PD-L1 IHC 22C3 pharmDx Research Articles

Exploration of different immunogenomic TMEs in gastric cancer based on HER2 and PD-L1 expression.

e16073 Background: Recent results from the KEYNOTE-811 study showed that first-line pembrolizumab was superior to placebo with respect to progression-free survival (PFS) in combination with trastuzumab and chemotherapy in patients with HER2 positive metastatic gastric cancer (GC). Interestingly, In the subgroup analysis, the PFS benefit with pembrolizumab was significant in patients with tumors with PD-L1 CPS ≥1, whereas there was no benefit in the small subgroup of patients with tumors with CPS < 1. Therefore, this study is to investigate immune-genomic differences in the tumor microenvironment according to the composition of surrounding cells and the expression status of HER2 and PD-L1. Methods: Utilizing single cell RNA sequencing (scRNA seq) and TCR sequencing, we examined 14 HER2 positive and 18 negative primary GC samples with CPS score based on PD-L1 IHC 22C3 pharmDx. Among the HER2-positive group, there were 4 samples in the CPS < 1 (negative) and 10 samples in the CPS ≥1 (positive) group. In the HER2 negative group, there were 6 samples in the CPS < 1 and 12 samples in the CPS ≥1. Results: First, when analyzing the distribution of total cells according to HER2 status, in the HER2 positive group, more endothelial cells ( p= 0.034) and fibroblasts ( p= 0.054) appeared in the PD-L1 negative group compared to the PD-L1 positive group, while there was no difference in the HER2 negative group. Furthermore, Through TCR analysis, the exhausted and cytotoxic score exhibit contrasting trends between HER2 negative and positive groups. In HER2-positive patients, the exhausted and cytotoxic score appear significantly higher in the CPS negative group. Next, we evaluated the proportion of immune cells according to HER2 status. The observed of CD4 Treg ( p= 0.084) and CD8 exhausted T (Tex), ( p= 0.036) cells was increased in the HER2 positive compared to the negative. When regrouped according to PD-L1 expression, only the HER2 positive group showed a tendency to increase the observation of CD4 Treg and CD8 Tex cells compared to positive in PD-L1 negative. In addition, we investigated whether the expression pattern of other immune checkpoint molecules differed depending on the PD-L1 expression pattern in both HER2 positive and negative patients. In the HER2 negative group, the expression of immune checkpoint proteins was similar regardless of the CPS expression group, or the expression of some proteins was higher in the CPS positive group. In other hands, in HER2 positive, CPS < 1 group had higher expression of immune checkpoint proteins, such as PDCD1, LAG2, BTLA, VISTA and TIGHT. Conclusions: The high proportion of CD4 Tregs, CD8 Tex and the elevated exhausted score in the subgroup with CPS < 1 in HER2 positive GCs suggesting immune exclusive environment compared to her-2 and PD-L1 coexpressing group. Considering increased expression of immune checkpoint proteins other than PD-1/PD-L1, for patients with HER2-positive and CPS < 1, combination therapy with other immune checkpoint inhibitors rather than anti-PD-1/PD-L1 may be suggested.

Abstract PO5-14-08: External Reproducibility of PD-L1 IHC 22C3 pharmDx on Breast Cancer Specimens at CPS ≥ 1 and CPS ≥ 10 Cutoffs

Abstract Background: PD-L1 IHC 22C3 pharmDx is an approved companion diagnostic for pembrolizumab treatment in triple-negative breast cancer (TNBC). Clinical evidence for pembrolizumab approval in TNBC was demonstrated by KEYNOTE-355 (NCT02819518), which investigated the clinical validity of PD-L1 IHC 22C3 pharmDx in identifying patients with PD-L1 expressing Combined Positive Score (CPS) ≥ 10 in previously untreated locally recurrent unresectable or metastatic TNBC.1 The role of immune checkpoint inhibitors for breast cancer as a whole is not as well defined as it is for TNBC. In this study, we show evidence of the reproducibility of PD-L1 IHC 22C3 pharmDx in PD-L1 expression determination in breast cancer specimens at the CPS ≥ 1 and CPS ≥ 10 cutoffs documenting robust assay performance in breast cancer. Methods: A blinded, randomized study was conducted at three external sites using formalin-fixed, paraffin-embedded breast cancer specimens. Reproducibility of PD-L1 IHC 22C3 pharmDx was assessed at the inter-site, intra-site/inter-day, inter-observer, and intra-observer endpoints at the CPS ≥ 1 and CPS ≥ 10 cutoffs. To assess inter-site and intra-site reproducibility, five replicate sets of pre-qualified unstained specimens were stained and evaluated at each of the three external sites. To assess inter-observer and intra-observer reproducibility, one set of pre-stained specimens was evaluated three times by each of three external pathologists. Negative percent agreement (NPA), positive percent agreement (PPA), and overall percent agreement (OA), based on comparisons to consensus diagnostic outcome, were computed with corresponding two-sided 95% percentile bootstrap confidence intervals. Acceptance criteria required at least 85.0% for the lower-bound (LB) of the two-sided 95% confidence interval (CI) on NPA, PPA, and OA for all endpoints. Results: All but one endpoint in the external reproducibility study met pre-determined acceptance criteria. Both the inter- and intra-site reproducibility endpoints had 95% CI LB values of 98.8% for NPA, 95.9% for PPA, and 97.9% OA at the CPS ≥ 1 cutoff. At the CPS ≥ 10 cutoff, the inter-site reproducibility endpoint had 95% CI LB values of 88.0% for NPA, 87.1% for PPA, and 89.5% OA, and the intra-site reproducibility endpoint had 95% CI LB values of 96.7% for NPA, 92.2% for PPA, and 95.6% OA. The inter-observer reproducibility endpoint had 95% CI LB values of 95.3% for NPA, 92.3% for PPA, and 94.7% OA at the CPS ≥ 1 cutoff. At the CPS ≥ 10 cutoff, the inter-observer reproducibility endpoint had 95% CI LB values of 84.9% for NPA, 86.8% for PPA, and 87.3% OA. The intra-observer reproducibility endpoint had 95% CI LB values of 97.0% for NPA, 95.0% for PPA, and 96.6% OA at the CPS ≥ 1 cutoff. At the CPS ≥ 10 cutoff, the intra-observer reproducibility endpoint had 95% CI LB values of 92.2% for NPA, 89.2% for PPA, and 91.7% OA. Conclusions: Acceptance criteria were met for all endpoints in the breast cancer external reproducibility study of PD-L1 IHC 22C3 pharmDx at the CPS ≥ 1 and CPS ≥ 10 cutoffs, except for inter-observer at the CPS ≥ 10 cutoff, which had a 95% CI LB value of 84.9% for NPA.

