OVERVIEW

PRODUCT INFORMATION

REPRESENTATIVE TRADE NAMES

Cladribine – Generic, Leustatin®

DRUG CLASS

Antineoplastic Agents

COMPLETE LABELING

Product labeling at DailyMed, National Library of Medicine, NIH

CHEMICAL FORMULA AND STRUCTURE

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DRUG	CAS REGISTRY NUMBER	MOLECULAR FORMULA	STRUCTURE
Cladribine	4291-63-8	C10-H12-Cl-N5-O3

ANNOTATED BIBLIOGRAPHY

References updated: 01 December 2025

• Zimmerman HJ. Oncotherapeutic and immunosuppressive agents. In, Zimmerman HJ. Hepatotoxicity: the adverse effects of drugs and other chemicals on the liver. 2nd ed. Philadelphia: Lippincott, 1999, pp. 673-708.

  (Expert review of hepatotoxicity of cancer chemotherapeutic agents published in 1999 mentions that fludarabine and cladribine were new purine analogues that had yet to be implicated in causing hepatic injury).
• DeLeve LD. Cancer chemotherapy. In, Kaplowitz N, DeLeve LD, eds. Drug-induced liver disease. 3rd ed. Amsterdam: Elsevier, 2013, p. 541-68.

  (Review of hepatotoxicity of anticancer agents does not discuss cladribine).
• Wellstein A, Giaccone G, Atkins MB, Sausville EA. Cytotoxic agents. 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. 1167-203.

  (Textbook of pharmacology and therapeutics).
• https://www​.accessdata​.fda.gov/drugsatfda_docs​/nda/2019/022561Orig1s000MedR.pdf

  (FDA website with the clinical review of efficacy and safety data submitted in support of the approval of an oral cladribine as therapy of multiple sclerosis, mentions a fatal case of reactivation of hepatitis B during therapy but in the largest randomized controlled trial, the rates of liver test abnormalities were similar in cladribine vs placebo recipients with any ALT elevation in 32% vs 33% and elevations above 3 times ULN in 7.5% vs 8%; among 5 instances of ALT elevations identified in monotherapy studies of cladribine, all resolved after treatment discontinuation and none were associated with jaundice).
• Piro LD, Carrera CJ, Carson DA, Beutler E. Lasting remissions in hairy-cell leukemia induced by a single infusion of 2-chlorodeoxyadenosine. N Engl J Med 1990; 322: 1117-21. [PubMed: 1969613]

  (Among 12 adults with hairy cell leukemia treated with a single 7 day course of cladribine, all responded and 11 had a long term complete remission; side effects included fever, but no patient developed liver test abnormalities).
• Estey EH, Kurzrock R, Kantarjian HM, O'Brien SM, McCredie KB, Beran M, Koller C, et al. Treatment of hairy cell leukemia with 2-chlorodeoxyadenosine (2-CdA). Blood 1992; 79: 882-7. [PubMed: 1346577]

  (Among 46 patients with hairy cell leukemia treated with a single 7 day course of cladribine, 78% had a complete response; side effects included neutropenia, fever, infections within the first month, but there were no other systemic side effects and no mention of ALT abnormalities of liver related side effects).
• Piro LD, Ellison DJ, Saven A. The Scripps Clinic experience with 2-chlorodeoxyadenosine in the treatment of hairy cell leukemia. Leuk Lymphoma 1994; 14 Suppl 1: 121-5. [PubMed: 7820043]

  (Among 144 patients with hairy cell leukemia treated with cladribine, 82% achieved a complete remission and side effects were few, but included fever in 42%; no mention of ALT abnormalities or hepatotoxicity).
• Sipe JC, Romine JS, Koziol JA, McMillan R, Zyroff J, Beutler E. Cladribine in treatment of chronic progressive multiple sclerosis. Lancet 1994; 344: 9-13. [PubMed: 7912347]

  (52 patients with multiple sclerosis were treated with 4 courses of intravenous cladribine or placebo; acute adverse events included 2 cases of herpes zoster and one case each of transient bone marrow suppression, fulminant acute hepatitis B, and salmonella enteritis).
• Juliusson G, Heldal D, Hippe E, Hedenus M, Malm C, Wallman K, Stolt CM, et al. Subcutaneous injections of 2-chlorodeoxyadenosine for symptomatic hairy cell leukemia. J Clin Oncol 1995; 13: 989-95. [PubMed: 7707128]

