A Phase 2a Multicenter, Randomized, Vehicle-Controlled, Dose Escalating Study to Evaluate the Safety, Efficacy and Pharmacokinetics of CBT-001 Ophthalmic Solution in Patients With Primary or Recurrent Pterygium

Stage 1: Single Ascending Dose, Safety, Tolerability and Pharmacokinetics (n=24)

Objectives are to evaluate ocular safety and tolerability by biomicroscopy, ophthalmoscopy, intraocular pressure and visual acuity, and to assess general safety by physical exams, vital signs, clinical laboratory tests and adverse events reporting and to evaluate systemic CBT-001 exposure by Cmax, Tmax and an estimation of the area under the curve (AUC).

Three dose cohorts will be planned with a dose ascending strategy to guide dose concentrations (n=8 per Cohort x 3 cohorts = 24). Primary pterygium patients will be selected in this phase because the main goal is to assess the safety and tolerability of CBT-001 and primary pterygium patients are much easier to recruit. The ~8 primary pterygium patients from each Cohort will be administered a single ocular drug dose at Day 1 in the eye with primary pterygium; the unaffected eye will be dosed with vehicle. Examinations will be performed at both screening day (Day 0) and Day 1. Blood samples at pre-dose, 0.25, 0.5, 1, 2, 4 and 8 hours post dose will be taken at Day 1 to assess systemic pharmacokinetics (PK). The data will be reviewed by Data Review Committee (DRC) to determine whether to initiate enrollment for the next Cohort.

Cohort 1 will begin at the lowest CBT-001 concentration of 0.02%, followed by an increasing dose to 0.05% for Cohort 2 and then to 0.2% for Cohort 3. If no safety issues are found at all doses, the highest dose of 0.2% will be used for the next phase study.

Stage 2: Multiple Dose, Safety and Efficacy Study with 28-day Dosing and 5 months Followup (n=51)