Abstract P077

Real-World Outcomes of IGEV Salvage Therapy in Relapsed or Refractory Pediatric Hodgkin Lymphoma: Challenges from a Resource-Limited Setting

Background: Outcomes for relapsed or refractory (R/R) pediatric classical Hodgkin lymphoma (HL) remain suboptimal in low- and middle-income countries (LMICs), where access to timely autologous stem cell transplantation (ASCT), immune checkpoint inhibitors, and targeted therapies is often restricted, limiting salvage treatment options. While the ifosfamide, gemcitabine, vinorelbine, and prednisone (IGEV) regimen is recommended as first-line salvage therapy, real-world data from resource-constrained settings remain scarce. We evaluated the efficacy, toxicity, and stem cell mobilization potential of IGEV, with a focus on treatment delays and their impact on outcomes.

Methods: We conducted a retrospective study of children and adolescents (≤18 years) with R/R classical HL treated with IGEV at Children's Cancer Hospital Egypt between August 2021 and December 2022. The response was assessed using FDG PET-CT per EuroNet criteria. Outcomes included overall response rate (ORR), toxicity, stem cell mobilization, event-free survival (EFS), and overall survival (OS).

Results: Forty patients were included (median age 12 years); 37.5% had primary refractory disease, 22.5% early relapse, and 40% late relapse. After two cycles of IGEV, ORR was 70% (CR 42.5%, PR 27.5%). Treatment was well tolerated, with grade 3–4 febrile neutropenia in 22.5% and no treatment-related mortality. Among responders, a substantial proportion experienced disease progression while awaiting stem cell collection or ASCT, with a median time to progression of 5.5 months during delays. Only 7 patients proceeded directly to ASCT after successful CD34+ mobilization. At 2 years, OS was 86% while EFS was 33.7%. Inferior EFS was significantly associated with positive interim PET-CT and with primary refractory or early relapsed disease.

Conclusions: IGEV demonstrates meaningful efficacy and acceptable toxicity as salvage therapy for pediatric R/R HL in LMIC settings. However, survival outcomes are substantially compromised by delays in ASCT, with progression occurring in a significant proportion of responding patients during the waiting period. These findings highlight a critical gap between response and consolidation in resource-limited settings and underscore the urgent need to improve transplant access and expand availability of novel targeted therapies for high-risk patients.

Key words: Hodgkin lymphoma; Pediatric; Relapsed/refractory; IGEV; Low- and middle-income countries