Travoprost intraocular implant (iDoseTR^®) delivers therapeutically relevant and durable aqueous humor drug concentration levels at 12 months and demonstrates safety of implant repeat dosing

Abstract

Purpose : The objectives of this prospective, open-label, single center, 24-month clinical study of the Travoprost Intraocular Implant, 75 µg (iDoseTR^®) were to determine in vivo drug elution rate and aqueous humor exposure to travoprost free acid and to demonstrate safety of the implant redosing procedure in subjects with open-angle glaucoma (OAG) or ocular hypertension (OHT).

Methods : This prospective, open label study enrolled 14 cohorts of 15 subjects each (~210 total subjects). Subjects were implanted with two lots of the iDose TR^® implant and each cohort was followed ranging between 3 to 24 months prior to further intervention. Implants were then removed at pre-determined timepoints, and a new implant was inserted. At this exchange visit, aqueous humor (AH) samples and the extracted implants were collected and analyzed for travoprost free acid (TFA) concentrations and remaining levels of travoprost, respectively. Safety and adverse events were also evaluated.

Results : Concentrations of TFA in AH averaged from (4.2±1.8)-(5.7±2.9) ng/ml at 3 months, (3.7±2.1)-(3.8±2.4) ng/ml at 6 months, and (5.5±3.2)-(5.6±3.0) ng/ml at 12 months post-implantation for the two lots of iDose TR^®. The TFA levels in most patients at all timepoints were above the estimated Cmax concentration of 1.78 ng/ml determined after the dosing of topical travoprost eye drops and were above in all patients at almost all timepoints of the 95 ± 41 pg/mL efficacious concentration level estimated after intracameral implant dosing of travoprost. The average amount of travoprost remaining in explants were ~60 µg, ~57 µg and ~38 µg at 3, 6 and 12 months post implantation, representing ~80%, ~75% and ~50% travoprost remaining, respectively. There were no adverse events observed in the study indicating the excellent tolerability of implants and the safety of the exchange procedure.

Conclusions : Concentrations of travoprost free acid were above the established efficacious concentration of 100 pg/ml in most patients at all timepoints, indicating that subjects achieved adequate concentrations to elicit IOP lowering. The ~50% levels of remaining travoprost in explants at the 12-month interim timepoint indicate the potential durability of the efficacious drug delivery for up to 24 months.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.