THEODORA

The European project THEODORA accelerates the development and clinical evaluation of innovative immunotherapies for Ewing sarcoma, a rare and aggressive form of bone cancer affecting children, adolescents, and young adults. The focus is on immunotherapies targeting so-called neoantigens: tumor-specific genetic alterations that are present in almost all patients with Ewing sarcoma. 

New Treatments for Ewing Sarcoma 

Ewing sarcoma is the second most common bone tumor in adolescents and young adults. For decades, treatment has consisted of a combination of chemotherapy, radiotherapy, and surgery. Especially for patients with an aggressive form of the disease, current treatment remains insufficiently effective. 

The project builds on years of research conducted by Institut Curie into the genetic characteristics of Ewing sarcoma. Based on these discoveries, innovative T-cell immunotherapies are being developed that can specifically recognize and attack tumor cells. 

Within THEODORA, a European master protocol will be established to enable early-stage clinical studies to be initiated more efficiently. The ultimate goal is to obtain the first clinical evidence of the effectiveness of these new immunotherapies in children and adolescents with sarcomas, starting with Ewing sarcoma. 

Two Innovative Clinical Studies 

The program consists of two subprojects. In 2026, the first project will begin: the design and launch of a clinical study on TCR-T cell therapy, using patient-specific T cells that recognize a tumor-specific neoantigen. In 2027, the second project will follow: THEODORA-B, the design and launch of a second clinical study on a therapeutic mRNA vaccine. 

This vaccine contains multiple neoantigens characteristic of Ewing sarcoma and has been developed to train the immune system to prevent disease recurrence in high-risk patients. 

European Collaboration 

The Princess Máxima Center is one of the partners within THEODORA. The Cell and Gene Therapy Unit at the Máxima Center produces the TCR-T cell therapy. In addition, the expertise within the Máxima in the field of Patient-Reported Outcome Measures (PROMs) makes it possible to integrate the patient voice into the clinical evaluation. As a result, not only the effectiveness of treatments is assessed, but also their impact on quality of life.

The collaboration brings together six leading research and patient organizations from four European countries. The project is coordinated by Institut Curie (France).

Funded by the European Union. However, the points of view and opinions expressed are the sole responsibility of their author(s) and do not necessarily reflect those of the European Union or the European Executive Agency for Health and Digital Technology (HaDEA). Neither the European Union nor the authority responsible for granting the subsidy can be held liable for this.