After careful consideration, the American Academy of Allergy, Asthma & Immunology canceled its annual meeting that was to take place in Philadelphia, Pennsylvania from March 13 to 16, because of concerns regarding the coronavirus disease 2019 (COVID-19) outbreak. Although the live events will not proceed as planned, our readers can still find coverage of research that was scheduled to be presented at the meeting.

Treatment with 300 mg lanadelumab every 2 weeks significantly reduced monthly hereditary angioedema (HAE) attack rates compared with the 3-month historic baseline of patients with and those without prior C1-inhibitor (C1-INH) deficiency long-term prophylaxis use, according to research intended to be presented at the 2020 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting.

Researchers are conducting an ongoing open-label extension (OLE; Identifier: NCT02741596) of the phase 3 HELP study, the results of which demonstrated that lanadelumab may prevent HAE attacks. Given that previous long-term prophylaxis use may indicate greater disease severity in HAE, researchers sought to investigate the efficacy of lanadelumab according to a history of long-term prophylaxis use.

A total of 212 participants aged >12 years with HAE type I/II received 300 mg lanadelumab every 2 weeks. These individuals included both rollover participants from the HELP study (n=109) and newly enrolled nonrollover participants (n=103) who could be given lanadelumab for <3 weeks and continue existing long-term prophylaxis. HAE attack frequency was reported as the monthly attack rate (number of attacks/4 weeks), and this rate was compared with the 3-month historic baseline rate for attacks preceding study enrollment.

Overall, 50.0% (n=106) of participants had received prior C1-INH long-term prophylaxis only, 9.0% (n=19) received other long-term prophylaxis, and 41.0% (n=87) had no prior long-term prophylaxis. Participants with a history of C1-INH long-term prophylaxis only had a mean baseline attack rate of 2.9 per 4 weeks, which was reduced to 0.3 with lanadelumab treatment (mean reduction, 77.1%; median reduction, 97.0%). Participants without a history of long-term prophylaxis use had a mean baseline attack rate of 3.0 per 4 weeks, which reduced to 0.2 with lanadelumab treatment (mean reduction, 91.4%; median reduction, 98.8%). Participants who switched from alternate long-term prophylaxis also experienced reductions in attack rate with lanadelumab. In all subgroups, attack rate reductions were comparable between rollover and nonrollover participants.

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The investigators concluded, “Long-term treatment with lanadelumab 300mg [every 2 weeks] significantly reduced monthly HAE attack rates compared with 3-month historical baseline in patients with and without prior C1-INH [long-term prophylaxis] use.”

Disclosure: This clinical trial was supported by Takeda. Please see the original reference for a full list of authors’ disclosures.


Paes K, Craig T, Bernstein J, et al. Efficacy of lanadelumab in hereditary angioedema patients with and without prior long-term prophylaxis use: Interim results from the HELP open-label extension study. J Allergy Clin Immunol. 2020;145(Suppl 2):AB102.

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This article originally appeared on Pulmonology Advisor