Our Approach
Unleashing the full potential of immuno-oncology therapies
Current immuno-oncology (I-O) therapies have curative potential for patients with cancer; however, their potential is significantly curtailed by systemic toxicity that results from activity of the therapeutic molecule outside the tumor microenvironment (TME). Our focus is to improve upon two of the foundational mechanisms of IO – cytokines and checkpoint inhibitors – with the goal of overcoming the limitations of current I-O therapies to develop products with an improved efficacy-to-toxicity ratio, or therapeutic index.
We are leveraging our geographically precise solutions (GPS) platform to rapidly engineer novel molecules, including cytokines and other biologics, that are designed to optimize their therapeutic index by geographically localizing their activity inside tumors.
Our GPS Platform
Our geographically precise solutions (GPS) platform enables us to engineer a broad range of immune-modulatory molecules, including cytokines and antibodies, that contain masking domains that minimize the activity of these molecules outside of the tumor microenvironment (TME). The molecules are then designed to be turned on selectively in the TME where they are activated by the unique conditions in the TME, including the preferential activity of matrix metalloproteases (MMPs), which are enzymes that are essential for tumor growth. Specifically, MMPs cleave a linker that connects the masking protein domain to the active agent. This separates the mask from the active agent, enabling the unmasked agent to promote an anti-tumor response within the TME. This approach is intended to bring the benefits of I-O therapy to patients by minimizing toxicity while enhancing anti-tumor activity.
Systemically Active
Immunotherapies




Lung Cancer Example
Xilio Tumor-Activated
Immunotherapies




Lung Cancer Example
We have shown preclinical validation of the ability of our GPS platform to develop tumor-activated antibodies and cytokines, as evidenced by our tumor-activated anti-CTLA-4 antibody, XTX101, and our tumor-activated IL-2, XTX202. In preclinical studies, each of these product candidates has exhibited tumor-selective biological activity, tumor growth inhibition and minimal to no toxicity outside of the TME. In addition, the reproducibility of these data, as evidenced by tumor-selective activity observed in preclinical studies with our engineered IL-12 cytokine, XTX301, highlights the potential breadth of application of our GPS platform to multiple structurally diverse cytokines or antibodies.
Leveraging our GPS platform, we intend to develop a number of additional product candidates using a range of tumor targeting approaches, with the goal of achieving a clinically meaningful improvement in their therapeutic index. We also plan to evaluate opportunities for better tolerated and more efficacious combination therapies, using product candidates from across our portfolio with other cancer therapies, to increase the potential for curative regimens in oncology. Beyond oncology, we also plan to apply our GPS platform to other disease areas in which the immune system is dysregulated, such as in autoimmune and inflammatory diseases.