EpiBiologics' New Drug Aims to Outsmart Stubborn Cancer Resistance

SAN MATEO, CA – April 19, 2026 – In a significant step toward addressing one of oncology's most persistent challenges, EpiBiologics today announced the first patient has been dosed in a global Phase 1 clinical trial for its novel drug, EPI-326. The therapy represents a new class of medicine designed to fight EGFR-driven solid tumors, including certain types of lung, head and neck, and colorectal cancers, by not just blocking cancer-causing proteins, but by systematically destroying them.

This first-in-human study marks a critical milestone for the company and its pioneering technology, which aims to overcome the widespread problems of drug resistance and severe side effects that plague current treatments. By selectively targeting and degrading the Epidermal Growth Factor Receptor (EGFR) protein on tumor cells while sparing healthy tissue, EPI-326 could offer a more potent and tolerable option for patients with advanced disease.

A New Strategy Against a Stubborn Target

The EGFR protein has long been a notorious driver of cancer growth. Its discovery led to a generation of targeted therapies, including tyrosine kinase inhibitors (TKIs) and monoclonal antibodies, that have transformed care for many patients. However, their effectiveness is often temporary. Cancers are relentlessly adaptive, frequently developing mutations that render these drugs useless. For instance, resistance mutations like T790M and C797S have become common hurdles for even the most advanced EGFR inhibitors in non-small cell lung cancer (NSCLC).

Furthermore, because EGFR is also present on healthy cells, particularly in the skin and gut, current therapies often cause debilitating side effects. Severe acne-like rashes, persistent diarrhea, and painful mouth sores can dramatically reduce a patient's quality of life and sometimes force them to stop treatment altogether.

EpiBiologics aims to rewrite this narrative with its EpiTAC (Epidermal Targeted Antibody Conjugate) platform. EPI-326 is a bispecific antibody, a sophisticated molecule with two distinct arms. One arm is engineered to grab onto the EGFR protein, while the other latches onto a different receptor found predominantly on tumor cells. This molecular matchmaking effectively tags the cancer-causing EGFR protein for destruction within the cell's own waste disposal system, the lysosome. The result is the complete removal of the target protein, not just its inhibition.

“Patients face persistent challenges with current EGFR-targeted therapies, including resistance and poor tolerability,” said Eric Humke, M.D., Ph.D., Chief Medical Officer of EpiBiologics. “EPI-326 was designed to address those limitations through a mutation-agnostic, tissue-selective approach to localize EGFR degradation to tumors while sparing healthy tissue. We believe EPI-326 can drive strong durable efficacy as a monotherapy and in combinations, and ultimately enable treatment in earlier settings.”

Promising Preclinical Data and Clinical Hopes

The initiation of the Phase 1 study (NCT07462377) is built on a foundation of compelling preclinical data, recently highlighted at the American Association for Cancer Research (AACR) conference. In laboratory and animal models, EPI-326 demonstrated a powerful one-two punch of potent efficacy and remarkable safety.

The drug showed robust anti-tumor activity across a wide range of cancer models, including those with the very EGFR mutations known to confer resistance to standard drugs. In one head-to-head comparison in an NSCLC model, EPI-326 monotherapy not only outperformed a leading EGFR inhibitor but also produced a high rate of complete responses, meaning the tumors disappeared entirely.

Crucially, toxicology studies in non-human primates revealed a highly favorable safety profile. Even at very high doses, EPI-326 did not cause the stereotypical EGFR-related toxicities, like skin rashes, that are the hallmark of current treatments. This supports the core principle of tissue-selective degradation: by focusing its destructive power only on the tumor, the therapy leaves healthy tissues unharmed.

“What stands out in these data is the combination of robust anti-tumor activity with an excellent tolerability profile,” said Shyra Gardai, Ph.D., Chief Scientific Officer of EpiBiologics. “This is the central promise of tissue-selective degradation. We are now pursuing similar therapeutic approaches across multiple targets in oncology and immunology.”

The global Phase 1 trial will now put this promise to the test in humans. The study will evaluate the safety, tolerability, and preliminary anti-tumor activity of EPI-326 in patients with advanced NSCLC and head and neck squamous cell carcinoma (HNSCC). Currently enrolling patients in the U.S., the trial is also planned for sites in the Asia-Pacific region, with a potential future expansion into colorectal cancer (CRC).

The Broader Platform and Investor Confidence

While EPI-326 is the company's first asset to enter the clinic, it serves as a vanguard for a much broader therapeutic platform. At the same AACR meeting, EpiBiologics presented promising data on other pipeline candidates, including a dual-action cMET degrader-ADC that combines protein degradation with a cytotoxic payload, and a cKIT degrader for gastrointestinal stromal tumors. These programs underscore the versatility of the EpiTAC platform to address a wide array of difficult-to-treat cancers by targeting different disease-driving proteins.

This scientific momentum has been matched by strong financial and strategic backing, signaling significant confidence from the investment community. The company's clinical progress builds on a recent Series B financing, which attracted a syndicate of top-tier healthcare investors, including the notable addition of Roche Venture Fund.

This convergence of clinical advancement, promising science, and robust funding places EpiBiologics at the forefront of the next wave of targeted cancer therapy. The journey for any new drug is long and fraught with uncertainty, but the initiation of the EPI-326 trial represents a tangible source of hope.

“Advancing EPI-326 into the clinic, alongside key data presented at AACR, gives us an early view into the broader opportunity for EpiTACs,” said Ann Lee-Karlon, Ph.D., Chief Executive Officer of EpiBiologics. “This milestone builds on the momentum of our recent Series B financing, and we are delighted to welcome Roche Venture Fund as a new investor in our syndicate. Our goal is to build highly differentiated bispecific antibodies to selectively degrade membrane and soluble targets for oncology and immunology where new approaches are needed the most.”

The coming months will be watched closely by oncologists, patients, and investors alike as data from the Phase 1 study begins to emerge. If the tissue-selective degradation approach proves as effective and safe in humans as it has in preclinical models, it could herald a new chapter in the fight against EGFR-driven cancers and potentially many other diseases.