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LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012-.

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LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet].

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Last Update: February 23, 2016.



Alemtuzumab is a recombinant humanized monoclonal antibody to human CD52 which is used in the therapy of chronic lymphocytic leukemia, and off-label for induction regimens for solid organ transplantation and for resistant or relapsing multiple sclerosis. Alemtuzumab has been linked to occasional serum enzyme elevations during therapy and, while alemtuzumab has not been linked to cases of idiosyncratic, clinically apparent liver injury, it is a potent immunosuppressive agent and can lead to reactivation of chronic hepatitis B and exacerbations of chronic hepatitis C that can be severe and even fatal.


Alemtuzumab (al” em tooz’ ue mab) is a recombinant, humanized IgG1 kappa monoclonal antibody which is directed at and binds avidly to the human cell surface marker CD52 which is present on T and B cells, monocytes, macrophages and other bone marrow cells. Alemtuzumab therapy leads to depletion of lymphocytes with suppression of B cells for 6 to 12 months and T cells for 12 to 24 months. Alemtuzumab was approved in the United States in 2004 for use in chronic lymphocytic leukemia. It has also been used extensively off-label as a part of induction therapy for prevention of rejection after solid organ transplantation. It is currently under evaluation in several autoimmune diseases including resistant or relapsing multiple sclerosis. Alemtuzumab is available in single use vials of 30 mg/mL under the brand name Campath. The typical dose and regimen varies with indication. Alemtuzumab has significant adverse side effects, largely due to the profound immunosuppression. Common adverse events include epistaxis, headache, hypertension, rhinitis, dry skin, back pain, excessive bleeding and skin rash. Uncommon, but serious complications include severe infusions reactions, cytopenias (including fatal autoimmune anemia and thrombocytopenia) and opportunistic infections.


In large clinical trials, alemtuzumab therapy has been associated with a high rate of side effects including serious infusion reactions, infections and bone marrow suppression, but hepatotoxicity and serum ALT elevations were usually not mentioned in published reports. Since its approval in the United States and clinical use, there have been no specific published reports of clinically apparent liver injury attributed to alemtuzumab.

Likelihood score: E (unlikely cause of clinically apparent liver injury).

Importantly, however, alemtuzumab is a potent immunosuppressive agent and predisposes to opportunistic bacterial, viral, fungal and viral infections including reactivation of hepatitis B and C. Several instances of reactivation of hepatitis B have been reported in patients with HBsAg in serum who were treated with this monoclonal antibody. In addition, some patients with anti-HBc without HBsAg in serum have developed HBV reactivation with reappearance of HBsAg (reverse seroconversion) with alemtuzumab therapy. These episodes can be severe and fatal instances have been reported. Finally, exacerbation and possibly reactivation of hepatitis C has been described in patients receiving alemtuzumab therapy.

Mechanism of Injury

Alemtuzumab is a monoclonal antibody and, while metabolized in the liver, is metabolized to small peptides and amino acids that are not likely to be immunogenic or toxic. The immunosuppression caused by alemtuzumab, on the other hand, may cause reactivation of hepatitis B and exacerbations of chronic hepatitis C.

Outcome and Management

Alemtuzumab appears to have little intrinsic hepatotoxicity and idiosyncratic liver injury must be very rare, if it occurs at all. In contrast, alemtuzumab is capable of causing reactivation of hepatitis B and worsening of hepatitis C. For these reasons, it is appropriate to screen patients for hepatitis B and C infection before starting therapy, and providing prophylaxis or treatment of these viral infections before or concurrent with starting monoclonal antibody therapy.

Drug Class: Antineoplastic Agents, Monoclonal Antibodies; Transplant Agents; Multiple Sclerosis Agents

Other Drugs in the Subclass, Transplant Agents, Monoclonal Antibodies: Basiliximab, Daclizumab, Muromonab



Alemtuzumab – Campath®


Antineoplastic Agents, Monoclonal Antibodies


Product labeling at DailyMed, National Library of Medicine, NIH


Alemtuzumab216503-57-0Monoclonal AntibodyNot Available


References updated: 23 February 2016

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    (Expert review of hepatotoxicity published in 1999, well before the availability of most monoclonal antibody therapies).
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    (Review of hepatotoxicity of immunosuppressive agents, mentions that "the biological immunosuppressants are largely free from hepatotoxicity, with the exception of the TNF alpha antagonists"; no specific discussion of alemtuzumab).
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  • Magliocca JF, Knechtle SJ. The evolving role of alemtuzumab(Campath-1H) for immunosuppressive therapy in organ transplantation. Transpl Int 2006; 19: 705-14. [PubMed: 16918530]
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  • Alemtuzumab (Campath) off-label for relapsing multiple sclerosis. Med Lett Drugs Ther 2009; 51 (1307) 17-8. [PubMed: 19265776]
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  • Hanaway MJ, Woodle ES, Mulgaonkar S, Peddi VR, Kaufman DB, First MR, Croy R, et al. INTAC Study Group. Alemtuzumab induction in renal transplantation. N Engl J Med 2011; 364: 1909-19. [PubMed: 21591943]
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  • Kim SJ, Moon JH, Kim H, Kim JS, Hwang YY, Intragumtornchai T, Issaragrisil S, et al. Non-bacterial infections in Asian patients treated with alemtuzumab: a retrospective study of the Asian Lymphoma Study Group. Leuk Lymphoma 2011; 53: 1515-24. [PubMed: 22273250]
    (Retrospective analysis of infectious complications among 182 patients treated with alemtuzumab between 2003-2009 in 6 Asian countries identified 66 cases of CMV, 25 VZV, 31 fungal infections, 4 PjP, HBV reactivation 4 [in previously HBsAg negative patients], and tuberculosis 16).
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    (59 year old man with T-cell leukemia treated with alemtuzumab developed fever and adenovirus hepatitis, responding to cidovir therapy).
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    (Review of the pathogenesis, clinical course, treatment and prevention of HBV reactivation in patients receiving immunosuppressive or anticancer therapies, with particular focus on rituximab and ofatumumab).


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