Marseille, France | July 21, 2026
Innate Pharma SA has announced the completion of enrollment in the dose-escalation portion of the Phase 1 IPH4502-101 clinical trial, marking a significant development for its proprietary Nectin-4-targeting antibody-drug conjugate (ADC), IPH4502. The open-label, multicenter study has enrolled 76 patients across sites in France and the United States to evaluate the safety, tolerability, pharmacological profile, and preliminary anti-tumor activity of IPH4502 in patients with advanced Nectin-4-expressing solid tumors. Preliminary clinical results are expected by the end of 2026 and will guide dose optimization as the program advances into the next stage of Phase 1 development. The milestone strengthens Innate Pharma’s growing oncology pipeline and supports continued development of a differentiated ADC designed to address treatment resistance and improve safety in patients with advanced cancers.
IPH4502 Demonstrates Encouraging Safety and Early Anti-Tumor Activity
According to interim findings, IPH4502 has continued to demonstrate a favorable safety profile, with limited hematological toxicity, supporting the company’s hypothesis that its proprietary stable linker technology enables the controlled release of the topoisomerase I inhibitor exatecan, thereby minimizing systemic toxicity. Early clinical activity has also been observed in heavily pre-treated patients with difficult-to-treat cancers, including urothelial carcinoma (UC) following enfortumab vedotin treatment, non-small cell lung cancer (NSCLC), and head and neck squamous cell carcinoma (HNSCC). These objective tumor responses suggest that IPH4502 may offer therapeutic potential for patients who have exhausted currently available treatment options and support further investigation across multiple solid tumor indications characterized by high unmet medical need.
Differentiated ADC Design Targets Resistant Nectin-4-Positive Tumors
IPH4502 has been engineered using three proprietary components designed to improve efficacy while reducing treatment-related toxicity. The investigational ADC combines a high-affinity humanized anti-Nectin-4 antibody, a stable proprietary linker, and exatecan, a potent topoisomerase I inhibitor. Unlike conventional MMAE-based antibody-drug conjugates, exatecan may overcome multidrug resistance protein 1 (MDR1)-mediated resistance and eliminates the need for CYP2D6 genotyping, potentially expanding treatment accessibility. Preclinical studies have also demonstrated anti-tumor activity in enfortumab vedotin-resistant tumors and cancers with low or heterogeneous Nectin-4 expression, highlighting the potential for broader clinical applications beyond urothelial carcinoma, including breast, ovarian, gastric, esophageal, and colorectal cancers.
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Phase 1 Results Will Shape Future Clinical Development Strategy
Sonia Quaratino, Executive Vice President and Chief Medical Officer of Innate Pharma, stated that completing dose-escalation enrollment represents an important milestone for the IPH4502 program. She noted that the safety observations generated thus far reinforce confidence in the ADC’s differentiated design, particularly the limited hematological toxicity associated with its proprietary linker technology. The comprehensive dataset expected later this year will play a critical role in identifying the optimal therapeutic dose, selecting priority tumor indications, and informing subsequent expansion cohorts within the ongoing Phase 1 study. As the oncology field continues to invest heavily in next-generation antibody-drug conjugates, Innate Pharma’s IPH4502 has the potential to emerge as a first-in-class Nectin-4 exatecan ADC capable of addressing treatment resistance and expanding targeted therapeutic options for patients with advanced solid tumors.
Source:Innate Pharma press release
