CBT-001 is currently in a Phase 3 clinical trial, being investigated as potentially the first disease-modifying topical treatment for pterygium.

Breakthrough Innovation

CBT-001 is a topical formulation being developed by Cloudbreak™ Pharma via the 505b(2) regulatory pathway to treat patients with pterygium.

Chronic sun exposure due to outdoor work or leisure activities can cause angiogenesis and fibrosis of the ocular tissue, which may lead to the development of pterygium in some patients.1 The currently available over-the-counter topical treatments may provide some symptom relief.2 However, ocular surgery is sometimes performed on patients with pterygium despite eye care professionals being unsure how well surgery corrects vision, reduces redness and/or irritation, and the procedure has a variable recurrence rate.1-4

CBT-001, a multi-kinase inhibitor of VEGFR, PDGFRs, and FGFRs, has been shown in a pre-clinical study to inhibit corneal neovascularization and lesion growth.5,6 Currently CBT-001 is being investigated as potentially the first disease-modifying topical treatment for patients with pterygium. By targeting the angiogenic and fibrotic pathways pharmacologically, CBT-001 may be able to delay or reduce the need for surgery in patients with pterygium.

Efficacy and Safety

Phase 2 Clinical Trial7

The Phase 2 clinical trial (NCT03049852) was divided into two stages. Stage 1 included a dose escalation of CBT-001 in 24 patients to determine the max tolerated dose. Results demonstrated ocular safety and tolerability with negligible systemic drug exposure.  In Stage 2, 51 patients were treated with a 4-week cycle of TID dosing of CBT-001 (n=25) or vehicle (n=23) and were monitored through week 24. By week 4, a significantly decreased mean vascularity score was observed that remained through week 16.  In addition, a significantly greater mean reduction in lesion length was observed at week 4 that remained through week 8.7

CBT-001 was well-tolerated, with the majority of commonly reported adverse events in the CBT-001 arm being ocular, mild in severity, and resolved after treatment. No patients discontinued CBT-001 treatment due to adverse events.7

Phase 3 Clinical Trial8

Phase 3 Study (NCT05456425) to evaluate the efficacy and safety of CBT-001 in patients with pterygium.8

Protocol Title: Multicenter, Double-Masked, Randomized, Vehicle-Controlled 12-Month Parallel Comparison of the Safety and Efficacy of 0.1% and 0.2% CBT-001 Versus Vehicle, Dosed Twice-Daily, in Patients With Pterygium

Study Objective: To evaluate the safety and efficacy of 0.1% and 0.2% CBT-001 emulsion dosed twice daily for 24 months compared to vehicle in reducing conjunctival hyperemia and preventing pterygium progression in eyes with pterygia

Target Enrollment: 600 patients

Key Inclusion Criteria:

  • Male or female ≥12 years of age
  • Pterygium lesion length ≥1.2 mm over the cornea
  • Conjunctival hyperemia of Grade ≥3

Key Exclusion Criteria:

  • Pterygium removal surgery within the last 6 months
  • Anticipated pterygium surgery within a year of study enrollment
  • Clinically significant corneal abnormalities other than pterygium

This phase 3 clinical trial is currently enrolling. More information can be found on ClinicalTrials.gov for NCT05456425 or 

you can email CBT-CS301Study@cloudbreakpharma.com for additional information. 

BID, twice daily; DRC, data review committee; FGFR, fibroblast growth factor receptor; M, month; PDGFR, platelet-derived growth factor receptor; PK, pharmacokinetics; TID, three times daily; VEGFR, vascular endothelial growth factor receptor.

1. Shahraki T, et al. Ther Adv Ophthalmol. 2021;13:25158414211020152. 2. Chu WK, et al. Eye (Lond). 2020;34(6):1047-1050. 3. Wanzeler ACV, et al. Clin Ophthalmol. 2018;12:833-837. 4. Palewski M, et al. Int J Environ Res Public Health. 2022;19:11357. 5. Hilberg F, et al. Cancer Res. 2008;68:4774–4782. 6. Yang R, et al. Invest Ophthalmol Vis Sci .2019;60(9):2087. 7. Whitcup SM, et al. Ophthalmol Sci. 2024. Publication in press. https://doi.org/10.1016/j.xops.2024.100502. 8. ClinicalTrials.gov. A clinical trial on safety and efficacy of CBT-001 in patients with pterygium. Updated March 15, 2024. Accessed March 15, 2024. https://clinicaltrials.gov/study/NCT05456425.