Kansai Medical University Hospital Administers First Patient Dose of DS1025 in Global Phase 1 Clinical Trial Sponsored by Daiichi Sankyo

First patient worldwide dosed with investigational DS1025, a potential first-in-class CD25 directed antibody drug conjugate being evaluated in patients with advanced solid tumors

OSAKA, Japan, Oct. 19, 2026 /PRNewswire/ -- On August 18, 2026, the Department of New Experimental Therapeutics and Early Phase 1 Drug Development Service at Kansai Medical University Hospital, led by Professor Toshio Shimizu, administered the first worldwide dose of DS1025 to a patient in Japan as part of a global, multicenter Phase 1 clinical trial sponsored by Daiichi Sankyo. The global first-patient-first-dose milestone makes Kansai Medical University Hospital the first clinical trial site to administer this specifically engineered, investigational, potential first-in-class CD25 directed antibody drug conjugate (ADC) to a patient.

DS1025 is an investigational, potential first-in-class CD25 directed ADC that builds on the DXd ADC Technology of Daiichi Sankyo by delivering an immune-oncology optimized cytotoxic payload that works to deplete immunosuppressive T-cells (Treg cells) in the tumor microenvironment and activate the immune system to detect and destroy cancer cells. Treg cells can accumulate within tumors and suppress antitumor immune responses. Because CD25 is highly expressed on Treg cells, including those found in tumor tissue, CD25 is being investigated as a target in cancer immunotherapy.

The multicenter, open-label, first-in-human, dose escalation phase 1 trial will assess the safety, tolerability, pharmacokinetics, and preliminary efficacy of DS1025 in patients with advanced or metastatic solid tumors with disease progression on or after at least one prior line of standard therapy.

The trial will evaluate primary endpoints of safety and tolerability, including dose-limiting toxicities and adverse events. Secondary endpoints include pharmacokinetics and immunogenicity. Exploratory endpoints include overall response rate, duration of response, and time to response.

The trial is expected to enroll up to 45 adults with advanced, metastatic, or unresectable solid tumors whose disease has progressed following at least one prior line of standard therapy and for whom no further standard treatment is considered suitable. Clinical sites are planned in Asia, including Japan, and Europe.

For Kansai Medical University Hospital, this milestone also reflects its growing role in early-stage international cancer drug development. Through its collaboration with Daiichi Sankyo and other domestic and international partners, Kansai Medical University will continue to contribute to early-stage clinical research and the development of new approaches to cancer treatment.

Reference
https://clinicaltrials.gov/study/NCT07681882

About the University
Kansai Medical University (KMU) is a private medical university in Osaka, Japan. Originally established in 1928 as Osaka Women's Medical College, KMU became co-educational and adopted its current name in 1954. Guided by its founding spirit of Jijinshinkyo—"Benevolence, Compassion, and Empathy"—the university fosters skilled medical professionals across its faculties of Medicine, Nursing, and Rehabilitation. Today, KMU operates an extensive network including four affiliated hospitals, advanced institutes like the Near InfraRed Photo-ImmunoTherapy (NIR-PIT) Research Institute, and global facilities such as the KMU Tower. Approaching its one-hundredth anniversary in 2028, KMU continues to advance medical education, clinical research, and public health.

Website: https://www.kmu.ac.jp/en/index.html

Media Contact
Toshio Shimizu
+81-72-804-0101
[email protected]

SOURCE Kansai Medical University