SUBCUTANEOUS SELF-ADMINISTRATION OF LANADELUMAB FOR PROPHYLACTIC TREATMENT IN PATIENTS WITH HEREDITARY ANGIOEDEMA (HAE)

Introduction Administration of a large C1 inhibitor (C1-INH) volume twice weekly for prophylaxis can be burdensome. Lanadelumab, a monoclonal antibody targeting plasma kallikrein, effectively prevents attacks in patients with HAE type I/II. Patients’ self-administration experience was investigated. Methods Interim data (May 2016-September 2017) from an ongoing open-label extension study (NCT02741596) on attack rates and injection site reactions (ISRs) in rollover patients from a phase 3 study (after their second dose) and non-rollover patients who received 300 mg (2 mL) subcutaneous (SC) lanadelumab every 2 weeks (Q2W) via self-administration versus administration by study staff were compared. Trained patients (aged ≥12 years) self-administered lanadelumab (at home or in-clinic) after two administrations by staff. Patients with intravenous C1-INH experience indicated their preferred administration route in a survey. Results In 212 patients, 56.4% of 3157 doses were self-administered. Of 209 patients who received ≥1 dose, ≥80% of doses were administered by staff versus self-administered in 61 versus 97 patients; mean (SD) attack rate reductions were -2.1 (1.98) and -3.3 (2.58) attacks/month, respectively. The proportion of doses causing ISRs post-administration by staff, self-administration at home and in-clinic were 19.4%, 21.5%, and 16.9%, respectively. At day 266, 70.9% versus 7.3% of 55 patients preferred SC over intravenous administration and 59.3% and 52.5% of 59 patients reported that SC injections were easier to administer and convenient, respectively. Conclusions Patients successfully self-administered SC lanadelumab (300 mg Q2W) to prevent HAE attacks effectively with no difference in efficacy or ISRs compared with patients who received doses by in-clinic staff.