Curacle announced top-line results from its U.S. phase 2a clinical trial of CU06, an oral treatment for diabetic macular edema, on Monday.

"In this short-term, three-month trial, we found that CU06 blocked endothelial dysfunction and improved visual acuity, with a 5.8 increase in the number of letters readable at best-corrected visual acuity after three months of treatment," CEO Rye Jae-hyeon said at a news conference.

Diabetic macular edema is a condition in which diabetes causes capillaries to close, resulting in swelling and microhemorrhages in the retina that impair vision. There are currently no oral treatments other than intraocular injections (anti-VEGF) injected directly into the eye.

The trial was conducted in the United States in 67 patients with diabetic macular edema who received 100, 200, or 300 mg of CU06 orally once daily for 12 weeks. The primary endpoint was the change in central macular thickness (CST) from baseline to week 12 to monitor the thickness of the edema. The secondary endpoint was the best-corrected visual acuity (BCVA) score change from baseline to week 12 to determine the improvement in vision.

Clinical results demonstrated that CU06 did not increase macular central thickness values, the primary endpoint, in any dose group. There was also no progression or worsening of edema. The secondary endpoint, best-corrected visual acuity score, also improved, with the 300 mg dose group showing an average increase of 5.8 letters in best-corrected visual acuity score, particularly among patients with low vision (69 letters or less of best-corrected visual acuity) who were corrected to less than 0.5 with glasses or lenses.

According to Curacle, intravitreal injections of anti-VEGF increased best-corrected visual acuity scores by an average of 5 to 5.4 letters at 12 months.

“With CU06, we found a group of patients who improved their vision by 5.8 letters after just three months of treatment, providing the basis to move forward with a phase 2b study," the company said.

In addition, CU06 demonstrated a dose-dependent increase in efficacy at 100, 200, and 300 mg, with a sustained increase in efficacy over one to three months post-dose. There were no serious adverse events (SAEs) associated with the drug.

"As patients with diabetic macular edema seek medical attention when they experience decreased vision or distorted vision, the most important therapeutic goal is the change in best corrected visual acuity," CEO Ryu said. "Given that CU06 showed a dose- and duration-dependent increase in efficacy, we look forward to seeing the effects of longer dosing in phase 2b."

The global market for retinal vascular disease is expected to reach $34 billion (45.3 trillion won) by 2031, according to Curacle.

"CU06 has a high potential for commercialization because it is an oral treatment that can be tried first for treatment even if it is less effective than injections," Ryu said. "There are various treatment options, such as combining it with existing injections, and it has great scalability for other retinal diseases such as wet macular degeneration."

Curacle expects to present a clinical study report (CSR) as early as late March. Following this, discussions with its partner, French pharmaceutical company Tea, which specializes in ophthalmic diseases, and its global clinical advisory board will determine the design of the late-stage trial, which is expected to enter phase 2b in the second half year.

Based on the results of phase 2a, Curacle plans to accelerate the export of CU06 technology to Asia.

"Even during Covid-19, we have been discussing license agreements for CU06 with Asian countries," Ryu said. "Based on the results of phase 2a, we will continue to discuss license agreements with large companies in Japan and China."