Comparison of immunohistochemical tests in the CLOVER study by Russian society of clinical oncology

Introduction. The goal of the CLOVER study performed by the Russian Society of Clinical Oncology, was a pairwise comparison of three validated PD-L1 immunohistochemical (IHC) tests (Ventana SP142, Ventana SP263, Dako 22C3) in the patient population with non-small cell lung cancer (NSCLC). This study is the first large Russian comparative study to evaluate PD-L1 expression levels using immunohistochemistry methods.

Materials and methods. The study was conducted on 473 NSCLC samples from Biobank. The IHC tests were carried out with 3 antibody clones. Four trained pathologists independently evaluated the percentage of positively stained tumor cells (TC) and immune cells (IC). To assess the correlation of TC and IC between different runs and the prognostic values of one test for another, a concordant analysis was used.

Results. The number of PD-L1‑positive cells (≥1 %) was higher among IC compared with TC in all three IHC tests. Pearson correlation coefficients (PCC) for TCs were 0.71, 0.87, and 0.75 for 22C3 / SP142, 22C3 / SP263 and SP263 / SP142, respectively. PCC values for ICs were 0.45, 0.61, and 0.68 for the same pairs. A high coincidence of positive and negative results (>91 %) was obtained between the staining with antibodies 22C3 and SP263 of immunooncological agents in the 1st line.

Conclusions. The highest correlation between IHC tests was obtained by pairwise comparison of 22C3 and SP263. Clone 22C3 can be considered as a substitute for SP263 in the first-line treatment of NSCLC. Clone SP142 showed weaker expression in TC and IC compared to the other two tests in patients with non-small cell lung cancer.

1. Rangachari D, Costa DB. From Hope to Reality: Durable Overall Survival With Immune Checkpoint Inhibitors for Advanced Lung Cancer. J Clin Oncol. 2019 Jun 2: JCO1901207. doi: 10.1200/JCO/19.01207. [Epub ahead of print].

2. Garon EB, Hellmann MD, Rizvi NA, Carcereny E, Leighl NB, et al. Five-Year Overall Survival for Patients With Advanced Non‒Small-Cell Lung Cancer Treated With Pembrolizumab: Results From the Phase I KEYNOTE-001 Study. J Clin Oncol. 2019 Jun 2: JCO1900934. doi: 10.1200/JCO.19.00934. [Epub ahead of print].

3. Mok TSK, Wu YL, Kudaba I, Kowalski DM, et al. Pembrolizumab versus chemotherapy for previously untreated, PD-L1 expressing, locally advanced or metastatic non-small-cell lung cancer (KEYNOTE-042): a randomised, openlabel, controlled, phase 3 trial. Lancet. 2019 May 4;393 (10183):1819 – 1830.

4. U. S. Food & Drug Administration. FDA approves pembrolizumab in combination with chemotherapy for first-line treatment of metastatic squamous NSCLC. https://www.fda.gov/drugs/fda-approves-pembrolizumab-combinationchemotherapy-first-line-treatment-metastatic-squamous-nsclc Accessed August 12, 2019.

5. Pai-Scherf L, Blumenthal GM, Li H, Subramaniam S, et al. FDA Approval Summary: Pembrolizumab for Treatment of Metastatic Non-Small Cell Lung Cancer: First-Line Therapy and Beyond. Oncologist. 2017 Nov;22 (11):1392 – 1399.

6. Laktionov K. K., Sarantseva K. A., Breder V. V., Okruzhnova M. A., Peregudova M. V. Immunotherapy for non-small cell lung cancer treatment. Malignant tumours. 2016; (3):17 – 24. (In Russ.).

7. NCCN Clinical Practice Guidelines in Oncology. Non-small cell lung cancer. Version 5.2019. https://www.nccn.org/professionals /physician_gls /PDF /nscl.pdf

8. Rittmeyer A, Barlesi F, Waterkamp D, Park K, et al. Atezolizumab versus docetaxel in patients with previously treated non-small-cell lung cancer (OAK): a phase 3, open-label, multicentre randomised controlled trial. Lancet. 2017 Jan 21;389 (10066):255 – 265.

9. Kazandjian D, Suzman DL, Blumenthal G, Mushti S, et al. FDA Approval Summary: Nivolumab for the Treatment of Metastatic Non-Small Cell Lung Cancer With Progression On or After Platinum-Based Chemotherapy. Oncologist. 2016 May;21 (5):634 – 42.

10. Antonia SJ, Villegas A, Daniel D, Vicente D, et al. Durvalumab after Chemoradiotherapy in Stage III Non-Small-Cell Lung Cancer. N Engl J Med. 2017 Nov 16;377 (20):1919 – 1929.

11. Imyanitov EN, Demidova IA, Gordiev MG, Filipenko ML, et al. Distribution of EGFR Mutations in 10,607 Russian Patients with Lung Cancer. Mol Diagn Ther. 2016 Aug;20 (4):401 – 6.

12. Zavalishina L, Tsimafeyeu I, Povilaitite P, Raskin G, et al. RUSSCO-RSP comparative study of immunohistochemistry diagnostic assays for PD-L1 expression in urothelial bladder cancer. Virchows Arch. 2018 Dec;473 (6):719 – 724.

13. Isobe K, Kakimoto A, Mikami T, Kaburaki K, et al. PD-L1 mRNA expression in EGFR-mutant lung adenocarcinoma. Oncol Rep. 2018 Jul;40 (1):331 – 338.

14. Tsao MS, Kerr KM, Kockx M, Beasley MB, et al. PD-L1 Immunohistochemistry Comparability Study in Real-Life Clinical Samples: Results of Blueprint Phase 2 Project. J Thorac Oncol. 2018 Sep;13 (9):1302 – 1311.

15. Ratcliffe MJ, Sharpe A, Midha A, Barker C, et al. Agreement between Programmed Cell Death Ligand-1 Diagnostic Assays across Multiple Protein Expression Cutoffs in Non-Small Cell Lung Cancer. Clin Cancer Res. 2017 Jul 15;23 (14):3585 – 3591.

16. Hendry S, Byrne DJ, Wright GM, Young RJ, et al. Comparison of Four PD-L1 Immunohistochemical Assays in Lung Cancer. J Thorac Oncol. 2018 Mar;13 (3):367 – 376.

17. Rimm DL, Han G, Taube JM, Yi ES et al. A prospective, multiinstitutional, pathologist-based assessment of 4 immunohistochemistry assays for PD-L1 expression in non-small cell lung cancer. JAMA Oncol. 2017;3:1051 – 1058.

18. Tsimafeyeu I, Imyanitov E, Zavalishina L, et al. Agreement between PDL1 immunohistochemistry assays and polymerase chain reaction in non-small cell lung cancer: CLOVER comparison study. Sci Rep. 2020;10 (1):3928. Published 2020 Mar 3. doi:10.1038/s41