Tumor PD-L1 Expression Research Articles

Efficacy and safety of nivolumab plus ipilimumab (N+I) versus sunitinib (S) for first-line treatment of patients with advanced sarcomatoid renal cell carcinoma (sRCC) in the phase 3 CheckMate 214 trial with extended 5-year minimum follow-up.

352 Background: sRCC is an aggressive histologic growth pattern in RCC with a poor prognosis and limited therapeutic options. First-line N+I provided efficacy benefits over S in patients (pts) with sRCC and intermediate/poor (I/P)-risk disease at 42 months follow-up. Here, we report an exploratory post hoc analysis of N+I vs S in pts with I/P-risk and sRCC with long-term follow-up of 5 years. Methods: Pts with clear cell advanced RCC were randomized 1:1 to N 3 mg/kg plus I 1 mg/kg every 3 weeks × 4, then N 3 mg/kg every 2 weeks vs S 50 mg once daily (4 weeks; 6-week cycles). Pts with sRCC were identified via independent central pathology review of archival tumor tissue or histological classification per local pathology. Outcomes in pts with sRCC were not prespecified. Endpoints in pts with sRCC and IMDC I/P risk included overall survival (OS), progression-free survival (PFS) per independent radiology review, and objective response rate (ORR) per RECIST v1.1. Outcomes were also assessed per baseline tumor PD-L1 expression level (≥1% vs <1%). Safety outcomes used descriptive statistics. Results: Of 1096 randomized pts in CheckMate 214, 139 I/P-risk pts with sRCC were identified (N+I, n = 74; S, n = 65). Of all treated pts, 9 of 73 (12%) in the N+I arm vs zero of 65 in the S arm remained on treatment. The primary reason for discontinuation was disease progression (N+I, 37%; S, 71%). OS continued to favor N+I vs S (HR 0.46 [95% CI 0.29–0.71]; P = 0.0004; table). PFS benefit with N+I vs S was similarly maintained (HR 0.50 [95% CI 0.32–0.80; P = 0.0036]). Additionally, ORR was higher (61% vs 23%; P < 0.0001), median duration of response was longer (NR vs 25 months), and more pts had complete responses (23% vs 6%) with N+I vs S, respectively. Efficacy was better with N+I vs S regardless of PD-L1 expression, yet the degree of OS, PFS, and ORR benefits with N+I was greater for pts with PD-L1 ≥ 1% (Table). No new safety signals emerged in either arm. Conclusions: N+I showed clinically meaningful benefits in long-term OS, PFS, and the frequency and depth of response vs S in previously untreated pts with sRCC and I/P-risk disease, supporting N+I as a preferred first-line therapy in this population. Clinical trial information: NCT02231749. [Table: see text]

Ag nanoparticles enhance immune checkpoint blockade efficacy by promoting of immune surveillance in melanoma

Immune checkpoint blockade (ICB) therapy, represented by programmed cell death protein 1 (PD-1) and its ligand (PD-L1) monoclonal antibodies (mAbs), has shown an obvious benefit for melanoma immunotherapy, but the overall response rate is still low. To find an effective combination therapy strategy, we successfully produced small size silver nanoparticles coated with sucrose (S-AgNPs) as potent adjuvants. The antitumor effects of S-AgNPs were tested in vitro and comparatively investigated in immunodeficient and immunocompetent mice with melanoma. Fluorescence-activated cell sorting and immunofluorescent staining analysis were conducted to identify the tumor microenvironments. The expression of PD-L1 in tumors was tested by multiple methods. The combination therapy and potential toxicity of S-AgNPs and PD-1 mAbs were assessed in melanoma-bearing mice. In our findings, S-AgNPs presented potent antitumor effects, good druggability and low systemic toxicity. Functionally, we found that S-AgNPs exhibited better antitumor effects in immunocompetent mice. Mechanistically, we showed that S-AgNPs suppress tumor cell proliferation by inducing cellular apoptosis and promote cytotoxic CD8+ T cell infiltration and activity. Preclinically, S-AgNPs showed excellent local antitumor activity and mild systemic immunotoxicity with PD-1 mAbs in the inhibition of melanoma proliferation, providing a novel clinical combination treatment strategy.

Abstract OT2-25-01: Irene study: Phase 2 study of Incmga00012 and the oncolytic virus pelareorep in metastatic triple negative breast cancer

Abstract Background: Triple negative breast cancer (TNBC) is an aggressive subtype accounting for 15% of all breast cancer subtypes. It is characterized by larger tumor size, higher grade, early peak of recurrence, and a worse 5-year overall survival rate compared to other breast cancer subtypes. Treatment with immunotherapy has been shown to be beneficial in PD-L1 positive patients in the metastatic setting. Priming the tumor environment can upregulate PD-L1 expression. Pelareorep, a proprietary isolate of the unmodified replication competent reovirus type 3 Dearing (T3D) strain, a non-enveloped reovirus has been shown to upregulate PD-L1 expression in tumor and inflammatory cells and promote a favorable CD8:regulatory T cell ratio indicating a less immunosuppressive tumor microenvironment. Retifanlimab (INCMGA00012) is PD-1 inhibitor currently in development. A phase 2 study is currently underway studying the combination with the rationale that the administration of pelareorep will prime the tumor microenvironment for enhanced tumor response to PD-1 inhibitor retifanlimab. Trial design: This is a phase II multi-site single-arm clinical trial to study the combination of PD-1 inhibitor retifanlimab and the oncolytic virus pelareorep in patients with metastatic triple negative breast cancer. Eligible patients will receive pelareorep 4.5x1010 TCID50/day, on Days 1, 2, 15 and 16 and retifanlimab 500 mg on day 3 of every 28-day cycle. Patients will be monitored clinically and radiologically for response to treatment. Tumor tissue, stool and blood samples will be collected during treatment to evaluate changes in PD-L1 expression, gut microbiome and inflammatory cells induced by the study drugs. (ClinicalTrials.gov Identifier: NCT04445844) Eligibility criteria: Premenopausal/postmenopausal women with metastatic TNBC who have previously received 1-2 prior lines of chemotherapy in the metastatic setting are eligible for the study. They must have adequate performance status (ECOG PFS 0-2). Specific aims: Primary endpoint will be objective response rate (ORR) and safety, determined by the number, frequency, duration, and severity of AEs using CTCAE v5.0. The Secondary end-points will be progression free survival (PFS), overall survival (OS), duration of response (DOR) and quality of life measures using EORTC QLQ-C30. Statistical methods: Simon’s optimal 2-stage design will be used to calculate sample size. In the first stage, 14 patients will be accrued. If there are 1 or fewer responses in these 14 patients, the study will be stopped. Otherwise, 11 additional patients will be accrued for a total of 25. The null hypothesis will be rejected if 4 or more responses are observed in 25 patients. The first 6 patients will be enrolled in a staggering interval for the safety run-in phase of the study. Accrual: The study is currently enrolling patients at Rutgers Cancer Institute of New Jersey and Ohio State University Comprehensive Cancer Center. There are no safety signals with the combination in patients who have received both drugs to date. Citation Format: Mridula George, Nicole Williams, Coral Omene, Nancy Chan, Shou-En Lu, Danielle Tang, Grey Wilkinson, Shridar Ganesan, Deborah Toppmeyer. Irene study: Phase 2 study of Incmga00012 and the oncolytic virus pelareorep in metastatic triple negative 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 OT2-25-01.

