Safety, tolerability, pharmacokinetics and pharmacodynamics of a single intravenous dose of SHR‐1707 in healthy adult subjects: two randomized, double‐blind, phase 1 studies

Abstract

AbstractBackgroundSHR‐1707 is a novel humanized anti‐Aβ IgG1 monoclonal antibody that binds to Aβ fibrils and monomers to block the formation of Aβ plaques and to promote the microglial phagocytosis of Aβ. Preclinical studies in 5xFAD transgenic mice showed that SHR‐1707 reduced brain Aβ deposition and ameliorated memory deficits. Herein, we conducted two phase 1 studies to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of a single intravenous dose of SHR‐1707 in healthy adult subjects.MethodTwo randomized, double‐blind, single‐ascending‐dose, phase 1 studies were conducted in China (Study CHN; NCT04973189) and Australia (Study AUS; NCT04745104). Study CHN consisted of 2 parts. In part 1, eligible healthy young adults (18‐45 years) were sequentially randomized 8:2 to receive SHR‐1707 (5 cohorts: 2, 6, 20, 40, and 60 mg/kg) or placebo in each cohort; in part 2, elderly subjects (55‐80 years) were randomized 8:4 to receive SHR‐1707 (20 mg/kg) or placebo. A similar design was used in Study AUS, but with only healthy young adults enrolled across 3 dosing cohorts (2, 20, and 60 mg/kg).Result62 (part 1/2, n = 50/12; mean age, 27.0/57.2 years) and 30 subjects (mean age, 26.1 years) were treated in Study CHN and Study AUS respectively. In Study CHN, across all dose levels, all TRAEs were mild in severity, with the most common being laboratory abnormalities. In Study AUS, TRAEs were mostly mild (1 moderate event each with SHR‐1707/placebo); the most common TRAEs with SHR‐1707 were dysgeusia and fatigue (8.3% each). In both studies, the exposure of SHR‐1707 increased in a slightly greater than dose‐proportional manner over the dose range of 2‐60 mg/kg in young adults; there was a dose‐dependent increase in plasma Aβ42 concentration following SHR‐1707 administration compared with the placebo group. The safety and PK/PD profiles of SHR‐1707 in the elderly subjects were consistent with the younger counterpart at the same dose level. No ethnic difference in safety and PK/PD of SHR‐1707 was observed.ConclusionA single intravenous dose of SHR‐1707 at 2‐60 mg/kg was safe and well tolerated in healthy young adult and elderly subjects. The PK/PD profiles are supportive of further clinical development.