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Safety and Efficacy of CBT-001 Ophthalmic Solution in Patients With Pterygium

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

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03049852
Acronym
Pterygium
Enrollment
75
Registered
2017-02-10
Start date
2017-04-15
Completion date
2018-04-30
Last updated
2020-02-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Pterygium

Brief summary

Stage 1: Single Ascending Dose, Safety, Tolerability and Pharmacokinetics (n=24) Stage 2: Multiple Dose, Safety and Efficacy Study with 28-day Dosing and 5 months Followup (n=51)

Detailed description

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) Objectives are to evaluate ocular and systemic safety of CBT-001 in primary or recurrent patients that have moderate to severe pterygium vascularity and to assess whether CBT-001 is efficacious in reducing pterygium vascularity and pterygium lesion growth. The dosing will be 4 weeks. The followup period will be 5 months. Study Population Characteristics: Approximately 50 (30 primary pterygium and 20 recurrent) patients will be enrolled at up to 3 centers to have an estimated 40 patients complete the study based on an anticipated dropout rate of 20%. Although we have no evidence to suggest attrition due to Adverse Effects (AEs), the dropout rate is most conservative based on industry experience in comparable clinical studies. Patients will be randomized in a 1:1 treatment allocation to receive either CBT-001 0.2% or Vehicle. Dosage/Dose regimen: One drop of the assigned study medication will be administered in the study eye TID for 4 weeks. The study eye is defined as the qualified eye (i.e., the eye meeting the inclusion criterion for primary or recurrent pterygium). If both eyes are qualified, then the eye with the more severe vascularity grade on the Pterygium Hyperemia Grading Scale at the baseline (Day 1) visit will be the study eye. If both eyes meet the criterion and have the same severity, the right eye will be the study eye. Patients with bilateral pterygium will administer study medication only in the study eye. The fellow eyes in all study subjects will be untreated.

Interventions

One drop in the study administered three times daily (TID) for 4 weeks

DRUGCBT-001 single dose

One drop in the study administered one time

DRUGVehicle

One drop in the study administered three times daily (TID) for 4 weeks

Sponsors

Cloudbreak Therapeutics, LLC
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Primary pterygium with moderate vascularity (Pterygium Hyperemia Grading Scale ≥ 3)

Exclusion criteria

* Active ocular disease, corneal abnormalities other than pterygium, active ocular infection, or any ocular pathology unrelated to pterygium in either eye that could affect the assessment of the pterygium * History of ocular herpes disease in either eye * Any ocular surgical procedure within the last 3 months * Female patients who are pregnant, nursing, or planning a pregnancy during the study

Design outcomes

Primary

MeasureTime frameDescription
Pterygium Vascularity Change Assessed Using the Pterygium Hyperemia Grading ScaleChange from baseline at 4 weeksThe primary efficacy variable is the change from baseline (Day 1) in severity grade of pterygium vascularity at Week 4. Pterygium vascularity intensity is based on color coordinates as measured by digital image analysis of pterygium photographs. The quantitative analysis of photographs using a 5-point Pterygium Hyperemia Grading Scale (0 = absent, 1 = trace, 2 = mild, 3 = moderate, 4 = severe) will be conducted at an independent image reading center.
Ocular and General Safety and TolerabilityOne dayThe ocular safety and tolerability are measured 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

Secondary

MeasureTime frameDescription
Corneal Pterygium Lesion Length Change From Baseline4 weeksThe Corneal Pterygium Lesion Length is measured from digital images of the eye by an independent image reading center.

Countries

United States

Participant flow

Participants by arm

ArmCount
CBT-001 Ophthalmic Solution Single Dose
One drop in the study administered one time CBT-001: One drop in the study administered one time
24
Vehicle Multi-dose
One drop in the study administered three times daily (TID) for 4 weeks Vehicle: One drop in the study administered three times daily (TID) for 4 weeks
25
CBT-001 Ophthalmic Solution Multi-dose
One drop in the study administered three times daily (TID) for 4 weeks CBT-001: One drop in the study administered three times daily (TID) for 4 weeks
26
Total75

Withdrawals & dropouts

PeriodReasonFG000FG001FG002
Overall StudyLost to Follow-up010

Baseline characteristics

CharacteristicCBT-001 Ophthalmic Solution Single DoseTotalCBT-001 Ophthalmic Solution Multi-doseVehicle Multi-dose
Age, Continuous50.8 years
STANDARD_DEVIATION 11.6
50.7 years
STANDARD_DEVIATION 11.4
52.0 years
STANDARD_DEVIATION 12.1
49.4 years
STANDARD_DEVIATION 10.7
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants1 Participants1 Participants0 Participants
Race (NIH/OMB)
Black or African American
0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants5 Participants1 Participants4 Participants
Race (NIH/OMB)
White
24 Participants69 Participants24 Participants21 Participants
Region of Enrollment
United States
24 participants75 participants26 participants25 participants
Sex: Female, Male
Female
13 Participants38 Participants14 Participants11 Participants
Sex: Female, Male
Male
11 Participants37 Participants12 Participants14 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
EG002
affected / at risk
deaths
Total, all-cause mortality
0 / 240 / 250 / 26
other
Total, other adverse events
4 / 242 / 2520 / 26
serious
Total, serious adverse events
0 / 241 / 250 / 26

Outcome results

Primary

Ocular and General Safety and Tolerability

The ocular safety and tolerability are measured 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

Time frame: One day

Population: mITT

ArmMeasureGroupValue (NUMBER)
Vehicle Multi-doseOcular and General Safety and TolerabilityMild eye irritation3 participants
Vehicle Multi-doseOcular and General Safety and TolerabilityMild foreign body sensation1 participants
Primary

Pterygium Vascularity Change Assessed Using the Pterygium Hyperemia Grading Scale

The primary efficacy variable is the change from baseline (Day 1) in severity grade of pterygium vascularity at Week 4. Pterygium vascularity intensity is based on color coordinates as measured by digital image analysis of pterygium photographs. The quantitative analysis of photographs using a 5-point Pterygium Hyperemia Grading Scale (0 = absent, 1 = trace, 2 = mild, 3 = moderate, 4 = severe) will be conducted at an independent image reading center.

Time frame: Change from baseline at 4 weeks

Population: Modified Intent-to-Treat Population

ArmMeasureValue (MEAN)Dispersion
Vehicle Multi-dosePterygium Vascularity Change Assessed Using the Pterygium Hyperemia Grading Scale0 gradeStandard Deviation 0.5
CBT-001 Ophthalmic Solution Multi-dosePterygium Vascularity Change Assessed Using the Pterygium Hyperemia Grading Scale-0.8 gradeStandard Deviation 0.7
p-value: <0.001Cochran-Mantel-Haenszel
Secondary

Corneal Pterygium Lesion Length Change From Baseline

The Corneal Pterygium Lesion Length is measured from digital images of the eye by an independent image reading center.

Time frame: 4 weeks

Population: Modified Intent-to-Treat Population

ArmMeasureValue (MEAN)Dispersion
Vehicle Multi-doseCorneal Pterygium Lesion Length Change From Baseline-0.11 mmStandard Deviation 0.3
CBT-001 Ophthalmic Solution Multi-doseCorneal Pterygium Lesion Length Change From Baseline0.16 mmStandard Deviation 0.36
p-value: 0.007ANOVA

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026