On October 20, 2025 Sairopa, a clinical-stage biotechnology company developing innovative cancer immunotherapies, reported new clinical data on ADU-1604, its differentiated CTLA-4 blocking antibody, at the European Society for Medical Oncology (ESMO) (Free ESMO Whitepaper) Congress 2025, taking place October 17-21, 2025 in Berlin, Germany.

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The company presented a scientific poster showcasing significant clinical advances with ADU-1604 in melanoma patients who had previously failed PD-1 inhibitor therapy (n=27). The poster presentation featured the full results from the SRP-21C101 Phase 1 combined dose escalation and dose expansion clinical trial. Clinical efficacy was observed in 4/27 patients indicative of efficacy similar to other CTLA-4 inhibitors. Importantly, ADU-1604 showed a significantly milder safety profile as compared to existing CTLA-4 inhibitors, as evidenced by the reduced severity of immune-related adverse events.

"We are excited to share the clinical results from ADU-1604 in PD1 relapse/refractory melanoma with the international oncology community at ESMO (Free ESMO Whitepaper) Congress," said Laura Lassouw-Polman, Chief Operating Officer at Sairopa. "ADU-1604’s milder safety profile as compared to other CTLA-4 blocking agents will support its future use as combination agent, with PD-1 blocking agents and/or other agents. We are grateful to all patients, their families and investigators that supported our study."

(Press release, Sairopa, OCT 20, 2025, View Source [SID1234656822])