DEM BioPharma Unveils Novel ADC Targeting GI Cancer's Immune Shield

CAMBRIDGE, Mass. – January 06, 2026 – In the relentless fight against gastrointestinal cancers, a new contender is preparing to make its public debut. DEM BioPharma, a Cambridge-based biopharmaceutical firm, has announced it will present the first preclinical data for its novel cancer therapy, DEM301, at the upcoming 2026 ASCO Gastrointestinal Cancers Symposium.

The presentation, scheduled for January 10 in San Francisco, will introduce a first-in-class bifunctional antibody-drug conjugate (ADC) designed to combat colorectal cancer and other GI malignancies through a unique dual-action mechanism. This marks a significant milestone for the company, which has been operating largely in stealth mode, leveraging a proprietary discovery platform to identify new ways to attack solid tumors.

DEM301 targets a previously unexploited protein, DEM-TXX, a glycoprotein that is overexpressed on the surface of GI cancer cells. By targeting this novel marker, DEM BioPharma hopes to offer a new therapeutic option for patients who have exhausted other treatments in a field with significant unmet medical need.

A New Weapon Against an Old Foe

The scientific foundation of DEM301 lies in its innovative approach to both identifying and attacking cancer. The target, DEM-TXX, was discovered using DEM BioPharma's proprietary CRISPR-based functional genomic screening platform, known as CHoMP (Co-culture with Human Myeloid Phagocytes). This platform is engineered to pinpoint novel "Don't Eat Me" (DEM) and "Eat Me" (EM) signals on cancer cells, which regulate whether the body's innate immune system—specifically myeloid phagocytes like macrophages—will consume and destroy them.

According to the company, DEM-TXX functions as one of these crucial "Don't Eat Me" signals, effectively creating an immune-suppressive shield around the tumor. The protein is implicated in promoting cell adhesion and suppressing myeloid cells, and its expression levels are negatively correlated with disease progression. This suggests that the more DEM-TXX a tumor has, the worse the patient's prognosis, making it a high-value target for therapeutic intervention.

“This ASCO GI presentation represents an important milestone for DEM BioPharma as we introduce DEM301 and its underlying biology to the oncology community for the first time,” said Nenad Grmusa, CEO of DEM Bio. “DEM-TXX emerged from our scientific founders’ functional genomics screen and validated by DEM BioPharma as a target that appears to contribute to immune suppression in GI cancers. DEM301 was purpose-built to translate that biology into a differentiated ADC designed with a dual mechanism of action to directly kill tumor cells while engaging immune-mediated mechanisms.”

DEM301 is not a standard ADC. It is described as a bifunctional molecule. The first function is the classic ADC mechanism: a monoclonal antibody selectively binds to DEM-TXX on tumor cells, delivering a potent, clinically validated cytotoxic payload directly to the cancer. The second, and perhaps more innovative, function comes from the antibody itself. It is an afucosylated antibody, a modification known to enhance its ability to trigger an immune response, a process called antibody-dependent cell-mediated cytotoxicity (ADCC). By simultaneously delivering a toxin and unmasking the tumor for immune attack, DEM301 aims to deliver a powerful one-two punch.

Entering the Crowded ADC Arena

DEM BioPharma is entering a dynamic and increasingly competitive field. Antibody-drug conjugates have transformed the treatment landscape for several cancers, and the GI cancer space is a hotbed of ADC development. Major successes, such as trastuzumab deruxtecan (T-DXd) for HER2-positive gastric cancer, have validated the ADC approach in this setting. Consequently, dozens of companies are now racing to develop ADCs against established targets like HER2, Claudin 18.2, and Trop-2.

DEM301's differentiation hinges on its novel target. By pursuing DEM-TXX, a protein not currently targeted by any other therapy in development, DEM BioPharma is carving out a unique niche. If successful, it could provide a treatment option for patients whose tumors do not express the more common targets, or for those who have developed resistance to existing therapies. This strategy mitigates direct competition and addresses a clear clinical gap.

Furthermore, the dual-mechanism design could offer advantages over traditional ADCs, which can be limited by challenges such as insufficient payload delivery or the development of resistance. By also recruiting the patient's own immune system, DEM301 may create more durable and potent anti-tumor responses. The preclinical data to be presented at ASCO GI will be the first test of this hypothesis, with the company reporting potent and durable single-agent efficacy in animal models of colorectal and other GI tumors, alongside a favorable safety profile in a humanized mouse model.

From Lab Bench to Clinical Hope

The true measure of any new cancer drug is its potential impact on patients. For those battling advanced gastrointestinal cancers, which remain difficult to treat, the announcement of a new therapeutic strategy moving toward the clinic offers a tangible sense of hope. The journey for DEM301 is just beginning, but the planned initiation of a Phase 1a/1b clinical trial in the second half of 2026 is a critical step forward.

This first-in-human study will be designed to evaluate the safety, tolerability, and preliminary efficacy of DEM301 in patients with GI malignancies. In preparation, DEM BioPharma is advancing the drug through final preclinical pharmacology and toxicology studies while simultaneously scaling up its manufacturing processes (CMC development), a complex but essential step for producing clinical-grade ADCs.

The upcoming poster presentation, titled "DEM301, a novel anti-DEM-TXX antibody-drug conjugate with potent anti-tumor activity for the treatment of gastrointestinal tumors," will be presented by Dr. Sarah Carden of DEM BioPharma. It will provide the first detailed, public look at the data supporting the drug's development and will be scrutinized by oncologists, researchers, and potential pharmaceutical partners.

The Company Behind the Science

Founded in 2022, DEM BioPharma launched with a substantial $70 million seed financing round led by Longwood Fund and Alta Partners, with a syndicate of high-profile investors including Pfizer Ventures and Astellas Venture Management. This strong financial backing, which PitchBook reports now totals $95 million, has enabled the company to rapidly advance its discovery platform and lead asset.

The company's scientific pedigree is equally impressive. Its approach is built on the foundational research of co-founders Drs. Jonathan Weissman and Kipp Weiskopf of the Whitehead Institute and Dr. Michael Bassik of Stanford University—all leaders in the fields of CRISPR functional genomics and macrophage biology. Under the leadership of CEO Nenad Grmusa, a veteran of Takeda's R&D strategy group, DEM BioPharma is strategically positioned to translate this cutting-edge science into clinical reality.

As the company prepares to step into the spotlight at one of the year's most important oncology conferences, the data on DEM301 will be pivotal. The oncology community will be watching closely as DEM BioPharma prepares to share the first detailed look at this promising new agent in San Francisco.