Sairopa Presents Promising ADU-1604 Clinical Data at ESMO Congress 2025: Novel CTLA-4 Blocking Antibody Demonstrates Benchmark Efficacy with Improved Safety Profile in Melanoma Patients
October 20, 2025 – ROTTERDAM, Netherlands – Sairopa, a clinical-stage biotechnology company developing innovative cancer immunotherapies, presented new clinical data on ADU-1604, its differentiated CTLA-4 blocking antibody, at the European Society for Medical Oncology (ESMO) Congress 2025, taking place October 17-21, 2025 in Berlin, Germany.
The company presented a scientific poster showcasing significant clinical advances with ADU-1604 in 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 Congress,” said Laura Lassouw-Polman, Chief Operating Officer at Sairopa. “ADU-1604 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.”
Sairopa reports research milestones achieved in partnership with Exelixis, totalling $35 Million from consecutive clinical milestone payments in 2024
December 17, 2024 – ROTTERDAM, Netherlands – Sairopa B.V. has reached significant research milestones under its clinical partnership with Exelixis, Inc. for ADU-1805, an innovative anti-SIRPα antibody aimed at enhancing immune system responses against cancer.
Sairopα’s anti-CTLA4 Antibody Shows Clinical Efficacy with a Mild Safety Profile
June 1, 2024 – ROTTERDAM, Netherlands – Sairopα, a leading developer of innovative cancer therapies, unveiled encouraging results from its dose-escalation Phase 1 study of ADU-1604 (anti-CTLA4 antibody) in advanced PD-1 relapsed/refractory melanoma patients at the ASCO Annual Meeting 2024 in Chicago. The study demonstrated that ADU-1604 is well tolerated across multiple dosages with no dose-limiting toxicities. Early signs of clinical efficacy were noted, particularly with a dose-dependent increase in CD8+ T-cell proliferation correlating with tumor reduction. The ongoing dose-expansion phase will further evaluate the 225mg dosage in 20 additional patients to support future combination therapies.
Sairopa to Continue Advancing Cancer Immunotherapy Under the Ownership of Van Herk Investments
Explore how Sairopa, with Van Herk Investments, is pioneering the future of cancer immunotherapy, offering innovative treatments and hope for patients worldwide.
Sairopa Presents Early Clinical Data on ADU-1604 Compound at SITC 38th Annual Meeting
The presentation, taking the form of a poster, presents early clinical data with encouraging early safety signals on ADU-1604, Sairopa’s anti-CTLA-4 antibody.
Chinook Therapeutics Announces Update on Non-Renal Legacy Programs from Aduro Biotech Merger
Van Herk Investments to Form and Invest in Sairopa, a New Company Focused on Research and Development of B-Select Monoclonal Antibody Platform Programs.