Dong-A ST received regulatory approval to conduct its third phase 1 clinical trial of donepezil transdermal patch for treating Alzheimer’s disease to check for optimum dose in long-term attachment.

The phase 1b clinical trial of DA-5207, the company’s donepezil patch, is an additional study requested by the regulator to verify the safety.

Dong-A ST has been developing DA-5207, an improved donepezil therapy that only requires application once a week. However, only oral preparations are available now due to the difficulty of creating a dosage form for donepezil-based drugs.

Incrementally modified drugs (IMD) win approval for marketing based on the data of completed phase 1 and 3 clinical trials. Still, Dong-A ST designed the study to receive approval just with phase 1 study results.

However, Dong-A ST still needs to conduct another clinical trial and the recently approved third study of DA-5207 to find the optimal dosage for long-term use.

The company will recruit 48 patients in the clinical trial. The study will be conducted at Jeonbuk National University Hospital with a domestic clinical research agency BioCore.

“The safety data for long-term attachment in patients are necessary, so we plan to discuss the additional clinical trials,” Dong-A ST official said. “

Once the company introduces its patch to the market, the product may increase patients’ convenience as it only requires application once a week. In addition, patches have reduced side effects, including nausea and vomiting, reported in the existing oral treatments for Alzheimer’s disease.

The company said it expects to continue its studies of drugs specialized for Alzheimer’s disease. It has experience transferring degenerative neuropathy treatment drug DA-9803 to U.S. pharmaceutical company NeuroBo Pharmaceuticals in 2018.