OVERVIEW

PRODUCT INFORMATION

REPRESENTATIVE TRADE NAMES

Alemtuzumab – Campath®, Lemtrada®

DRUG CLASS

Antineoplastic Agents, Monoclonal Antibodies

COMPLETE LABELING

Product labeling at DailyMed, National Library of Medicine, NIH

CHEMICAL FORMULA AND STRUCTURE

ANNOTATED BIBLIOGRAPHY

References updated: 30 September 2025

Abbreviations: CLL, chronic lymphocytic leukemia; CMV, cytomegalovirus.

• Zimmerman HJ. Drugs used to treat rheumatic and musculospastic disease. In, Zimmerman HJ. Hepatotoxicity: the adverse effects of drugs and other chemicals on the liver. 2nd ed. Philadelphia: Lippincott, 1999, pp. 517-54.

  (Expert review of hepatotoxicity published in 1999, well before the availability of most monoclonal antibody therapies).
• Reuben A. Hepatotoxicity of immunosuppressive drugs. In, Kaplowitz N, DeLeve LD, eds. Drug-induced liver disease. 3rd ed. Amsterdam: Elsevier, 2011, pp. 569-91.

  (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).
• Wellstein A, Giaccone G, Atkins MB, Sausville EA. Pathway-targeted therapies: monoclonal antibodies, protein kinase inhibitors, and various small molecules. In, Brunton LL, Hilal-Dandan R, Knollman BC, eds. Goodman & Gilman's the pharmacological basis of therapeutics. 13th ed. New York: McGraw-Hill, 2018, pp. 1203-36.

  (Textbook of pharmacology and therapeutics).
• Krensky AM, Azzi JR, Hafler DA. Immunotherapy for multiple sclerosis. Immunosuppressants and tolerogens. In, Brunton LL, Hilal-Dandan, Knollman BC, eds. Goodman & Gilman's the pharmacological basis of therapeutics. 13th ed. New York: McGraw-Hill, 2018, pp. 649-652.

  (Textbook of pharmacology and therapeutics).
• Coles AJ, Wing M, Smith S, Coraddu F, Greer S, Taylor C, Weetman A, et al. Pulsed monoclonal antibody treatment and autoimmune thyroid disease in multiple sclerosis. Lancet 1999; 354(9191): 1691-5. [PubMed: 10568572]

  (Among 27 patients with multiple sclerosis given a 5 day course of alemtuzumab and followed for 18 months, 9 [33%] developed Graves disease [2 with ophthalmopathy] and antibodies to thyrotropin receptor, an autoimmune response not seen with alemtuzumab therapy of other conditions including rheumatoid arthritis).
• Rai KR, Freter CE, Mercier RJ, Cooper MR, Mitchell BS, Stadtmauer EA, Santábarbara P, et al. Alemtuzumab in previously treated chronic lymphocytic leukemia patients who also had received fludarabine. J Clin Oncol 2002; 20: 3891-7. [PubMed: 12228210]

  (Among 24 patients with resistant CLL treated with alemtuzumab, all [100%] developed infusion reactions and ten [41%] severe, opportunistic infections including 4 with pneumocystis jirovecii pneumonia; no mention of ALT elevations, hepatitis or hepatotoxicity).
• Marcos A, Eghtesad B, Fung JJ, Fontes P, Patel K, Devera M, Marsh W, et al. Use of alemtuzumab and tacrolimus monotherapy for cadaveric liver transplantation: with particular reference to hepatitis C virus. Transplantation 2004; 78: 966-71. [PMC free article: PMC2993510] [PubMed: 15480160]

  (Among 76 adults undergoing liver transplantation who received induction therapy with alemtuzumab, subsequent rates of rejection, graft loss, death and adverse reactions were similar to a cohort of 84 contemporaneous transplant recipients; no mention of hepatotoxicity).
• Tzakis AG, Tryphonopoulos P, Kato T, Nishida S, Levi DM, Madariaga JR, Gaynor JJ, et al. Preliminary experience with alemtuzumab (Campath-1H) and low-dose tacrolimus immunosuppression in adult liver transplantation. Transplantation 2004; 77: 1209-14. [PubMed: 15114087]

