Early decrease of blood myeloid-derived suppressor cells during checkpoint inhibition is a favorable biomarker in metastatic melanoma

• DOI: 10.1136/jitc-2023-006802
• Publication Date: 2023-06-07T16:36:57Z
• Authors: Andrea Gaißler; Jonas Bochem; Janine Spreuer; Shannon Ottmann; Alexander Martens; Teresa Amaral; Nikolaus Benjamin...; Manfred Claassen; Friedegund Meier; Patrick Terheyden; Claus Garbe; Thomas Eigentler; Benjamin Weide; Graham Pawelec; Kilian Wistuba-Ha...
• Keywords: Myeloid-derived Suppressor Cell; Immune checkpoint

Background The need for reliable clinical biomarkers to predict which patients with melanoma will benefit from immune checkpoint blockade (ICB) remains unmet. Several different parameters have been considered in the past, including routine differential blood counts, T cell subset distribution patterns and quantification of peripheral myeloid-derived suppressor cells (MDSC), but none has yet achieved sufficient accuracy utility. Methods Here, we investigated potential cellular counts as well several myeloid subsets, using flow cytometry, two independent cohorts a total 141 stage IV M1c before during ICB. Results Elevated baseline frequencies monocytic MDSCs (M-MDSC) were confirmed shorter overall survival (OS) (HR 2.086, p=0.030) progression-free 2.425, p=0.001) whole patient cohort. However, identified subgroup highly elevated M-MDSC that fell below defined cut-off therapy found these had longer OS was similar low frequencies. Importantly, high exhibited skewed certain other did not influence survival, illustrating paramount utility MDSC assessment. Conclusion We general, are associated poorer outcomes ICB metastatic melanoma. one reason an imperfect correlation between outcome individual may be here, rapidly decreasing M-MDSCs on therapy, whom negative effect lost. These findings might contribute developing more predictors late-stage response at level. A multifactorial model seeking such markers yielded only behavior serum lactate dehydrogenase treatment outcome.