Validated Immunohistochemistry Assay Research Articles

Best practices for achieving consensus in HER2-low expression in breast cancer: current perspectives from practising pathologists.

Human epidermal growth factor receptor 2 (HER2) expression is an important biomarker in breast cancer (BC). Most BC cases categorised as HER2-negative (HER2-) express low levels of HER2 [immunohistochemistry (IHC) 1+ or IHC 2+/in-situ hybridisation not amplified (ISH-)] and represent a clinically relevant therapeutic category that is amenable to targeted therapy using a recently approved HER2-directed antibody-drug conjugate. A group of practising pathologists, with expertise in breast pathology and BC biomarker testing, outline best practices and guidance for achieving consensus in HER2 IHC scoring for BC. The authors describe current knowledge and challenges of IHC testing and scoring of HER2-low expressing BC and provide best practices and guidance for accurate identification of BCs expressing low levels of HER2. These expert pathologists propose an algorithm for assessing HER2 expression with validated IHC assays and incorporate the 2023 American Society of Clinical Oncology and College of American Pathologist guideline update. The authors also provide guidance on when to seek consensus for HER2 IHC scoring, how to incorporate HER2-low into IHC reporting and present examples of HER2 IHC staining, including challenging cases. Awareness of BC cases that are negative for HER protein overexpression/gene amplification and the related clinical relevance for targeted therapy highlight the importance of accurate HER2 IHC scoring for optimal treatment selection.

Abstract 6143: Association of polygenic risk score and prostate tumor biomarkers with lethal prostate cancer

Abstract Prostate cancer (PCa) is a highly heritable cancer. While polygenic risk scores (PRS) stratify overall PCa risk among cancer-free men, they have not been reported to predict lethal outcomes in PCa patients. We aimed to examine to what extent PRS modifies associations between tumor biomarkers with cancer prognosis after diagnosis. We included men with primary, non-metastatic PCa in the Health Professionals Follow-up Study (HPFS) and Physicians’ Health Study (PHS). The PRS was constructed with 451 risk variants identified from prior PCa GWAS, measured on DNA from blood or buccal, standardized by adjusting for mean and standard deviation (SD) based on men without PCa with array-based genotyping data in HPFS/PHS. Prostate tumor biomarkers of molecular subtypes (TMPRSS2:ERG fusion, PTEN loss, and TP53 missense mutations from validated immunohistochemistry assays), insulin/lipid signaling pathways (FASN, IR, and IGF1-R), and cellular proliferation and tumor microenvironment (Ki-67, apoptosis rates, and angiogenesis) were measured on tumor tissue from radical prostatectomy or TURMP. Sample sizes varied by tumor biomarkers, ranging from 214 for angiogenesis markers to 598 for ERG protein expression. We first used either logistic or negative binomial regression to evaluate the association between the PRS and the protein expression (levels) of each individual biomarker, and then evaluated the addition of multiplicative interaction terms between PRS and biomarkers to logistic regression models for lethal PCa, defined as metastases or death from PCa. Lastly, we evaluated the predictive performance for lethal PCa by area under the curve (AUC). All models adjusted for age at diagnosis and Gleason score. Among all patients included in the analysis, the median age at diagnosis was 66 (interquartile range: 62-70) years, with 20% having a Gleason score≥8 and 10% having lethal PCa. PRS showed no association with lethal PCa (OR per SD increase PRS=0.95, 95%CI 0.85-1.06) or most tumor biomarkers, except for the apoptosis index (per SD in PRS corresponding to 0.22 units increase, 95%CI 0.02-0.42). Statistically significant interactions were found between PRS and p53 overexpression (p interaction = 1.6x10-5), PTEN loss (p=3.7x10-3), FASN (p=0.03), and Ki-67 (p=1.6x10-3), suggesting that compared to men with a PRS higher than the median, TP53 missense mutation, PTEN loss, higher FASN intensity, and higher Ki-67 indices were more strongly associated with lethal PCa in patients with lower PRS. Incorporating PRS with tumor biomarkers into predictive models enhanced the AUC beyond a model with tumor biomarker and age. The largest improvements were observed when combining the PRS with Ki-67 and apoptosis, showing absolute increases of 5% and 7% respectively. In conclusion, PRS integration with tumor biomarkers at diagnosis potentially improves the prediction of lethal PCa, thereby informing more targeted management strategies. Citation Format: Anqi Wang, Anna Plym, Konrad H. Stopsack, Lorelei A. Mucci, Kathryn L. Penney. Association of polygenic risk score and prostate tumor biomarkers with lethal prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6143.

Immunohistochemistry-Based Biomarkers and Impact on Outcomes Following Salvage Radiotherapy for Prostate Cancer.

Salvage radiation therapy (SRT) is a mainstay of treatment for prostate cancer patients who experience biochemical relapse following radical prostatectomy. We sought to characterize the prognostic impact of previously identified deleterious molecular phenotypes-loss of PTEN, ERG expression, and p53 mutation- upon survival in patients undergoing SRT. We analyzed an institutional database of 320 patients treated with SRT for whom prostatectomy tissue was available; tissue microarrays (TMAs) were constructed and used for genetically validated immunohistochemistry assays for PTEN, ERG, and p53. Chi-squared and Mann-Whitney's tests were used to assess association between molecular expression and clinical risk factors for adverse survival. Uni- and multivariate Cox-proportional hazards models were constructed to determine effects on biochemical (bRFS) and metastasis-free survival (MFS), calculated from end of SRT to event. Loss of PTEN (n = 123, 50%) and ERG expression (n = 118, 39.1%) were common, while p53 overexpression (signifying TP53 missense mutation) was less common (n = 21, 6.6%). On univariate Cox regression, loss of PTEN portended worse bRFS [HR 1.86; 95% CI 1.36-2.57] and MFS [HR 1.89; 1.21-2.94], with homogeneous loss associated with particularly worse MFS [HR 2.47; 1.54-3.95]. Similarly, p53 overexpression predicted worse bRFS [HR 1.95; 1.14-3.32] and MFS [HR 2.79; 1.50-5.19]. ERG expression was associated with only worse MFS [HR 1.6; 1.03-2.48]. On multivariate analysis adjusting for known prognostic features (grade, nodal involvement, pathologic stage, androgen deprivation therapy (ADT), and PSA velocity), homogeneous PTEN loss remained predictive of adverse bRFS [HR 1.73; 1.06-2.82] and MFS [HR 2.35; 1.04-5.34]. PTEN loss identified by immunohistochemistry is an independent adverse prognostic factor for both biochemical and metastasis-free survival in prostate cancer patients treated with SRT. Although clinically validated RNA expression assays also exist which are prognostic for outcomes following SRT, stromal contamination in bulk RNA could mask "loss" signals specific to tumor cells, such as PTEN. Further work is necessary to determine the optimal approach to treating patients with poor molecular prognostic features in a salvage setting.

