Periodic Reporting for period 1 - MiTE (Developing the next generation of cis-targeting macrophage-T cell cancer immunotherapies)
Reporting period: 2023-06-01 to 2025-05-31
Cancer remains one of the leading causes of death, affecting millions of people every year. Immunotherapy - a treatment that activates the body’s own immune system to fight cancer - has already transformed the way some cancers are treated. The global market for immunotherapy is worth around 168 billion USD and is expected to nearly double within the next decade. Yet, as of today, most patients still did not benefit from available immunotherapies. Even in cancers where immune cells are present in the tumor, treatments often failed for two main reasons: 1. Insufficient immune activation - the immune system was not triggered strongly enough to destroy the cancer. 2. Severe side effects - treatments activated the immune system in a non-specific way, harming healthy tissues.
In this project, we set out to address both challenges with a new class of therapeutic molecules, called MiTEs (Myeloid-targeted Immunocytokine and NK–T cell Enhancers). These fusion proteins were designed to trigger a powerful, highly targeted immune attack inside the tumor microenvironment (TME) in cancers resistant to current treatments.
We successfully developed MiTEs with a unique design that: 1. Reprogram myeloid cells in the tumor, building on our discovery that the TREM2 protein acts as a key “brake” on immune activation. 2. Simultaneously boost the activity of natural killer (NK) cells and T cells, the immune system’s main cancer-killing forces.
To achieve this, we used a hybrid approach - combining AI-based prediction and design with advanced engineering of antibody-cytokine fusion proteins. This work was made possible by our team’s combined expertise in cancer immunology, single-cell multiomics, antibody engineering, AI, and biotech development.
We have delivered the next generation of dual-arm immunotherapies that overcome key limitations of current treatments. Our MiTEs show strong potential to extend the reach of immunotherapy to a broad range of cancers, improve patient outcomes, and reduce treatment-related toxicity.
In this project, we set out to address both challenges with a new class of therapeutic molecules, called MiTEs (Myeloid-targeted Immunocytokine and NK–T cell Enhancers). These fusion proteins were designed to trigger a powerful, highly targeted immune attack inside the tumor microenvironment (TME) in cancers resistant to current treatments.
We successfully developed MiTEs with a unique design that: 1. Reprogram myeloid cells in the tumor, building on our discovery that the TREM2 protein acts as a key “brake” on immune activation. 2. Simultaneously boost the activity of natural killer (NK) cells and T cells, the immune system’s main cancer-killing forces.
To achieve this, we used a hybrid approach - combining AI-based prediction and design with advanced engineering of antibody-cytokine fusion proteins. This work was made possible by our team’s combined expertise in cancer immunology, single-cell multiomics, antibody engineering, AI, and biotech development.
We have delivered the next generation of dual-arm immunotherapies that overcome key limitations of current treatments. Our MiTEs show strong potential to extend the reach of immunotherapy to a broad range of cancers, improve patient outcomes, and reduce treatment-related toxicity.
We designed and tested a new class of immunotherapies - MiTEs - that combine myeloid checkpoint inhibition with NK and T cell activation in the TME. Over the course of the project, we developed the full experimental pipeline, identified lead molecules, and demonstrated their strong anti-tumor potential.
1. Targeting TREM2 to reprogram myeloid cells
Using our humanized TREM2 mouse model, we established in-vitro screening systems based on bone-marrow-derived tumor-associated macrophages (TAMs). Flow cytometry and single-cell RNA sequencing (scRNA-seq) showed that monocytes lacking TREM2 do not become immunosuppressive macrophages. We generated hundreds of anti-TREM2 antibodies, identified lead candidates with blocking activity equal to genetic deletion of TREM2, and confirmed that our top antibody (E3C7) replicated the beneficial profiles of TREM2-deficient cells.