  (Among 73 patients with hairy cell leukemia treated with subcutaneous rather than intravenous cladribine, complete responses occurred in 81% of patients and 38% developed neutropenic fever requiring hospitalization; no mention of ALT elevations or hepatotoxicity).
• Kurzrock R, Strom SS, Estey E, O'Brien S, Keating MJ, Jiang H, Adams T, et al. Second cancer risk in hairy cell leukemia: analysis of 350 patients. J Clin Oncol 1997; 15: 1803-10. [PubMed: 9164188]

  (Among 350 patients with hairy cell leukemia treated and followed for an average of 7 years, secondary cancers occurred in 26 [7%], which was minimally higher than might be expected and was not associated with any specific therapy, interferon, cladribine or pentostatin).
• Fridrik MA, Jär G, Kienzer HR, Hausmaninger H, Oppitz P, Krieger O, Zabernigg A, et al. Efficacy and toxicity of 2-Chlorodeoxyadenosine (Cladribine)--2 h infusion for 5 days--as first-line treatment for advanced low grade non-Hodgkin's lymphoma. Eur J Cancer 1998; 34: 1560-4. [PubMed: 9893628]

  (Among 50 patients with non-Hodgkin lymphoma treated with four 5-day courses of cladribine, the major side effect was leucopenia [44%] and infections [14%]; no mention of ALT abnormalities or hepatotoxicity).
• Saven A, Burian C, Koziol JA, Piro LD. Long-term follow-up of patients with hairy cell leukemia after cladribine treatment. Blood 1998; 92: 1918-26. [PubMed: 9731048]

  (Long term follow up on 358 patients with hairy cell leukemia treated with cladribine found 91% complete response rate to a single 7 day infusion, 26% relapse rate, 8% occurrence of secondary malignancies; no reported early or delayed hepatic side effects).
• Chadha P, Rademaker AW, Mendiratta P, Kim B, Evanchuk DM, Hakimian D, Peterson LC, et al. Treatment of hairy cell leukemia with 2-chlorodeoxyadenosine (2-CdA): long-term follow-up of the Northwestern University experience. Blood 2005; 106: 241-6. [PubMed: 15761021]

  (Among 86 patients with hairy cell leukemia treated with cladribine and followed for a median period of 9 years, 15 [17%] developed a second malignancy, which were largely solid tumors, none developed a secondary leukemia, lymphoma or hematologic malignancy).
• Else M, Ruchlemer R, Osuji N, Del Giudice I, Matutes E, Woodman A, Wotherspoon A, Swansbury J, Dearden C, Catovsky D. Long remissions in hairy cell leukemia with purine analogs: a report of 219 patients with a median follow-up of 12.5 years. Cancer 2005; 104: 2442-8. [PubMed: 16245328]

  (Among 219 patients with hairy cell leukemia treated with either cladribine [n=34] or pentostatin [n=185], rates of complete remission [81% vs 82%] and 10 year survival [100% vs 96%] were similar).
• Cannon T, Mobarek D, Wegge J, Tabbara IA. Hairy cell leukemia: current concepts. Cancer Invest 2008; 26: 860-5. [PubMed: 18798068]

  (Review of the clinical features, course and therapy of hairy cell leukemia; cladribine and pentostatin are first line therapies for this disease and have similar rates of long term response; infections may be less common with pentostatin, but cladribine is given in a single course, whereas pentostatin must be given as multiple courses).
• Ravandi F, O'Brien S, Jorgensen J, Pierce S, Faderl S, Ferrajoli A, Koller C, et al. Phase 2 study of cladribine followed by rituximab in patients with hairy cell leukemia. Blood 2011; 118: 3818-23. [PMC free article: PMC4081440] [PubMed: 21821712]

