Brentuximab Vedotin Combined with Chemotherapy in the Treatment of Pediatric Patients with R/R Hodgkin Lymphoma: Results of a Real World Setting Study

INTRODUCTION:

Hodgkin Lymphoma (HL) is a familiar malignant lymphoma of the lymphatic system that accounts for 10% of all lymphoma diagnoses and 5% of lymphoma-related deaths. According to statistics, the incidence of HL in children and adolescents (0-19 years old) in China is about 1.78/million, and an average of 569 new cases are estimated annually from 2019 to 2021 . Brentuximab vedotin (BV) is an antibody-drug conjugates (ADC) that selectively delivers monomethyl auristatin E, an antimicrotubule agent, into CD30-expressing cells. Most of the data on the efficacy and safety of BV came from prospective and retrospective studies in adults or foreign children, and there are insufficient data in Chinese children. The purpose of this study is to explore the efficacy and safety of BV Combined with chemotherapy in Chinese pediatric patients with refractory and/or relapsed Hodgkin's lymphoma.

METHODS:

Retrospective analysis of clinical data of 9 children with refractory and/or relapsed Hodgkin's lymphoma from October 2021 to May 2023 at Beijing Children's Hospital, Capital Medical University. Patients were classified according to: clinical stage(Ann Arbor stage), huge tumor, huge tumor in the mediastinum, symptoms of B, and whether multiple lymph nodes were involved. Among them, the low-risk group was IA, ⅡA without giant tumor. The middle risk group was IB and ⅢA without huge tumor. High-risk groups were patients with stage ⅡB, ⅢB, Ⅳ or (each stage) with large tumors, or children with > 4 lymph node regions. All patients received BV in combination with chemotherapy for at least 2 cycles, and patients were assessed for remission response according to the Revised Response Criteria for Malignant Lymphoma at the end of every 2 cycles and followed up until July 20, 2023.

RESULTS:

Totally 32 cycles of chemotherapy were recorded, including 36 doses of BV administration(Table 1). The overall response rate of the children after 2 cycles of treatment was 100%, and the complete response rate was 88.89%. After remission, 2 cases (P1, P2) were treated with BV single drug 1.8mg/kg, Q3W for 6 months, and 3 cases (P3, P4, P7) were treated with radiotherapy. Two patients (P5, P6) received sequential chemotherapy, and two patients (P8, P9) were followed by programmed cell death 1(PD-1) antibody maintenance treatment for 6 months. After receiving PD-1 antibody for 6 months, 1 patient (P9) was transferred to BV monotherapy for maintenance, with 18 times planned. 2 cases (P1, P2) were then treated with autologous stem cell transplantation. None of the children developed disease progression during treatment. All patients successfully completed all planned dosage of BV, and serious adverse events were dominated by grade 3 or higher hematocrit, none of which interfered with normal treatment. Interpretation. BV had demonstrated the better efficacy and tolerable safety profile in the treatment of refractory and/or relapsed Hodgkin's lymphoma in children.

CONCLUSIONS:

BV has been approved by National Medical Products Administration in China since 2020, the clinical cases are mostly from adult lymphoma patients, and children data of in China is rare. In this study, we retrospectively reviewed and analyzed the data of BV combined chemotherapy in the treatment of refractory and relapsed Hodgkin lymphoma from single center, and found that the treatment response was rapid, continuousand safe. However, this study is a single-center retrospective study with a small sample size So We are conducting a prospective study of BV in first-line Hodgkin lymphoma children patients in China and aiming to generate more data for this specific population.