  (Among 40 adults undergoing liver transplantation who received induction therapy with alemtuzumab and low dose tacrolimus, subsequent rates of graft loss, death and adverse reactions were similar to a cohort of 50 contemporaneous transplant recipients given conventional immunosuppressive therapy; routine liver test results were similar between the two groups).
• Heider U, Fleissner C, Zavrski I, Jakob C, Dietzel T, Eucker J, Ockenga J, et al. Treatment of refractory chronic lymphocytic leukemia with Campath-1H in combination with lamivudine in chronic hepatitis B infection. Eur J Haematol 2004; 72: 64-6. [PubMed: 14962266]

  (69 year old man with CLL and anti-HBc without HBsAg in serum developed reactivation of hepatitis B after chemotherapy with CHOP, rituximab and fludarabine that responded to lamivudine therapy and did not worsen when he was subsequently treated with alemtuzumab).
• Iannitto E, Minardi V, Calvaruso G, Mulè A, Ammatuna E, Di Trapani R, Ferraro D, et al. Hepatitis B virus reactivation and alemtuzumab therapy. Eur J Haematol 2005; 74: 254-8. [PubMed: 15693796]

  (Two patients with CLL with anti-HBc without HBsAg in serum developed reactivation of hepatitis B with alemtuzumab therapy, one 4 weeks after starting and one 5 months after alemtuzumab treatment and two months after withdrawal of lamivudine prophylaxis; both recovered with antiviral therapy).
• Cortelezzi A, Viganò M, Zilioli VR, Fantini NN, Pasquini MC, Deliliers GL, Colombo M, et al. Adefovir added to lamivudine for hepatitis B recurrent infection in refractory B-cell chronic lymphocytic leukemia on prolonged therapy with Campath-1H. J Clin Virol 2006; 35: 467-9. [PubMed: 16316778]

  (49 year old man with CLL and anti-HBc without HBsAg in serum developed severe reactivation of HBV after treatment with high doses of chlorambucil, responding to lamivudine and adefovir therapy, and without rise in HBV DNA levels during subsequent rescue therapy with alemtuzumab).
• Moses SE, Lim ZY, Sudhanva M, Devereux S, Ho AY, Pagliuca A, Zuckerman M, et al. Lamivudine prophylaxis and treatment of hepatitis B Virus-exposed recipients receiving reduced intensity conditioning hematopoietic stem cell transplants with alemtuzumab. J Med Virol 2006; 78: 1560-3. [PubMed: 17063522]

  (Among 8 alemtuzumab treated bone marrow transplant recipients who had anti-HBc without HBsAg in serum, reactivation occurred in 1 of 2 patients who did not receive prophylaxis, but in none of 6 who did receive prophylactic lamivudine).
• Fiegl M, Falkner A, Hopfinger G, Brugger S, Zabernigg A, Bauer F, Haslbauer F, et al.; Austrian Collaborative Study Group on Alemtuzumab in Chronic Lymphocytic Leukemia. Routine clinical use of alemtuzumab in patients with heavily pretreated B-cell chronic lymphocytic leukemia: a nation-wide retrospective study in Austria. Cancer 2006; 107: 2408-16. [PubMed: 17054106]

  (Retrospective analysis of results of alemtuzumab therapy in 115 patients with CLL reported side effects of severe infections in 51%, severe neutropenia in 26%, and severe hypersensitivity reactions in 8%, but did not mention ALT elevations or hepatotoxicity).
• 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]

  (Review of efficacy of alemtuzumab in various forms of organ transplantation; no discussion of ALT elevations or hepatotoxicity).
• James DF, Kipps TJ. Alemtuzumab in chronic lymphocytic leukemia. Future Oncol 2007; 3: 29-42. [PubMed: 17280499]