Abstract OT1-18-08: Randomized phase II trial of pembrolizumab/carboplatin vs. carboplatin alone for breast cancer with chest wall recurrence: TBCRC044

Abstract Background: A significant number of patients with breast cancer may develop chest wall recurrence, which can be difficult to treat, and is associated with a poor prognosis. Given the inflammatory nature of chest wall disease, and the association of chest wall disease with lymphovascular invasion, we hypothesized that immunotherapy may be beneficial in this setting. Furthermore, combining immunotherapy and chemotherapy may have a synergistic effect; indeed, the combination of the anti-programmed cell death 1 (PD-1) antibody, pembrolizumab, with chemotherapy has been approved for metastatic triple negative breast cancer (TNBC). Consequently, in this study, we are evaluating the combination of pembrolizumab/carboplatin vs. carboplatin alone for chest wall recurrence. Trial design: This is a phase II study of patients with chest wall disease from breast cancer. Patients are randomized in a 2:1 manner to pembrolizumab/carboplatin x 6 cycles (Arm A) with the option to continue pembrolizumab +/- carboplatin after 6 cycles (Arm Ax) vs. carboplatin alone (Arm B) with the option to cross-over to pembrolizumab +/- carboplatin on progression (Arm Bx). Carboplatin is dosed at AUC 5 IV every 3 weeks, and pembrolizumab at 200 mg IV every 3 weeks. Trastuzumab may be continued with study treatment in patients with HER2 positive disease. Imaging scans (CT chest, abdomen, and pelvis, and bone scan) occur at baseline and every 3 cycles. Chest wall biopsies and peripheral blood is collected at baseline and after completing 2 cycles of treatment for correlative studies. Eligibility criteria: Patients must have chest wall disease from breast cancer. Distant metastases are allowed. TNBC, hormone receptor positive/HER2 negative disease (after 2 prior hormone therapies), and HER2 positive disease (progressed on standard HER2 directed treatment) are eligible. Any number of prior lines of chemotherapy are acceptable, including a prior platinum chemotherapy in the absence of disease progression on the platinum. Specific Aims: Primary aim is to determine disease control rate in the chest wall and other distant sites at 18 weeks of treatment with RECIST 1.1. Secondary aims including determining toxicity, progression-free survival, response based on irRECIST, and response based on tumor PD-L1 expression. Exploratory aims include studying changes in: 1) immune composition of tumor and peripheral blood, 2) peripheral blood cell-free DNA and circulating tumor cells, 3) soluble PD-L1 expression, and 4) association of MYC with PD-1 and immune markers, based on preclinical data demonstrating that MYC upregulates these markers. Statistical Methods: 84 patients (Arm A: 56, Arm B: 28) are being enrolled at 7 sites in the Translational Breast Cancer Research Consortium. The study is powered to identify a 20% difference in disease control rates between Arms A and B (HR 0.52, α= 0.10, ß=0.20). A futility analysis will occur for Arm B after 18 patients are enrolled to allow for early closure if lack of efficacy. Accrual: Present accrual is 57 patients (Arm A: 39, Arm B: 18). (NCT03095352). This trial is partly funded by grants from Merck and University of California San Francisco. Contact information: Neelima Vidula, MD, Massachusetts General Hospital, nvidula@mgh.harvard.edu Citation Format: Neelima Vidula, Rita Nanda, Kathy Miller, Leisha Emens, Vandana Abramson, Ben Park, Minetta C. Liu, Andrei Goga, Hope Rugo. Randomized phase II trial of pembrolizumab/carboplatin vs. carboplatin alone for breast cancer with chest wall recurrence: TBCRC044 [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 OT1-18-08.

Abstract OT1-18-06: KEYNOTE-B49: A phase 3, randomized, double-blind, placebo-controlled study of pembrolizumab plus chemotherapy in patients with HR+/HER2− locally recurrent inoperable or metastatic breast cancer