  (Among 36 patients with hairy cell leukemia treated with a 5 day course of intravenous cladribine followed one month later by rituximab, all had a complete response with resolution of splenomegaly; adverse events included significant infections in 33%, but there were no nonhematologic severe adverse events and no mention of ALT elevations or hepatotoxicity).
• Jain P, Pemmaraju N, Ravandi F. Update on the biology and treatment options for hairy cell leukemia. Curr Treat Options Oncol 2014; 15: 187-209. [PMC free article: PMC4198068] [PubMed: 24652320]

  (Review of the clinical features, etiology and therapy of hairy cell leukemia, which has been linked to mutations in the BRAF gene [V600E] and, while usually responsive to therapy with cladribine or pentostatin, promising future approaches include inhibitors of the BRAF signaling pathway).
• Donadieu J, Bernard F, van Noesel M, Barkaoui M, Bardet O, Mura R, Arico M, et al.; Salvage Group of the Histiocyte Society. Cladribine and cytarabine in refractory multisystem Langerhans cell histiocytosis: results of an international phase 2 study. Blood 2015; 126: 1415-23.. [PMC free article: PMC4624454] [PubMed: 26194764]

  (Among 27 patients with refractor Langerhans cell histiocytosis treated with the combination of cladribine and cytarabine, the overall response rate was 92% and the major side effect was profound pancytopenia; no mention of ALT elevations or hepatotoxicity, but one patient with severe liver involvement later developed sclerosing cholangitis requiring liver transplantation).
• Stelmasiak Z, Solski J, Nowicki J, Jakubowska B, Ryba M, Grieb P. Effect of parenteral cladribine on relapse rates in patients with relapsing forms of multiple sclerosis: results of a 2-year, double-blind, placebo-controlled, crossover study. Mult Scler. 2009;15:767-70.. [PubMed: 19482866]

  (Among 84 patients with multiple sclerosis treated with subcutaneous cladribine [5 mg) or placebo once daily in seven 5-day courses, the mean relapse rate decreased with cladribine from 0.86 to 0.15 vs 1.05 to 0.61, while lymphocyte counts decreased by 60%, “cladribine was well tolerated and had a favorable safety profile”; no mention of ALT levels or hepatotoxicity).
• Giovannoni G, Comi G, Cook S, Rammohan K, Rieckmann P, Soelberg Sørensen P, et al.; CLARITY Study Group. A placebo-controlled trial of oral cladribine for relapsing multiple sclerosis. N Engl J Med. 2010;362:416-26.. [PubMed: 20089960]

  (Among 1326 adults with multiple sclerosis treated with cladribine [total dose 3.5 or 5.25 mg/kg] vs placebo in 4 to 6 short courses over 52 weeks, the mean annual rate of relapse at week 96 was 0.14 and 0.15 vs 0.33, while adverse events included lymphocytopenia [22% and 32% vs 1.8%] and herpes zoster [1.9% and 2.6% vs no cases] and serious adverse event rates were 8.4% and 9.0% vs 6.4% which included serious hepatobiliary disorders in 0.7% and 1.3% vs 0.7%).
• Cook S, Vermersch P, Comi G, Giovannoni G, Rammohan K, Rieckmann P, Sørensen PS, et al.; CLARITY Study Group. Safety and tolerability of cladribine tablets in multiple sclerosis: the CLARITY (CLAdRIbine Tablets treating multiple sclerosis orally) study. Mult Scler. 2011;17:578-93.. [PubMed: 21228029]

  (In depth analysis of the adverse events that arose in the large, controlled trial of cladribine [3.5 and 5.25 mg/kg] vs placebo in 1326 adults with relapsing multiple sclerosis [Giovannoni 2010], found ALT elevations above 5 times ULN in 1.2% and 0.7% vs 0.9% but all resolved upon stopping, and none were accompanied by elevations in serum bilirubin above twice normal).
• Leist TP, Comi G, Cree BA, Coyle PK, Freedman MS, Hartung HP, Vermersch P, et al.; oral cladribine for early MS (ORACLE MS) Study Group. Effect of oral cladribine on time to conversion to clinically definite multiple sclerosis in patients with a first demyelinating event (ORACLE MS): a phase 3 randomised trial. Lancet Neurol. 2014;13:257-67.. [PubMed: 24502830]