Using our Zman-Seq time-stamping technology, we mapped in vivo how monocytes differentiate into TAMs in glioblastoma. Blocking TREM2 disrupted this process, preventing the development of highly immunosuppressive macrophages and shifting them toward a pro-inflammatory state. However, anti-TREM2 alone did not achieve strong tumor control, highlighting the need for combination approaches.
2. Selecting and engineering potent cytokines
To boost anti-tumor immunity, we screened clinically relevant cytokines (including IL-2 “superkine” (IL2SK), IL-12, GM-CSF, and IL-15 “sushi”) in inducible tumor cell line models. IL2SK showed the strongest individual activity, and combinations - particularly IL2SK with IL-12 - were highly synergistic.
We created an anti-TREM2–IL2SK fusion protein, which strongly activated immune cells in vitro but caused severe systemic toxicity in vivo. To solve this, we used single-cell multiomics and machine learning to identify a TAM-specific protease expressed alongside TREM2 in tumors but absent from healthy tissues. We then engineered MiTE prototypes with cytokines “masked” by a cleavable blocking moiety that activates only in the presence of this protease.
3. Safe, tumor-specific activation
Our tumor-activated cytokines remained inert in vitro until exposed to the TAM-specific protease, at which point they matched the potency of unmasked cytokines. In mice, these protease-activated MiTEs showed no toxicity - even at high repeated doses - and no weight loss or systemic cytokine spikes.
4. In vivo efficacy of lead MiTEs
Our lead molecule, MiTE-144, completely eliminated MC38 tumors and outperformed anti-TREM2, anti-PD-1, or their combination. Single-cell analysis revealed a massive increase in cytotoxic and proliferating NK and T cells, with NK cells showing the strongest expansion and activation, even in conditions where T cells typically fail (e.g. tumors lacking MHC-I). This NK response is critical for targeting PD-1–resistant tumors.
Outcomes
We have established a robust, data-driven pipeline for designing safe and effective MiTEs that combine myeloid checkpoint inhibition with NK and T cell activation. Our work demonstrates:
• Proof-of-concept that TREM2 blockade reprograms suppressive macrophages.
• Identification of optimal cytokines and synergistic combinations.
• Development of tumor-specific cytokine activation technology that avoids systemic toxicity.
• Discovery of a lead MiTE molecule with complete tumor-eradicating potential in vivo.
These results position our TREM2-focused MiTEs as a promising therapeutic strategy for immune checkpoint blockade–resistant solid tumors, with a clear path toward clinical translation.
1. Targeting TREM2 to reprogram myeloid cells
Using our humanized TREM2 mouse model, we established in-vitro screening systems based on bone-marrow-derived tumor-associated macrophages (TAMs). Flow cytometry and single-cell RNA sequencing (scRNA-seq) showed that monocytes lacking TREM2 do not become immunosuppressive macrophages. We generated hundreds of anti-TREM2 antibodies, identified lead candidates with blocking activity equal to genetic deletion of TREM2, and confirmed that our top antibody (E3C7) replicated the beneficial profiles of TREM2-deficient cells.
Using our Zman-Seq time-stamping technology, we mapped in vivo how monocytes differentiate into TAMs in glioblastoma. Blocking TREM2 disrupted this process, preventing the development of highly immunosuppressive macrophages and shifting them toward a pro-inflammatory state. However, anti-TREM2 alone did not achieve strong tumor control, highlighting the need for combination approaches.
2. Selecting and engineering potent cytokines
To boost anti-tumor immunity, we screened clinically relevant cytokines (including IL-2 “superkine” (IL2SK), IL-12, GM-CSF, and IL-15 “sushi”) in inducible tumor cell line models. IL2SK showed the strongest individual activity, and combinations - particularly IL2SK with IL-12 - were highly synergistic.
