Brenus Pharma's Vaccine Shows Promise Against "Cold" Colorectal Cancer

NEW YORK, NY – February 19, 2026 – French biotechnology firm Brenus Pharma has unveiled encouraging new data for its lead immunotherapy candidate, STC-1010, suggesting a potential breakthrough for a vast and underserved group of colorectal cancer patients. Presented at the prestigious American Association for Cancer Research (AACR) Immuno-Oncology conference, the findings from preclinical studies and an early-stage human trial indicate the treatment could effectively "heat up" tumors that are notoriously resistant to modern immunotherapies.

The data, detailed in a poster presentation, positions STC-1010 as a hopeful new weapon against microsatellite stable (MSS), or "immune-cold," colorectal cancer. This subtype represents a formidable challenge in oncology, and the early success of Brenus Pharma's novel approach is drawing attention from researchers and clinicians seeking to expand the reach of immunotherapy.

The 'Cold' Cancer Conundrum

For years, the advent of immune checkpoint inhibitors has revolutionized treatment for a subset of cancer patients, particularly those with "hot" tumors teeming with immune cells. However, the majority of colorectal cancer patients—an estimated 80 to 85%—have MSS tumors, which are considered "immune-cold" or "immune deserts." These cancers lack the necessary immune cell infiltration and mutational flags that allow checkpoint inhibitors to work, leaving patients with limited options beyond traditional chemotherapy.

This "cold" tumor microenvironment effectively renders the cancer invisible to the body's natural defenses. The unmet medical need for this population is immense, as they have largely been excluded from the benefits of the immunotherapy revolution. This has spurred a global race to develop strategies that can successfully convert these non-responsive tumors into ones that the immune system can recognize and attack.

"There is a strong need for drugs that can 'heat up' cold tumors for pMMR/MSS patients," stated Pr François GHIRINGHELLI of the CGFL Cancer Center in Dijon, a key contributor acknowledged by the company. He noted that current immunotherapies are primarily effective in the smaller subset of patients with "hot" tumors.

A Novel Strategy to Awaken the Immune System

Brenus Pharma's STC-1010 tackles this problem with a unique mechanism. It is an "off-the-shelf" allogeneic cancer vaccine, meaning it is not personalized for each patient but can be mass-produced, making it a more accessible and scalable solution. The therapy is built from whole tumor cells that have been modified with haptens—small molecules that act like red flags, enhancing the visibility of tumor antigens to the immune system.

The goal is to trigger a powerful, multi-pronged immune response. According to the new preclinical data, this strategy appears to be effective. In mouse models of colorectal cancer, STC-1010 not only significantly inhibited tumor growth but also extended survival by a remarkable 40%.

Mechanistic studies revealed how it achieves this. The therapy was shown to be efficiently captured by dendritic cells, the "generals" of the immune system responsible for training T-cells. Transcriptomic analysis confirmed that these dendritic cells became highly activated, subsequently processing and presenting the tumor antigens. This process successfully primed CD8⁺ T-cells—the "killer" cells of the immune system—to seek out and destroy colorectal cancer cells with robust and reproducible cytotoxicity. Furthermore, the treatment led to an expansion of both CD4⁺ and CD8⁺ T-cells in lymph nodes, demonstrating a coordinated and powerful immune activation.

Promising Safety Signals in First Human Trial

While promising preclinical results are a crucial first step, the true test of any new therapy lies in human clinical trials. Here, too, Brenus Pharma reported positive early news from its first-in-human BreAK CRC 001 trial (NCT06934538).

The Phase I/IIa study is evaluating STC-1010 in combination with standard-of-care chemotherapy for patients with unresectable, metastatic, or locally advanced colorectal cancer. Preliminary data from the first cohort of patients, who have MSS and KRAS-mutant tumors, revealed a good safety profile with no dose-limiting toxicities observed.

This is a critical milestone in any Phase I trial, as the primary goal is to establish safety and determine the right dose for further study. The absence of significant early safety concerns allows Brenus to proceed with its investigation, providing a green light to explore the therapy's efficacy. The company has stated that complete safety data from the initial dose-escalation phase, along with exploratory efficacy results, are expected in the second quarter of 2026.

Charting a Course in a Competitive Field

Brenus Pharma is entering a competitive but opportunity-rich landscape. Numerous companies are pursuing strategies to overcome immune resistance in cold tumors, from combining checkpoint inhibitors with chemotherapy and radiation to developing novel cell therapies and oncolytic viruses. STC-1010's hapten-enhanced, off-the-shelf vaccine approach represents a distinct and potentially advantageous path forward.

The company appears well-positioned to advance its clinical program, having secured a €22.2 million ($25 million) Series A financing round in late 2024. This funding is dedicated to advancing STC-1010 through its proof-of-concept trial and expanding the company's proprietary STC platform to other hard-to-treat solid tumors, including pancreatic cancer.

With a strong scientific rationale, encouraging preclinical evidence, and a clean early safety profile in humans, STC-1010 is a notable candidate in the quest to help the majority of colorectal cancer patients. All eyes will now be on the forthcoming data release in the next quarter, which will provide the first crucial insights into whether this novel vaccine can truly turn the tide against one of oncology's most persistent challenges.