Abstract
Purpose :
A pterygium is a commonly occurring, benign fibrovascular growth onto the cornea that can impair vision. There are no FDA-approved drugs for pterygia and treatment often involves surgery. The purpose of this study is to evaluate the safety and efficacy of CBT-001, a topical multi-kinase inhibitor eyedrop, for pterygia.
Methods :
CBT-001 was evaluated in a Phase 2 clinical trial that included two stages. Stage 1 was a single center, open-labeled, vehicle-controlled study, 24 eyes of 24 patients received one drop of CBT-001 in a dose escalation fashion to determine the maximally tolerated dose. Stage 2 was a multicenter, randomized, double-masked, vehicle-controlled, parallel-group clinical trial. Patients with primary or recurrent pterygia were randomly assigned to receive the maximally tolerated dose of CBT-001 or vehicle dosed TID for 4 weeks with a 20 week follow up. The primary efficacy endpoint was lesion vascularity based on masked grading of color photographs on a validated scale (0:absent-4:severe scale) by an independent reading center. Other endpoints included dimensions of the cornea portion of the pterygium head (measured based on photographs analyzed using ImageJ software) and safety.
Results :
Stage 1 demonstrated good ocular and systemic safety of all three doses of CBT-001 with negligible systemic drug exposure. In stage 2, baseline demographic characteristics were similar between patients receiving CBT-001 (n=25) and vehicle (n=23). After 4 weeks of dosing, mean vascularity scores were significantly decreased in patients receiving CBT-001 (-0.8) compared to vehicle (0.0) (p<0.001). Vascularity remained significantly decreased at weeks 8 and 16, but not at week 24. CBT-001 also showed significantly greater mean reductions in lesion length at weeks 4 and 8 (p<0.05). The most commonly reported adverse events associated with CBT-001 were ocular, mild in severity, resolved after therapy, and did not result in discontinuation.
Conclusions :
CBT-001 decreased pterygia vascularity and lesion length after 4 weeks of dosing with a prolonged effect. CBT-001 was well tolerated with minimal systemic exposure.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.