The proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab has produced significant reductions in LDL-C at a dose of 300 mg q4w administered as 2 separate 150-mg injections via a 1-mL autoinjector (AI). A recently developed 2-mL device (SYDNEY) permits the administration of a single 300mg dose of alirocumab. We assessed the usability and product technical complaints (PTCs) reported by patients using the 2-mL SYDNEY device in unsupervised settings, adverse events, and effects on LDL-C, in a multicenter, randomized, open-label, 16-week study conducted in the United States. For their first dose, 69 patients with hypercholesterolemia despite receiving statin with or without other lipid-lowering therapy randomly received supervised, self-administered alirocumab 300 mg via 1 × 300 mg injection with the SYDNEY device (n = 35) or 2 × 150-mg injections with the currently approved AI (n = 34). All continuing patients subsequently received unsupervised, self-administered alirocumab 300 mg q4w using the SYDNEY device at weeks 4, 8, and 12. The primary end point was the proportion of SYDNEY device–associated PTCs related to the use of the unsupervised injections. Baseline characteristics between the study arms varied only in a higher percentage of males being randomized to the study arm using the SYDNEY device (74.3%) compared with the AI arm (44.1%). A single PTC was reported during the unsupervised injections (0.5%; 1 of 196 injections; 95% CI, 0.0%–3.2%). This event was classified as patient related as opposed to device related. No PTCs occurred during supervised injections. Mean LDL-C reductions from baseline at week 4 were 66.2% with SYDNEY and 51.2% with the AI; after adjustment for sex differences between groups, mean LDL-C reductions were 63.5% and 53.9%, respectively. LDL-C reductions persisted for 16 weeks. The most common adverse event was upper respiratory tract infection (3 with SYDNEY and 0 with the AI during weeks 0–4). The SYDNEY device allowed for a single 2-mL injection of alirocumab 300 mg, providing substantial LDL-C reductions with no new product technical issues or no new safety concerns compared with the currently marketed 1-mL AI device. In conclusion, the 2-mL SYDNEY device provides patients with the possibility of injecting the 300-mg alirocumab dose as a single injection. ClinicalTrials.gov identifier: NCT03415178.