A phase I/II dose escalation and expansion trial to evaluate safety and preliminary efficacy of BNT141 in patients with claudin-18.2-positive solid tumors.

TPS2670 Background: Claudin-18.2 (CLDN18.2), whose expression is normally restricted to short-lived gastric epithelial cells, is ectopically expressed in tumors with unmet needs such as gastric, gastroesophageal junction (GEJ), pancreatic, ovarian, and biliary tract tumors. CLDN18.2 has thus emerged as a promising target for therapeutic antibody development. BNT141 is a novel RNA-based therapeutic that comprises two pseudouridine-modified mRNAs encapsulated in lipid nanoparticles. Upon intravenous injection, BNT141 is preferentially taken up by the liver where RNAs are translated and released into the circulation as fully assembled anti-CLDN18.2 antibodies. The resulting antibody is sequence identical to IMAB362, a CLDN18.2-targeted antibody that provided clinical benefit as an add-on to chemotherapy in the Phase III SPOTLIGHT trial (Shitara et al. J Clin Oncol. 2023). RNA-encoded antibodies can be developed more rapidly compared with recombinant antibodies and have the potential for favorable PK/PD properties and improved tolerability. Methods: This is a Phase I/II, open-label, multisite, dose escalation and expansion trial to examine safety, efficacy, and PK/PD of BNT141 in patients with CLDN18.2+ tumors (NCT04683939). The trial comprises 3 parts: dose escalation with BNT141 as monotherapy, dose escalation with BNT141 in combination with nab-paclitaxel and gemcitabine, and dose expansion. For monotherapy dose escalation, patients with CLDN18.2+ gastric, GEJ, pancreatic, mucinous ovarian, and biliary tract cancers who have exhausted or are ineligible for the current standard of care are eligible. CLDN18.2 positivity is defined as intermediate/strong staining intensity in ≥50% of tumor cells evaluated using a validated immunohistochemistry assay. Doses of BNT141 are escalated in up to 8 planned dose levels (DLs) until the maximum tolerated dose (MTD) is reached. For combination dose escalation, patients with advanced CLDN18.2+ pancreatic adenocarcinoma or cholangiocarcinoma who are eligible for treatment with nab-paclitaxel/gemcitabine will be included. Combination therapy will start at the first safe DL where the target antibody concentration is reached during monotherapy. Combination dose escalation will continue in parallel with the monotherapy part and will define the recommended Phase II dose (RP2D). For both parts, up to 10 additional patients may be enrolled at the MTD level to collect further safety and PK/PD data. For dose expansion, 2 cohorts of patients with CLDN18.2+ pancreatic adenocarcinoma or cholangiocarcinoma will receive combination therapy (nab-paclitaxel/gemcitabine) together with BNT141 at the defined RP2D. The study was initiated in January 2022 and recruitment is ongoing in the USA and Canada. Sites in Spain, Portugal, Germany, Denmark, Netherlands and the UK will be opened in 2023. Clinical trial information: NCT04683939 .

Abstract 2763: Characterization of a novel immunohistochemistry (IHC) assay for CEACAM5 using a commercial antibody

Abstract Introduction: Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) is expressed on the surface of some tumor epithelial cells and is a potential therapeutic target for antibody-drug conjugates such as tusamitamab ravtansine in development. An IHC assay has been fit-for-purpose validated in non-small cell lung cancer (NSCLC) for evaluation of clinical samples using a proprietary CEACAM5-specific murine antibody (Sanofi clone 769) and the Dako/Agilent Autostainer Link 48 platform. Here we compare 5 commercial antibody clones to the validated IHC assay for CEACAM5. Methods: We tested 5 commercial clones (CI-P83-1 [Santa Cruz Biotechnology], 487609 [R&D Systems], OTI1D4 [Thermo Fisher], EPCEAR7 [Abcam], and 327 [Sino Biological]) to evaluate CEACAM5 detection in formalin-fixed, paraffin-embedded (FFPE) human cancer tissues from Discovery Life Sciences using the Leica BOND III platform. The staining pattern and intensity of CEACAM5 reactivity were compared for clone 769 and the commercial clones in the same FFPE samples. Initial IHC testing used gastric cancer tissues with continued assay development in colorectal cancer tissues. Commercially available (HT-29, MKN-45, BxPC-3, and PC-3) cell lines and CHO cells overexpressing other CEACAM targets (Sanofi) were used to test for cross reactivity and specificity. IHC staining in cell line controls and human cancer tissues (small cell lung cancer, NSCLC adenocarcinoma, squamous cell NSCLC, and pancreatic cancer), was performed to further evaluate staining accuracy to CEACAM5 and to better compare clones. Results: Of the 5 antibodies tested, 3 were deemed unsatisfactory due to diffuse cytoplasmic staining or overstaining and were not evaluated further. Clones CI-P83-1 and 487609 best matched the pattern and intensity of clone 769 staining and were evaluated at various dilutions in gastric and colorectal cancer samples to determine optimal antibody concentration and to demonstrate range and linearity of the IHC assays. Clones CI-P83-1 and 487609 accurately and specifically detected CEACAM5 without cross reactivity to similar targets in cell lines. In the human cancer tissues, clone CI-P83-1 tended to show greater parity to clone 769 than clone 487609, which sometimes showed slightly higher CEACAM5 signal than clone 769. Clone CI-P83-1 was appropriately reactive in CEACAM5 expression control cells, highly reactive in CHO cells overexpressing CEACAM5, and lacked cross reactivity in CHO cells overexpressing CEACAM types 1, 6, 7, or 8. A fit-for-purpose validation of clone CI-P83-1 in non-squamous NSCLC with clone 769 showed comparable staining in this indication. Conclusions: Among the 5 tested clones, there were differences in staining pattern, intensity, and cross reactivity. CI-P83-1 was the closest to 769 among the 5 clones. Further testing and validation are required to understand the finer differences between 769 and CI-P83-1. Citation Format: Chin Leng Cheng, Hongli Chen, Karen Kirchner, Gregory Cesarone. Characterization of a novel immunohistochemistry (IHC) assay for CEACAM5 using a commercial antibody [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2763.

