Outcomes of immune checkpoint inhibitor rechallenge in relapsed/refractory Hodgkin lymphoma

Immune checkpoint inhibitors (ICIs) have revolutionized therapy for relapsed/refractory (R/R) Hodgkin lymphoma (HL). Some patients discontinue ICIs after initial response or owing to immune-related adverse events (AEs). Efficacy and safety of ICI rechallenge, defined as reintroducing ICIs after previous discontinuation, remain unclear. A systematic literature search was performed through 10 January 2025, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO CRD42023403204). Studies reporting outcomes of ICI rechallenge in patients with R/R HL were included. Data on overall response rate (ORR), complete response (CR) rate, progression-free survival (PFS), and treatment-related AEs were extracted. Pooled response rates and 95% confidence intervals (CIs) were calculated. A total of 207 patients from 17 studies were included. The pooled ORR was 63% (95% CI, 55-70) with a CR rate of 43% (95% CI, 35-52). Median PFS after rechallenge was 13.3 months (95% CI, 7.9-18.8). Any-grade and grade 3 to 5 AEs occurred in 47% (95% CI, 17-80) and 31% (95% CI, 23-40), respectively. ICI rechallenge in R/R classic HL can lead to high response rates and durable remissions comparable with uninterrupted ICI therapy with acceptable safety profiles. This strategy may be a viable option, although careful patient selection and monitoring are still necessary.