Abstract CT283: Phase 3 MK-2870-007 study: MK-2870 (SKB264) plus pembrolizumab vs pembrolizumab alone as first-line treatment for metastatic non-small-cell lung cancer with PD-L1 tumor proportion score (TPS) ≥50%

Abstract Background: Pembrolizumab (anti-PD-1) monotherapy is a standard of care first-line treatment for advanced or metastatic non-small-cell lung cancer (NSCLC) with PD-L1 TPS ≥50% without actionable genetic alterations; however, some patients do not respond to therapy or experience disease progression. Trophoblast cell-surface antigen 2 (TROP2) is another candidate for anticancer treatment and overexpression of TROP2 is associated with poor prognosis in patients with NSCLC. MK-2870 (SKB264) is an antibody-drug conjugate (ADC) composed of the humanized TROP2 monoclonal antibody, a hydrolytically cleavable linker, and the cytotoxic drug KL610023. In patients with relapsed or refractory locally advanced or metastatic NSCLC, MK-2870 monotherapy showed encouraging antitumor activity with a manageable safety profile. The complementary mechanisms of action of MK-2870 and pembrolizumab may provide more potent antitumor activity when given in combination compared with each therapy alone. To investigate this further, the MK-2870-007 study will evaluate the efficacy and safety of the addition of MK-2870 to pembrolizumab vs pembrolizumab alone in patients with previously untreated metastatic NSCLC with PD-L1 TPS ≥50%. Trial Design: Approximately 614 eligible patients aged ≥18 y with previously untreated histologically or cytologically confirmed stage IV (per American Joint Committee on Cancer v8.0) NSCLC, PD-L1 TPS ≥50% and no EGFR, ALK, or ROS1 alterations (nonsquamous only); ECOG PS 0 or 1; and measurable disease per RECIST v1.1 will be enrolled. Patients with well-controlled HIV are permitted. Patients will be randomized 1:1 to receive either pembrolizumab 400 mg Q6W for up to 18 cycles plus MK-2870 4 mg/kg Q2W or pembrolizumab 400 mg IV Q6W alone until progressive disease, intercurrent illness, patient withdrawal, unacceptable toxicity, prolonged interruption of study drug, or until maximum number of cycles (18 cycles for pembrolizumab). Randomization stratification factors include ECOG PS (0 vs 1), histology (squamous vs nonsquamous), TROP2 expression (low vs medium vs high), and geographic region (East Asia vs North America/Western Europe/Australia vs Rest of World). The primary endpoint is OS. Secondary endpoints include PFS, ORR, and duration of response per RECIST v1.1 by blinded independent central review, patient-reported outcomes, and safety. Tumor imaging will occur at baseline, Q6W until wk 48, and Q12W thereafter until PD, start of new anticancer treatment, or withdrawal of consent. PD-L1 TPS will be assessed centrally using PD-L1 IHC 22C3 pharmDx (Agilent Technologies, Carpinteria, CA). AEs will be graded according to National Cancer Institute Common Terminology Criteria for Adverse Events v5.0. Enrollment began in December 2023 and is currently ongoing. Citation Format: Nikolaj Frost, Razi Ghori, Ananya Roy, Ana Tablante Nunes, James Chih-Hsin Yang. Phase 3 MK-2870-007 study: MK-2870 (SKB264) plus pembrolizumab vs pembrolizumab alone as first-line treatment for metastatic non-small-cell lung cancer with PD-L1 tumor proportion score (TPS) ≥50% [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT283.

Abstract CT095: Phase 1 evaluation of triple therapy with boserolimab (anti-CD27 agonist), pembrolizumab, and chemotherapy in patients with triple-negative breast cancer (TNBC) with PD-L1 combined positive score (CPS) <10: Safety, antitumor activity, and association between biomarkers and response

