OBJECTIVES: Risk-adapted combined modality treatment has made cHL one of most curable cancers; however, still around 20% of patients experience disease progression after first line therapy. The objective of this study was to summarize the clinical outcomes of treatments for R/R cHL in the UK.

METHODS: An SLR was conducted to identify trials featuring R/R cHL populations, with results stratified according to autologous stem cell transplantation (auto-SCT) status (naïve/ineligible, failed, and mixed) which is a potentially curative treatment. Relevant interventions used in the UK were pembrolizumab, nivolumab, brentuximab vedotin (BV), chemotherapy, and auto-SCT. Eligible studies were identified by searching MEDLINE, Embase, and Cochrane Central Register of Controlled Trials using pre-defined search strategies (up to May 2020), as well as manual searches of major conference proceedings (last two years) and clinicaltrials.gov.

RESULTS: The SLR included 38 unique trials. Inclusion/exclusion criteria varied substantially, especially with respect to lines of prior treatment and auto-SCT status. Trials investigating pembrolizumab (n=6, including one comparative study with BV) and nivolumab (n=4) tended to be in more heavily pretreated patients, although median overall survival (OS) was not reached in any of these studies. Trials of BV were more diverse in terms of prior treatments; median OS ranged from not reached (mixed auto-SCT status) to 40.5 months (auto-SCT failed) and progression-free survival ranged from 4.8 (auto-SCT ineligible) to 11.1 months (mixed auto-SCT status). The chemotherapy and auto-SCT trials generally evaluated these interventions in earlier lines, with a significant proportion of patients in the former going on to receive auto-SCT.

CONCLUSIONS: Despite the introduction of new therapies, unmet need remains for R/R cHL patients in the UK. Significant heterogeneity was observed among the populations of the included trials, particularly with regards to prior treatment. These between study differences pose challenges for conducting comparisons between interventions based on published results.