Abstract Background Hereditary angioedema (HAE) is associated with a heavy burden of illness. Objective To evaluate use of lanadelumab in a French Authorization for Temporary Use (ATU) program. Methods ATU requests were made between October 12, 2018, and March 13, 2019; patients were followed through September 23, 2019. At entry, patients received lanadelumab 300 mg every 2 weeks. HAE attack characteristics were evaluated at day (D) 0 and months (M) 3 and 6. Patients completed the Angioedema Quality of Life (AE-QoL) questionnaire at initiation and monthly and the Angioedema Activity Score questionnaire daily in 28 day cycles (AAS28). Results In total, 77 patients received ≥ 1 lanadelumab dose; 69 had ≥ 1 quarterly follow-up visit (analyzed population). Mean (standard deviation [SD]) lanadelumab exposure was 240.4 (53.7) days. Lanadelumab dose was modified in 12 patients (mostly to every 4 weeks). For the analyzed population, compared with attacks/month (mean [SD]) within 6 months before ATU (2.68 [2.54]), fewer attacks occurred between initiation and first visit (0.16 [0.42]; P < 0.001) or last visit (0.16 [0.42]; P < 0.001); D15 and last visit (0.15 [0.41]); and D70 and last visit (0.17 [0.70]). AE-QoL total and domain scores were significantly higher at initiation versus M3 and M6; 55% and 65% of patients, respectively, achieved a minimal clinically important difference from D0 to M3 and D0 to M6. Proportion of patients with AAS28 of 0 was higher during M3 (90%) and M6 (83%) than initiation (59%). The most frequently reported adverse events included headache (7.3%) and injection site pain (6.3%). Conclusions Lanadelumab reduced attack rates, improved quality of life, and was generally well tolerated.