Abstract Background: For patients with HR+/HER2− advanced breast cancer who experience disease progression on endocrine therapy, cytotoxic chemotherapy (chemo) regimens are standard of care. Adding immunotherapy to chemo may improve patient outcomes. The anti-PD-1 antibody pembrolizumab (pembro) has demonstrated efficacy in patients with triple-negative breast cancer, including those with metastatic disease (KEYNOTE-355) and with early-stage disease (KEYNOTE-522). The phase 1b KEYNOTE-028 trial showed durable activity with pembro monotherapy among patients with previously treated HR+/HER2−, PD-L1-positive (ie, combined positive score [CPS] ≥1) advanced breast cancer. KEYNOTE-B49 (NCT04895358) is a phase 3, randomized, double-blind study comparing pembro plus chemo vs placebo plus chemo in patients with PD-L1-positive, HR+/HER2− locally recurrent inoperable or metastatic breast cancer who progressed on prior endocrine therapy. Methods: Approximately 800 patients with HR+/HER2− locally recurrent inoperable or metastatic breast cancer who are candidates for chemo (no prior chemo for metastatic disease) and who have a PD-L1 CPS ≥1 and documented progression on prior endocrine therapy will be enrolled. Prior endocrine therapy comprises ≥2 lines (≥1 in combination with a CDK4/6 inhibitor) in the metastatic setting or 1 line plus CDK4/6 inhibitor treatment with relapse within 24 months of surgery in the adjuvant setting. Patients without CDK4/6 inhibitor treatment may enroll if they have progression within 6 months of starting endocrine therapy for metastatic disease and within 24 months of surgery while on adjuvant endocrine therapy. Patients are randomized 1:1 to receive pembro 200 mg IV or placebo Q3W, each in combination with investigator’s choice of 1 of 4 chemo regimens: paclitaxel 90 mg/m2 IV on days 1, 8, and 15 Q4W; nab-paclitaxel 100 mg/m2 IV on days 1, 8, and 15 Q4W; liposomal doxorubicin 50 mg/m2 IV on day 1 Q4W; or capecitabine 1000 mg/m2 PO BID on days 1-14 Q3W. Randomization is stratified by tumor PD-L1 expression (CPS 1-9 vs ≥10), visceral metastases (yes vs no), and chemo (taxanes vs liposomal doxorubicin vs capecitabine). Participants, investigators, and study personnel are blinded to treatment assignment and tumor PD-L1 status. Treatment is continued until radiographic disease progression, unacceptable toxicity, withdrawal, or, for pembro/placebo, completion of 35 administrations (~2 years); chemo can be continued per investigator discretion. Tumor PD-L1 status is determined centrally using the PD-L1 IHC 22C3 pharmDx assay (Agilent Technologies; Carpinteria, CA, USA). Radiologic assessments are performed every 9 weeks through the first 54 weeks and then every 12 weeks thereafter to detect evidence of progression. AEs occurring from randomization until 30 days after treatment discontinuation (90 days for serious AEs) are graded per NCI-CTCAE v 5.0. Primary endpoints are PFS per RECIST v1.1 by blinded independent central review in patients with PD-L1 CPS ≥10 and ≥1 tumors, separately. A key secondary endpoint is OS; additional secondary endpoints are investigator-assessed PFS, ORR, disease control rate, duration of response, and health-related quality of life using EORTC QLQ-C30 (each assessed in patients with PD-L1 CPS ≥10 and ≥1 tumors), as well as safety in the overall population. The family-wise type-I error rate is controlled at 0.025 (one-sided) across the PFS and OS endpoints. PFS and OS will be estimated using the Kaplan-Meier method. Treatment differences will be assessed using a stratified log-rank test, and HRs and 95% CIs will be determined using a stratified Cox proportional hazards model. Enrollment is ongoing. Citation Format: Peter Schmid, Carlos Baccan, Zifang Guo, Kostas Tryfonidis, Hope S. Rugo. KEYNOTE-B49: A phase 3, randomized, double-blind, placebo-controlled study of pembrolizumab plus chemotherapy in patients with HR+/HER2− locally recurrent inoperable or metastatic 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 OT1-18-06.

Abstract PD4-09: Comprehensive assessment of the genomic landscape of breast cancer brain metastases reveals targetable alterations and genomic signatures relevant to immune-checkpoint and PARP inhibitors

Abstract Background: Central nervous system (CNS) disease secondary to breast cancer (BC) is a growing clinical problem and a cause of significant morbidity and mortality. A better understanding of the genomic landscape is key to understanding its cause and to developing novel treatments. In this study, we examined the genomic landscape of a large cohort of breast cancer brain metastases (BMs) and compared them to a cohort of local breast cancers (BCs) and non-CNS metastases (N-CNS). Material and Methods: We analyzed 822 BMs and compared them to 11,988 local, breast-biopsied BCs and 15,516 N-CNS (unpaired samples) with comprehensive genomic profiling (CGP) for all classes of alterations in at least 324 genes (Foundation Medicine, Cambridge, MA, USA). Homologous recombination deficiency detected by genome-wide loss of heterozygosity (HRD-gLOH; cutoff 16%), tumour mutation burden (TMB; cutoff 10 mutations/Mb), microsatellite instability (MSI) and PD-L1 prevalence and expression by VENTANA SP142 immune cell immunohistochemistry (IHC; cutoff 1%) was also investigated within and across the cohorts. Results: As compared to local BCs, 31 genes were significantly enriched for genomic alterations in BMs with BM prevalence >3% and false-discovery rate (FDR) <0.1. The most enriched genes were: TP53 (71.8%), MYC (25.9%), ERBB2 (24.6%), PTEN (16.7%), CDKN2A and RB1 (10.3% each), NF1 (8.6%), GNAS (7.9%), BRCA1, CDKN2B and ZNF217 (7.8% each), ARID1A (7.3%), CCNE1 (6.7%), ESR1 (6.4%), MAP2K4 (5.8%), AURKA (5.5%) and PIK3R1 (5.1%). Of these 31 genes, 26 were also enriched between BM vs N-CNS. The BM-enriched. genes that lost significance in comparison to N-CNS were: ZNF217, ARID1A, MAP2K4, AURKA and ARFRP1. PIK3CA prevalence was BMs: 30.2%, BCs: 31.8% and N-CNS: 38.9% (no significant difference between cohorts). HRD-gLOH was higher in BMs: 52.0% vs BCs: 33.7% and N-CNS: 31.5%. The prevalence of immune checkpoint inhibition (ICPI) biomarkers in BM were as follows: TMB-High 15.5%, MSI-High 2.0%, PD-L1 (CD274) 3.5% and its paralogue PDCD1LG2 (PD-L2, CD273) 3.4%. All were significantly higher in the BM vs primary BC and N-CNS group (p<0.05, FDR<0.1 for all comparisons). PD-L1 copy number (CN) variation was also higher in BMs: 3.4% vs BCs: 1.6% and N-CNS: 1.1%. PD-L1 positive expression was lower in BMs: 38.7% vs BCs: 54.3% but higher than N-CNS: 26.2%. Higher PD-L1 positive expression was observed in ER-/HER2- BMs: 48.3% vs BCs: 50.0% vs N-CNS: 21.4%. Table 1 summarizes the genomic signatures and PD-L1 positivity in the BC, BM and N-CNS cohorts and within different receptor subtypes. Conclusion: A high prevalence of clinically-relevant genomic alterations in BM is identified in comparison to the local BCs and/or N-CNS disease. A high proportion of BMs have high HRD-gLOH, TMB, MSI and PD-L1 alterations rendering them potentially amenable to treatment with ICPIs and PARP inhibitors. These data reinforce the importance of acquiring BM material and/or cerebrospinal fluid for CGP to enable rationale treatment decisions as well for enrolment into genomically driven BM studies of targeted agents. Table 1.Prevalence (%) of the genomic signatures HRD-gLOH, TMB, MSI and PD-L1+ expression.Site% HRD-gLOH% TMB-H% MSI-H% PDL1+ALLlocal BC33.70%. (2573/7636)5.04%. (527/10464)0.37%. (39/10464)54.25%. (1092/2013)BM52.01%. (362/696)15.51%. (116/748)2.01%. (15/748)38.73%. (55/142)N-CNS31.55%. (3237/10260)9.82%. (1395/14210)0.23%. (32/14210)26.21%. (615/2346)ER+/HER2-local BC31.48%. (119/378)3.41%. (19/557)0.36%. (2/557)40.00%. (14/35)BM43.17%. (79/183)11.40%. (22/193)1.04%. (2/193)23.08%. (9/39)N-CNS29.65%. (126/425)8.92%. (51/572)0.17%. (1/572)12.99%. (10/77)ER+/HER2+local BC19.57%. (9/46)2.78%. (2/72)0.00%. (0/72)42.86%. (3/7)BM26.67%. (16/60)9.68%. (6/62)0.00%. (0/62)27.27%. (3/11)N-CNS47.37%. (18/38)19.57%. (9/46)0.00%. (0/46)14.29%. (1/7)ER-/HER2+local BC32.26%. (10/31)8.70%. (4/46)0.00%. (0/46)100.00%. (5/5)BM33.33%. (23/69)21.33%. (16/75)2.67%. (2/75)57.14%. (4/7)N-CNS34.38%. (11/32)4.26%. (2/47)0.00%. (0/47)42.86%. (3/7)ER-/HER2-local BC52.25%. (186/356)2.70%. (14/518)0.19%. (1/518)50.00%. (30/60)BM70.45%. (174/247)17.41%. (47/270)2.59%. (7/270)48.33%. (29/60)N-CNS43.52%. (84/193)10.04%. (27/269)0.74%. (2/269)21.43%. (6/28) Citation Format: Athina Giannoudis, Ethan Sokol, Shakti H Ramkissoon, Talvinder Bhogal, Kimberly McGregor, Allison Clark, Evangelia D Razis, Rupert Bartsch, Richard SP Huang, Carlo Palmieri. Comprehensive assessment of the genomic landscape of breast cancer brain metastases reveals targetable alterations and genomic signatures relevant to immune-checkpoint and PARP inhibitors [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 PD4-09.