Genotype-to-Phenotype Associations in the Aggressive Variant Prostate Cancer Molecular Profile (AVPC-m) Components.

Simple SummaryWe treat prostate cancer like it is one disease, but it is clear that it behaves like different diseases in different patients, with some having excellent responses to hormonal therapies and prolonged survivals, and others having virulent, aggressive courses and short survivals. These differences reflect different tumor biologies and therapeutic sensitivities, but the absence of molecular markers that identify each of these subsets makes it difficult to develop treatments specific to each. We found that alterations in two or more of the tumor suppressors TP53, RB1 and PTEN characterize the more virulent prostate cancers, and that patients with this molecular profile (called the aggressive variant prostate cancer molecular profile) appear to benefit more from combination chemotherapies than those without. The alterations in these markers can be determined either by staining tumor tissues or by examining their DNA. In this study, we used 28 mouse models of the human disease to assess the performance of various assays in determining these alterations. We found that although both staining and DNA sequencing are complementary, staining (which is a broadly available technique) is likely sufficient to make these determinations. Our results will inform the use of this molecular signature in clinical research and clinical practice.The aggressive variant prostate cancer molecular profile (AVPC-m), composed of combined defects in TP53, RB1 and PTEN, characterizes a subset of prostate cancers linked to androgen indifference and platinum sensitivity. To contribute to the optimization of the AVPC-m assessment for inclusion in prospective clinical trials, we investigated the status of the AVPC-m components in 28 patient tumor-derived xenografts (PDXs) developed at MDACC. We subjected single formalin-fixed, paraffin-embedded (FFPE) blocks from each PDX to immunohistochemistry (IHC), targeted next-generation genomic sequencing (NGS) and Clariom-S Affymetrix human microarray expression profiling. Standard validated IHC assays and a 10% labeling index cutoff resulted in high reproducibility across three separate laboratories and three independent readers for all tumor suppressors, as well as strong correlations with loss-of-function transcriptional scores (LOF-TS). Adding intensity assessment to labeling indices strengthened the association between IHC results and LOF-TS for TP53 and RB1, but not for PTEN. For TP53, genomic alterations determined by NGS had slightly higher agreement scores with LOF-TS than aberrant IHC, while for RB1 and PTEN, NGS and IHC determinations resulted in similar agreement scores with LOF-TS. Nonetheless, our results indicate that the AVPC-m components can be assessed reproducibly by IHC using various widely available standardized assays.

Phase 1a/b open-label study of IK-175, an oral AHR inhibitor, alone and in combination with nivolumab in patients with locally advanced or metastatic solid tumors and urothelial carcinoma.

TPS3169 Background: Aryl Hydrocarbon Receptor (AHR) is a ligand-activated transcription factor that regulates the activity of multiple innate and adaptive immune cells. Kynurenine, generated from tryptophan by IDO1 and TDO2, is a ligand that binds AHR and leads to a net immunosuppressive tumor microenvironment, making AHR an attractive therapeutic target in multiple cancer types. IK-175 is a selective, small molecule inhibitor of AHR being developed as an oral agent. In preclinical mouse tumor models, IK-175 demonstrates antitumor activity as a single agent or in combination with checkpoint inhibitors. AHR immunohistochemistry (IHC) tumor microarray analysis across 15 different tumor types revealed that bladder cancer has the highest level of AHR protein expression and nuclear localization indicative of ligand-bound and active AHR signaling. Therefore, nuclear AHR in urothelial carcinoma tumors is being investigated for potential predictive clinical benefit with IK-175. Methods: This is a first-in-human, phase 1a/b, open-label, multicenter, dose-escalation and expansion study of IK-175 as a single agent and in combination with nivolumab. The primary objectives are to determine the maximum tolerated dose (MTD) and/or maximum administered dose (MAD), identify the recommended phase 2 dose (RP2D), and evaluate the safety and tolerability of IK-175 alone and in combination with nivolumab. Secondary objectives are to evaluate the pharmacokinetics (PK) of IK-175, evaluate pharmacodynamic (PD) immune effects, and assess preliminary antitumor activity. Key exploratory objectives are to evaluate the PD effects on peripheral immune cells and target gene expression, to assess candidate baseline biomarkers, and correlative analyses of tumor AHR nuclear localization with clinical response. The study is exploring tumor AHR nuclear localization by IHC as a predictive biomarker in patients with urothelial carcinoma. A minimum of 10 patients with a positive AHR nuclear localization test (cutoff for positive AHR is 65% tumor cells positive for 2+/3+ nuclear AHR by a validated IHC assay) will be enrolled in the combination arm. IK-175 is administered daily in 21 or 28 day-cycles as a single agent, and in combination with nivolumab (480 mg q4w on Day 1 of every cycle), in adult patients with advanced solid tumors (dose escalation) and urothelial carcinoma (dose expansion). Key eligibility criteria include patients with histologically confirmed solid tumors (including urothelial carcinoma) who have locally recurrent or metastatic disease that have progressed on or following all standard of care therapies deemed appropriate by the treating physician including prior checkpoint inhibitors. Estimated enrollment is 93 patients; the study began in January 2020 and is ongoing. Clinical trial information: NCT04200963.