Abstract Background: Pembrolizumab (pembro) plus chemotherapy (chemo) is an approved therapy for patients (pts) with locally recurrent unresectable or metastatic TNBC whose tumors express PD-L1 (CPS ≥10) based on results from KEYNOTE-355. However, there is unmet need for effective treatment options in pts with PD-L1 CPS <10. In a first-in-human, open-label, phase 1 study (NCT03396445), treatment with escalating doses of the humanized anti-CD27 agonist boserolimab (MK-5890) alone and with pembro had acceptable safety and preliminary evidence of antitumor activity in pts with advanced solid tumors. We report results for a dose-expansion cohort of this study in pts with metastatic TNBC and PD-L1 CPS <10 tumors who received first-line triple therapy with boserolimab, pembro, and chemo. Exploratory analyses in this cohort assessed the association of baseline T-cell-inflamed gene expression profile (TcellinfGEP) and tumor mutational burden (TMB) with ORR. Methods: This dose-expansion cohort enrolled pts aged ≥18 y with previously untreated locally recurrent inoperable or metastatic TNBC, measurable disease per RECIST v1.1, ECOG PS of 0/1, and tumors expressing PD-L1 at the cutoff of CPS <10 per PD-L1 IHC 22C3 pharmDx (local or central testing). Pts received boserolimab 30 mg IV Q6W plus pembro 400 mg IV Q6W for 18 cycles plus nab-paclitaxel 100 mg/m2 (3 weeks on [days 1, 8, and 15]/1 week off). Primary objectives were safety/tolerability. A secondary objective was ORR per RECIST v1.1 by investigator assessment. Baseline TcellinfGEP was assessed using the NanoString PCI assay (N=31); TMB was assessed using the Illumina TSO500 mutational panel assay (N=21). Results: 41 pts were enrolled in the dose-expansion cohort. Median study follow-up at data cutoff (Apr 25, 2023) was 11.1 (range, 2.2-20.5) mo. The most common treatment-related AEs were fatigue (51.2%), pruritus (51.2%), and alopecia (46.3%). Grade 3/4 treatment-related AEs occurred in 56.1% of pts (23/41); no grade 5 treatment-related AEs occurred. 9.8% of pts (4/41) discontinued ≥1 study treatment due to treatment-related AEs. Confirmed ORR was 46.3% (95% CI, 30.7%-62.6%), with 2 CRs and 17 PRs; 14 pts had SD, 5 had PD, and 3 had no postbaseline assessment at data cutoff. Median PFS was 10.3 (95% CI, 4.2-not reached) mo. No clear association between TcellinfGEP or TMB and confirmed ORR was observed; responses were observed in pts with non-TcellinfGEP-high (less than −0.318) and non-TMB-high (<10 mut/Mb) tumors. Conclusions: In pts with TNBC and tumors expressing PD-L1 at the cutoff of CPS <10, triple therapy with boserolimab, pembro, and chemo had acceptable safety and showed preliminary evidence of antitumor activity regardless of baseline TcellinfGEP expression or TMB status. Citation Format: Carlos Rojas, Bernard Gaston Doger de Spéville, Seock-Ah Im, Ronnie Shapira-Frommer, María De Miguel, Lucía González Cortijo, Margarita Romeo Marin, Maja de Jonge, Mark Ayers, Yiwei Zhang, Song Zhai, Elliot Chartash, Konstantin Dobrenkov, Joohyuk Sohn. Phase 1 evaluation of triple therapy with boserolimab (anti-CD27 agonist), pembrolizumab, and chemotherapy in patients with triple-negative breast cancer (TNBC) with PD-L1 combined positive score (CPS) <10: Safety, antitumor activity, and association between biomarkers and response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT095.

PD-L1 IHC 22C3 pharmDx Demonstrates Precision and Reproducibility in Triple-negative Breast Cancer

In the United States, the PD-L1 IHC 22C3 pharmDx indications for use have expanded to include the assay’s use as an aid in identifying triple-negative breast cancer (TNBC) patients for treatment with pembrolizumab (KEYTRUDA®). Analytical validation for TNBC was conducted by Agilent Technologies in support of the device performance and FDA-approval. Analytical validation studies included device precision (inter-instrument, inter-operator, inter-day, inter-lot, and intra-run) and external reproducibility (inter- and intra-site, inter- and intra-observer) using the Combined Positive Score (CPS) ≥ 10 cutoff. All precision and external reproducibility studies achieved confidence interval lower bound values of greater than 85% for positive, negative, and overall percent agreement. These analytical validation studies demonstrate that PD-L1 IHC 22C3 pharmDx is precise and reproducible in evaluating PD-L1 protein expression at a CPS ≥ 10 cutoff when used for testing TNBC tissues.

1548P PD-L1 assessment in oesophageal and gastro-oesophageal adenocarcinoma with PD-L1 IHC 22C3 pharmDx and PD-L1 IHC 28-8 pharmDx assays on Autostainer Link 48: The University Hospitals Birmingham experience over a period of 18 months

1548P PD-L1 assessment in oesophageal and gastro-oesophageal adenocarcinoma with PD-L1 IHC 22C3 pharmDx and PD-L1 IHC 28-8 pharmDx assays on Autostainer Link 48: The University Hospitals Birmingham experience over a period of 18 months

Performance of endobronchial ultrasound transbronchial needle aspiration as the first nodal staging procedure for the determination of programmed death ligand-1 expression in non-small cell lung cancer patients.

The determination of the programmed death ligand-1 (PD-L1) expression is part of the diagnostic algorithm for advanced non-small cell lung cancer (NSCLC) patients. We aimed to analyze the diagnostic performance of EBUS-TBNA performed as first-choice nodal staging procedure for the determination of PD-L1 expression in NSCLC patients. Longitudinal-prospective study including NSCLC patients diagnosed between January 2018 and October 2019, for whom a primary tumor biopsy sample and an EBUS-TBNA cytological malignant sample were available. Samples with fewer than 100 malignant cells were considered inadequate. PDL-1 IHC 22C3 pharmDx antibody was used. The percentage of tumor cells expressing PD-L1, setting 1% and 50% as cutoff points, was collected. The weighted kappa coefficient was used to assess the concordance of PD-L1 expression. The PD-L1 expression was compared inprecision terms. From a total of 43 patients, 53 pairs of samples were obtained, of which 23 (43.4%) were adequate and included for analysis. The weighted kappa coefficient for PD-L1 expression was 0.41 (95% CI 0.15-0.68) and 0.56 (95% CI 0.23-0.9) for cutoff values ≥ 1% and ≥ 50%, respectively. In advanced stages, the weighted kappa coefficient was 0.6 (95% CI 0.3-0.9) and 1 (95% CI 1-1) for PD-L1 expression cutoff values ≥ 1% and ≥ 50%, respectively. EBUS-TBNA showed a sensitivity, specificity, positive predictive value, and negative predictive value of 1 to detect PDL-1 expression ≥ 50% in advanced stages. EBUS-TBNA performed as first nodal staging procedure in advanced NSCLC patients provides reliable specimens for the detection of PD-L1 expression ≥ 50% and could guide immunotherapy.

