Abstract P129

Radiomic and biological biomarkers in relapsed/ refractory classical Hodgkin Lymphoma: an analysis from the ANIMATE study

Background: The ANIMATE study was a single arm phase II trial in classical Hodgkin lymphoma (cHL) patients fit for transplantation. It was designed to assess response to single-agent nivolumab in patients responding incompletely to first-line relapse chemotherapy. Patients were registered at start of salvage therapy (n=78), with 50% achieving complete metabolic response (CMR) and 31 incomplete responders receiving nivolumab. The overall response (partial metabolic response (PMR) and CMR) to 4-8 doses of nivolumab was 41.9% (80% CI: 29.7-55%). Traditionally, prediction of prognosis at cHL relapse has relied on baseline clinical and laboratory features as well as positron emission tomography (PET) response to initial salvage therapy. In newly diagnosed cHL functional radiomic markers are associated with survival. We assessed radiological and biological biomarkers in ANIMATE with the aim of refining these tools in the era of checkpoint inhibition.

Methods: PET radiomic features (metabolic tumour volume (MTV), total lesion glycolysis and disease dissemination) were assessed at first progression or relapse. Association with PET response and 2-year progression-free survival (PFS) was explored using Logistic regression, Kaplan-Meier survival analysis, Cox regression and survival ROC.

Results: PET features at first progression were neither significantly associated with response nor PFS including MTV pre-salvage (ROC AUC 0.41). We explored this further by assessing patients by PET response after first-line treatment. Patients with CMR or PMR at end of first-line treatment had a better PFS from the time of relapse than patients with progressive metabolic disease (p=0.013 for trend) but responding patients also had higher MTV (p=0.019), probably due to later detection of relapse. This unanticipated finding of higher MTV in patients with better PFS suggests that MTV as a prognostic factor must be considered carefully in the context of relapsed/refractory (R/R) studies. Radiomic analysis of PET0 for nivolumab-treated patients did not reveal any predictive value for response to nivolumab or PFS albeit with small patient numbers (n=30). Data will be presented on the association of PDL1 expression and 9p24 copy number with response to salvage chemotherapy and nivolumab.

Conclusion: Increased MTV is not associated with poorer outcomes in this cohort of R/R cHL patients. Further analysis of radiomics in R/R patients including those treated with checkpoint inhibitors is warr

Authors

Aisling Barrett, Amy A. Kirkwood, Maria Micaela Vidal, Victoria Warbey, Cathy Burton, Sharon Barrans, Tracey Mell, Reuben Tooze, John R Davies, David Westhead, Charlotte Tyson, Emma Lawrie, Laura Clifton-Hadley, Fiona Miall, Rifca LeDieu, Elizabeth H. Phillips, Wendy Osborne, Dominic Culligan, Nimish Shah, Bryson Pottinger, David Cunningham, Ruth Pettengell, Nicolas Martinez-Calle, Peter Johnson, Eve Gallop-Evans, Karl Peggs, Stephen Booth, Arzhang Ardavan, Sally F. Barrington, Graham P. Collins