  (Among 903 adults with relapsing multiple sclerosis treated with cladribine [3.5 or 5.25 mg/kg total dose] vs placebo, there was a reduction in the risk of conversion to “definite” multiple sclerosis with therapy while adverse event rates were 82% and 81% vs 79%, which were serious in 45% and 50% vs 29%, leading to discontinuation in 5% and 10% vs 4%, while ALT elevations [above 3 or 5 times ULN?] arose in 0% and 0% vs 1%).
• Cook S, Leist T, Comi G, Montalban X, Giovannoni G, Nolting A, Hicking C, et al. Safety of cladribine tablets in the treatment of patients with multiple sclerosis: An integrated analysis. Mult Scler Relat Disord. 2019;29:157-167.. [PubMed: 30885374]

  (An integrated review of adverse events in randomized controlled trials and extension studies of 923 recipients of cladribine and 641 placebo controls found increased rates of lymphopenia, but no increase in rates of malignances or infections [except for herpes zoster]; no mention of ALT elevations or hepatotoxicity).
• Giovannoni G, Soelberg Sorensen P, Cook S, Rammohan K, Rieckmann P, Comi G, et al. Safety and efficacy of cladribine tablets in patients with relapsing-remitting multiple sclerosis: Results from the randomized extension trial of the CLARITY study. Mult Scler. 2018;24:1594-1604.. [PubMed: 28870107]

  (Among 806 patients with multiple sclerosis who participated in a controlled trial of cladribine [Giovannoni 2010] and were enrolled in an extension study for 2 years, clinical benefits were sustained and no new safety signals arose; no mention of ALT elevations or hepatotoxicity).
• Cladribine (Mavenclad) for multiple sclerosis. Med Lett Drugs Ther. 2019;61(1577):118-120.. [PubMed: 31381552]

  (Concise review of the mechanism of action, clinical efficacy, safety, and costs of cladribine shortly after its approval for use in relapsing multiple sclerosis in the United States, discusses adverse events of lymphocytopenia, herpes zoster, infections, and possibility of increased risk of cancer; no mention of ALT elevations or hepatotoxicity but does state that patients should be screened for hepatitis B and C because of risk of reactivation).
• 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).
• 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 in controlled trials, fingolimod therapy was associated with abnormal liver test elevations in 11% of patients that were above 5 times ULN in 2%, while cases of clinically apparent liver injury were not reported, but that since its approval several cases including 3 cases of acute liver failure leading to emergency liver transplantation have been reported, as have examples of reactivation of hepatitis B and C, so that frequent monitoring of liver tests is recommended).
• McGinley MP, Goldschmidt CH, Rae-Grant AD. Diagnosis and treatment of multiple sclerosis: a review. JAMA. 2021;325:765-779.. [PubMed: 33620411]

  (Review of the clinical features, diagnosis, and therapy of multiple sclerosis, discusses nine classes of disease modifying therapies including cladribine, the side effects of which include lymphopenia, herpes zoster and increase risk of cancer, but does not mention hepatoxicity, which the other approved agents all share).
• Oh J, Walker B, Giovannoni G, Jack D, Dangond F, Nolting A, Aldridge J, et al. Treatment-emergent adverse events occurring early in the treatment course of cladribine tablets in two phase 3 trials in multiple sclerosis. Mult Scler J Exp Transl Clin. 2021;7:20552173211024298.. [PMC free article: PMC8283088] [PubMed: 34345436]

  (Among 1277 patients with multiple sclerosis treated in two controlled trials of cladribine [3.5 mg/kg] vs placebo, early onset [within 12 weeks] adverse events were more frequent with cladribine than placebo [61% vs 55%], the most frequent being headache, lymphopenia, and nausea, but serious adverse events arose in only 2.2% vs 1.7% and leading to discontinuation in 1.6% vs 1.4%, including due to ALT elevations in 2 vs 1 participants [0.3% vs 0.2%]).
• Rejdak K, Zasybska A, Pietruczuk A, Baranowski D, Szklener S, Kaczmarek M, Stelmasiak Z. Long-term safety and efficacy of subcutaneous cladribine used in increased dosage in patients with relapsing multiple sclerosis: 20-year observational study. J Clin Med. 2021;10:5207.. [PMC free article: PMC8584572] [PubMed: 34768726]

