent adverse events/reactions (TEAE) are summarized. […]

No drug interaction studies have been performed. THYMOGLOBULIN can stimulate the production of antibodies that cross-react with rabbit immune globulins [see Clinical Pharmacology (12.3) ] .

8.1 Pregnancy Risk Summary Animal reproduction studies have not been conducted with THYMOGLOBULIN. It is also not known whether THYMOGLOBULIN can cause fetal harm. THYMOGLOBULIN should be given to a pregnant woman only if the benefit outweighs the risk.

8.2 Lactation Risk Summary THYMOGLOBULIN 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 THYMOGLOBULIN therapy.

8.3 Females and Males of Reproductive Potential Contraception Females There is a lack of information on the risks associated with the administration of THYMOGLOBULIN during pregnancy. Therefore, effective contraception is recommended during and for a minimum of 3 months after treatment.

8.4 Pediatric Use The safety and effectiveness of THYMOGLOBULIN in pediatric patients have been established in pediatric patients for the prophylaxis and treatment of acute rejection. The use of THYMOGLOBULIN in pediatric patients was supported by extrapolation of adult data from Study 1, Study 2 and Study 3 [see Adverse Reactions (6) and Clinical Studies (14) ].

The mechanism of action by which polyclonal antilymphocyte preparations suppress immune responses is not fully understood. Possible mechanisms by which THYMOGLOBULIN may induce immunosuppression in vivo include: T-cell clearance from the circulation and modulation of T-cell activation, homing, and cytotoxic activities. THYMOGLOBULIN 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 , THYMOGLOBULIN (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 THYMOGLOBULIN therapy. THYMOGLOBULIN has not been shown to be effective for treating antibody-mediated (humoral) rejections.