Phase 1 IM-1617 undisclosed RTK–targeting ADC with TOP1 inhibitor payload in solid tumors

Immunome, Inc. is running a first-in-human, open-label Phase 1 dose-escalation (Part A) followed by dose-expansion (Part B) study to define the recommended dose/schedule and assess early antitumor activity of IM-1617 given IV. IM-1617 is an antibody-drug conjugate (ADC) that binds an undisclosed receptor tyrosine kinase (RTK) preferentially expressed across multiple solid tumors, delivering a topoisomerase I (TOP1) inhibitor payload to drive tumor-cell DNA damage; Immunome also describes potential biology beyond payload delivery via RTK involvement in tumor survival and immune exclusion. Part A enrolls advanced/metastatic unresectable solid tumors (including NSCLC, breast cancer subtypes, HNSCC, CRC, and several GI/GU tumors) after no remaining standard options, while Part B focuses on tougher post-standard subsets such as CRC after FOLFOXIRI and NSCLC after platinum plus PD-1/PD-L1 therapy. The key angle is broad, histology-agnostic development for an ADC with a non-public target and a TOP1 payload class that has been clinically validated in other ADCs, aiming to widen applicability beyond a single biomarker-defined niche. For these populations, today’s care is sequential systemic therapy (chemo backbones, targeted agents when actionable alterations exist, and immunotherapy in eligible tumors), but once patients progress after these regimens, options are largely additional single-agent therapies or trials—this study tests whether targeted TOP1 payload delivery can produce responses with a manageable safety profile.