GOBLET: A phase 1/2 multiple-indication biomarker, safety, and efficacy study in advanced or metastatic gastrointestinal cancers exploring treatment combinations with pelareorep and atezolizumab.

TPS216 Background: Checkpoint blockade therapy only benefits a small subset of GI cancer patients (approximately 4%) with microsatellite instability-high (MSI-H) tumors, which are characterized as immunologically ‘hot’ (Bonneville et al., 2017). Most GI cancers, however, have microsatellite stable (MSS) tumors, which have an immunologically “cold” phenotype with fewer genetic mutations, reduced immune cell infiltration, and downregulated immune checkpoint proteins. These attributes make MSS tumors resistant to conventional immunotherapy including checkpoint blockade therapy (Ooki et al., 2021). Pelareorep is a naturally occurring, non-genetically modified reovirus. Upon intravenous administration, pelareorep selectively kills tumor cells and promotes several immunologic effects that prime tumors to respond to checkpoint blockade. These include the stimulation of tumor-directed innate and adaptive immune responses, increased T cell infiltration, expansion of new T cell clones, and increased PD-L1 expression in tumors (Samson et al., 2018, Manso et al. 2021 AACR). Given its expected synergy with checkpoint blockade, as well as its encouraging efficacy in prior GI cancer studies (Mahalingam et al. 2020), the GOBLET study is designed to evaluate pelareorep plus atezolizumab in multiple GI cancer indications. Methods: GOBLET is an open-label, non-randomized, multiple-cohort, phase 1/2 study in patients with advanced or metastatic GI cancers. This study employs a Simon two-stage design. Stage 1 comprises four treatment groups: Cohort 1 – First-line pancreatic cancer treated with pelareorep plus atezolizumab and chemotherapy (gemcitabine and nab-paclitaxel) (N = 12); Cohort 2 – First-line MSI-H colorectal cancer (CRC) treated with pelareorep plus atezolizumab (N = 19); Cohort 3 – Third-line CRC treated with pelareorep plus atezolizumab and chemotherapy (trifluridine/tipiracil) (N = 14); and Cohort 4 – Second-line or later squamous cell carcinoma of the anal canal treated with pelareorep plus atezolizumab (N = 10). The first 3-6 patients enrolled into the chemotherapy-containing cohorts (Cohorts 1 and 3) comprise a safety run-in that must be successfully concluded prior to enrolling additional patients into these cohorts. The primary objectives are safety and efficacy based on objective response rate (ORR) at week 16. Any cohort showing a promising ORR in Stage 1, based on pre-specified criteria, may be advanced to Stage 2 and enroll additional patients. Clinical trial information: 2020-003996-16.

Pembrolizumab (PEM) plus granulocyte macrophage colony stimulating factor (GM-CSF) in advanced biliary cancers (ABC): Final outcomes of a phase 2 trial.

