OBSERVATION Delayed Allergic Reaction to Natalizumab Associated With Early Formation of Neutralizing Antibodies Markus Krumbholz, MD; Hannah Pellkofer, MD; Ralf Gold, MD; Lisa Ann Hoffmann, MD; Reinhard Hohlfeld, MD; Tania Ku¨mpfel, MD Background: Natalizumab is a new therapeutic option exanthema, and a swollen lower lip during several days for relapsing-remitting multiple sclerosis. As with other an- after his second infusion of natalizumab. tibody therapies, hypersensitivity reactions have been ob- served. In the Natalizumab Safety and Efficacy in Relapsing- Results: The patient developed a delayed, serum sick- RemittingMultipleSclerosis(AFFIRM)trial,infusion-related ness–like, type III systemic allergic reaction to natali- hypersensitivity reactions developed in 4% of patients, usu- zumab. Five weeks after initiation of this therapy, he tested ally within 2 hours after starting the infusion. positive for antinatalizumab antibodies and exhibited persistent antibody titers 8 and 12 weeks later. His symp- Objective: To report a significant, delayed, serum sick- toms completely resolved with a short course of oral ness–like, type III systemic allergic reaction to natali- glucocorticosteroids. zumab. Conclusion: Clinicians and patients should be alert not Design: Case report describing clinical follow-up and only to immediate but also to significantly delayed sub- the serial measurement of antinatalizumab antibodies. stantial allergic reactions to natalizumab. Patient: A 23-year-old man with relapsing-remitting mul- tiple sclerosis developed a fever, arthralgias, urticarial Arch Neurol. 2007;64(9):1331-1333 ATALIZUMAB IS A MONO- resulting in severe gait ataxia (Expanded clonal antibody targeting Disability Status Scale, 5.5). Previous treat- ␣ 4 integrin. It is highly ef- ments included steroid pulses for relapses fective in reducing the re- and 44 µg of interferon beta-1a 3 times lapse rate and disease pro- weekly. Interferon therapy was discontin- gressioninpatientswithrelapsing-remitting ued after 1 year because of insufficient ef- N 1 multiple sclerosis and was approved by the ficacy. The first dose of natalizumab was US Food and Drug Administration in June given 24 days later. The patient did not re- 2006 as monotherapy given intravenously port any adverse reactions within 2 hours every 4 weeks. Adverse effects include pro- after the first and second infusions. On both gressive multifocal leukoencephalopathy occasions there were no immediate adverse in about 0.1% and systemic allergic reac- effects and the patient returned home. Eight tions in about 4% of treated patients. Hy- hours after the second infusion, however, persensitivityreactionsusuallyoccurwithin he collapsed and developed a fever of up 1 hour after the infusion of natalizumab and to 39.4°C. Initially, he thought he had ac- frequently concur with the second infusion. quired a viral infection and therefore did Here we describe a patient who pre- not seek medical advice. His body tempera- sented to us 6 days after the second dose ture returned to normal, but 3 days later an of natalizumab with a substantial sys- itching rash appeared on his thighs and temic allergic reaction. Subsequently, he chest. Another 3 days later, his lower lip Author Affiliations: Institute tested permanently positive for antibod- swelled and the general practitioner referred for Clinical Neuroimmunology, ies against natalizumab. the patient back to our outpatient clinic. Ludwig Maximilian University, The patient reported arthralgias and a Munich, Germany feeling like he had a swollen tongue and (Drs Krumbholz, Pellkofer, REPORT OF A CASE Hoffmann, Hohlfeld, and throat. On examination, there was an ur- Ku¨ mpfel); and Department of ticarial erythema accentuated on his thighs Neurology, St Josef-Hospital, A 23-year-old white man was treated with and chest. His lower lip was swollen Ruhr University, Bochum, natalizumab for severe relapsing-remitting (Figure 1). His concurrent medications Germany (Dr Gold). multiple sclerosis with recurrent myelitis had been unchanged during the past (REPRINTED) ARCH NEUROL / VOL 64 (NO. 9), SEP 2007 WWW.ARCHNEUROL.COM 1331 ©2007 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/28/2021 A First mitoxantrone dose 3 2 Presentation with allergic symptoms 1 Antinatalizumab Antibodies, µg/mL 0 Second natalizumab dose 04812 16 Time After First Dose of Natalizumab, wk Figure 2. Time course of antibodies against natalizumab. Antibodies were B measured by sandwich enzyme-linked immunosorbent assay in serum samples obtained as indicated immediately before the second dose of natalizumab, at peak of symptoms when the patient presented in our outpatient clinic (6 days after the second dose of natalizumab), immediately