[Clinical study of immune-targeting combined with attenuated chemotherapy in the treatment of children with classic Hodgkin lymphoma].

To evaluate the efficacy and safety of brentuximab vedotin (BV) combined with rituximab and attenuated chemotherapy in the treatment of children with classic Hodgkin lymphoma (cHL). A prospective, non-randomized, risk-assigned study. Clinical data (including age, gender, B symptoms, bulky disease, CD30 and Epstein-Barr virus-encoded RNA(EBER) expression, clinical stage, risk stratification, etc.) of 28 intermediate to high-risk cHL children diagnosed and treated at Beijing Children's Hospital Affiliated to Capital Medical University from October 2022 to May 2024 were collected. Immuno-targeted combined with attenuated chemotherapy was administered based on risk stratification and early treatment response. The patients were followed up until May 1st, 2024. The infusion reactions and adverse reactions after treatment were recorded. In all 28 patients, there were 22 males and 6 females, the age was 12 (5,16) years, 16 cases (57%) presented with bulky disease and 10 cases (36%) with B symptoms. The most common pathological type was nodular sclerosis (14 cases, 50%). There were 7 cases of stage Ⅱ, 14 cases of stage Ⅲ and 7 cases of stage Ⅳ according to the Ann Arbor staging system. There were 5 cases in the intermediate-risk group and 23 cases in the high-risk group. EBER was positive in 20 cases (71%) and negative in 6 cases (21%), and CD30 antigen was expressed in tumor cells of all enrolled children. Treatment duration: 5 cases (18%) received 4 courses of treatment, 21 cases (75%) received 6 courses of treatment, and 2 cases (7%) received 8 courses of treatment, 25 cases (89%) achieved complete metabolism response (CMR) through early assessment after 2 courses of chemotherapy. The CMR rates were 100% in intermediate-risk group and 87% (20/23) in high-risk group, respectively. Four patients (14%) finally received residual field radiotherapy. Toxicities included grade Ⅰ-Ⅱ myelosuppression, early infusion reaction and mild peripheral neuropathy, only one case of grade 3 adverse events was recorded and did not affect sequential treatment. At the end of treatment and 3 months of follow-up, the levels of IgA, IgG and IgM were all decreased compared with the baseline before chemotherapy, and the total B cell count began to be lower than the level before chemotherapy at the early stage of treatment (after 2 courses). The total B cell count monitored during treatment was 50 (0, 101)×10/L and was 12 (0, 25)×10/L at the end of treatment. The follow-up time was 6 (3, 13) months, all 28 children had event-free survival and all achieved complete remission. At 6 and 9 months of follow-up, IgA, IgG, IgM and total B cell counts returned to pre-chemotherapy baseline levels, respectively. BV combined with rituximab attenuated chemotherapy has demonstrated efficacy and a tolerable safety profile in the treatment of cHL in children, and significantly reduce radiation rate.