  (Review of history of development, clinical efficacy and toxicity of alemtuzumab as therapy of CLL, no mention of hepatotoxicity or ALT elevations).
• Hillmen P, Skotnicki AB, Robak T, Jaksic B, Dmoszynska A, Wu J, Sirard C, et al. Alemtuzumab compared with chlorambucil as first-line therapy for chronic lymphocytic leukemia. J Clin Oncol 2007; 25: 5616-23. [PubMed: 17984186]

  (Among 297 patients with chronic lymphocytic leukemia treated with alemtuzumab or chlorambucil, adverse events included infusion reactions, cytomegalovirus [CMV] infections, anemia and neutropenia; no mention of ALT elevations or hepatotoxicity).
• Demko S, Summers J, Keegan P, Pazdur R. FDA drug approval summary: Alemtuzumab as single-agent treatment for B-cell chronic lymphocytic leukemia. Oncologist 2008; 13: 167-74. [PubMed: 18305062]

  (Independent FDA review of studies in support of alemtuzumab as therapy of chronic lymphocytic leukemia listed common side effects including infusion reactions [87%], CMV viremia [56%], neutropenia [14%] and anemia [13%]; no mention of hepatotoxicity or ALT elevations).
• Hui CK, Cheung WW, Leung KW, Cheng VC, Tang BS, Li IW, Luk JM et al. Retracted: outcome and immune reconstitution of HBV-specific immunity in patients with reactivation of occult HBV infection after alemtuzumab-containing chemotherapy regimen. Hepatology 2008; 48: 1-10. [PubMed: 18452145]

  (Among 21 patients with HBV DNA without HBsAg in serum [17 with anti-HBc] treated with alemtuzumab chemotherapy, 6 developed reactivation of hepatitis B with reappearance of HBsAg in all and rise in liver enzymes in 5, despite early intervention with lamivudine therapy; this article was later retracted).
• Alemtuzumab (Campath) off-label for relapsing multiple sclerosis. Med Lett Drugs Ther 2009; 51(1307) 17-8. [PubMed: 19265776]

  (Discussion of the off-label use of alemtuzumab for relapsing multiple sclerosis mentions that side effects include infusion reactions, autoimmune thyroid disorders and thrombocytopenic purpura, but does not mention ALT elevations or clinically apparent hepatotoxicity).
• Dhesi S, Boland B, Colquhoun S. Alemtuzumab and liver transplantation: a review. Curr Opin Organ Transplant 2009; 14: 245-9. [PubMed: 19417659]

  (Short review of induction therapy using alemtuzumab in preparation of liver transplantation summarizing results from two US studies suggesting lower rates of rejection and ability to use lower doses of maintenance therapy).
• Jones JL, Phuah CL, Cox AL, Thompson SA, Ban M, Shawcross J, Walton A, et al. IL-21 drives secondary autoimmunity in patients with multiple sclerosis, following therapeutic lymphocyte depletion with alemtuzumab (Campath-1H). J Clin Invest 2009; 119: 2052-61. [PMC free article: PMC2701868] [PubMed: 19546505]

  (Analysis of lymphocyte function in patients with multiple sclerosis who develop reconstitution autoimmunity suggest that lymphocytes that proliferate after ablation by alemtuzumab are skewed towards self-reactivity and susceptible to apoptosis features that are promoted by high levels of IL21).
• Cai J, Terasaki PI. Induction immunosuppression improves long-term graft and patient outcome in organ transplantation: an analysis of United Network for Organ Sharing registry data. Transplantation 2010; 90: 1511-5. [PubMed: 21057388]

