Every year, more than 240,000 people die of colorectal cancer in Europe. In recent years, various methods have been developed to mobilize the immune system against cancer (checkpoint inhibition, CAR-T cells, bispecific antibodies). These achieve impressive success in various tumor entities, but for the majority of patients with colorectal cancer, no immunotherapeutic treatment is available so far. The project CD276xCD3 aims to further develop a novel bispecific antibody called CC-3 with CD276xCD3 specificity and, in particular, to conduct the first clinical evaluation in patients. CC-3 not only binds to the colon cancer cells themselves, but also to the blood vessels of the tumor, thus mediating a "double" antitumor effect. The GMP-compliant production of CC-3 was financed by the Helmholtz Validation Fund. The DKTK-funded project will now enable the first clinical trial to evaluate the safety and efficacy of CC-3 in colorectal cancer patients. The trial will consist of two parts: (i) a dose-escalation part to determine safety and the maximum tolerated dose, and (ii) a dose-expansion part to determine the recommended phase II dose and efficacy. The project is therefore an important step towards the development of a new treatment option for colorectal cancer patients.