Abstract P5-08-01: Globo H: A Globo series glycosphingolipid target antigen in breast cancer

Abstract Cancer cells may be differentiated from normal cells by the surface expression of unusual glycosylation patterns: tumor-associated carbohydrate antigens (TACAs) may be expressed as membrane-bound glycoproteins or glycolipids. Differential expression of TACAs in multiple cancer types represents a potential therapeutic target for anticancer therapies. At least 16 different types of epithelial cancers have been found to be Globo H–positive, with 60% to 65% of patients with breast cancer having Globo H–positive tumors. It has been shown that tumor-infiltrating lymphocytes in breast cancer tissues could take up Globo H ceramide (GHCer) released by tumor cells masking cancer cells from immune surveillance through the suppression of Notch 1 signaling. Globo series antigens, including Globo H and stage-specific embryonic antigen 4 could associate with the FAK/CAV1/AKT/RIP complex to trigger the downstream β-catenin signaling pathway to promote tumor cell survival. Moreover, exogenous addition of GHCer promoted tumor cell migration. Thus, treatment-mediated depletion of GHCer may overcome the immunosuppressive mechanism of cancer cells, with resulting decreases in tumor cell survival and migration. OBI Pharma, Inc., in collaboration with NeoGenomics, has developed a validated immunohistochemistry assay to measure the expression of Globo H in clinical specimens. The intensity and extent of Globo H expression are determined microscopically using the histochemical scoring system (H-score), defined as the sum of the products of the staining intensity (score of 0-3) multiplied by the percentage of cells (0-100) stained at a given intensity. To date, 420 patients with triple-negative breast cancer (TNBC) have been screened across 4 separate clinical trials. Of those patients, 173 (41%) had an H-score of ≥15, with a median H-score of 70. Of the 173 patients with an H-score of ≥15, 69 (40%) had an H-score of ≥100. Adagloxad simolenin (AS/OBI-822) is a Globo H conjugate vaccine that when administered in combination with the adjuvant OBI-821 results in anti–Globo H IgM and IgG humoral immune responses. These responses have been assessed in all clinical trials of AS/OBI-821 to date. In the early trials that administered up to 9 doses, early and robust IgM responses were noted but with delayed and lower-titer IgG responses. When the number of doses was increased to 9-12 doses over an extended time (up to either 37 or 68 weeks), it became apparent that the peak IgG titers occurred at around the time of the last AS/OBI-821 dose. The time course for the development of anti–Globo H IgM and IgG humoral responses showed that following injection, anti–Globo H IgM and IgG antibody titers demonstrated a geometric mean ratio (GMR) increase of 10.26 and 12.47, respectively, from almost nondetectable levels at baseline. The GMR in the placebo group remained low in comparison. Mean time to peak titer was approximately 4 weeks for IgM and 40 weeks for IgG. These data were employed in the design of the phase 3, randomized, open-label study of the anti–Globo H vaccine AS/OBI-821 in the adjuvant treatment of patients with high-risk, early-stage Globo H–positive TNBC (The GLORIA Study). To enter the GLORIA study, patients must have a centrally confirmed Globo H IHC H-score of ≥15, and it is anticipated that approximately 40% of patients screened will have this level of expression. The GLORIA study is presently enrolling patients in 7 countries, with another 9 countries anticipated to begin recruiting in 2021. Citation Format: Darren S. Sigal, Apostolia Maria Tsimberidou, I-Ju Chen, Pei Hsu, Tillman Pearce. Globo H: A Globo series glycosphingolipid target antigen in breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-08-01.

Biomarker analyses in the phase III ASCENT study of sacituzumab govitecan versus chemotherapy in patients with metastatic triple-negative breast cancer

The pivotal phase III ASCENT trial demonstrated improved survival outcomes associated with sacituzumab govitecan (SG), an anti-trophoblast cell-surface antigen 2 (anti-Trop-2) antibody-drug conjugate linked with the topoisomerase-inhibitor SN-38, over single-agent chemotherapy treatment of physician's choice (TPC) in previously treated metastatic triple-negative breast cancer (mTNBC). This prespecified, exploratory biomarker analysis from the ASCENT trial evaluates the association between tumor Trop-2 expression and germline BRCA1/2 mutation status with clinical outcomes. Patients with mTNBC refractory to or progressing after two or more prior chemotherapies, with one or more in the metastatic setting, were randomized to receive SG (10 mg/kg intravenously days 1 and 8, every 21 days) or TPC (capecitabine, eribulin, vinorelbine, or gemcitabine) until disease progression/unacceptable toxicity. Biopsy or surgical specimens were collected at study entry to determine Trop-2 expression level using a validated immunohistochemistry assay and histochemical scoring. Germline BRCA1/2 mutation status was collected at baseline. Of 468 assessable patients, 290 had Trop-2 expression data [64% (n= 151 SG) versus 60% (n= 139 TPC)] and 292 had known BRCA1/2 mutation status [63% (n= 149 SG) versus 61% (n= 143 TPC)]. Median progression-free survival in SG- versus TPC-treated patients was 6.9, 5.6, and 2.7 months versus 2.5, 2.2, and 1.6 months for high, medium, and low Trop-2 expression, respectively. Median overall survival (14.2, 14.9, and 9.3 months versus 6.9, 6.9, and 7.6 months) and objective response rates (44%, 38%, and 22% versus 1%, 11%, and 6%) were numerically higher with SG versus TPC in patients with high, medium, and low Trop-2 expression, respectively. Efficacy outcomes were numerically higher with SG versus TPC in patients with and without germline BRCA1/2 mutations. SG benefits patients with previously treated mTNBC expressing high/medium Trop-2 compared with standard-of-care chemotherapy and regardless of germline BRCA1/2 mutation status. The small number of patients with low Trop-2 expression precludes definitive conclusions on the benefit of SG in this subgroup.

A phase 1b, open-label, single-arm study of cofetuzumab pelidotin (a PTK7-targeting antibody-drug conjugate) in patients with PTK7-expressing, recurrent non-small cell lung cancer (NSCLC).