444 Background: Immune checkpoint inhibitors (ICI) have limited activity as monotherapy in unselected patients with ABC; the objective response rate (ORR) of PEM was 5.8% in the multicenter phase 2 KEYNOTE-158 trial. GM-CSF modulates immune cells including monocytes and the innate immune response and has demonstrated safety and prolonged survival (OS) in combination with ipilimumab in melanoma. This phase 2 trial was designed to evaluate the efficacy and safety of PEM in combination with GM-CSF in ABC. Methods: Single-center, phase 2 trial with Simon’s 2-stage design and expansion cohort (EC) (NCT02703714). Key eligibility: ABC with progression/intolerance on ≥ 1 standard therapy, no prior ICI, bilirubin ≤1.5xULN. Treatment: PEM 200 mg IV Q21 days plus 2 cycles of GM-CSF 250 µg SC D1-14 Q21 days in cycles 2 and 3 (Stage 1 and EC) or in cycles 1 and 2 (Stage 2). Primary endpoint was objective response rate (ORR) by RECIST 1.1, H0 5% vs. H1 20%. Key secondary endpoints were safety, progression-free survival (PFS), OS, PD-L1 expression. Exploratory endpoints included relationship between efficacy outcomes and anatomic subsite, risk factors, and tumor genotype. Results: Overall, 42 patients enrolled between 5/2016-12/2019: n = 9 in Stage 1, n = 18 in Stage 2, and n = 15 in EC. Overall: median age 61; female 67%; intrahepatic (ICC) 67%, extrahepatic (ECC) 26%, gallbladder (GBC) 7%; stage IV 90%; hepatitis B/C virus positive (HBV/HCV+) 24%; microsatellite instability (MSI-H)/stable (MSS)/unknown n = 1/35/6. Immune-related (ir)AE occurred in 69%, grade 3/4 treatment-related (tr)AE in 10%, all-cause serious (S)AE in 36%, and trSAE in 7%. ORR was 12% (95% CI: 4, 26), with median PFS of 63 days (95% CI: 55, 125), PFS at 6 months in 27% (95% CI: 14, 43), and median OS 3of 93 days (95% CI: 243, 573). There was no significant difference in ORR, PFS, or OS by anatomic subsite or tumor PD-L1 expression; HBV/HCV+ showed trends toward higher ORR (30% vs 6%, p = 0.08) and longer median PFS (276 vs 63 days, p = 0.06) and OS (1033 vs 323 days, p = 0.052). Conclusions: The combination of PEM plus GM-CSF was safe and well-tolerated with higher ORR than expected for PEM monotherapy in a predominantly MSS ABC population but did not meet target ORR threshold for efficacy. ORR and median PFS and OS were highest in patients with underlying HBV or HCV infection. Immune profiling of on-treatment biopsies and peripheral blood are ongoing to ascertain influence of both PEM and GM-CSF on circulating and tumor immune microenvironment. Clinical trial information: NCT02703714.

Risk factors for immune checkpoint inhibitor-related pneumonitis in non-small cell lung cancer

BackgroundImmune checkpoint inhibitors (ICIs) have led to dramatic improvements in survival a subset of patients with non-small cell lung cancer (NSCLC); however, they have been shown to cause life-threatening toxicity such as immune checkpoint inhibitor-related pneumonitis (CIP). Our previous studies have shown that chronic obstructive pulmonary disease (COPD) and circulating cytokines are associated with clinical outcomes in NSCLC patients receiving ICIs. However, the relationship between these factors and the development of CIP is unclear. In this study, we retrospectively assessed NSCLC patients receiving ICIs to identify CIP risk factors.MethodsThis retrospective cohort study reviewed medical records of NSCLC patients receiving ICIs targeting programmed cell death 1 (PD-1) or its ligand PD-L1 between March 2017 and December 2020 at Zhongshan Hospital Fudan University. CIP was diagnosed by the treating investigator. Clinical characteristics and baseline plasma cytokines were collected. Logistic regression was used to compare clinical characteristics and circulating cytokine levels between patients with and without CIP to identify CIP risk factors.ResultsOf 164 NSCLC patients who received ICIs, CIP developed in 20 cases (12.2%). The presence of COPD [odds ratio (OR), 7.194; 95% confidence interval (CI): 1.130 to 45.798; P=0.037] and PD-L1 expression of ≥50% (OR, 7.184; 95% CI: 1.154 to 44.721; P=0.035) were independently associated with a higher incidence of CIP, whereas a higher baseline level of interleukin-8 (IL-8) was associated with a lower incidence of CIP (OR, 0.758; 95% CI: 0.587 to 0.978; P=0.033). The independent risk factors from final multivariate analysis were incorporated into a nomogram to predict the incidence of CIP. The nomogram model receiver operating characteristic (ROC) curve had a good predictive accuracy of 0.883 (95% CI: 0.806 to 0.959).ConclusionsIncreased risk of CIP independently associated with history of COPD, tumor PD-L1 expression ≥50%, and low baseline IL-8 level. The nomogram may hold promise for CIP risk assessment in the administration of ICIs.

Cilengitide, an αvβ3-integrin inhibitor, enhances the efficacy of anti-programmed cell death-1 therapy in a murine melanoma model

ABSTRACT Integrins play an important role in multiple stages of tumor progression and metastasis. Previous studies have shown synergistic effects of combined αvβ6-integrin and αvβ8-integrin inhibitors with immunotherapy. However, the role of αvβ3-integrin inhibitor in tumor immunity is still unclear. In this study, we aimed to elucidate the impact of the αvβ3-integrin inhibitor on PD-L1 expression and sensitivity to immune checkpoint blockade in melanoma. We investigated the effects of cilengitide, an αvβ3-integrin inhibitor, on cell viability and apoptosis of melanoma cell lines. And we explored how cilengitide regulated the expression of PD-L1 in melanoma cells in vitro and in vivo, using immunofluorescence, flow cytometry, Western blotting, and immunohistochemistry. A subcutaneous B16 murine melanoma model was utilized to determine whether combining cilengitide with anti-PD1 therapy inhibited tumor growth and positively regulated tumor microenvironment (TME). Our results showed that cilengitide inhibited cell viability and induced apoptosis in B16 and A375 cell lines. Furthermore, cilengitide decreased PD-L1 expression by reducing STAT3 phosphorylation in two melanoma cell lines. Cilengitide also reduced subcutaneous tumor PD-L1 expression in the B16 murine melanoma model. Accordingly, cilengitide positively regulated antitumor immune responses and provided durable therapy when combined with anti-PD1 monoclonal antibody in the murine melanoma model. This combination therapy reduced tumor growth and extended survival. Our study highlights that cilengitide enhances the efficacy of anti-PD1 therapy and produces a stronger antitumor immune response. This combination therefore represents a novel therapeutic regimen that may improve immunotherapy treratment.

