The Use of Lanadelumab as Treatment in a Patient with Acquired Angioedema

ABSTRACT

Introduction: There are no FDA-approved therapies for acquired angioedema (AAE). In AAE patients whose underlying disease process is not amenable to therapy, options are limited, sometimes requiring off-label use of medications used for hereditary angioedema (HAE). Lanadelumab with rescue use of icatibant has not been officially studied for the management of AAE but has shown efficacy in HAE patients. Case Description A 75-year-old male with history of stage 1 colon adenocarcinoma in remission presented with angioedema initially attributed to apixaban used for treatment of post-COVID-19 pulmonary embolus. Despite discontinuing apixaban, he continued to experience monthly episodes of angioedema involving orofacial and gastrointestinal symptoms, requiring 4 hospitalizations and steroid, oral antihistamine, tranexamic acid, and fresh frozen plasma treatments. One episode involved airway compromise requiring emergency icatibant use and transient intubation. Diagnostic results showed low C4, C1 total protein, and C1 inhibitor function, with negative C1 auto-antibody. Subsequent testing revealed monoclonal gammopathy of undetermined significance (MGUS) of low to intermediate risk (IgG kappa subtype);treatment was not recommended given MGUS staging and risk of treatment. He was started on lanadelumab every 2 weeks with continued icatibant for rescue use and has had remission of AAE over the following 3 months. Discussion(s) Lanadelumab in combination with rescue icatibant is emerging as an effective regimen to reduce hospitalizations and morbidity in AAE patients, particularly in patients whose underlying etiology of disease is unknown or for which treatment is not indicated. Investigation on a larger scale is warranted to better understand this therapeutic option for patients with AAE. Copyright © 2022