Abstract P074

Outcomes of Second-Line EuroNet Salvage Regimens in Pediatric Patients with Relapsed and Primary Refractory Hodgkin Lymphoma

Background: Since EuroNet-PHL-C1 protocols are standard but real-world data on salvage outcomes in resource-limited settings are scanty. The majority of patients with Hodgkin's lymphoma (HL) are cured with first-line therapy; however, approximately 15% – 25% of patients relapse or become refractory. The importance of chemosensitivity, stage at relapse, time to relapse, and the type of response after salvage chemotherapy and before HDT/ASCT in predicting outcome has been stated in several studies.

Aim: We aim in this study to evaluate the response rates and survival outcomes (PFS/OS) of pediatric patients treated with EuroNet-PHL salvage regimens, and to test the efficacy of IGEV and IEP/ABVD regimens in a large cohort of pediatric Hodgkin lymphoma patients.

Methodology: A retrospective review was conducted on 79 cases of patients between 2019 and 2023 having a relapsed or primary refractory cHL treated at the Children Cancer Hospital of Egypt. Patients were given the EuroNet-PHL recommended salvage regimens such as IGEV or IEP/ABVD regimens. PET-CT using Lugano 2014 criteria, assessed the response after two cycles of chemotherapy.

Result: The 3-year OS was 73.4%. However, PFS at 3 years was merely 26.5% for the whole cohort. For High-Risk patients, the 3-year PFS was 11.4% (95% CI: 5.0-25.9%), for Standard-Risk patients 3-year PFS was 45.3% (95% CI: 26.5-77.5%) while for Low-Risk 3-year PFS was 74.3% (95% CI: 51.7-100%).(p < 0.0001). Surprisingly, all the 6 patients who were low-risk and received radiation therapy relapsed later and underwent ASCT.

Conclusion: The survival outcomes in our cohort were much lower than in international trials, most probably due to non-availability of new agents as PDL1 inhibitors, and delays in stem cell transplantation.