  (Since 2003, most solid organ transplant recipients have received induction therapy and analyses of the UNOS registry for this period shows highest rates of patient and graft survival with alemtuzumab [89% 5 year patient survival] as compared to antithymocyte globulin [89%], basiliximab [84%], daclizumab [77%], steroids [75%], or no induction [71%]).
• Anoop P, Wotherspoon A, Matutes E. Severe liver dysfunction from hepatitis C virus reactivation following alemtuzumab treatment for chronic lymphocytic leukaemia. Br J Haematol 2010; 148: 484-6. [PubMed: 19874308]

  (39 year old man with CLL had anti-HCV and normal ALT levels without HCV RNA in serum, but developed high levels of HCV RNA and ALT levels 34 days after starting weekly infusions of alemtuzumab and prednisone, not having had reactivation during rituximab or previous fludarabine and prednisone therapy).
• 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]

  (Among 474 patients undergoing renal transplantation and given alemtuzumab or convention induction therapy, acute rejection rates during the first 3 years were lower with alemtuzumab than basiliximab in low risk patients [15% vs 24%], but were similar with alemtuzumab and antithymocyte globulin in high risk patients [30% vs 24%]).
• 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 2012; 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 varicella-zoster virus, 31 fungal infections, 4 pneumocystis jirovecii pneumonia, HBV reactivation 4 [in previously HBsAg negative patients], and tuberculosis 16).
• Coles AJ, Twyman CL, Arnold DL, Cohen JA, Confavreux C, Fox EJ, Hartung HP, et al.; CARE-MS II investigators. Alemtuzumab for patients with relapsing multiple sclerosis after disease-modifying therapy: a randomised controlled phase 3 trial. Lancet 2012; 380(9856): 1829-39. [PubMed: 23122650]

  (Among 798 patients with relapsing remitting multiple sclerosis treated with alemtuzumab [12 or 24 mg for 5 and 3 days at month 0 and 12] or interferon beta-1a [44 mcg three times weekly], relapse rates were lower with alemtuzumab [35% vs 53%] and adverse event rates were slightly higher [77% vs 69%], particularly for autoimmune thyroid abnormalities [16% and 19% vs 5%] and autoimmune thrombocytopenia [1% vs none]; while liver toxicity was reported in 3-4% vs 6%], details of which were not provide).
• Costelloe L, Jones J, Coles A. Secondary autoimmune diseases following alemtuzumab therapy for multiple sclerosis. Expert Rev Neurother 2012; 12: 335-41. [PubMed: 22364332]

  (Review of the secondary autoimmune conditions associated with alemtuzumab therapy of multiple sclerosis including Graves disease in 12-33% of subjects, thrombocytopenic purpura in 1-3% and Goodpasture’s syndrome in <1%).
• Putra J, Suriawinata AA. Adenovirus hepatitis presenting as tumoral lesions in an immunocompromised patient. Ann Hepatol 2014; 13: 827-9. [PubMed: 25332270]

  (59 year old man with T-cell leukemia treated with alemtuzumab developed fever and adenovirus hepatitis, responding to cidofovir therapy).
• Di Bisceglie AM, Lok AS, Martin P, Terrault N, Perrillo RP, Hoofnagle JH. Recent US Food and Drug Administration warnings on hepatitis B reactivation with immune-suppressing and anticancer drugs: just the tip of the iceberg? Hepatology 2015; 61: 703-11. [PMC free article: PMC5497492] [PubMed: 25412906]

  (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).
• Tuohy O, Costelloe L, Hill-Cawthorne G, Bjornson I, Harding K, Robertson N, May K, et al. Alemtuzumab treatment of multiple sclerosis: long-term safety and efficacy. J Neurol Neurosurg Psychiatry. 2015;86:208-15.. [PubMed: 24849515]