Comparison of PD-L1 IHC 22C3 PharmDx Combined Positive Score (CPS) in Primary Versus Metastatic Nodal Squamous Cell Carcinomas of the Head and Neck: Is There a Significant Difference?

PD-L1 IHC 22C3 pharmDx is an FDA-approved companion test to select patients for anti-PD-L1 immunotherapy. In head and neck squamous cell carcinoma PD-L1 expression is determined using a Combined Positive Score (CPS), which evaluates expression in tumor cells and tumor-associated leukocytes. We hypothesized that in nodal metastasis, the CPS should be higher given their inherent higher proportion of leukocytes. A significant difference in CPS between sites would mean that the tissue chosen for PD-L1 testing would impact patient eligibility for therapy. Currently, guidelines about which tissue should be tested do not exist. PD-L1 22C3 IHC was performed in the primary and nodal metastases of 35 head and neck squamous cell carcinoma, and a CPS was generated by 3 pathologists. Mean CPS was higher at the primary than the nodal metastasis: 47.2 versus 42.2; however, the difference was not statistically significant: P=0.259 . By therapeutic groups: negative (CPS <1), low (CPS 1-19) and high (CPS≥20), low-expression was more common in the primary: 40 vs. 26%, and high-expression in the nodal metastasis: 74 vs. 60% but this difference was not statistically significant: P=0.180. Stratified by positive versus negative (CPS <1 vs. ≥1), there were no differences between sites. Interobserver agreement for CPS among the 3 raters was slight for both sites: ƙ = 0.117 and 0.025, fair if stratified by therapeutic group: ƙ = 0.371 and 0.318, and near perfect if stratified as negative versus positive: ƙ = 0.652 and 1. There were no statistically significant differences in CPS between primary and nodal metastases independent of how the CPS was stratified.

Equivalence of laboratory-developed test and PD-L1 IHC 22C3 pharmDx across all combined positive score indications.

We conducted an analysis across multiple PD-L1 combined positive score (CPS) indications to establish concordance of a 22C3 antibody-based laboratory-developed test (LDT) on the Ventana BenchMark XT or BenchMark ULTRA platform and the regulatory-approved PD-L1 IHC 22C3 pharmDx in cervical cancer (CC), esophageal squamous cell carcinoma (ESCC), head and neck squamous cell carcinoma (HNSCC), triple-negative breast cancer (TNBC), and urothelial carcinoma (UC). Tumor specimens from each tumor type were stained with 22C3 antibody and scored using the 22C3 antibody-based LDT, and scores were compared with those using PD-L1 IHC 22C3 pharmDx. PD-L1 status was measured by the pathologist using CPS as a continuous score and using clinically relevant cutoffs (CC, ≥1 and ≥10; HNSCC, ≥1 and ≥20; ESCC, TNBC, and UC, ≥10). The agreement between the BenchMark platforms and PD-L1 IHC 22C3 pharmDx was assessed by intraclass correlation coefficient (ICC) and a contingency table for clinical interpretation. A total of 522 samples were evaluated for the pan-tumor analysis (CC, n = 77; ESCC, n = 80; HNSCC, n = 126; TNBC, n = 118, UC, n = 121). Most clinical interpretations of PD-L1 status were concordant between the BenchMark XT and PD-L1 IHC 22C3 pharmDx for all five tumor types with regard to negative percentage agreement (NPA; 83-97%), positive percentage agreement (PPA; 86-100%), and overall percentage agreement (OPA; 90-97%); the ICC by tumor type was high (≥0.88). Importantly, the pan-tumor ICC was 0.95 (95% CI 0.94-0.96). Thirty additional TNBC samples were evaluated using the BenchMark ULTRA and PD-L1 IHC 22C3 pharmDx; the NPA, PPA, and OPA were 100%. The 22C3 antibody-based LDT on Ventana BenchMark XT and BenchMark ULTRA platforms demonstrated high concordance with the regulatory-approved PD-L1 IHC 22C3 pharmDx across multiple tumor types. These findings suggest the comparability of PD-L1 IHC 22C3 pharmDx with an LDT based on the 22C3 antibody.

Neoadjuvant tislelizumab, a PD-1 mAb plus nab-paclitaxel (nab-P) followed by tislelizumab plus epirubicin/cyclophosphamide (EC) for triple-negative breast cancers (TNBC): Interim analysis of clinical response in a phase 2 TREND trial.