TPS3142 Background: Protein tyrosine kinase 7 (PTK7) is a highly conserved receptor tyrosine kinase involved in the Wnt signaling pathway and is overexpressed in multiple cancer types, including non-small cell lung cancer (NSCLC). Cofetuzumab pelidotin (ABBV-647) is an anti-PTK7 antibody-drug conjugate comprising the hu6MO24 monoclonal antibody, a cleavable cysteine-reactive linker, and Aur0101 (an auristatin microtubule inhibitor). It has shown promising preclinical anti-tumor effects (Damelin et al. Sci Transl Med 2017;9[372]:eaag2611) and clinical activity with a manageable safety profile in a Phase 1 study in patients with advanced solid tumors, with promising anti-tumor activity noted in NSCLC (Sachdev et al. DOI: 10.1200/JCO.2018.36.15_suppl.5565). Methods: This open-label, single-arm, multicenter Phase 1b study (NCT04189614) will assess the anti-tumor activity and safety of cofetuzumab pelidotin in approximately 40 patients with PTK7-expressing, recurrent NSCLC. The primary objective is to assess the objective response rate of cofetuzumab pelidotin according to Response Evaluation Criteria in Solid Tumors version 1.1. Secondary objectives include the duration of response, progression-free survival, overall survival, and safety and tolerability. Pharmacokinetic and biomarker samples will also be collected throughout for analysis. Patients must be aged ≥18 years with an Eastern Cooperative Oncology Group performance status of 0–1 and have recurrent histologically confirmed NSCLC with PTK7-expressing tumor (using a validated immunohistochemistry assay). Patients must have progressed after treatment with a platinum-based chemotherapy doublet and an immune checkpoint inhibitor (for tumors without targetable genetic alterations), or a platinum-based chemotherapy doublet and targeted agent(s) (for tumors with targetable genetic alterations). Patients must also have received ≤2 prior lines of systemic therapy (≤3 prior lines for tumors treated with targeted agent[s] for genetic alterations), including no more than 1 line of systemic chemotherapy. Cofetuzumab pelidotin (2.8 mg/kg) is administered intravenously every 3 weeks until the patient experiences disease progression, intolerable toxicity, or other study treatment discontinuation criteria are met. The study commenced on February 13, 2020 and enrollment is ongoing. Clinical trial information: NCT04189614.

Abstract GS3-06: Biomarker evaluation in the phase 3 ASCENT study of sacituzumab govitecan versus chemotherapy in patients with metastatic triple-negative breast cancer

Abstract Background: Trophoblast cell-surface antigen-2 (Trop-2) is highly expressed in many epithelial tumors, including triple-negative breast cancer (TNBC). Sacituzumab govitecan (SG) is an antibody-drug conjugate composed of an anti-Trop-2 antibody coupled to SN-38, an active metabolite of irinotecan, via a unique hydrolyzable linker that allows for SN-38 release intracellularly and in the tumor microenvironment (bystander effect). Preclinical studies have shown a great range of efficacy with SG in mice bearing tumors with low, moderate, and high Trop-2 expression levels. We report subgroup analyses by Trop-2 expression from ASCENT, a randomized, phase 3 confirmatory study of SG versus standard-of-care chemotherapy in patients with metastatic TNBC (mTNBC). Methods: In the global, multicenter, open-label, phase 3 ASCENT study (NCT02574455), 529 patients with mTNBC refractory to or relapsing after at least 2 prior chemotherapies were randomized 1:1 to receive SG (10 mg/kg intravenously on days 1 and 8 every 21 days) or single-agent treatment of physician’s choice (capecitabine, eribulin, vinorelbine, or gemcitabine) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) measured by central independent review per RECIST v1.1. Secondary endpoints included objective response rate (ORR) per RECIST v1.1, duration of response, overall survival (OS), and safety. Exploratory endpoints included biomarker assessments, including Trop-2 and BRCA1/2. Trop-2 expression was assessed using a validated immunohistochemistry assay. Results: Subgroup analyses by biomarker expression including Trop-2 and BRCA1/2 were performed, and outcomes by PFS, OS, ORR, and safety results will be reported. Conclusions: These analyses will provide further insights into the relationship of Trop-2 expression and the activity of SG in previously treated patients with mTNBC. Citation Format: Sara A. Hurvitz, Sara M. Tolaney, Kevin Punie, Delphine Loirat, Mafalda Oliveira, Kevin Kalinsky, Amelia Zelnak, Philippe Aftimos, Florence Dalenc, Sagar Sardesai, Erika Hamiltion, Priyanka Sharma, Sabela Recalde, Eva Ciruelos Gil, Tiffany Traina, Joyce O'Shaughnessy, Javier Cortés, Michaela Tsai, Linda Vahdat, Véronique Diéras, Lisa Carey, Hope S. Rugo, David M. Goldenberg, Quan Hong, Martin Olivo, Loretta M. Itri, Aditya Bardia. Biomarker evaluation in the phase 3 ASCENT study of sacituzumab govitecan versus chemotherapy in patients with metastatic triple-negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr GS3-06.

Abstract 2946: The prevalence of Globo H in different tumor types: Breast, pancreatic, lung, gastric, colorectal, liver, and esophageal cancers

Abstract Background: Globo H (GH) is a hexassacharide glycosphingolipid overexpressed on tumor epithelial cells in several cancer types. Ongoing clinical trials of GH-targeting drugs include therapeutic vaccines, a monoclonal antibody, and an antibody drug conjugate. Consequently, the level of GH expression may provide a critical biomarker for appropriate patient selection. We present the prevalence of GH expression in various human cancers using a validated immunohistochemistry (IHC) assay. Methods: A validated IHC assay was used to analyze a total of 562 specimens across 7 cancer types, including breast (131), lung (77), colorectal (75), gastric (73), pancreatic (72), liver (70), and esophageal cancer (64) specimens. Anti-GH monoclonal antibody (VK9) was used for IHC staining. GH expression level was assessed by certified pathologists, and results are presented using an H-score system (0 to 300). The H-score was calculated as: H-score = (% of weak intensity x 1) + (% of moderate intensity x 2) + (% of strong intensity x 3). Results: Among the specimens tested, pancreatic cancer had the highest median H-score of 90.0 (range 0-300) with a 76.4% prevalence using cutoff of H-score ≥ 1, while liver cancer had the lowest median H-score of 0.0 (range 0 to 80) with a 17.1% prevalence. Using an H-score of 100 as a cutoff [approved in the Investigational Device Exemption (IDE) application as a pre-screening criterion of GH monoclonal antibody in the Phase 2 clinical trial OBI-888-001 (NCT03573544)], the GH prevalence of the pancreatic, esophageal, gastric, breast, lung, colorectal, and liver cancers are 50%, 17.2%, 24.7%, 13%, 10.4%, 16%, and 0%, respectively. In addition, subtypes of each cancer differ in expression profile. While immune cells are typically GH negative, some GH-positive immune cells were observed in the intra- or peri-tumor region, suggesting the shedding of GH to tumor-surrounding or infiltrated immune cells. Conclusions: Overexpression of GH in human pancreatic, gastric, lung, colorectal, esophageal, and breast tumors renders GH a potential therapeutic target for these cancers. Furthermore, the presence of GH-positive immune cells in the intra- or peri-tumor region lends support to the proposed mechanism of cancerous cells shedding GH-ceramide to suppress normal immune functions. The heterogeneous expression of GH among different molecular subtypes may provide a biomarker in the selection of patients for GH-directed therapies. The GH IHC assay has now been validated for use and the IDE approved by the FDA for patient screening. Citation Format: I-Ju Chen, Ming-Chen Yang, Yu-Jung Chen. The prevalence of Globo H in different tumor types: Breast, pancreatic, lung, gastric, colorectal, liver, and esophageal cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2946.

