A phase I clinical study to evaluate rapid, high-volume, subcutaneous auto-injector tolerability with recombinant human hyaluronidase

Until recently, approved handheld auto-injectors (AIs) have been limited to volumes ≤ 2 mL. A prototype rapid high-volume AI (HVAI) that can deliver 10 mL in 30 s was developed to administer therapeutics co-formulated with a proprietary recombinant human hyaluronidase PH20 (rHuPH20). This phase I, open-label study assessed the tolerability of subcutaneous (SC) injections of 10% (100 mg/mL) immunoglobulin G (IgG) solution co-administered with 4000 U/mL rHuPH20, delivered using a syringe pump at a target rate of 5 or 10 mL/30 seconds or the prototype HVAI at a target rate of 10 mL/30 seconds in healthy human subjects. Subjects received 5 mL (Cohort A, n = 12) or 10 mL (Cohort B, n = 12) of test solution via syringe pump (injection visit 1), and 10 mL of test solution via HVAI (Cohorts A & B; injection visit 2). Primary endpoints were tolerability and safety outcomes. Secondary endpoints included HVAI injection duration. All 24 subjects completed visit 1; 23/24 completed visit 2. All injections were tolerated, with no serious adverse events (AEs). Following syringe pump administration, 6/24 subjects (25%) reported eight treatment-emergent AEs (TEAEs); after HVAI administration, 4/23 (17%) reported four TEAEs, all mild in severity. Mean (± SEM) injection duration via HVAI was 27.9 ± 0.8 s. Most subjects (91%, 21/23) experienced no or mild injection-site pain following HVAI administration, and 96% (22/23) said they would be willing to have the HVAI injection again. SC injection of a 10% IgG solution in combination with rHuPH20 was well tolerated at an injection rate of 10 mL/~30 s using the prototype HVAI.