In situ detection of PD1-PD-L1 interactions as a functional predictor for response to immune checkpoint inhibition in NSCLC

Amanda Lindberg; Lars Muhl; Hui Yu; Louise Hellberg; Rebecca Artursson; Jakob Friedrich; Max Backman; Neda Hekmati; Johanna Mattsson; Cecilia Lindskog; Hans Brunnström; Johan Botling; Artur Mezheyeuski; Erika Broström; Miklos Gulyas; Klas Kärre; Johan Isaksson; Patrick Micke; Carina Strell

doi:10.1016/j.jtho.2024.12.026

In situ detection of PD1-PD-L1 interactions as a functional predictor for response to immune checkpoint inhibition in NSCLC

J Thorac Oncol. 2024 Dec 30:S1556-0864(24)02547-4. doi: 10.1016/j.jtho.2024.12.026. Online ahead of print.

Authors

Amanda Lindberg¹, Lars Muhl², Hui Yu¹, Louise Hellberg¹, Rebecca Artursson¹, Jakob Friedrich¹, Max Backman¹, Neda Hekmati¹, Johanna Mattsson¹, Cecilia Lindskog¹, Hans Brunnström³, Johan Botling¹, Artur Mezheyeuski⁴, Erika Broström¹, Miklos Gulyas¹, Klas Kärre⁵, Johan Isaksson¹, Patrick Micke¹, Carina Strell⁶

Affiliations

¹ Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
² Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden; Centre of Cancer Biomarkers CCBIO, Department of Clinical Medicine, University of Bergen, Bergen, Norway.
³ Division of Pathology, Lund University, Lund, Sweden.
⁴ Vall d'Hebron Institute of Oncology, Molecular oncology group, Barcelona, Spain; Vall d'Hebron Institute of Research, Barcelona, Spain.
⁵ Department of Microbiology, Cell and Tumor Biology, Karolinska Institutet, Stockholm, Sweden.
⁶ Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden; Centre of Cancer Biomarkers CCBIO, Department of Clinical Medicine, University of Bergen, Bergen, Norway. Electronic address: carina.strell@igp.uu.se.

PMID: 39743139
DOI: 10.1016/j.jtho.2024.12.026

Abstract

Background: Immune checkpoint inhibitors (ICIs) have transformed lung cancer treatment, yet their effectiveness appears restricted to certain patient subsets. Current clinical stratification based on PD-L1 expression offers limited predictive value. Given the mechanism of action, directly detecting spatial PD1-PD-L1 interactions might yield more precise insights into immune responses and treatment outcomes.

Methods: We applied a second-generation in situ proximity ligation assay (PLA) to detect PD1-PD-L1 interactions in diagnostic tissue samples from 16 different cancer types, a tissue microarray from 352 surgically resected early-stage non-small cell lung cancer (NSCLC) patients, and finally diagnostic biopsies from 242 advanced NSCLC patients with and without ICI treatment. RNAseq analysis was used to identify potential resistance mechanisms.

Results: In the early-stage NSCLC, only about half of the cases with detectable PD-L1 and PD1 expression showed PD1-PD-L1 interactions, with significantly lower levels in EGFR-mutated tumors. Interaction levels varied across cancer types, aligning with reported ICI response rates. In ICI-treated NSCLC patients, higher PD1-PD-L1 interactions were linked to complete responses and longer survival, outperforming standard PD-L1 expression assays. Patients who, despite high PD1-PD-L1 interactions, did not respond to ICIs, showed additional expression of stromal immune mediators (EOMES, HAVCR1/TIM-1, JAML, FCRL1).

Conclusion: Our study proposes a diagnostic shift from static biomarker quantification to assessing active immune pathways, providing more precise ICI treatment. This functional concept applies to tiny lung biopsies and can be used to further immune checkpoints. Accordingly, our results indicate concerted ICI resistance mechanisms, highlighting a need for combination diagnostics and therapies.

Keywords: Immune checkpoint inhibitor (ICI); Programmed cell death protein 1 (PD1); Programmed death-ligand 1 (PD-L1); Proximity ligation assay (PLA); non-small cell lung cancer (NSCLC).