e14623 Background: Chemo-based immunotherapy improves the prognosis of TNBC. However, the dominant population and optimal chemo-backbone of neoadjuvant immunotherapy remain undefined. Aim of TREND trial was to assess the efficacy and safety of tislelizumab in combination with nab-P and EC (nab-P-EC) in neoadjuvant therapy of TNBC. Methods: In this prospective, single-arm phase 2 clinical study, untreated TNBC patients who have clinically node-positive or at least T2 disease without distant metastasis were eligible. Before surgery, enrolled patients received tislelizumab (200 mg IV Q3W) plus weekly nab-P (100 mg/m² IV Q3W) for 12 weeks, followed by tislelizumab (200 mg IV Q3W) plus epirubicin (75 mg/m² IV Q3W) and cyclophosphamide (600 mg/m² IV Q3W) for the subsequently 12 weeks. The primary endpoint was pCR (ypT0/Tis ypN0) and secondary endpoints was objective response rate (ORR, RECIST v1.1). Combined positive score (CPS) of PD-L1 expression in pre-treatment biopsy samples was tested by PD-L1 IHC 22C3 PharmDx. Single-cell RNA sequencing, single-cell TCR sequencing, mass cytometry by time of flight, whole exome sequencing, RNA-seq and olink-assay were performed on pre- and post-treatment samples from primary tumors, metastatic lymph nodes and peripheral blood. Results: Of 43 enrolled patients from Nov 2020 to Nov 2022, 21 patients completed neoadjuvant therapy and accepted surgery in per protocol set (PPS; median age 48 years; range 25-69 years), and 16 were still on treatment. In PPS, the pCR (ypT0/is ypN0) rate was 71.43% (15/21). For different target lesions, 15 patients achieved ypT0/Tis (pCR rate = 71.43%) and 20 reached ypN0 (pCR rate = 95.24%). When stratified by CPS, pCR (ypT0/is ypN0) rate were 68.4%,72.2% and 76.9% in CPS ≥ 1, CPS ≥ 5 and CPS ≥ 10 subgroups, respectively. The ORR in PPS was 90.48% (n = 19/21, 95% CI: 68.18 - 98.33) and DCR reached 95.24% (n = 20/21, 95% CI: 74.13 - 99.75), including 9 complete response and 10 partial response. Treatment emergent adverse event (TEAE) occurred in 74.4% patients (32/43), of which 69.8% were Immune-related adverse event (irAE) (30/43). Grade ≥ 3 IrAE was 7.0% (3/43) and no treatment-related deaths were found. Conclusions: Combining tislelizumab and neoadjuvant nab-P-EC achieved favorable efficacy in TNBC, supporting that platinum-free regimen was non-inferior as a chemo-backbone. For heterogeneity of efficacy to immunotherapy, metastatic tumors in lymph nodes responded better to tislelizumab than primary tumor, suggesting that node-positive patients were potentially dominant population of neoadjuvant immunotherapy. Further results from the ongoing TREND trial and subsequent analysis of mechanism are urgently awaited. Clinical trial information: ChiCTR2000035262 .

Postoperative prognosis in patients with NSCLC with different EGFR mutation sites.

e20528 Background: Lung cancer can be divided into small cell lung cancer and non-small cell lung cancer. At the same time, non-small cell lung cancer can be divided into non-small cell lung cancer with different molecular mutations. Among them, the EGFR mutation accounts for about 50% of the patients with non-small cell lung cancer in China, which is a large group of patients. The EGFR mutation has many sites and many forms of mutational subtypes, including common mutations such as L858R, and rare mutations. Although the proportion of rare mutations is small, it is still different from common mutations in patients with TKI treatment and immunity. Methods: This study collected and analyzed the data from Formalin-Fixed Paraffin-Embedded (FFPE) tissues of 330 NSCLC patients which received surgery and underwent a targeted next-generation sequencing (NGS) assay performed by 3DMed Clinical Laboratory Inc., a College of American Pathologists (CAP) certified and Clinical Laboratory Improvement Amendments (CLIA) certified laboratory of 3D Medicines Inc. between January, 2019 and June, 2022 in China, to obtain a comprehensive molecular profile of EGFR mutations. genomic alterations, tumor mutational burden (TMB) and PD-L1 expression were analyzed. Gene mutation and TMB level were analyzed by NGS, detected PD-L1 expression by using Dako PD-L1 IHC 22C3 pharmDx, Tumor Proportion Score (TPS) was used to determine expression of PD-L1. Finally, the postoperative follow-up data were also collected and analyzed in this study. Results: Therefore, we retrospectively analyzed the tissue samples of patients with non-small cell lung cancer who received surgical treatment, and carried out NGS detection and analysis, as well as postoperative follow-up. Among them, patients with EGFR mutations accounted for 51.2%. We further analyzed the TMB and PD-L1 expression levels of different EGFR mutation subtypes. First, we found that different EGFR mutation sites, whether common mutations such as L859R, 19del or unusual mutations such as S768I, There is no difference in the prognosis after operation, but it is very significant that our results show that there are two or more EGFR mutations at the same time. Conclusions: NSCLC with EGFR mutation is a very large group of patients, which should be further subdivided into different subtypes according to different EGFR mutation sites, and should perform individualized management. This study found that patients with two or more EGFR mutations and patients with EGFR single site mutations are different types of NSCLC, with different postoperative prognosis, and it may be related to the differences in the expression levels of TMB and PD-L1, which is a direction worthy of further exploration in the future.

PD-L1 expression in Chinese patients with solid tumor and its correlation with gene alternations.

