Patient Enrollment Started for Phase IIa Clinical Trial on δ-Opioid Receptor Agonist NC-2800 in Patients with Depression.

Nippon Chemiphar Co., Ltd.

(TSE: 4539)

January 15, 2026

Nippon Chemiphar Co., Ltd. (Head Office: Chiyoda-ku, Tokyo; President and CEO: Kazuhiro Yamaguchi; hereinafter "Chemiphar") announces that we have received a report from a clinical trial site indicating that the first patients have been enrolled in Phase IIa clinical trial on NC-2800, a novel candidate compound for the treatment of depression and anxiety disorders.

NC-2800 is the subject of the research and development project "Development of innovative emotion regulators with a mechanism of action based on activating opioid δ receptors", which was adopted under the Cyclic Innovation for Clinical Empowerment program of the Japan Agency for Medical Research and Development (hereinafter, "AMED") in January 2018.

With the support of AMED, Chemiphar has been advancing research and development efforts, and has entered into a joint research and development agreement and an option agreement with Sumitomo Pharma Co., Ltd.

NC-2800 targets δ-opioid receptors to regulate emotions through a mechanism of action distinct from existing drugs based on the monoamine hypothesis, while showing potential of safety and efficacy.

This Phase IIa clinical trial will be conducted at 27 facilities in Japan, and will investigate the efficacy and safety of continuous administration of NC-2800 in patients with depression, using a double-blind, placebo-controlled comparative study design.

Chemiphar is focusing on the development of this drug candidate, which is expected to be a Japan-originating groundbreaking new medicine, deliver it to patients around the world as soon as possible. Furthermore, we will continue to actively pursue drug discovery projects aimed at developing innovative new medicines for patients suffering from diseases for which sufficient treatment options are as yet unavailable.