Granzyme B Degraded Type IV Collagen Products in Serum Identify Melanoma Patients Responding to Immune Checkpoint Blockade

Christina Jensen, Dovile Sinkeviciute, Daniel Hargbøl Madsen, Patrik Önnerfjord, Morten Hansen, Henrik Schmidt, Morten Asser Karsdal, Inge Marie Svane, Nicholas Willumsen


A T-cell permissive tumor microenvironment, characterized by the presence of activated T cells and low fibrotic activity is crucial for response to immune checkpoint inhibitors (ICIs). Granzyme B has been shown to promote T-cell migration through the basement membrane by the degradation of type IV collagen. In this study, we evaluated the biomarker potential of measuring granzyme B-mediated degradation of type IV collagen (C4G) in combination with a fibroblast activation biomarker (PRO-C3) non-invasively for identifying metastatic melanoma patients responding to the ICI ipilimumab. A monoclonal antibody was generated against C4G and used to develop a competitive electro-chemiluminescence immunoassay. C4G and PRO-C3 were measured in pretreatment serum from metastatic melanoma patients (n = 54). The C4G assay was found specific for a granzyme B-generated neo-epitope on type IV collagen. The objective response rate (ORR) was 2.6-fold higher (18% vs. 7%) in patients with high C4G levels (>25th percentile) vs. low levels (≤25th percentile). Likewise, high C4G levels at baseline were associated with longer overall survival (OS) (log-rank, p = 0.040, and hazard ratio (HR) = 0.48, 95%CI: 0.24-0.98, p = 0.045). Combining high C4G with low PRO-C3 correlated with improved OS with a median OS of 796 days vs. 273 days (p = 0.0003) and an HR of 0.30 (95%CI: 0.15-0.60, p = 0.0006). In conclusion, these results suggest that high granzyme B degraded type IV collagen (C4G) combined with low PRO-C3 quantified non-invasively has the potential to identify the responders to ICI therapy.

Original languageEnglish
Issue number10
Publication statusPublished - 28 Sep 2020


  • tumor microenvironment
  • extracellular matrix
  • collagen
  • fibrosis
  • T-cell infiltration
  • biomarker
  • immunotherapy
  • immune checkpoint inhibitor
  • ipilimumab
  • melanoma


Dive into the research topics of 'Granzyme B Degraded Type IV Collagen Products in Serum Identify Melanoma Patients Responding to Immune Checkpoint Blockade'. Together they form a unique fingerprint.

Cite this