PTEN Loss with ERG Negative Status is Associated with Lethal Disease after Radical Prostatectomy.

Few groups have investigated the combined effects of PTEN loss and ERG expression on the outcomes of metastasis of or death from prostate cancer in surgically treated patients. We examined the association of PTEN/ERG status with lethal prostate cancer in patients treated with radical prostatectomy. Included in analysis were 791 patients with clinically localized prostate cancer treated with radical prostatectomy at a single institution. Genetically validated immunohistochemistry assays for PTEN and ERG were performed on tissue microarrays. Multivariable Cox proportional hazard models were used to assess the association of PTEN/ERG status with lethal prostate cancer (defined as metastasis or prostate cancer specific death), adjusting for patient age, race, pathological grade and stage, and surgical margin status. Median followup in the cohort was 12.8 years. Of 791 cases 203 (25%) demonstrated PTEN loss and 330 of 776 (43%) were ERG positive. On multivariable analysis PTEN loss (HR 1.9, 95% CI 1.2-3.0, p=0.012) but not ERG expression (HR 0.6, 95% CI 0.4-1.1, p=0.11) was associated with an increased risk of lethal prostate cancer. The association of PTEN loss with lethal disease only remained among men with ERG negative tumors (HR 2.3, 95% CI 1.3-4.1, p=0.005) and not ERG positive tumors (HR 1.1, 95% CI 0.6-2.1, p=0.81). PTEN loss is associated with an increased risk of lethal prostate cancer after radical prostatectomy and this risk is most pronounced in the subgroup of patients with ERG negative tumors. This work corroborates the use of PTEN and ERG status for risk stratification in surgically treated patients.

SPINK1 expression and outcomes postprostatectomy in race-specific cohorts.

23 Background: The SPINK1 molecular subtype has been shown to be more common in African American (AA) men with prostatic adenocarcinoma (PCa) than European Americans (EA). Other studies have suggested that SPINK1 expression is associated with more aggressive disease. However, there have been limited studies examining clinical outcomes by SPINK1 status in racially diverse cohorts. Methods: The objective was to determine the associations between SPINK1 subtype, race, and clinical and pathologic outcomes after radical prostatectomy (RP). A total of 186 AA and 206 EA men who underwent RP at Johns Hopkins were matched according to pathologic Gleason grade. We examined SPINK1 status by immunohistochemistry on tissue microarrays using a genetically validated assay. ERG and PTEN were assessed previously using validated immunohistochemistry assays. SPINK1 prevalence was compared between races. Logistic regression and Cox proportional hazard analyses assessed the association of SPINK1 status with pathologic and oncologic outcomes in race-specific multivariate models. Results: SPINK1-positive subtype was present in 25% (45/186) of AA and 15% (30/206) of EA men (p = 0.013). SPINK1 expression was generally mutually exclusive with ERG expression and PTEN loss in both racial cohorts. There were no differences in pathologic grade group (GG), pathologic stage, biochemical recurrence (BCR)-free survival, or metastasis-free survival between SPINK1-positive and SPINK1-negative tumors in the overall cohort or by race. In multivariable analyses, SPINK1 expression was not associated with BCR (AA: HR 0.99, 95% CI 0.56-1.75, p = 0.976; EA: HR 0.88, 95% CI 0.43-1.77, p = 0.720) or metastasis (AA: HR 0.79, 95% CI 0.25-2.49, p = 0.691; EA: HR 1.55, 95% CI 0.58-4.11, p = 0.381) in either the AA or the EA cohort. Conclusions: SPINK1-positive subtype is more prevalent in AA than EA men with PCa. While previous studies showed that SPINK1 may be associated with more aggressive PCa, we found that SPINK1 protein expression was not associated with worse pathologic or oncologic outcomes including BCR and metastasis after RP in either AA men or EA men.

Abstract 5771: Targeting EphA2 in bladder cancer using a novel antibody-directed nanotherapeutic