Clinical Significance and Immune Landscape of Recurrence-Associated Ferroptosis Signature in Early-Stage Lung Adenocarcinoma.

BackgroundThe prevalence of patients newly diagnosed with early-stage lung adenocarcinoma (LUAD) is growing alongside significant advances in screening approaches. This study aimed to construct ferroptosis-related gene score (FRGscore) for predicting recurrence, explore immune-molecular characteristics, and determine the benefit of immunotherapy in distinct ferroptosis-based patterns and FRGscore-defined subgroups.MethodsA total of 1,085 early-stage LUAD patients from four independent cohorts were included. Consensus clustering analysis was performed using 217 co-expressed FRGs to explore different ferroptosis-mediated patterns. An FRG scoring system was established to predict relapse, quantify ferroptosis-mediated patterns, and evaluate the response to immunotherapy in individual patients based on Lasso-penalized and stepwise Cox regression analyses. Immune landscape involving multiple parameters was further evaluated, stratified by cluster subtypes and FRGscore subgroups.ResultsTwo ferroptosis-mediated patterns were identified and verified, which were characterized by significantly distinct prognosis and immune profiles. Analyses of immune characteristics showed that identified ferroptosis patterns were characterized as immune-inflamed phenotype and immune-exhausted phenotype. The FRG scoring model based on 11 FRG-derived signatures panel classified patients into the FRGscore-high and FRGscore-low subgroups. Significantly longer recurrence-free survival (RFS) and overall survival (OS) were observed in the FRGscore-low subgroup. FRGscore-low patients were characterized by higher tumor mutational burden (TMB), immunoscore, immunophenoscore, and PD-L1 expression level and were associated with lower Tumor Immune Dysfunction and Exclusion (TIDE) score, whereas the opposite was observed in FRGscore-high patients. Immune-active pathways were remarkably enriched in the FRGscore-low subgroup. This scoring model remained highly predictive of prognosis across different clinical, molecular, and immune subgroups. Further analysis indicated that FRGscore-low patients exhibited higher response to anti-PD-1/PD-L1 immunotherapy and better clinical benefits based on two independent immunotherapy cohorts.ConclusionThe proposed FRGscore could highly distinguish the recurrence patterns and molecular and immune characteristics and could predict immunotherapy prognosis, potentially representing a powerful prognostic tool for further optimization of individuated treatment and management strategies in early-stage LUAD.

Crosstalk Between Four Types of RNA Modification Writers Characterizes the Tumor Immune Microenvironment Infiltration Patterns in Skin Cutaneous Melanoma.

The “writers” of four types of adenosine (A)-related RNA modifications (N6-methyladenosine, N1-methyladenosine, alternative polyadenylation, as well as A-to-inosine RNA editing) are closely related to the tumorigenesis and progression of many cancer types, including skin cutaneous melanoma (SKCM). However, the potential roles of the crosstalk between these RNA modification “writers” in the tumor microenvironment (TME) remain unclear. The RNA modification patterns were identified using an unsupervised clustering method. Subsequently, based on differentially expressed genes responsible for the aforementioned RNA modification patterns, an RNA modification “writer” scoring model (W_Score) was constructed to quantify the RNA modification-associated subtypes in individual patients. Moreover, a correlation analysis for W_Score and the TME characteristics, clinical features, molecular subtypes, drug sensitivities, immune responses, and prognosis was performed. We identified three RNA modification patterns, corresponding to distinct tumor immune microenvironment characteristics and survival outcomes. Based on the W_Score score, which was extracted from the RNA modification-related signature genes, patients with SKCM were divided into high- and low-W_Score groups. The low-W_Score group was characterized by better survival outcomes and strengthened immunocyte infiltration. Further analysis showed that the low-W_Score group was positively associated with higher tumor mutation burden and PD-L1 expression. Of note, two immunotherapy cohorts demonstrated that patients with low W_Score exhibited long-term clinical benefits and an enhanced immune response. This study is the first to systematically analyze four types of A-related RNA modifications in SKCM, revealing that these “writers” essentially contribute to TME complexity and diversity. We quantitatively evaluated the RNA modification patterns in individual tumors, which could aid in developing personalized immunotherapy strategies for patients.

PD-L1 tumor expression is associated with poor prognosis and systemic immunosuppression in glioblastoma.

Glioblastoma is the most common primary malignant brain tumor in the adult, whose grim prognosis largely relates to the absence of effective treatment targets. Given its success in other cancers, immunotherapy has been trialed in glioblastoma and failed to demonstrate the expected benefit. Importantly, these disappointing results highlight the importance of understanding the unique and transforming biology of glioblastoma and its microenvironment. Our goal was to evaluate and characterize the expression of PD-L1 through immunohistochemistry in a large glioblastoma cohort. We further studied PD-L1 expression-associated prognosis and its correlation to systemic and neuropathological parameters. A series of 352 glioblastoma specimens (313 initial resection, 39 matched recurrences) was collected, with a detailed characterization of tumor neuropathological characteristics, including the presence, density and location of tumor infiltrating lymphocytes (TIL). Two hematological markers, absolute lymphocyte count and neutrophil-lymphocyte ratio (NLR), were used to analyze and correlate with systemic inflammation and immunosuppression. Immunohistochemistry was performed to evaluate PD-L1 expression. Membranous PD-L1 expression was identified in 31% (98/313) of newly diagnosed and 46% (18/39) of matched recurrent tumors. TIL were found in 26% (82/313) of primary tumors and both density and location were found to be significantly associated with PD-L1 expression (p < 0.001). Interestingly, PD-L1 expressing tumors had more frequently areas with sarcomatous differentiation (p < 0.001) and were significantly associated with lower lymphocyte count (p = 0.018) and higher NLR ratio (p = 0.004) upon diagnosis. Importantly, PD-L1 expression was an independent poor prognostic marker in our cohort. Taken together, our data points to a putative role for PD-L1 expression in glioblastoma biology, which correlates to poor patient overall survival, as well as with a general systemic inflammatory status and immunosuppression.

A Novel Ferroptosis-Based Molecular Signature Associated with Biochemical Recurrence-Free Survival and Tumor Immune Microenvironment of Prostate Cancer.

