Second International Inter-Group Study for Classical Hodgkin Lymphoma in Children and Adolescents

The EuroNet-PHL-C2 trial is an international, multicentre, randomised controlled trial with the aims to reduce the indication for radiotherapy in newly diagnosed patients with classical Hodgkin lymphoma without compromising cure rates and to investigate a chemotherapy intensification randomisation in intermediate and advanced classical Hodgkin lymphoma to compensate for reduction in radiotherapy.

EuroNet-PHL-C2 is a comprehensive treatment strategy for all first line classical Hodgkin Lymphoma (cHL) patients under 18 years (under 25 years in UK, Italy and France). The overall strategy is risk stratified (defining chemotherapy) and response adapted (defining radiotherapy) to tailor the amount of treatment to the individual patient and decrease long term complications. * Radiotherapy indication will be restricted. Patients with a negative PET scan after two cycles of OEPA chemotherapy (Early Response Assessment - ERA) will not receive radiotherapy. The threshold for negative PET scan at ERA shifts from the previously used Deauville 1 and 2 = negative (as in the C1 trial) to Deauville 1, 2 and 3 = negative, thereby increasing the number of negative patients without indication for RT. * Chemotherapy Randomisation All intermediate (TL-2) and advanced stage (TL-3) patients will be randomised between respectively 2 or 4 standard COPDAC-28 or intensified DECOPDAC-21 consolidation chemotherapy cycles. To avoid delayed consolidation, randomisation has to be performed before ERA and as soon as the TL-assignment is confirmed by central review. Therefore two randomised sub-studies arise based on the ERA PET response: Patients with adequate response at ERA do not receive radiotherapy - a randomised controlled chemotherapy comparison to show that intensified DECOPDAC-21 consolidation chemotherapy improves EFS as compared to standard COPDAC-28 Patients with inadequate response at ERA - a randomised controlled chemotherapy-radiotherapy comparison - to show that DECOPDAC-21 combined with radiotherapy restricted to sites that remain FDG-PET positive at the end of all chemotherapy (Late response assessment - LRA) has comparable EFS compared to COPDAC-28 plus standard involved node radiotherapy as in the C1 trial. * Risk stratification is refined Former treatment groups (TG) of the EuroNet-PHL-C1 trial are reassigned into treatment levels (TL) by shifting early stage patients (former TG-1) with risk factors into TL-2. * Semi-quantitative 'qPET' Results of semi-quantitative qPET are formally integrated into the response assessment.