  (Among 87 adults with multiple sclerosis treated with alemtuzumab between 1999 and 2012 at a single UK referral center, 52% required only two 2 cycles, but 45% required 3 or more; in long term follow up [median of 7 years] secondary autoimmunity arose in 41 patients [48%], mostly thyroid conditions [n=35], but less commonly thrombocytopenic purpura [3] and single cases of autoimmune neutropenia, hemolytic anemia, and Goodpasture’s syndrome [eventually requiring renal transplantation] most cases occurring within 2 years and all within 5 years of last cycle).
• Pfeuffer S, Beuker C, Ruck T, Lenze F, Wiendl H, Melzer N, Meuth SG. Acute cholecystitis during treatment with alemtuzumab in 3 patients with RRMS. Neurology. 2016;87:2380-2381.. [PubMed: 27794114]

  (3 adults with multiple sclerosis developed acute abdominal pain on day 3 of an initial or second cycle of alemtuzumab with elevations in AST but not Alk P, no gallstones or biliary dilation on imaging but edema or thickening of the gallbladder wall, responding rapidly to antibiotic therapy and medical management).
• Croteau D, Flowers C, Kulick CG, Brinker A, Kortepeter CM. Acute acalculous cholecystitis: A new safety risk for patients with MS treated with alemtuzumab. Neurology. 2018;90:e1548-e1552.. [PubMed: 29602912]

  (Among 8 reports of acute acalculous cholecystitis attributed to alemtuzumab made to the Food and Drug Administration , 7 arose during the period of infusions and resolved spontaneously with conservative management without corticosteroids or surgery. abstract only).
• Baker D, Herrod SS, Alvarez-Gonzalez C, Giovannoni G, Schmierer K. Interpreting lymphocyte reconstitution data from the pivotal phase 3 trials of alemtuzumab. JAMA Neurol 2017; 74: 961-9. [PMC free article: PMC5710323] [PubMed: 28604916]

  (Analysis of depletion and reconstitution of B and T cell subsets after alemtuzumab therapy suggests that the secondary autoimmunity is due to rebound in autoreactive B cells with relative deficiency in T cell regulatory function).
• Willis MD, Hope-Gill B, Flood-Page P, Joseph F, Needham E, Jones J, Coles A, Robertson NP. Sarcoidosis following alemtuzumab treatment for multiple sclerosis. Mult Scler 2018; 24: 1779-82. [PubMed: 30307364]

  (Among 187 patients with multiple sclerosis treated with alemtuzumab, 3 developed sarcoidosis, 2 to 4 years after the last infusion).
• El Sankari S, Dahlqvist G, Monino L, van Pesch V. Auto-immune hepatitis in a patient with multiple sclerosis treated with alemtuzumab. Acta Neurol Belg 2018; 118: 331-3. [PubMed: 29713905]

  (25 year old woman with multiple sclerosis developed Graves disease 11 months after a second course of alemtuzumab and liver injury 1 month after starting thiamazole for the hyperthyroidism [bilirubin 14 times ULN, ALT 5 times ULN], not responding to stopping antithyroid drug but improving with prednisone therapy).
• Filippi M, Bar-Or A, Piehl F, Preziosa P, Solari A, Vukusic S, Rocca MA. Multiple sclerosis. Nat Rev Dis Primers. 2018;4:43. [PubMed: 30410033]

  (Review of the pathogenesis, clinical features, natural history, management and therapy of multiple sclerosis).
• Saarela M, Senthil K, Jones J, Tienari PJ, Soilu-Hänninen M, Airas L, Coles A, et al. Hemophagocytic lymphohistiocytosis in 2 patients with multiple sclerosis treated with alemtuzumab. Neurology. 2018;90:849-851.. [PubMed: 29602914]

  (Two cases: 20 year old female with multiple sclerosis developed acalculous cholecystitis 1 year after a second cycle of alemtuzumab which was followed by cytopenias, abnormal liver enzymes, hemophagocytosis, and hepatic failure leading to death one month later; a 28 year old man with multiple sclerosis developed fever, abdominal pain, and bleeding episodes with acquired factor VIII hemophilia, a bone marrow biopsy showing erythrophagocytic histiocytes with mild liver test abnormalities that responded to corticosteroids and rituximab).
• Holmøy T, Fevang B, Olsen DB, Spigset O, Bø L. Adverse events with fatal outcome associated with alemtuzumab treatment in multiple sclerosis. BMC Res Notes 2019; 12: 497. [PMC free article: PMC6689881] [PubMed: 31405369]