Objective: To identify ferroptosis-related molecular clusters, and to develop and validate a ferroptosis-based molecular signature for predicting biochemical recurrence-free survival (BCRFS) and tumor immune microenvironment of prostate cancer (PCa). Materials and Methods: The clinical data and transcriptome data of PCa were downloaded from TCGA and GEO database. Ferroptosis-related genes (FRGs) were obtained from FerrDb database. We performed consensus clustering analysis to identify ferroptosis-related molecular subtypes for PCa. Univariate and multivariate Cox regression analysis were used to establish a ferroptosis-based signature for predicting BCRFS. Internal verification, external verification and subgroup survival analysis were then successfully performed. Results: There was a total of 40 differentially expressed FRGs in PCa. We then identified three ferroptosis-related molecular clusters of PCa, which have significantly different immune infiltrating cells, tumor immune microenvironment and PD-L1 expression level. More importantly, a novel ferroptosis-based signature for predicting BCRFS of PCa based on four FRGs (including ASNS, GPT2, NFE2L2, RRM2) was developed. Internal and external verifications were then successfully performed. Patients with high-risk score were associated with significant poor BCRFS compared with those with low-risk score in training cohort, testing cohort and validating cohort, respectively. The area under time-dependent Receiver Operating Characteristic (ROC) curve were 0.755, 0.705 and 0.726 in training cohort, testing cohort and validating cohort, respectively, indicating the great performance of this signature. Independent prognostic analysis indicated that this signature was an independent predictor for BCRFS of PCa. Subgroup analysis revealed that this signature was particularly suitable for younger or stage T III-IV or stage N0 or cluster 1-2 PCa patients. Patients with high-risk score have significantly different tumor immune microenvironment in comparison with those with low-risk score. The results of qRT-PCR successfully verified the mRNA expression levels of ASNS, GPT2, RRM2 and NFE2L2 in DU-145 and RWPE-1 cells while the results of IHC staining exactly verified the relative protein expression levels of ASNS, GPT2, RRM2 and NFE2L2 between PCa and BPH tissues. Conclusions: This study successfully identified three ferroptosis-related molecular clusters. Besides, we developed and validated a novel ferroptosis-based molecular signature, which performed well in predicting BCRFS and tumor immune microenvironment of PCa.

The integration of systemic and tumor PD-L1 as a predictive biomarker of clinical outcomes in patients with advanced NSCLC treated with PD-(L)1blockade agents.

Tumor PD-L1 expression is a predictive biomarker for patients with NSCLC receiving PD-(L)1 blockade agents. However, although increased tumor PD-L1 expression predicts responsiveness, clinical benefit has been observed regardless of tumor PD-L1 expression, suggesting the existence of other PD-L1 sources. Theaim of our study was to analyze whether integrating systemic and tumor PD-L1 is more predictive of efficacy in patients with advanced NSCLC receiving PD-(L)1 blockade agents. Twenty-nine healthy donors and 119 consecutive patients with advanced NSCLC treated with PD-(L)1 drug were prospectively included. Pretreatment blood samples were collected to evaluate PD-L1 levels on circulating immune cells, platelets (PLTs), platelet microparticles (PMPs), and the plasma soluble PD-L1 concentration (sPD-L1). Tumor PD-L1 status was assessed by immunohistochemistry. The percentages of circulating PD-L1 + leukocytes, sPD-L1 levels, and tumor PD-L1 were correlated with efficacy. No differences in the percentages of circulating PD-L1 + leukocytes were observed according to tumor PD-L1 expression. Significantly longer progression-free survival was observed in patients with higher percentages of PD-L1 + CD14 + , PD-L1 + neutrophils, PD-L1 + PLTs, and PD-L1 + PMPs and significantly longer overall survival was observed in patients with higher percentages of PD-L1 + CD14 + and high tumor PD-L1 expression. Integrating the PD-L1 data of circulating and tumor PD-L1 results significantly stratified patients according to the efficacy of PD-(L1) blockade agents. Our results suggest that integrating circulating PD-L1 + leukocytes, PLT, PMPs, and sPD-L1 and tumor PD-L1 expression may be helpful to decide on the best treatment strategy in patients with advanced NSCLC who are candidates for PD-(L)1 blockade agents.

COX-2 Inhibitors Decrease Expression of PD-L1 in Colon Tumors and Increase the Influx of Type I Tumor-infiltrating Lymphocytes.

Nonsteroidal anti-inflammatories (NSAID) are an essential component of any combination chemoprevention of colon cancer. We show NSAID treatment reduces PD-L1 expression on intestinal tumor cells. NSAID regulation of PD-L1 is dependent on COX-2 expression. These data underscore an important immunologic mechanism of action for NSAID in colon cancer prevention. See related Spotlight, p. 209.

Urogenital Microbiota:Potentially Important Determinant of PD-L1 Expression in Male Patients with Non-muscle Invasive Bladder Cancer

BackgroundUrogenital microbiota may be associated with the recurrence of bladder cancer, but the underlying mechanism remains unclear. The notion that microbiota can upregulate PD-L1 expression in certain epithelial tumors to promote immune escape has been demonstrated. Thus, we hypothesized that the urogenital microbiota may be involved in the recurrence and progression of non-muscle invasive bladder cancer (NMIBC) by upregulating the PD-L1 expression. To test this hypothesis, we investigated the relationship between urogenital microbial community and PD-L1 expression in male patients with NMIBC.Results16S rRNA gene sequencing was performed to analyse the composition of urogenital microbiota, and the expression of PD-L1 in cancerous tissues was detected by immunohistochemistry. The subjects (aged 43–79 years) were divided into PD-L1-positive group (Group P, n = 9) and PD-L1-negative group (Group N, n = 19) respectively based on their PD-L1 immunohistochemical results. No statistically significant differences were found in the demographic characteristics between group P and N. We observed that group P exhibited higher species richness (based on Observed species and Ace index, both P < 0.05). Furthermore, subgroup analysis showed that the increase in number of PD-L1 positive cells was accompanied by increased richness of urogenital microbiota. Significantly different composition of urogenital microbiota was found between group P and group N (based on weighted Unifrac and unweighted Unifrac distances metric, both P < 0.05). Enrichment of some bacterial genera (e.g., Leptotrichia, Roseomonas, and Propionibacterium) and decrease of some bacterial genera (e.g., Prevotella and Massilia) were observed in group P as compared with group N. These findings indicated that these genera may affect the expression of PD-L1 through some mechanisms to be studied.ConclusionOur study provided for the first time an overview of the association between urogenital microbiota and PD-L1 expression in male patients with NMIBC, indicating that urogenital microbiota was an important determinant of PD-L1 expression in male NMIBC patients.