We created an anti-TREM2–IL2SK fusion protein, which strongly activated immune cells in vitro but caused severe systemic toxicity in vivo. To solve this, we used single-cell multiomics and machine learning to identify a TAM-specific protease expressed alongside TREM2 in tumors but absent from healthy tissues. We then engineered MiTE prototypes with cytokines “masked” by a cleavable blocking moiety that activates only in the presence of this protease.
3. Safe, tumor-specific activation
Our tumor-activated cytokines remained inert in vitro until exposed to the TAM-specific protease, at which point they matched the potency of unmasked cytokines. In mice, these protease-activated MiTEs showed no toxicity - even at high repeated doses - and no weight loss or systemic cytokine spikes.
4. In vivo efficacy of lead MiTEs
Our lead molecule, MiTE-144, completely eliminated MC38 tumors and outperformed anti-TREM2, anti-PD-1, or their combination. Single-cell analysis revealed a massive increase in cytotoxic and proliferating NK and T cells, with NK cells showing the strongest expansion and activation, even in conditions where T cells typically fail (e.g. tumors lacking MHC-I). This NK response is critical for targeting PD-1–resistant tumors.
Outcomes
We have established a robust, data-driven pipeline for designing safe and effective MiTEs that combine myeloid checkpoint inhibition with NK and T cell activation. Our work demonstrates:
• Proof-of-concept that TREM2 blockade reprograms suppressive macrophages.
• Identification of optimal cytokines and synergistic combinations.
• Development of tumor-specific cytokine activation technology that avoids systemic toxicity.
• Discovery of a lead MiTE molecule with complete tumor-eradicating potential in vivo.
These results position our TREM2-focused MiTEs as a promising therapeutic strategy for immune checkpoint blockade–resistant solid tumors, with a clear path toward clinical translation.
We created and tested a new type of cancer treatment called MiTEs, which work by both removing immune “brakes” and boosting the body’s cancer-killing cells (NK and T cells) directly inside tumors. We developed powerful anti-TREM2 antibodies that reprogram suppressive immune cells in tumors, found the best immune-boosting signals (cytokines) and combinations, and built a safety switch that keeps them inactive until they reach the tumor, avoiding harmful side effects. Our lead molecule, MiTE-144, completely removed tumors in mice, even in cancers that resist today’s best treatments, and worked especially well against tumors that hide from T cells by losing key immune markers. Next, we will prepare for human trials by testing MiTEs in more cancer types, scaling up safe production, and partnering with industry. MiTEs could bring effective and safer immunotherapy to many patients who currently have no good options.Results
PROD: MiTE (Myeloid-targeted Immunocytokine and NK–T cell Enhancer) platform - a new class of cancer immunotherapies combining myeloid checkpoint inhibition with NK and T cell activation, active only inside tumors to avoid toxicity. Lead molecule MiTE-144 eradicated tumors in resistant models. Platform ready for preclinical expansion.
Impact Continuation
The project achieved its scientific goals, creating the MiTE platform and lead molecule MiTE-144, which eradicated tumors in resistant models by reprogramming immune cells and boosting NK and T cell activity inside tumors. We are in licensing negotiations for MiTE-144. Economically, the platform could expand the immunotherapy market by addressing patients unserved by current drugs. Societally, it offers safer, more effective cancer treatments with minimal side effects.
PROD: MiTE (Myeloid-targeted Immunocytokine and NK–T cell Enhancer) platform - a new class of cancer immunotherapies combining myeloid checkpoint inhibition with NK and T cell activation, active only inside tumors to avoid toxicity. Lead molecule MiTE-144 eradicated tumors in resistant models. Platform ready for preclinical expansion.
Impact Continuation
The project achieved its scientific goals, creating the MiTE platform and lead molecule MiTE-144, which eradicated tumors in resistant models by reprogramming immune cells and boosting NK and T cell activity inside tumors. We are in licensing negotiations for MiTE-144. Economically, the platform could expand the immunotherapy market by addressing patients unserved by current drugs. Societally, it offers safer, more effective cancer treatments with minimal side effects.