Many of today's immunotherapies are designed to strengthen an immune response that already exists. Cold tumors present a different challenge. They often show limited immune recognition, so there is relatively little activity for those therapies to build on.
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That is not a flaw in any of these approaches; it is just where they operate. The trouble is that downstream only works if something upstream already happened. In immune-cold tumors, it has not.
| Modality | How it works | What it needs that cold tumors lack |
|---|---|---|
| Checkpoint inhibitors | Release the inhibitory signals that keep already-active T-cells in check. | T-cells already engaging the tumor |
| CAR-T and TCR therapy | Engineer T-cells to seek a specific antigen and traffic into the tumor. | A consistent surface target |
| Cancer vaccines | Prime the immune system against tumor-specific antigens. | Intact antigen presentation |
| Bispecific antibodies | Bridge an immune cell directly to a target on the tumor surface. | A surface target to bridge to |
Read the right-hand column down the page. Four different mechanisms, four different decades of research, and broadly the same missing precondition each time.
It is tempting to treat immune-cold as a single diagnosis with a single fix. It is not. Researchers generally describe at least two distinct ways a tumor can end up cold, and they call for different solutions.
The tumor does not display the surface signals, danger cues, or antigens the immune system uses to flag something as foreign. No recognition, no response. There is nothing for even a fully functional immune system to act on.
This is the problem our early-stage research is focused on.
In some tumors, T-cells may be present nearby but are physically excluded from the tumor core, kept out by dense stroma, abnormal vasculature, or an immunosuppressive microenvironment. Recognition may be intact; access is not.
A recognition signal is not, by itself, a fix for a trafficking or stromal-exclusion problem*
These two failure modes can overlap, and MSS colorectal cancer and PDAC likely involve some degree of both. We would rather state that plainly than gloss over it.
Our early-stage research focuses on these two because they are both large patient populations with limited immunotherapy benefit today, and because a platform addressing the recognition problem in one has reason to be relevant in the other.
Microsatellite-stable, so it lacks the DNA damage signals checkpoint inhibitors rely on.
No broadly effective immunotherapy exists for unselected disease.
Figure 3. Patients in 100 who respond to a checkpoint inhibitor*
Immune-hot tumorsmelanoma, MSI-H disease
35–45%
MSS colorectal cancerimmune-cold
<5%
Pancreatic cancerimmune-cold
<3%
Sources: Frontiers in Oncology (2023); The Oncologist (2024); PMC/NIH (2020); ACS/SEER. PDAC figure reflects tumors lacking the dMMR biomarker.
That is the question our early-stage research is designed to test. Not by amplifying a response that isn't there, but by trying to install the recognition signal cold tumors are missing in the first place.