e14640 Background: Immune checkpoint blockade are recommended in more and more solid tumors for first-line or posterior treatment, and PD-L1 expression is a crucial predictive biomarker for immunotherapy. However, the expression can be influenced by many factors. Methods: A total of 1743 Chinese patients with solid tumor was retrospectively identified. The Dako PD-L1 IHC 22C3 pharmDx assay was used to detect PD-L1 protein expression. And Tumor Proportion Score (TPS) ≥ 1% was defined as positive expression, TPS ≥ 50% was defined as high expression. Genomic profiling was performed on tumor tissue and matched peripheral blood samples. Only the tumor subtypes with sufficient sample size were used for correlation analysis. Results: PD-L1 positive expression occurred in 45.6% patients and high expression occurred in 8.1% patients. The highest expression incidences occurred in cervical cancer as of 78.8%, followed by lung cancer (53.8%), esophageal cancer (53.7%) and gastric cancer (42.7%). The PD-L1 expression assessed by TPS was consistent with that assessed by Combined Positive Score (CPS) in multiple tumors. However, it was significantly different in gastrointestinal tumors, especially in colorectal cancer (TPS&gt;1%: 30.4% vs. CPS&gt;1: 80.6%). In addition, gene alternations including TP53, CDKN2A, LRP1B, KRAS and PIK3CA apparently occurred in patients with high PD-L1 expression. Moreover, high tumor mutation burden (TMB-H) was associated with PD-L1 positive expression in these Chinese patients. Besides, no correlation was found between microsatellite instability (MSI) and PD-L1 expression. Conclusions: Our results illustrated genomic correlates of PD-L1 expression in Chinese solid tumor patients. These findings may broaden the application of immune checkpoint blockade to patients harboring specific molecular characteristics.

Abstract CT067: Pembrolizumab with and without sacituzumab govitecan as first-line treatment for metastatic non-small-cell lung cancer (NSCLC) with PD-L1 TPS ≥50%: phase 3 KEYNOTE-D46/EVOKE-03 study

Abstract Background: Sacituzumab govitecan is an antibody-drug conjugate comprising an anti-trophoblast cell-surface antigen 2 (Trop-2) antibody coupled to a potent payload, SN-38, via a proprietary, hydrolysable linker. In heavily pretreated patients with metastatic NSCLC, sacituzumab govitecan showed a durable antitumor response and was well tolerated with a 10-mg/kg dose regimen. Monotherapy with the anti-PD-1 monoclonal antibody pembrolizumab is a standard-of-care therapy for patients with previously untreated advanced/metastatic NSCLC with no sensitizing EGFR or ALK alterations and a PD-L1 tumor proportion score (TPS) ≥50%. KEYNOTE-D46 evaluates whether adding sacituzumab govitecan to pembrolizumab monotherapy can improve outcomes in patients with metastatic NSCLC with PD-L1 TPS ≥50%. Trial Design: In this phase 3, open-label, active comparator-controlled, randomized study, ~614 eligible adults with previously untreated metastatic NSCLC; no EGFR, ALK, or ROS1 alterations; PD-L1 TPS ≥50%; and measurable disease per RECIST version 1.1 will be randomized 1:1 to receive either pembrolizumab 200 mg Q3W for up to 35 cycles plus sacituzumab govitecan 10 mg/kg on days 1 and 8 of each Q3W cycle (no maximum treatment duration) or pembrolizumab 200 mg Q3W for up to 35 cycles. Randomization is stratified by ECOG PS (0 vs 1), histology (squamous vs nonsquamous), and geographic region (East Asia vs North America/Western Europe/Australia vs Rest of World). Treatment continues until PD, death, unacceptable toxicity, or another treatment discontinuation criterion is met, or (for pembrolizumab) completion of 35 cycles. Dual primary endpoints are PFS per RECIST version 1.1 by blinded independent central review (BICR) and OS. Secondary endpoints include ORR and duration of response per RECIST version 1.1 by BICR, safety, and patient-reported outcomes. Radiographic imaging occurs at baseline; weeks 6, 12, 18, and 24 from randomization; every 9 weeks thereafter through week 51; and then once every 12 weeks until BICR-confirmed PD or the start of new anticancer treatment, pregnancy, withdrawal of consent, or death. PD-L1 expression status is assessed at a central laboratory using PD-L1 IHC 22C3 pharmDx (Agilent, Santa Clara, CA). Health-related quality of life is assessed using validated patient-reported outcome instruments including the EORTC Quality of Life Questionnaire-Core 30 and Quality of Life Questionnaire-Lung Cancer 13. AEs are assessed according to National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0. Enrollment started on December 9, 2022 and is currently ongoing. Citation Format: Mor Moskovitz, Isamu Okamoto, Peng Chen, Jilpa Patel, Sabeen Mekan, M. Catherine Pietanza, Yalin Zhu, Renata Eiras, Marcello Tiseo. Pembrolizumab with and without sacituzumab govitecan as first-line treatment for metastatic non-small-cell lung cancer (NSCLC) with PD-L1 TPS ≥50%: phase 3 KEYNOTE-D46/EVOKE-03 study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT067.

Expression of PD-L1 in triple negative breast cancer

Introduction: The second leading cause of cancer deaths in women is breast cancer. Breast cancer awareness has increased due to mammography screenings. The aim of study is to evaluate the prevalence of PD-L1 expression in TNBC cases and to correlate it with clinicopathological parameters. Method: PDL1 expression is measured by immunohistochemical technique using Dako kits, PD-L1 IHC 22C3 pharm Dx, on 44 paraffin block samples from Duhok municipal labs. If the specimen has a combined positive score (CPS) of 10 or higher, it expresses PD-L1. Age groups, grades, kinds, stages, and PDL1, lymph node involvement are studied. Results: 44 cross-sectional patients, mean and SD (47.7±14) years old. (54.5%) of patients in middle age group, (63.6%) at grade III, majority (88.6%) have IDC type and (75%) have negative PDL1, (63.6%) have KI69 less than 20, (70.5%) at stage T2, and (45.5%) have N1 lymph node involvement. There is significant association between PDL1 and Ki67, (100%) of patients with positive PDL1 have Ki67 more than 20 while (15.2%) of patients with negative PDL1 have Ki67 more than 20. Conclusion: 75% of middle-aged individuals with grade III had negative PDL1. All PDL1-positive patients have Ki67 above 20. Different research employ 1%, 5%, or 10% cutoff values, which affects PDL1.&#x0D;

The impact of combined PD-L1 positive score on clinical response to nivolumab in patients with advanced esophageal squamous cell carcinoma.

