The study is a phase II study open-label for paediatric and young adult patients with first-line Hodgkin lymphoma. I am the lead of the part for the advanced stage patients. We try to incorporate pembrolizumab, an immune checkpoint inhibitor, into the consolidation treatment when patients have a slow early response to initial induction chemotherapy. The aim is to reduce possibly radiotherapy by the addition of an enhancer, therefore saving toxicity and long-term effects for a lot of patients.

What is the study design?

The study design is, as I have a little bit alluded right now, that patients who have a slow early response to chemotherapy receive pembrolizumab, this is an immune checkpoint inhibitor, with the current backbone for consolidation of the EuroNet group together with the pembrolizumab to enhance their responses at the end of chemotherapy.

Patients start with an induction treatment, two cycles of OEPA, then receive an early response PET and only those patients that have a slow early response receive that new medication. After having had four cycles of COPDAC the patients get another late response assessment by PET and only those that are still PET positive at some sites receive radiotherapy to that spot and all others forego radiotherapy but carry on with pembrolizumab maintenance treatment for up to 17 cycles.

What were the results of this study?

Patients in slow early response up to the last evaluation were 84 patients evaluated and 70% of the patients had PET negativity, so a complete metabolic remission, and could forego radiotherapy. Only 30% of the patients received residual node for PET positive spots radiotherapy.

The overall response was 99%, only one patient was progressive, so we are looking forward with this for the observation time to get it very longer if these results are stable.

What do you think is the clinical significance of these results?

We were very happy to enhance the PET negativity after all treatment with the addition of the new compound to the standard treatment with COPDAC. Patients are at advanced stage and all slow early responders in the former studies or in the standard of care arm received radiotherapy at that point so we saved 70% of those young patients from radiotherapy. We are hoping that this might be a stable effect. More time has to elapse but this would hopefully save patients from late effects of radiotherapy from second cancers, cardiovascular disease and so on.