Abstract Ephrin receptor A2 (EphA2) is a member of the Ephrin-Ephrin receptors cell to cell signaling family of molecules and plays a key role in proliferation, differentiation, and migration. EphA2 is overexpressed in a broad range of cancers, including bladder cancer, and is associated with increased metastasis and poor prognosis. Several potential EphA2-targeted therapies were developed and showed promising preclinical activity which failed to translate clinically due to narrow therapeutic window. we propose to use a novel antibody-directed nanotherapeutic (ADN) approach to target EphA2 for the treatment of bladder cancer. This work characterizes the expression of EphA2 in bladder cancer patients, evaluates its prognostic power, and tests an EphA2-targeted ADN, MM-310, in patient-derived xenograft (PDX) models. EphA2 expression in tumors was investigated using a validated immunohistochemistry assay performed in 147 bladder cancer samples, enabling analysis of prevalence and prognostic power. Whole sections of primary and metastatic tumor resections were used to assess EphA2 expression in tumor-associated vessels and tumor cells. Four EphA2+ PDX models were used to evaluate the activity of MM-310 compared to free docetaxel, alone or in combination with gemcitabine. EphA2 was expressed in tumor cells and tumor-associated blood vessels in primary and metastatic lesions. EphA2 overexpression was seen in 80%-100% of tumors and correlated with shorter survival. In the PDX models, MM-310 controlled tumor growth, mediated greater regression, and was more active than free docetaxel at equitoxic dosing (Table). Additionally, the combination of MM-310 and gemcitabine controlled tumor growth better than each drug alone, and outperformed the combination of free docetaxel and gemcitabine in the single PDX model where it was compared. Thus, in bladder cancer models, a docetaxel-based ADN as a monotherapy and in combination with gemcitabine targeted EphA2 and led to significant tumor regression. Maximum tumor regression (%) & Time to regrowth (days)Model NameControlDocetaxelMM-310p valueBL0293-2% & 3 days-58% & 55 days-100% & 120 days<.05 & <.001BL03820% & 3 days-16% & 34 days-100% & 106 days<.001 & <.001BL04400% & 7 days-43% & 41 days-84% & 67 days<.01 & <.01BL4173620% & 5 days-47% & 69 days-100% & 121 days<.05 & <.05 Citation Format: Walid Kamoun, Elden Swindell, Christine Pien, Lia Luus, Jason Cain, Irawati Kandela, Richard Huang, Suresh Tipparaju, Dmitri Kirpotin, Wiam Bshara, Vasileios Askoxylakis, Carl Morrison, Daryl Drummond. Targeting EphA2 in bladder cancer using a novel antibody-directed nanotherapeutic [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5771.

Androgen Receptor Immunohistochemistry as a Companion Diagnostic Approach to Predict Clinical Response to Enzalutamide in Triple-Negative Breast Cancer.

The androgen receptor (AR) is increasingly recognized as a potential biomarker for identifying a subset of patients with possible hormonally driven triple-negative breast cancer (TNBC). However, its performance as a companion diagnostic remains elusive. Thus, we evaluated AR expression by immunohistochemistry in patients with advanced TNBC before treatment with the AR inhibitor enzalutamide. We optimized and validated immunohistochemistry assays in breast and prostate cancer cell lines and tissues using two commercial AR monoclonal antibodies (SP107 and AR441). AR expression was then examined in patients with advanced TNBC enrolled in a phase II study of enzalutamide (ClinicalTrials.gov identifier: NCT01889238) on archived or fresh tissue before treatment. Association with clinical response was assessed by sensitivity, specificity, positive predictive value (PPV), drop-out rate, and survival. AR expression was detected in 80% and 63% of breast cancer tissue using SP107 and AR441, respectively. SP107 was selected for additional analyses because of its higher sensitivity and robustness. Total AR nuclear staining demonstrated the best accuracy in predicting clinical response (area under receiver operating characteristic curve, 0.72; P = .0001). At a threshold of 10%, 74.6% of patients were AR positive, leading to 30% PPV, 90% sensitivity, and 30% specificity. These patients showed a significantly higher median progression-free survival (hazard ratio, 0.56; 95% CI, 0.36 to 0.88; P = .011) and overall survival (hazard ratio, 0.54; 95% CI, 0.32 to 0.91; P = .019) compared with those with AR-negative (< 10%) TNBC. At a threshold of ≥ 10% nuclear expression, the AR was associated with TNBC response to enzalutamide. However, the modest PPV may restrict its clinical application, and additional diagnostic tools may be helpful for improved patient selection.

Abstract 5324: ERG expression and PTEN loss by BMI and weight change in men with prostate cancer

Abstract Background: Obesity and weight gain are associated with poor prostate cancer outcome; underlying mechanisms are unknown. Obesity has been more strongly associated with lethal disease in men positive for the TMPRSS2:ERG gene fusion than negative for this fusion. PTEN loss is associated with increased risk of lethal progression; its association with obesity has not been explored. We evaluated whether prevalence of ERG expression and PTEN loss in prostate tumors differs by BMI and weight change. Methods: From a retrospective cohort study of 1,337 men with clinically-localized prostate cancer who underwent prostatectomy at Johns Hopkins (1993-2006), we sampled 291 men by combination of BMI at 1 year after surgery (normal, overweight, obese) and weight change from 5 years before to 1 year after surgery (loss, maintenance, gain). Within each category, men were frequency-matched on age, Gleason sum, organ confinement, and surgery year. We used genetically validated immunohistochemistry assays to assess ERG positivity and heterogeneous PTEN loss. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association of BMI and weight change (adjusted for height, starting weight) with ERG positivity and heterogeneous PTEN loss. Results: Mean age was 56.1 years and mean Gleason sum was 6.2; 73% had organ-confined disease. Prevalence of ERG positivity did not statistically significantly differ by BMI or weight change. However, when jointly categorized by BMI and weight change, overweight/obese men who maintained (OR=2.5; 95%CI 1.1-5.7) or gained weight (OR=2.5; 95%CI 1.1-5.8), and normal weight men who gained weight (OR=4.7; 95%CI 1.4-15.2) were significantly more likely to have ERG positive tumors compared with normal weight men who maintained weight. Overweight/obese men were also significantly more likely (OR=2.4; 95%CI 1.3-4.7) to have PTEN loss compared with normal weight men. When stratified by ERG status, this association appeared to be stronger for men with ERG positive tumors (OR=2.9; 95%CI 1.3-6.8) than for men with ERG negative tumors (OR=1.6; 95%CI 0.6-4.9). Prevalence of PTEN loss did not differ by weight change. When jointly categorized by BMI and weight change, overweight/obese men who maintained (OR=2.0; 95%CI 0.8-5.3) or gained weight (OR=1.9; 95%CI 0.7-5.1) appeared to be more likely to have PTEN loss compared with normal weight men who maintained weight. Conclusions: Overweight/obese men who maintained or gained weight circa diagnosis and normal weight men who gained weight were more likely to have ERG positive tumors. Overweight/obese men were more likely to have tumors with PTEN loss; this association was stronger among overweight/obese men who also had ERG positive tumors. The TMPRSS2:ERG gene fusion and PTEN loss may contribute to the increased risk of poor prostate cancer outcomes among overweight/obese men. Funding: Prostate Cancer Foundation Citation Format: Janelle S. Ho, Ibrahim Kulac, Tamara L. Lotan, John R. Barber, Patrick C. Walsh, Misop Han, Angelo M. De Marzo, Elizabeth A. Platz, Corinne E. Joshu. ERG expression and PTEN loss by BMI and weight change in men with prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5324. doi:10.1158/1538-7445.AM2017-5324

Clinical and biologic covariates of outcomes in ZUMA-1: A pivotal trial of axicabtagene ciloleucel (axi-cel; KTE-C19) in patients with refractory aggressive non-Hodgkin lymphoma (r-NHL).

