Immunotherapy in NSCLC Pathologist role Pimpin Incharoen, M.D. Assistant Professor, Thoracic Pathology Department of Pathology, Ramathibodi Hospital
Genetic alterations in NSCLC Khono et al, Trans Lung Cancer Res, 2015
Immune checkpoint pathway Maintenance of self tolerance in normal physiological conditions Can be dysregulate by tumor cell immune resistance T-cells key antitumor immunity selective recognition of peptides derived from proteins directly recognize and kill antigen-expressing cells orchestrate diverse immune responses
Immune checkpoint pathway + Co-stimulatory _ Inhibitory Pardoll et al, Nat Rev Cancer, 2016
Mechanism of tumor immune reaction Topalian et al, Nature reviews, 2016
Mechanisms for intratumoral PDL1 expression Topalian et al, Nature reviews, 2016
Consistent benefit in OS of Anti-PD-1 drugs Nivolumab Pembrolizumab Atezolizumab 1. Horn et al, J Clin oncol, 2017, 2. Brahmer et al, NEJM, 2016, 3. Rittmeyer et al, Lancet, 2017
Immune checkpoint inhibitors and matching PD-L1 assay Sao MS et al, IASLC 18th World Conference on Lung Cancer
PD-L1 immunohistochemistry (IHC) assays Sao MS et al, IASLC 18th World Conference on Lung Cancer
Goals: To compare analytical performance of 4 assays; 22C3, 28-8, SP142 and SP263 (using staining protocols in corresponding to clinical trials) To compare the treatment-determining scoring algorithm developed for each assays and used in clinical trials
PD-L1 expression on tumor cells
PD-L1 expression on immune cells
Overall percent agreement
Limitation of Blueprint 1 study
Goals of Blueprint phase 2 study
Material (Blueprint phase 2A)
Methods (Blueprint phase 2A)
Statistical Analyses Plan
Summary of Blueprint 2A
Ramathibodi data January 2017 to October 2017 PDL-1 IHC 22C3 assay 64 cases 14 strong positive (TPS 50%) 10 adenocarcinoma 1 squamous cell carcinoma 1 adenosquamous carcinoma 1 NSCLC, NOS 10 weak positive (TPS 1-49%) 40 negative
Scoring guidelines PD-L1 22C3 from DAKO All viable tumor cells on the entire slide must be evaluated Minimum of 100 viable tumor cells Determine percentage of viable tumor cells showing partial or complete membrane staining at any intensity (TPS) Cytoplasmic staining considered as non-specific staining Do not score immune cells
500 FFPE tissue archives establishes concordance between three validated, commercially available PD-L1 IHC diagnostic assays for NSCLC patients; Ventana SP263 (durvalumab), Dako 22C3 (pembrolizumab), and Dako 28-8 (nivolumab) An overall percentage agreement of >90% was achieved between assays at multiple expression cutoffs, including 1%, 10%, 25%, and 50% tumor membrane staining.
Ratcliffe et al, Clin Cancer research, 2017
JTO, November 2017 Serial sections from tissue microarrays from 100 lung adenocarcinomas, stained and scored in four centers. The overall concordances between 22C3 and SP263 data were 0.99
Agilent PD-L1 IHC 22C3 pharmdx and VENTANA PD-L1 (SP263) Assays 22C3 SP263 Reagents/Ab Mouse Monoclonal PD-L1 Rabbit Monoclonal PD-L1 Tissue type FFPE FFPE Preparation and Platform Recommended controls EnVision FLEX visualization system on Agillent Autostainer Link 48 1. Control cell line (+/-) slide 2. Negative reagent control 3. Tissue control (+ and -) Slide thickness 4-5 micron 4-5 microns Maximum storage 6 months 12 months OptiView DAB IHC Detection kit, fully automated on VENTANA Benchmarks 1. No cell line control 2. Negative reagent control 3. Tissue control (+ and -) Counted cells Minimum 100 viable tumor cells No required minimum Apply from Targos webinar, October 2017
Agilent PD-L1 IHC 22C3 pharmdx and VENTANA PD-L1 (SP263) Assays 22C3 SP263 H&E Must be acceptable Must be acceptable Controls Must be acceptable Must be acceptable Counted cells Minimum of 100 No required minimum number of cells Scoring Tumor cells TPS (Tumor Proportion Score) expressed as a % % of tumor cells (TC) Immune cells (Ics) Do not score ICs Do not score ICs Intensity Any perceptable staining (partial or complete) Any intensity above background (partial or complete) Cytoplasmic staining Non-specific staining Non-specific staining Relevant cutoffs 1% 50% 1% 50%
TC >50%
TC <1%
22C3 <1%, SP263 1%
Conclusion Agilent PD-L1 22C3 IHC PharmDx and Ventana PD-L1 (SP263) assays are both approved for selection of patients for treatment with Pembrolizumab. Both assays results in several centers are interpretational high concordant and could be used interchangeably at relevant clinical cutoffs.
Benefit in OS with no known PD-L1 status Nivolumab Pembrolizumab Atezolizumab
Multifactorial biomarkers of clinical response to PD1 pathway blockade Topalian et al, Nature reviews, 2016
The prevalence of somatic mutations across human cancer types Alexandrov et al, Nature, 2013
Pitfalls of using PDL1 IHC as a biomarker test for anti-pd1 PDL1 therapy Focal PDL1 expression may be missed in small biopsy specimens PDL1 expression can vary over time and by anatomical site PDL1 expression in tumor biopsies collected months or years earlier might not accurately reflect PDL1 status at the time of treatment initiation Therapies given after biopsy but before administration of anti- PD1 may alter PDL1 expression PDL1 epitopes detected by some antibodies are potentially unstable with prolonged specimen fixation or inadequate tissue handling
Pitfalls of using PDL1 IHC as a biomarker test for anti-pd1 PDL1 therapy PDL1 can be expressed by multiple cell types within TME, which poses challenges for scoring and interpretation PDL1 expression is not absolutely predictive of response from anti -PD1 drug nevertheless identify patients with a greater likelihood of response, thereby guiding clinical decisionmaking for treatment sequencing