SIOPE ATRT01: An International Prospective Umbrella Trial for Children with ATRT

A new trial, SIOPE ATRT01, has been launched in Belgium in August 2024. SIOPE ATRT01 is an international prospective umbrella trial for children with Atypical Teratoid/Rhabdoid Tumours (ATRT) including a randomized phase III study evaluating the non-inferiority of three courses of high-dose chemotherapy (HDCT) compared to focal radiotherapy (RT) as consolidation therapy. 

ATRT is a very rare type of brain tumour that occurs mainly in very young children and has poor survival rates despite aggressive multimodal treatment approaches. This trial will evaluate and compare the use of RT, which is the most commonly used treatment approach for these patients, with HDCT, trying to increase cure rates and at the same time keeping the side effects as low as possible, including the neuropsychological effects. 

The patients will initially receive at least four, and up to six courses of conventional chemotherapy, followed by 3 different parts of treatment (A, B or C), depending on the treatment groups defined by the children’s age and risk profile. 

The first part, A, involves a randomized trial for children between 12–35 months of age and compares conventional RT (consisting of radio-chemotherapy with 12 courses of chemotherapy and parallel RT) with three courses of HDCT. HDCT is the experimental arm and exists of three courses of HDCT, each consisting of Carboplatin, Thiotepa and autologous stem cell reinfusion. 

Children below 12 months of age will be treated according to part B, consisting of three courses of HDCT, while children above 35 months of age will be treated according to part C, which is the RT group consisting of RT and 12 courses of conventional chemotherapy. In order to investigate the results of parts B and C, a comparison will be made with historical controls (patients from the EU-RHAB registry and other data from the literature). 

The primary objective of this trial is to improve treatment efficacy (in terms of overall survival (EFS)) in ATRT patients, with as secondary objective to evaluate its neurocognitive outcome. 

The international sponsor of the ATRT trial is the German Society for Paediatric Oncology and Haematology (GPOH) of Berlin (Germany). In Belgium, the study is coordinated by the University Hospital of Ghent, with Dr. Leen Willems acting as the national coordinating investigator. Five Belgian paediatric haematology-oncology centres are participating in this trial (UZ Gent, UZ Leuven, CUSL, HUDERF and CHC Montlégia). For Belgium, we expect to recruit 16 patients over a period of 4 years. 

This trial is made possible in Belgium thanks to the financial support of the Foundation against Cancer.