before the first dose of mitoxantrone, and 21 days after mitoxantrone. Whiskers indicate SDs of triplicates. The dotted line indicates the cutoff for antibody-positive samples at 0.5 µg/mL. zumab antibodies in this patient was similar to other pa- tients who have tested positive for antibodies against na- talizumab. COMMENT This patient showed a delayed allergic reaction that de- veloped during several days after the second infusion of natalizumab. Tests were persistently positive for antina- talizumab antibodies as early as 5 weeks after the first dose. Most previously reported hypersensitivity reac- tions to natalizumab occurred within in the first 2 hours after infusion. By contrast, our patient developed symp- toms gradually during several days. Because we could not detect any other cause for this hypersensitivity reaction, a causal relationship with the second natalizumab infu- sion is very likely. So far, typical infusion-related allergic reactions after natalizumab treatment include anaphylactoid hyper- sensitivity reactions with urticaria,2 allergic dermatitis,2 flushing, headache, and hypotension. These symptoms occurred within 2 hours after infusion and would be classified as type I allergic reactions. However, in our Figure 1. Swollen lower lip (A) and erythema on the right thigh (B) case, the clinical course points to a serum sickness–type documented in a 23-year-old patient with multiple sclerosis 6 days after his reaction (type III), because symptoms progressed dur- second dose of natalizumab. ing several days. Three cases (2 patients in treatment groups, 1 patient in a placebo group, each at a single weeks. He had no history of allergic reactions. After ex- study center) of serum sickness were noted in the phase cluding infectious causes, we started treatment with 2 trial of natalizumab in multiple sclerosis,3 but no fur- 60 mg of prednisolone orally for 2 days; all symptoms ther information about the time course, symptoms, or disappeared in the subsequent days. We diagnosed a de- treatment of these patients was provided. Serum sick- layed allergic reaction, discontinued natalizumab, and ini- ness has also been described in association with other tiated mitoxantrone therapy after 8 weeks instead. monoclonal antibody therapies, including chimeric an- Evaluation of antinatalizumab antibodies by stan- tibodies, such as infliximab4 and rituximab,5 as well as dard sandwich enzyme-linked immunosorbent assay1 re- humanized antibodies, such as alemtuzumab.6 In one vealed that the patient had seroconverted after the sec- study with infliximab in patients with Crohn disease, ond dose of natalizumab. The number of antibodies rose serum sickness occurred in 2.8% of patients, indicating further during the following 8 weeks until the first dose that type III allergic reactions may be more frequent of mitoxantrone, when they started to decrease slightly with chimeric monoclonal antibodies than with hu- (Figure 2). The order of magnitude of the antinatali- manized monoclonal antibodies.7 (REPRINTED) ARCH NEUROL / VOL 64 (NO. 9), SEP 2007 WWW.ARCHNEUROL.COM 1332 ©2007 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/28/2021 Data from the Natalizumab Safety and Efficacy in Re- Pellkofer, Gold, and Ku¨ mpfel. Analysis and interpreta- lapsing-Remitting Multiple Sclerosis (AFFIRM) trial point tion of data: Krumbholz and Ku¨ mpfel. Drafting of the manu- to an association of infusion-related reactions with the script: Krumbholz and Ku¨ mpfel. Critical revision of the presence of antinatalizumab antibodies, as 68% of na- manuscript for important intellectual content: Pellkofer, talizumab-treated patients who had hypersensitivity re- Gold, Hoffmann, and Hohlfeld. Administrative, techni- actions were persistently positive for antibodies,2 whereas cal, and material support: Krumbholz. Study supervision: the incidence of persistent antibodies was 6% in the en- Hohlfeld and Ku¨ mpfel. tire treatment cohort. Financial Disclosure: Drs Gold and Hohlfeld have re- Antinatalizumab antibodies in patients with mul- ceived grant support and consultancy fees from Scher- tiple sclerosis have already been detected in 2 former stud- ing, Teva, Serono, and Biogen-Idec. ies as early as 4 weeks after a single natalizumab infu- Funding/Support: The Institute for Clinical Neuroim- sion.8,9 However, there are no data reported about adverse munology is supported by the Hermann and Lilly Schill- events or infusion-related reactions in these patients. ing Foundation, the Deutsche Forschungsgemeinschaft Our observation supports the view that hypersensi- (German Research Foundation) (Sonderforschungsbe- tivity reactions are associated with antibody formation reich 571 [Collaborative Research