Abstract IA22: Immunotherapy for melanoma: Checkpoint blockade combinations

Abstract Given the activity noted with both CTLA-4 or PD-1 blockade, clinical trials are now investigating combination checkpoint blockade. The most mature data with a combination of ipilimumab + nivolumab in melanoma showed a response rate of 60% in the context of increased, yet manageable toxicity. Such responses are generally durable, even when treatment was stopped early for toxicity. Unlike in studies of PD-1 blockade monotherapy, there was no significant difference in clinical activity based on tumor expression of PD-L1. This approach has gained US regulatory approval for metastatic melanoma and is in late stage clinical trials for other malignancies. Attention is being paid to the reasons underlying the efficacy of checkpoint blockade in certain malignancies. One hypothesis has been that cancers having a high mutational load may be more amenable to immune modulation by virtue of the larger number of potential neo-epitopes present, fostering baseline immune recognition that can then be potentiated by checkpoint blockade. We have found that melanoma patients having long term clinical activity with ipilimumab have a significantly greater median number of non-synonymous passenger mutations, compared with patients who do not respond or those who have only short-term regression. Strategies to enhance baseline immune reactivity are therefore necessary to investigate as means to improve the impact of checkpoint blockade on a broad spectrum of cancers. The presence of suppressive myeloid cells and regulatory T cells in the tumor microenvironment is emerging as a mechanism of resistance to the anti-tumor activity for checkpoint blockade. Strategies to overcome this include agonism of GITR and selective suppression of PI3K-g. Citation Format: Jedd D. Wolchok. Immunotherapy for melanoma: Checkpoint blockade combinations [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr IA22.

Role of immunotherapy in metastatic EGFRm NSCLC: Is it relevant?

EGFR-TKIs have changed the landscape of metastatic NSCLC treatment with a significant improvement in survival of EGFRm patients compared to wild-type EGFR. Even with the newer third generation EGFR TKIs like, Osimertinib, which has proven efficacy against the resistance mutation of EGFRm T790M, progression eventually occurs. There are limited treatment options for patients with metastatic EGFRm NSCLC with other acquired resistance. Therefore, novel therapeutic combination strategies are being researched to overcome potential resistance to EGFR-TKI-targeted therapy. The ICIs targeting the programmed cell death-1 pathway in patients with EGFRm NSCLC were greatly anticipated based on preclinical studies showing increased PD-L1 expression. In clinical settings, this increased expression did not translate into a survival benefit. Treatment with ICIs failed to positively affect EGFRm patients because of multiple reasons: nonsynonymous tumor mutational burden, lower PD-L1 expression in tumors, and cancer cells utilizing alternate immune escape mechanisms. The NCCN guidelines currently do not recommend immunotherapy in patients with metastatic EGFRm NSCLC. Recently, a subgroup analysis in the IMpower150 study provided a signal for overall survival of atezolizumab with bevacizumab plus chemotherapy in EGFRm-TKI progressed patients. Based on these encouraging findings, several combinations of ICIs and EGFR-TKIs are being evaluated in TKI-failed EGFRm patients. These regimens might provide a favorable therapeutic effect by combining higher response rates of TKIs and durable disease control of ICIs. However, further research is warranted to understand the exact underlying molecular and cellular mechanisms responsible for the clinical benefits. In this article, we explored the TKI failed metastatic EGFRm NSCLC, reviewed the available clinical data of ICI use in metastatic EGFRm NSCLC, and discussed its emerging role as a combination regimen in this patient population.

Economic Evaluation of First-Line Camrelizumab for Advanced Non-small-cell Lung Cancer in China.

Background: As the first domestic PD-1 antibody approved for lung cancer in China, camrelizumab has exhibited proven effectiveness for non-small-cell lung cancer (NSCLC) patients. However, the cost-effectiveness of this new regimen remains to be investigated.Objective: To evaluate the cost-effectiveness of camrelizumab combination therapy vs. chemotherapy for previously untreated patients with advanced, non-squamous NSCLC without Alk or Egfr genomic aberrations from the perspective of China's healthcare system.Methods: Based on the CameL trial, the study developed a three-health state Markov model to evaluate the cost-effectiveness of adding camrelizumab to chemotherapy compared to chemotherapy alone in NSCLC patients. The analysis models were conducted for patients unselected by PD-L1 tumor expression (the base case) and the patient subgroup with PD-L1-expressing tumors (≥1%). Primary model outcomes included the costs in US dollars and health outcomes in quality-adjusted life-years (QALYs) as well as the incremental cost-effectiveness ratio (ICER) under a willingness-to-pay threshold of $31,500 per QALY. Additionally, a scenario analysis that adjusted within-trial crossover was employed to evaluate camrelizumab combination therapy compared to chemotherapy without subsequent use of PD1/PD-L1 antibodies.Results: Camrelizumab combination therapy was more costly and provided additional 0.11 QALYs over chemotherapy in the base case analysis (0.86 vs. 0.75 QALYs), 0.12 QALYs over chemotherapy in the subgroup analysis (0.99 vs. 0.88 QALYs), and 0.34 QALYs over chemotherapy in the scenario analysis (0.86 vs. 0.52 QALYs). Correspondingly, the ICER was $63,080 per QALY, $46,311 per QALY, and $30,591 per QALY, in the base case, the subgroup, and the scenario analysis, respectively. One-way sensitivity analyses revealed that ICERs of the base case and the subgroup analysis were most sensitive to the cost of camrelizumab, the cost of pemetrexed. Besides, the base case and subgroup analysis were more sensitive to the risk of neutrophil count decreased in the camrelizumab and the utility of stable disease, respectively.Conclusion: Although camrelizumab combination therapy is not cost-effective as first-line therapy for NSCLC patients in China in the base case, adjusting within-trial crossover would move the treatment regimen toward cost-effectiveness in the scenario analysis.