Solid IO is building a new way to personalize cancer treatment, starting with immunotherapies. Our technology shows how a patient’s own tumor and immune cells respond to different treatment options in a human-relevant model. This opens up new possibilities for both cancer drug development and personalized treatment decisions. Immunotherapies are transforming cancer care, but they still work for only a fraction of patients. Today, treatment decisions are made with limited ability to predict who will actually benefit. For patients, this can mean lost time, unnecessary side effects and ineffective treatment. For pharma and biotech companies, the same biological uncertainty makes developing new drugs and combinations slower, riskier and more expensive. Solid IO brings the patient’s own cancer biology into the equation. By testing treatment responses outside the body before treatment, our technology aims to help identify which therapies are most likely to work for an individual patient. At the same time, it can help pharma and biotech companies generate human-relevant evidence, identify responders and develop new therapies and combinations more effectively. Our mission to end guesswork in cancer care. Solid IO was founded in 2025 and is a spinout from the University of Helsinki. We have established technical proof of concept, started clinical feasibility validation, raised €2M in funding, and are already working with our first paying customer.