Nivolumab is recommended for patients with advanced esophageal squamous cell carcinoma (aESCC) refractory or intolerant to fluoropyrimidine- and platinum-based chemotherapy regardless of the tumor proportion score (TPS). However, the role of combined positive score (CPS) in predicting nivolumab efficacy remains unclear. We aimed to study whether TPS or CPS is a more suitable biomarker for predicting nivolumab efficacy in these patients. We retrospectively collected data from patients with aESCC treated with fluoropyrimidines and platinum and subsequently received nivolumab monotherapy between January 1, 2014 and September 15, 2020. Next, we evaluated the efficiencies of TPS and CPS in predicting the clinical response to nivolumab using PD-L1 IHC 22C3 pharmDx assay. This study included 50 patients (CPS groups: ≥ 10/1-10/ < 1, n = 24/18/8, respectively; TPS groups, ≥ 10%/1%-10%/ < 1%, n = 17/8/25, respectively). The median progression-free survival was 3.2, 2.5, and 1.5months in the ≥ 10, 1-10 [hazard ratio (HR) vs. CPS of ≥ 10 group, 1.01; p = 0.98; adjusted HR, 1.33; p = 0.56], and < 1 CPS groups (HR vs. CPS of ≥ 10 group, 3.44; p = 0.006; adjusted HR, 1.67; p = 0.41), respectively. For the patients with CPS of ≥ 10/1-10/ < 1 and TPS of ≥ 10%/1%-10%/ < 1%, the objective response rate was 30%/25%/0% and 36%/0%/19% and the disease control rate was 60%/50%/12% (p = 0.06) and 65%/40%/38% (p = 0.30), respectively. This study suggests that a CPS of < 1 is not a strong predictor of efficacy but can predict the absence of response to nivolumab in patients with aESCC.

High interobserver and intraobserver reproducibility among pathologists assessing PD-L1 CPS across multiple indications.

A common concern among pathologists scoring PD-L1 immunohistochemical staining is interobserver and intraobserver variability. We assessed the interobserver and intraobserver reproducibility of PD-L1 scoring among trained pathologists using a combined positive score (CPS; tumour cell and tumour-associated immune cell staining). Data were collected for 2 years (2017-2019) from 456 pathologists worldwide. Digital training encompassed unique, tumour-specific training, and test sets. Samples were stained using PD-L1 IHC 22C3 pharmDx and evaluated at specific CPS cutoffs for gastric cancer (GC), cervical cancer (CC), urothelial cancer (UC), oesophageal cancer (OC), and head and neck squamous cell carcinoma (HNSCC). Pathologists underwent expert-to-peer training and scored 20 blinded samples on day 1 and 25 blinded samples on day 2 (including 15 of the day 1 samples). Interobserver and intraobserver reproducibility were assessed. For GC (120 observers) and CC (32 observers) samples assessed at CPS ≥1, average interobserver agreement was 91.5% and 91.0%, respectively, and average intraobserver agreement was 90.2% and 96.6%, respectively. For UC (139 observers) and OC (52 observers) samples measured at CPS ≥10, average interobserver agreement was 93.4% and 93.7%, respectively, and average intraobserver agreement was 92.0% and 92.5%, respectively. For HNSCC samples (113 observers), average interobserver agreement was 94.1% at CPS ≥1 and 86.5% at CPS ≥20; intraobserver agreement was 94.7% at CPS ≥1 and 90.5% at CPS ≥20. The consistently high interobserver and intraobserver concordance rates support the effectiveness of face-to-face training of many global pathologists for scoring PD-L1 CPS across multiple indications at several specific cutoffs.

T cell-inflamed gene expression profile and PD-L1 expression and pembrolizumab efficacy in advanced esophageal cancer.

Aim: Investigate the relationship between response to pembrolizumab and expression of the 18-gene T cell-inflamed gene expression profile (TcellinfGEP) or PD-L1 combined positive score (CPS) in esophageal cancer. Materials & methods: This analysis included heavily pretreated patients with advanced/metastatic esophageal/gastroesophageal junction adenocarcinoma or squamous cell carcinoma who received pembrolizumab in the single-arm, phase II study KEYNOTE-180. PD-L1 CPS was evaluated with PD-L1 IHC 22C3 pharmDx. Results: In patients with squamous cell carcinoma, trends toward enrichment for responders were observed for patients with PD-L1 CPS ≥10 tumors. In patients with adenocarcinoma, a trend was observed for TcellinfGEP but not for PD-L1. Conclusion: TcellinfGEP and PD-L1 CPS may enrich for responders to pembrolizumab in patients with esophageal cancer. Clinical trial registration: NCT02559687 (ClinicalTrials.gov).

Evaluation of pembrolizumab monotherapy in patients with previously treated advanced salivary gland carcinoma in the phase 2 KEYNOTE-158 study