  (Systematic review of the literature and of adverse event databases identified 9 cases of alemtuzumab-attributed severe adverse events leading to death, including 1 case of autoimmune hepatitis arising a year after therapy; no further details given).
• Beattie W, Yan B, Sood S. Acute severe hepatitis with alemtuzumab and rechallenge after a year. J Clin Neurosci 2019; 60: 158-60. [PubMed: 30348589]

  (49 year old woman with relapsing remitting multiple sclerosis developed test abnormalities within 2 days of starting alemtuzumab and methylprednisolone [bilirubin 0.7 mg/dL, ALT 378 rising to 577 U/L, Alk P 87], which resolved within 4 weeks and had recurrence with a second course 12 months later [bilirubin normal, ALT 400 rising to 700] again resolving within 4 weeks).
• Antonazzo IC, Poluzzi E, Forcesi E, Riise T, Bjornevik K, Baldin E, Muratori L, et al. Liver injury with drugs used for multiple sclerosis: a contemporary analysis of the FDA Adverse Event Reporting System. Mult Scler. 2019;25:1633-1640. PIMD: 30230957. [PubMed: 30230957]

  (Among 4873 cases of severe liver injury attributed to agents used to treat multiple sclerosis reported to the FDA’s Adverse Event Reporting System between 2004 and 2016, the most frequently implicated agents were interferon-beta 1a [n=2343], natalizumab [n=759], interferon beta 1b [535], fingolimod [496], dimethyl fumarate [223], glatimer acetate [212], teriflunomide [158], mitoxantrone [199], and alemtuzumab [93].
• Romero A, Midaglia L, Salcedo MT, Viladomiu L, Guillén E, Bajaña I, Escolà-Vergé L, et al. Hemophagocytic syndrome following alemtuzumab treatment for multiple sclerosis: A case report. Mult Scler Relat Disord. 2020;40:101973.. [PubMed: 32028116]

  (44 year old man with multiple sclerosis developed rash, fever, and jaundice 1 month after a second course of yearly alemtuzumab [bilirubin 19.7 mg/dL, ALT 299, Alk P 799] biopsy suggesting hemophagocytic syndrome which responded to methylprednisolone).
• Drugs for multiple sclerosis. Med Lett Drugs Ther. 2021;63(1620):42–8.. [PubMed: 33976089]

  (Concise review of the relative clinical efficacy, safety and costs of drugs for relapsing multiple sclerosis including parenteral agents [such as interferon-beta, glatiramer acetate, natalizumab, alemtuzumab, ocrelizumab, ofatumumab, rituximab and mitoxantrone] and the oral agents [such as the S1P receptor modulators, cladribine, fumarates, and teriflunomide], many of which are associated with serum ALT elevations and several have been reported to cause clinically apparent liver injury or reactivation of hepatitis B).
• Bolte FJ, Schmidt HH, Schlevogt B. Immune-mediated hepatitis induced by therapy with alemtuzumab in a patient with multiple sclerosis. Hepatology. 2021;73:460-463.. [PubMed: 32583445]

  (36 year old woman with multiple sclerosis developed ALT elevations after the initial course of alemtuzumab [bilirubin 0.8 mg/dL, ALT 599 U/L, Alk P 106 U/L,INR 0.9] responding to corticosteroids and a more severe episode after the second course 1 year later [bilirubin 3.2 mg/dL, ALT 5389 U/L, Alk P 86, INR 5.4] with 3 additional episodes when corticosteroids were tapered or stopped eventually needing maintenance therapy with mycophenolate and then cyclosporine).
• Biolato M, Bianco A, Lucchini M, Gasbarrini A, Mirabella M, Grieco A. The disease-modifying therapies of relapsing-remitting multiple sclerosis and liver injury: a narrative review. CNS Drugs. 2021;35:861-880.. [PMC free article: PMC8354931] [PubMed: 34319570]