  (Among 52 patients with multiple sclerosis treated with a subcutaneous, “off-label” formulation of cladribine, 41 of whom were offered chronic maintenance therapy for up to 20 years, cladribine was considered effective and well tolerated; no mention of ALT elevations or hepatotoxicity).
• Barbieri MA, Sorbara EE, Battaglia A, Cicala G, Rizzo V, Spina E, Cutroneo PM. Adverse drug reactions with drugs used in multiple sclerosis: an analysis from the Italian Pharmacovigilance Database. Front Pharmacol. 2022;13:808370.. [PMC free article: PMC8904918] [PubMed: 35281926]

  (Among 13,880 spontaneous reports to Italian pharmacovigilance registries of adverse events attributed to disease modifying therapies for multiple sclerosis between 2002 and 2020, there were marked increase in the annual numbers starting in 2013, but only 72 were attributed to cladribine, most of which were mild and only two were hepatobiliary disorders – most liver events being attributed to fingolimod [n=170], interferon beta [94], dimethyl fumarate [49], natalizumab [42], and teriflunomide [41]).
• Buonomo AR, Viceconte G, Calabrese M, De Luca G, Tomassini V, Cavalla P, Maniscalco GT, et al.; Raising Italian Researchers in Multiple Sclerosis (RIREMS) study group. Management of hepatitis B virus prophylaxis in patients treated with disease-modifying therapies for multiple sclerosis: a multicentric Italian retrospective study. J Neurol. 2022;269:3301-3307.. [PMC free article: PMC9119877] [PubMed: 35165767]

  (Among 931 Italian patients with multiple sclerosis who were being treated with monoclonal anti-CD20 [ocrelizumab or rituximab] or cladribine in 2020 to 2021, 94% had been screened for HBV markers before starting therapy of whom none were HBsAg positive but 53 [6%] were possibly harboring HBV (anti-HBc positive or anti-HBs positive and denied vaccination) of whom 20 received antiviral prophylaxis, but done developed evidence of reactivation of HBV).
• Saraceno L, Pirro F, Stigliano R, Agostoni EC, Protti A. Acute idiosyncratic liver injury after cladribine treatment for multiple sclerosis: first case report and review on associated hepatic disorders. Mult Scler. 2022;28:2142-2145.. [PubMed: 36169305]

  (19 year old woman with multiple sclerosis developed rash, nausea, and jaundice 12 days after starting cladribine reponding to a 6-day course of prednisone with rapid improvement and normal liver tests 2 months later).
• Brownlee WJ. Cladribine-induced liver injury: implications for practice. Mult Scler. 2022;28:2146.. [PubMed: 36169282]

  (Editorial in response to Saraceno [2022] mentions that 2 cases of liver injury among 2200 patients treated with oral cladribine have been reported to a UK Regulatory Agency making the possibility that cladribine can cause liver injury more likely).
• Sorensen PS, Pontieri L, Joensen H, Heick A, Rasmussen PV, Schäfer J, Ratzer R, et al. Real-world experience of cladribine treatment in relapsing-remitting multiple sclerosis: A Danish nationwide study. Mult Scler Relat Disord. 2023;70:104491.. [PubMed: 36623393]

  (Among 268 patients with multiple sclerosis treated with cladribine enrolled in a Danish national registry between 2017 and 2021, during a median follow up of 2.7 years adverse events were reported in 44 patients including 5 referred to and 7 discontinued because of adverse events).
• Velișcu EM, Liguori V, Anatriello A, Maniscalco GT, Cantone A, Di Costanzo L, Stefanelli P, et al. Hepatobiliary adverse reactions during treatment with cladribine: analysis of data from the European Spontaneous Reporting System. Pharmaceuticals (Basel). 2023;16:1071.. [PMC free article: PMC10459297] [PubMed: 37630986]

