Ocular Pharmacokinetics of Faricimab Following Intravitreal Administration in Patients With Retinal Disease.

Purpose: To characterize faricimab ocular and systemic pharmacokinetics (PK) in patients with neovascular age-related macular degeneration (nAMD) or diabetic macular edema (DME) and to assess the effect of faricimab ocular exposure on clinical endpoints.

Methods: A population PK (popPK) model was developed using pooled data from phase 1 to 3 studies in patients with nAMD/DME. The dataset included 1095 faricimab aqueous humor (AH) concentrations from 284 patients and 8372 faricimab plasma concentrations from 2246 patients.

Results: Following intravitreal administration, faricimab PK was accurately described by a linear three-compartment model with sequential vitreous humor (VH), AH, and plasma compartments. Faricimab VH elimination to AH is the slowest process, with an estimated half-life (t1/2) of 7.5 days. Due to flip-flop kinetics, plasma, AH, and VH concentrations declined in parallel. Disease had no effect on faricimab PK. Plasma exposure was ∼6000-fold lower than VH exposure. Age, anti-drug antibodies, body weight, and sex statistically significantly influenced PK parameters but had no clinically meaningful effect on ocular and systemic exposure. VH t1/2 alone could not explain faricimab dosing frequency. Exposure-response analyses showed similar gains in best-corrected visual acuity across faricimab exposure ranges and dosing regimens.

Conclusions: Faricimab ocular and systemic pharmacokinetics were quantified and accurately described by the popPK model, developed using a large dataset from patients with nAMD/DME. Exposure-response analyses suggest that faricimab phase 3 dosing algorithms are appropriate to select the most suitable dosing regimen.

Translational relevance: The popPK analysis suggested that faricimab dosing frequency was influenced by several factors and not by VH t1/2 alone.