Immune Checkpoint Inhibitors Treatment in Children with Relapsed/Refractory Hodgkin Lymphoma

Introduction: Immune checkpoint inhibitors (ICIs) are successfully used for treatment of relapsed/refractory Hodgkin lymphoma (r/r HL) mostly in adults.Here we report our experience of ICIs therapy in children with r/r HL.The aim was to assess effectiveness of ICIs in children and adolescents with r/r HL.Methodology: 14 children aged < 18 years with r/r HL without response to second-line therapy received ICIs (Nivo 3 mg/kg every 2 weeks and Pembro 2 mg/kg every 3 weeks).The response was measured by PET-CT.Results: Before administration of ICIs all 14 patients got intensive second-line chemotherapy, mostly IGEVNo2 and then 5-13 courses (median 5) of brentuximab vedotin (BV), 6 patients (43%) received auto-HSCT.Refractoriness (10 pts) or next relapses (4 pts) became indications for ICIs.The median number of ICIs courses was 9 (range 4-16).No severe side effects were observed.12 children received just ICIs -Nivo (10 pts) or Pembro (2 pts), 2 in combination -Nivo plus BV and Pembro plus chemotherapy.Among 12 patients with mono ICIs 8 (67%) achieved full metabolic response (all after Nivo), none achieved PET-negative response after Pembro (n=3).In two PET-positive patients (Nivo and Pembro) biopsy of PET-positive lesions did not confirm vital tumor.