  (Among 4181 spontaneous adverse event reports made to the European Pharmacovigilance registry as of 2023 , 118 belonged to “hepatobiliary disorders” which included “drug-induced liver injury” [n=14], “ALT increased” [n=11], “liver disorder” [n=11], “hepatotoxicity” [n=8], and “hepatic failure” [n=9], and the proportion of liver related events were higher with cladribine than glatiramer, natalizumab, ofatumumab, dimethyl fumarate, and peginterferon beta).
• Rakers F, Fritsch A, Herrmann A, Tannapfel A, Schwab M. Oral cladribine treatment and idiosyncratic drug-induced liver injury in multiple sclerosis. BMJ Neurol Open. 2023;5:e000481.. [PMC free article: PMC10496679] [PubMed: 37705760]

  (35 year old woman with multiple sclerosis developed acute hepatocellular injury with jaundice 10 weeks after starting cladribine and 6 weeks after a 3-day course of 400 mg of prednisolone [bilirubin 31 rising to 45 mg/dL, ALT 912 U/L, Alk P normal] which resolved within 2 months of stopping, but she later tolerated restarting cladribine without recurrence).
• Biolato M, Bianco A, Giustiniani MC, Mirabella M, Pompili M. A case report of cladribine-induced IgG4-associated liver injury. Acta Neurol Belg. 2024;124:1695-1697.. [PubMed: 38587719]

  (42 year old woman with multiple sclerosis developed jaundice 2 weeks after starting cladribine and 1 month after a 5-day course of high dose methylprednisolone [bilirubin 17 rising to 20.5 mg/dL, ALT 1463 U/L, Alk P 164 U/L, INR 1.9] with rapid resolution with oral prednisone).
• Giovannoni G, Boyko A, Correale J, Edan G, Freedman MS, Montalban X, Rammohan K, et al. Long-term follow-up of patients with a first clinical demyelinating event (clinically isolated syndrome) who received cladribine tablets in CLASSIC-MS: Findings for the ORACLE-MS cohort. Mult Scler. 2025;31:44-58.. [PubMed: 39690897]

  (Among 227 patients with a first demyelinating event enrolled in placebo controlled studies of cladribine who were then followed for a median of 9.5 years, conversion to definite multiple sclerosis occurred in 55% [median time 7.6 years] of those treated with cladribine vs 81% [median time 1.4 years] who were never treated; no discussion of adverse events).
• Sönmez MT, Yetkin MF, Mehdiyev DA, Köseoğlu M, Mungan S, Kale N, Terzi M, et al. Safety and efficacy of cladribine in patients discontinuing fingolimod due to elevated transaminase levels: The FinClad Study. Mult Scler Relat Disord.2025;101:106578.. [PubMed: 40570400]

  (Among 45 patients with multiple sclerosis who switched from fingolimod to cladribine therapy because of serum aminotransferase elevations, both ALT and AST fell into the normal range in all patients and 87% “maintained effective disease control”).
• Hu Y, He J, Tu Z, Ye H, Zhuang C, Jin Z, Hu H, et al. Post-marketing safety profile of cladribine in multiple sclerosis: a disproportionality analysis based on the FDA adverse event reporting system. Int J Clin Pharm. 2025 Nov 15. Epub ahead of print.. [PMC free article: PMC12992368] [PubMed: 41240270]

  (Among 4833 spontaneous adverse event reports on cladribine made to the FDA’s Adverse Event Reporting System [FAERS] made between 2019 and 2024, 75% were in women and many were for pneumonia [n=190] and lymphopenia [111], while 22 were for liver injury and 60 for ALT elevations).
• Monschein T, Untersteiner H, Ponleitner M, Krajnc N, Zrzavy T, Bsteh G, Rommer P, et al.; Austrian MS Treatment Registry (AMSTR). Safety of disease-modifying therapies in multiple sclerosis: real-world data from the Austrian MS Treatment Registry (AMSTR). J Neurol. 2025;272:774.. [PMC free article: PMC12630275] [PubMed: 41258942]

  (Among 7913 patients enrolled in the Austian multiple sclerosis therapy registry between 2006 and 2025, adverse event reports were received on 35 [8%] of 458 enrolled patients receiving cladribine, which were mostly infections [21] including herpes zoster [10], while “hepatobiliary disorders” were reported in 3 [0.7% of enrollees]).
• 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).