Grafalon

Grafalon is a rabbit anti‑thymocyte globulin preparation for human use, supplied as an injectable solution for intravenous administration. The product contains polyclonal antibodies that bind T‑lymphocyte surface antigens, producing profound immunosuppression. Although the exact strength is not listed, Grafalon is marketed in the European Union as a prescription‑only immunosuppressive agent used in transplantation. It is classified under ATC code L04AA02 and is administered under specialist supervision.

Grafalon is indicated for several transplant‑related indications where strong T‑cell depletion is required to prevent immune‑mediated complications. It is used as part of induction or conditioning regimens in solid organ, hematopoietic stem cell, and bone marrow transplantation protocols. - Prevention of acute rejection in kidney, liver, heart, or lung transplantation. - Prophylaxis of graft‑versus‑host disease (GVHD) following allogeneic hematopoietic stem cell transplantation. - Conditioning component of the preparative regimen for bone marrow transplantation. - Adjunctive immunosuppression in high‑risk or sensitized transplant recipients. - Use in combined organ‑bone marrow transplant procedures when intensified T‑cell depletion is desired.

The immunologic activity of Grafalon can produce a range of adverse events, which are generally categorized by frequency and clinical severity.

Common: - Fever, chills, or rigors during or shortly after the infusion. - Nausea, vomiting, or mild gastrointestinal discomfort. - Transient elevation of liver enzymes (ALT/AST) without clinical hepatitis. - Headache or dizziness occurring during the infusion period. - Mild infusion‑site reactions such as erythema or swelling.

Serious: - Cytokine release syndrome presenting with hypotension, tachycardia, or respiratory distress. - Severe infections, including bacterial, viral, or fungal sepsis, due to profound immunosuppression. - Hematologic abnormalities such as thrombocytopenia, neutropenia, or anemia. - Acute renal impairment or hemolytic anemia secondary to immune‑mediated mechanisms. - Severe cytokine release syndrome or uncontrolled infection requiring therapy discontinuation.

Because Grafalon produces deep and prolonged T‑cell depletion, several precautions and monitoring measures are recommended before, during, and after therapy. - Perform baseline complete blood count, liver function tests, and renal function assessment. - Screen for active infections, including hepatitis B/C, HIV, and tuberculosis, prior to initiation. - Use pre‑medication (e.g., antipyretics, antihistamines, corticosteroids) to reduce infusion‑related reactions. - Monitor vital signs and laboratory parameters closely during each infusion. - Adjust dosage or discontinue therapy in the event of severe cytokine release syndrome or uncontrolled infection. - Avoid use in patients with known hypersensitivity to rabbit proteins or rabbit‑derived products.

Grafalon may interact with other agents that affect immune function, hemodynamics, or organ toxicity, requiring careful assessment of concomitant medications.

Avoid: - Live attenuated vaccines administered during or shortly after treatment, due to risk of uncontrolled infection. - Concurrent use of other potent T‑cell depleting agents (e.g., alemtuzumab, anti‑CD52) without specialist guidance.

Use with caution: - Calcineurin inhibitors (cyclosporine, tacrolimus) – monitor drug levels and renal function. - Mycophenolate mofetil or azathioprine – increased risk of bone‑marrow suppression. - Antiviral prophylaxis (e.g., ganciclovir) – adjust dosing based on renal clearance. - Corticosteroids – may augment immunosuppression but also mask infection signs.