Daiichi Sankyo has announced that the first patient has been dosed in a phase 1 clinical trial evaluating DS3610, an investigational STING agonist Antibody Drug Conjugate (ADC), in patients with advanced, metastatic, or unresectable solid tumours. DS3610 marks the first STING agonist ADC to enter clinical development within the company’s industry-leading ADC portfolio.

DS3610 is designed to combine precise tumour targeting with an immunomodulatory payload that activates the body’s immune system against cancer cells.

“By combining precise tumour targeting with an immunotherapy payload, Daiichi Sankyo is exploring a new way to harness the body’s own defences to attack cancer. The initiation of this first-in-human trial represents an important step forward in advancing the next wave of our ADC portfolio and reaffirms our commitment to creating transformative medicines for patients with cancer,” said Ken Takeshita, MD, Global Head, R&D, Daiichi Sankyo.

The multicentre, open-label phase 1 trial will assess the safety, tolerability, pharmacokinetics, and preliminary efficacy of DS3610, with endpoints including dose-limiting toxicities, adverse events, and exploratory measures such as response rate, disease control rate, Progression-Free Survival (PFS), and Overall Survival (OS). The study will enroll patients across multiple sites in Asia, Europe, and North America.

DS3610 consists of a monoclonal antibody with novel Fc modifications linked to an immunomodulatory payload that acts as a stimulator of interferon genes (STING) agonist. By directly delivering this payload to the tumour microenvironment, DS3610 aims to enhance immune activation and overcome resistance to existing immunotherapies.

The trial is part of Daiichi Sankyo’s expanding ADC pipeline, which currently includes eight ADCs in clinical development, leveraging the company’s proprietary DXd ADC Technology. The portfolio features programmes such as ENHERTU and DATROWAY, co-developed with AstraZeneca, and others in partnership with Merck & Co., Inc.

With DS3610 entering clinical development, Daiichi Sankyo continues to strengthen its leadership in next-generation ADC research, exploring innovative mechanisms to improve outcomes for patients with hard-to-treat cancers.