  (Extensive review of the frequency and characteristics of hepatic injury associated with different disease modifying drugs for multiple sclerosis, mentions that elevations in serum aminotransferase levels arise in 5% of treated patients but are generally transient and mild, but that rare instances of acute liver injury with autoimmune features have been reported).
• Rauma I, Mustonen T, Seppä JM, Ukkonen M, Männikkö M, Verkkoniemi-Ahola A, Kartau M, et al. Safety of alemtuzumab in a nationwide cohort of Finnish multiple sclerosis patients. J Neurol. 2022;269:824-835.. [PMC free article: PMC8782800] [PubMed: 34255182]

  (Among 121 patients with multiple sclerosis treated with alemtuzumab in Finland between 2013 and 2019 with a median follow up of 30 months, 95% had an adverse event [84% with acute infusion reactions], 32% [n=37] had serious adverse events, including 2 with liver injury [1 with suspected autoimmune hepatitis and 1 with eosinophilic cholangitis of unclear cause], and 1 each with hemophagocytic lymphohistocytosis [fatal], thrombotic thrombocytopenic purpura [TTP], and type 1 diabetes), 3 other patients developed acalculous cholecystitis, 2 at the time of the third infusion in cycle one and in another 1 year after the cycle 2.
• Ošep AB, Brecl E, Škerget M, Savšek L. An unforeseen reality: Hemophagocytic lymphohistiocytosis following alemtuzumab treatment for a multiple sclerosis. Clin Neurol Neurosurg. 2023;228:107675.. [PubMed: 36965418]

  (19 year old female with multiple sclerosis developed thyroiditis 7 months after an initial cycle of alemtuzumab and hemophagocytic lymphocytosis 11 months after a second cycle presenting with rash, fever, chest pain, and cough and with elevations in liver tests [values not given] as well as hyperferritinemia and cytopenia, responding to methylprednisolone and anakinra).
• Ng HS, Zhu F, Zhao Y, Yao S, Lu X, Ekuma O, Evans C, Fisk JD, Marrie RA, Tremlett H. Adverse Events associated with disease-modifying drugs for multiple sclerosis: a multiregional population-based study. Neurology. 2024;102:e208006.. [PMC free article: PMC11097763] [PubMed: 38181306]

  (Among 35,894 people from 4 Canadian provinces who received therapy for multiple sclerosis and had available health data there was an increased risk for incident chronic liver disease in patients on teriflunomide and acute liver injury in those on dimethyl fumarate, but rates of acute liver injury on alemtuzumab were too few [<6 in among 222 patient-years] to calculate risk).
• Chiu CY, Brumble LM, Vikram HR, Watt KD, Beam E. Hepatitis B virus reactivation in non-liver solid organ transplantation: incidence and risk analysis. Clin Transplant. 2024;38:e15389.. [PubMed: 38952185]

  (Among 180 solid organ [non-liver] transplants in patients with HBsAg [n=71] or anti-HBc without HBsag [n=109], 14 developed reactivation of HBV, all of whom did not receive prophylaxis with antiviral therapy, arising in 2 of 6 with HBsAg and 12 of 97 with anti-HBc without HBsAg; 4 of the 14 having received an induction regimen with alemtuzumab).
• Bessone F, Hernandez N, Medina-Caliz I, García-Cortés M, Schinoni MI, Mendizabal M, Chiodi D, et al. Drug-induced liver injury in Latin America: 10-year experience of the Latin American DILI (LATINDILI) Network. Clin Gastroenterol Hepatol. 2025;23:89-102.. [PubMed: 38992407]

  (Among 483 cases of drug-induced liver injury enrolled in a prospective Latin American database, one case was attributed to fingolimod and one to natalizumab, but no other agents used to treat multiple sclerosis were listed: personal communication).