AimWe evaluated pembrolizumab monotherapy in patients with advanced salivary gland carcinoma on the phase 2 KEYNOTE-158 study (NCT02628067). MethodsEligible patients had histologically/cytologically confirmed advanced salivary gland carcinoma with prior failure or intolerance to standard therapy, measurable disease per Response Evaluation Criteria in Solid Tumours (RECIST) v1.1., and ECOG performance status 0–1. Patients were enrolled irrespective of tumour PD-L1 expression. Patients received pembrolizumab 200 mg Q3W for up to 35 cycles (∼2 years). Radiographic imaging occurred every 9 weeks through month 12, then every 12 weeks. PD-L1 positivity was defined as combined positive score ≥1 (evaluated using PD-L1 IHC 22C3 pharmDx). The primary endpoint was objective response rate per RECIST v1.1. ResultsIn total, 109 patients were enrolled (PD-L1–positive, 25.7%). At the data cutoff (October 5, 2020), median follow-up was 53.3 (range, 50.8–56.3) months. Objective response rate was 4.6% (95% CI, 1.5–10.4%) among all patients (complete response, n = 1; partial response, n = 4) and was 10.7% (95% CI, 2.3–28.2%) in patients with PD-L1–positive disease and 2.6% (95% CI, 0.3–9.1%) in patients with PD-L1–negative disease. Duration of response was ≥24 months for all 5 responders; median duration of response was not reached (range, 25.1–49.8+ months). Median progression-free survival and overall survival were 4.0 (95% CI, 2.6–4.2) and 21.1 (95% CI, 15.9–25.5) months, respectively. Treatment-related adverse events occurred in 75.2% (grade 3–4, 15.6%; grade 5, 0%) of patients. Immune-mediated adverse events occurred in 22.0% of patients (grade 3, 5.5%; grade 4–5, 0). ConclusionsA small subset of patients with advanced salivary gland carcinoma treated with pembrolizumab had a response; all had response duration ≥2 years. The safety profile of pembrolizumab was manageable.

Abstract 5098: Genetic and immunologic characteristics of biliary tract cancer patients with LRP1B mutation

Abstract Background: Although the initial clinical results of immune checkpoint inhibitors (ICI) have been obtained in biliary tract cancer (BTC), and previous researches explored potential biomarkers for predicting response to ICI in BTC, and gene LRP1B was found as one of predictive biomarkers. Here we evaluated the mutation information of LRP1B in Chinese patients with BTC, and analyzed the potential explanation for more benefit from ICI treatment in patients with LRP1B mutation. Methods: The formalin-fixed paraffin-embedded specimens of 1324 cancer patients who have underwent next-generation sequencing (NGS) from 2016 to 2021, were included in this study. NGS was performed to detect gene mutation, and tumor mutational burden (TMB) measured by a 733 gene panel. PD-L1 expression detected by using Dako PD-L1 IHC 22C3 pharmDx. Result: The NGS results revealed that 12.76% (169/1324) patients with BTC have LRP1B mutation. Among these 1324 patients, 931 (patients with or without LRP1B mutations were 129 and 802, respectively) patients were available for analysis of TMB level, 820 ((patients with or without LRP1B mutations were 114 and 706, respectively)) patients for analysis of PD-L1 expression, and 1163 (patients with or without LRP1B mutations were 172 and 991, respectively) patients for analysis of MSI-H. TMB level and PD-L1 expression level were compared between groups with and without LRP1B mutation, and results showed that both these two biomarkers were higher in group with LRP1B mutation than without LRP1B mutation, especially TMB level was significantly higher (p&amp;lt;0.001).Further analysis revealed that the median TMB level, proportion of strong positive PD-L1 expression, and proportion of MSI-H were all higher in group of LRP1B mutation than wild type. Conclusion:These results suggest that LRP1B can be considered as one of effective biomarkers for ICI treatment in BTC, the underly mechanism may be related to the high TMB level. Citation Format: Weiwei Chen, Hushan Zhang, Hongmin Dong, Gang Wang, Xiaokai Li, Wanghua Chen, Guodong Li, Saixi Bai, Juan Chen, Wenling Wang. Genetic and immunologic characteristics of biliary tract cancer patients with LRP1B mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5098.

Abstract 5100: Analysis of genetic alterations related to hyper-progressive disease after immunotherapy in patients with non-small cell lung cancer

Abstract Background Hyper-progressive disease (HPD) is an unexpected response pattern observed in immune checkpoint therapy, such patients experience a very rapid disease progression (usually progressed seriously in three months). Predictors of HPD are one of the keys to the management of patients receiving immune checkpoint inhibitors. Some factors, such as MDM2/4 amplification, EGFR mutations and old age may be risk factors for HPD, but the results of different studies are inconsistent. Herein, we evaluated the characteristics of MDM2/4 alterations in Chinese patients with NSCLC. Methods The formalin-fixed paraffin-embedded specimens of cancer patients who have underwent next-generation sequencing (NGS) in 3D Medicines, a laboratory accredited by CAP and Clinical Laboratory Improvement Amendments (CLIA) from May 2017 to May 2020, were included in this study. NGS was performed to detect gene mutation, and tumor mutational burden (TMB) measured by a 733 gene panel. PD-L1 expression detected by using Dako PD-L1 IHC 22C3 pharmDx. Results The proportion of MDM2/4 amplification in Chinese NSCLC patients is 0.86%, the proportion of MDM2 and MDM4 amplification in Chinese NSCLC patients were 0.74% and 0.12%. respectively. Further analysis found lower TMB level in patients with MDM2/4 amplification than patients without MDM2/4 amplification (p&amp;lt;0.001). The median TMB level was also found lower in patients with MDM2/4 amplification than without, and higher ratio of patients with TMB-high (defined as TMB≥10mutant/Mb) was displayed in group with MDM2/4 amplification. Conversely, patients with TMB-high showed lower copy number gain in MDM2/4. However, no difference was found in level of PD-L1 expression between patients with and without MDM2/4 amplification. Conclusion HPD happened during ICI treatment in solid tumor with MDM2/4 amplification may associated with lower TMB level, and PD-L1 expression level has limit effect on MDM2/4 alteration related HPD. Citation Format: Xudong Xiang, Hushan Zhang, Deguang Wang, Heng Li, Qing Lei, Qianli Ma. Analysis of genetic alterations related to hyper-progressive disease after immunotherapy in patients with non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5100.