Purpose: Lifitegrast is approved in the United States for the treatment of dry eye disease (DED). We assessed lifitegrast's ocular distribution/pharmacokinetic profile in rabbits, and 14C-lifitegrast mass balance/excretion in dogs.
Methods: Female pigmented rabbits received a single topical ocular dose of lifitegrast (Formulation No. 1, n = 25; No. 2, n = 25) per eye twice daily (target, 1.75 mg/eye/dose). Blood/ocular tissues were collected on day 5. Beagle dogs received single intravenous (n = 10; target, 3 mg, 262 μCi/animal) and ocular (n = 8, target, 3 mg, 30 μCi/eye) doses of 14C-lifitegrast (∼8 weeks between doses). Blood, excreta, and cage rinse/wipes were collected. Concentrations were measured by mass spectrometry/liquid scintillation counting. Pharmacokinetic analyses (noncompartmental) included maximum concentration (Cmax), time to Cmax (tmax), and area under the concentration-time curve from 0 to 8 h (AUC0-8).
Results: In rabbits, lifitegrast Cmax and AUC0-8 were similar between formulations. Cmax was highest in ocular anterior segment tissues: 5,190-14,200 ng/g [conjunctiva (palpebral/bulbar), cornea, anterior sclera]. Posterior segment tissues had lower concentrations (0-826 ng/g). AUC0-8 followed a similar trend. Plasma concentrations were low (Cmax <18 ng/mL). Tissue/plasma tmax was ∼0.25-1 h. In dogs, after intravenous/ocular doses, 14C-lifitegrast was eliminated primarily through feces. Excreted radioactivity was mainly unchanged lifitegrast.
Conclusions: High exposure of lifitegrast in rabbit ocular anterior segment tissues and low exposure in posterior segment tissues/plasma suggests that lifitegrast reaches target tissues for DED treatment, with low potential for off-target systemic/ocular effects. Excretion of unchanged 14C-lifitegrast suggests minimal drug metabolism in vivo. This is consistent with lifitegrast clinical trial efficacy/safety data.
Keywords: dry eye disease; lifitegrast; mass balance; ocular distribution; pharmacokinetics.