A phase 3 study of Cloudbreak Pharma’s eye disease drug candidate has hit its co-primary endpoints, boosting a biotech embroiled in an IPO investigation.
Officials in Hong Kong suspended trading of Cloudbreak shares in September over concerns that the biotech's IPO may have been rigged to create an artificial impression of demand for the stock. Against that backdrop, Cloudbreak continued to advance CBT-001, a multi-kinase inhibitor eye drop. The biotech is developing the eye drop for pterygium, an ocular surface disease that lacks FDA-approved therapies.
Thursday, Cloudbreak reported statistically significant improvements on both the primary endpoints of its phase 3 trial. Given twice daily for three months, both CBT-001 doses had a statistically larger effect on conjunctival hyperemia than the placebo control, achieving one primary endpoint.
Conjunctival hyperemia, a medical term for when the white of the eye looks red, improved on the study drug starting from Week 2. The improvements were maintained through every visit up to Month 12.
Cloudbreak tracked patients through Month 12 to assess the other primary endpoint, which evaluated the effect of CBT-001 on pterygium lesion length. Again, both CBT-001 doses beat placebo. Cloudbreak has yet to share detailed data, but said the treatment-versus-vehicle benefit was about 10% of baseline and was yet to plateau at Month 12.
Superficial punctate keratitis, an eye disorder caused by cell death, was the most common adverse event on CBT-001, affecting 20% of patients on the low dose compared to 8% on placebo. Most cases resolved following treatment with artificial tears. Cloudbreak reported a similar adverse event profile for the high dose, although at a higher incidence.
The biotech plans to meet with the FDA to review the findings and discuss potential next steps for the program. In March, Cloudbreak said (PDF) it planned to start a second phase 3 trial in the third quarter of 2026 and complete the study in late 2028. In September, Cloudbreak estimated (PDF) that it would commercialize CBT-001 in the U.S. between 2030 and 2032.
Cloudbreak has a commercialization partnership for Greater China and another deal covering Asian markets, including Japan and South Korea. As of March, the biotech was exploring self-commercialization and outlicensing options for the U.S. and other regions.
The biotech published (PDF) the latest update on the IPO investigation and the suspension of its stock in late September. At that time, Cloudbreak’s board had decided to form an independent special committee to investigate concerns about its IPO. The company delayed its 2026 interim report in response to the internal investigation.