Immunome Doses First Patient in Phase 1 Trial of Potential First-in-Class ADC IM-1617 for Advanced Solid Tumors

Immunome has announced the first patient has been dosed in a phase 1 clinical trial evaluating IM-1617, a potential first-in-class antibody-drug conjugate (ADC) designed for the treatment of advanced solid tumors.¹

The first-in-human study marks the latest advancement for the company's growing ADC portfolio and represents the first clinical evaluation of IM-1617, which combines an undisclosed solid tumor target with HC74, Immunome's proprietary topoisomerase I (TOP1) inhibitor payload.¹

"The first patient dosed with IM-1617 is a significant milestone for Immunome's ADC platform and a meaningful step toward our mission of delivering targeted therapies for patients with cancer," said Clay Siegall, PhD, president and chief executive officer of Immunome, in a company statement.¹

The open-label, multicenter phase 1 study is designed to evaluate the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of IM-1617. Investigators expect to enroll patients with advanced solid tumors, including colorectal cancer, non-small cell lung cancer, and breast cancer.¹

What makes IM-1617 different from other ADCs?

IM-1617 targets an undisclosed receptor tyrosine kinase that Immunome says promotes tumor cell survival and contributes to immune cell exclusion within the tumor microenvironment.¹ By combining a tumor-targeting antibody with a potent cytotoxic payload, ADCs are designed to deliver chemotherapy directly to cancer cells while limiting systemic exposure.²

The investigational therapy incorporates HC74, a proprietary TOP1 inhibitor payload. TOP1 inhibitors have become increasingly important components of modern ADC development because of their potent anti-cancer activity and ability to generate durable responses across multiple tumor types.³

Preclinical studies demonstrated significant tumor regression following a single clinically relevant dose of IM-1617 across several solid tumor models, supporting advancement into human testing.¹

Why are TOP1 inhibitor ADCs attracting industry interest?

The ADC field has experienced rapid growth in recent years as developers seek to improve the therapeutic index of traditional chemotherapy. Several approved ADCs utilize TOP1 inhibitor payloads, validating the mechanism and driving continued investment in next-generation platforms.²˒³

Researchers are increasingly exploring novel targets, linker technologies, and payloads to improve efficacy and overcome resistance mechanisms. In addition to IM-1617, Immunome plans to submit investigational new drug applications for two additional ADC candidates, IM-1340 and IM-1335, in mid- and late-2026, respectively.¹

The company's broader oncology pipeline also includes IM-1021, a ROR1-targeted ADC, and IM-3050, a fibroblast activation protein-targeted radiotherapy.¹

What could early clinical data reveal?

As a first-in-human study, the phase 1 trial is primarily intended to establish a safe and tolerable dose while generating initial evidence of anti-tumor activity. Early clinical findings may also provide insight into the performance of the HC74 payload platform, which Immunome hopes to leverage across multiple future ADC programs.¹

Although efficacy conclusions remain premature, the initiation of clinical testing represents an important milestone for the company as it seeks to expand its presence in the increasingly competitive ADC market.²

References

1. Immunome Announces First Patient Dosed in Phase 1 Trial Evaluating IM-1617, a Potential First-in-Class ADC, in Patients with Advanced Solid Tumors. (2026 Jun 11). Business Wire. https://www.businesswire.com/news/home/20260611016477/en/Immunome-Announces-First-Patient-Dosed-in-Phase-1-Trial-Evaluating-IM-1617-a-Potential-First-in-Class-ADC-in-Patients-with-Advanced-Solid-Tumors
2. Lambert JM, Berkenblit A. (2018 Jan 29). Antibody–Drug Conjugates for Cancer Treatment. Annu Rev Med. https://pubmed.ncbi.nlm.nih.gov/29414262/
3. Beck A, Goetsch L, Dumontet C, Corvaïa N. (2017 May). Strategies and Challenges for the Next Generation of Antibody-Drug Conjugates. Nat Rev Drug Discov. https://pubmed.ncbi.nlm.nih.gov/28303026/