SAN MATEO, Calif., April 19, 2026

EpiBiologics has announced that the first patient has been dosed in its global Phase 1 clinical study of EPI-326, a tissue-selective bispecific antibody designed to degrade Epidermal Growth Factor Receptor in EGFR-driven solid tumors. The first-in-human trial is evaluating the therapy in patients with advanced Non-Small Cell Lung Cancer and Head and Neck Squamous Cell Carcinoma, with plans to expand into Colorectal Cancer. This milestone marks a critical step in advancing next-generation targeted oncology therapies, particularly in cancers where drug resistance and toxicity continue to limit treatment outcomes.

Phase 1 Study Targets Safety and Early Efficacy

The ongoing Phase 1 study (NCT07462377) is designed to evaluate safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of EPI-326 as a monotherapy. The trial is currently enrolling patients across sites in the United States, with expansion planned in the Asia-Pacific region, including South Korea. EPI-326 introduces a mutation-agnostic mechanism, enabling selective degradation of both mutant and wild-type EGFR directly within tumor tissues while minimizing exposure to healthy cells.

This targeted approach aims to overcome the key limitations of conventional EGFR inhibitors, including treatment resistance and systemic side effects, which often reduce long-term clinical benefit and patient compliance.

AACR Data Highlight Strong Preclinical Activity

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Data presented at the AACR Annual Meeting 2026, including the “New Drugs on the Horizon” session, demonstrated robust anti-tumor activity of EPI-326 across multiple tumor models. Preclinical studies showed strong efficacy in both classical and drug-resistant EGFR-mutant NSCLC models, including those with the C797S resistance mutation. Additionally, the therapy exhibited activity in wild-type HNSCC and CRC tumor models, expanding its potential applicability. Notably, EPI-326 monotherapy achieved high complete response rates and outperformed standard EGFR inhibitors in certain models, supporting its potential as a best-in-class therapeutic candidate.

Combination Potential and Favorable Safety Profile

Beyond monotherapy, EPI-326 demonstrated promising results in combination with tyrosine kinase inhibitors (TKIs) and KRAS inhibitors, leading to deeper and more durable anti-tumor responses in preclinical settings. Importantly, the therapy showed a favorable tolerability profile in multidose non-human primate studies, with no evidence of typical EGFR-related toxicities even at high doses.

This improved safety window is significant, as toxicity remains a major limitation of current EGFR-targeted therapies. The ability to maintain efficacy while reducing adverse effects positions EPI-326 as a strong candidate for both standalone and combination treatment strategies in oncology.

EPI-326 is part of EpiBiologics’ broader EpiTAC platform, which focuses on developing bispecific antibodies for targeted protein degradation. The platform includes additional programs such as cMET degrader-antibody drug conjugates (ADCs) and cKIT-targeted therapies, aimed at addressing high unmet medical needs across multiple tumor types. Recent data from these programs further validate the platform’s potential to deliver precision-targeted therapies with improved therapeutic index. As the Phase 1 study progresses, the company aims to generate critical clinical data that will guide future development and expand the role of tissue-selective degradation technologies in oncology and immunology.

Source: EpiBiologics press release