In patients with hereditary angioedema (HAE) associated with C1-inhibitor (C1-INH) deficiency, health care resource utilization (HCRU) declined following subcutaneous treatment with lanadelumab or a plasma-derived C1-INH concentrate (SC-C1-INH), according to findings from a retrospective cohort study published in Allergy and Asthma Proceedings.   

HAE linked to C1-INH deficiency is a rare genetic condition triggered by mutations in the SERPING-1 gene. Patients experience painful, recurrent, unpredictable edematous attacks, which can occur in multiple locations in the body. Laryngeal attacks, the most severe presentation, can cause fatal asphyxiation due to upper airway obstruction.

Management of HAE involves the on-demand treatment of attacks and prevention of attacks with the use of short-term and long-term prophylactic therapies. Recently introduced long-term treatments for patients with HAE include 2 subcutaneously administered options: (1) the monoclonal antibody lanadelumab and (2) SC-C1-INH.

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Data on the real-world use of these treatments are limited, with all relevant studies having been published prior to the approval of lanadelumab and SC-C1-INH. The researchers of the present analysis sought to depict new users of lanadelumab and SC-C1-INH, including patient demographics, HCRU, treatment patterns, and costs both prior to (ie, in the 180 days before the index date) and up to 365 days following treatment initiation.

The current study utilized the US administrative claims MarketScan database. Study participants included patients with HAE aged 18 to 64 years who were new users of either lanadelumab or SC-C1-INH and had undergone at least 180 days of continuous treatment. Costs and HCRU were both calculated as annualized rates.

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A total of 47 new users of lanadelumab and 38 new users of SC-C1-INH were enrolled in the study. The median patient age was 41 years in the lanadelumab group and 40 years in the SC-C1-INH group. Overall, 72.3% and 76.3% of those in the lanadelumab and the SC-C1-INH cohorts, respectively, were female.

At baseline, the most commonly used treatments for HAE were the same in both arms:

  • Bradykinin B2 antagonists: 48.9% of participants in the lanadelumab cohort vs 52.6% in the SC-C1-INH cohort
  • C1-INHs: 40.4% of participants in the lanadelumab cohort vs 57.9% in the SC-C1-INH cohort

The use of on-demand treatments declined following the initiation of prophylactic therapy—from 9.8 to 3.7 claims annually in the lanadelumab arm and from 9.8 to 3.1 claims annually in the SC-C1-INH arm. More than 33% of participants continued to fill prescriptions for on-demand medications following treatment initiation. Among participants with 365 days of follow-up, 63.0% of those taking lanadelumab and 72.7% of those taking SC-C1-INH had at least 1 claim for an on-demand therapy in the year following the index date.

Annualized HAE-related emergency department (ED) visits and hospitalizations decreased following treatment initiation—from 1.8 to 0.6 in the lanadelumab cohort and from 1.3 to 0.5 in the SC-C1-INH cohort.

“[A]lthough HCRU was reduced with [lanadelumab and SC-C1-INH], fills for on-demand treatments, ED visits, and hospitalizations ([inpatient] visits) remained,” the researchers noted. “Therapeutic advances have improved HAE management; however, this study demonstrates a remaining burden of disease associated with modern HAE long-term prophylaxis,” they concluded.


Riedl MA, Hinds DR, Prince PM, et al. Healthcare utilization of patients with hereditary angioedema treated with lanadelumab and subcutaneous C1-inhibitor concentrate. Allergy Asthma Proc. Published online June 16, 2023. doi:10.2500/aap.2023.44.230026