7512 Background: Outcomes in activated B cell subtype diffuse large B cell lymphoma (ABC-DLBCL) and r-NHL are poor (Sehn Blood 2015, Crump ASCO 2016). ZUMA-1 is the first, multicenter trial of anti-CD19 chimeric antigen receptor (CAR) T cells, axi-cel, in r-NHL. Methods: Dosing and eligibility were per Neelapu ASH 2016. The primary endpoint was objective response rate (ORR); secondary endpoints were duration of response (DOR), overall survival (OS), and safety. Cell of origin (COO) and CD19 status were assessed centrally using Lymphoma Subtyping Test NanoString (Wallden JCO 2015) and a validated immunohistochemistry assay, respectively. Results: As of Jan 27, 2017, 111 patients (pts) were enrolled; the manufacturing success rate was 99% with an average 17-d turnaround time; 101 pts (modified intent-to-treat [mITT] population) received axi-cel. In the mITT population, the ORR was 82% (complete response [CR], 54%). With 8.7 m median follow-up, 44% remain in response and 39% in CR. The median DOR was 8.1 m and not reached (NR) for pts with CR. Median OS was NR. Results for clinical and biologic covariates are listed in the table. In pts who received tocilizumab (n = 43) and/or steroids (n = 27) for cytokine release syndrome (CRS) and/or neurologic events (NE), ORR was 84% and 78%, respectively. Most common grade ≥3 adverse events (AEs) were neutropenia (66%), leukopenia (44%), anemia (43%), febrile neutropenia (31%), thrombocytopenia (24%), and encephalopathy (21%). Rates of grade ≥3 CRS and NE were 13% and 28%, respectively. There were 3 grade 5 AEs (Neelapu ASH 2016). Conclusions: Axi-cel induced an ORR of 82% in pts with r-NHL, response is ongoing in 44% of pts at 8.7 m. Similar clinical responses were observed in pts with r-ABC-DLBCL. AEs were manageable and the use of tocilizumab/steroids did not appear to impact ORR. Drs Locke and Neelapu contributed equally. Funding source: Kite Pharma and Leukemia &amp; Lymphoma Society Therapy Acceleration Program Clinical trial information: NCT02348216. [Table: see text]

BAP1 and PBRM1 in metastatic clear cell renal cell carcinoma: tumor heterogeneity and concordance with paired primary tumor

BackgroundBAP1 and PBRM1 are frequently mutated in primary clear cell renal cell carcinoma (ccRCC) tumors; however, the frequency and clinical relevance of these mutations in metastatic ccRCC tumors is unknown. Additionally, while intra-tumor heterogeneity has been shown to be common in primary ccRCC, little is known regarding heterogeneity in metastatic ccRCC tumors.Materials and methodsWe analyzed BAP1 and PBRM1 loss of protein expression in patient-matched primary and metastatic tumors from 97 patients. Expression was determined using a validated immunohistochemistry assay, which has been shown to be correlated with mutation status.ResultsOf the 97 patients evaluated, 20 and 57% showed loss of BAP1 and PBRM1 in their primary tumors, respectively. Comparing expression across patient-matched primary-metastatic tumor pairs, 98 and 90% had concordant BAP1 and PBRM1 expression, respectively. Both patients who demonstrated discordant BAP1 expression showed loss of BAP1 expression during progression to metastatic ccRCC. Similarly, seven of the ten patients that demonstrated discordant PBRM1 expression showed loss of PBRM1 expression during progression to metastatic ccRCC. We evaluated intra-metastatic tumor heterogeneity using 12 patients who had multiple blocks available from the same tumor with representative pathology; 100 and 92% showed concordant BAP1 and PBRM1 expression, respectively. Amongst 32 patients who had serial metastatic tumors available, both BAP1 and PBRM1 had 97% concordant expression.ConclusionsWe observed minimal intra- and inter- tumor heterogeneity in metastatic ccRCC tumors. Patients with discordant BAP1 or PBRM1 expression across their matched primary and metastatic tumors usually showed loss of expression during progression to metastatic ccRCC.

Glucocorticoid receptor expression in 20 solid tumor types using immunohistochemistry assay.

BackgroundGlucocorticoid receptor (GR) activity plays a role in many aspects of human physiology and may play a crucial role in chemotherapy resistance in a wide variety of solid tumors. A novel immunohistochemistry (IHC) based assay has been previously developed and validated in order to assess GR immunoreactivity in triple-negative breast cancer. The current study investigates the standardized use of this validated assay to assess GR expression in a broad range of solid tumor malignancies.MethodsArchived formalin-fixed paraffin-embedded tumor bank samples (n=236) from 20 different solid tumor types were analyzed immunohistochemically. Nuclear staining was reported based on the H-score method using differential intensity scores (0, 1+, 2+, or 3+) with the percent stained (out of at least 100 carcinoma cells) recorded at each intensity.ResultsGR was expressed in all tumor types that had been evaluated. Renal cell carcinoma, sarcoma, cervical cancer, and melanoma were those with the highest mean H-scores, indicating high levels of GR expression. Colon, endometrial, and gastric cancers had lower GR staining percentages and intensities, resulting in the lowest mean H-scores.ConclusionA validated IHC assay revealed GR immunoreactivity in all solid tumor types studied and allowed for standardized comparison of reactivity among the different malignancies.ImpactBaseline expression levels of GR may be a useful biomarker when pharmaceutically targeting GR in research or clinical setting.