Anti PD-L1 Research Articles

Access to systemic treatment of non-melanoma skin cancer in Spain: a survey analysis.

Novel and highly effective drugs for non-melanoma skin cancer (NMSC) improve patient outcomes, but their high cost strains healthcare systems. Spain's decentralized public health system, managed by 17 autonomous communities (AaCc), raises concerns about equitable access. A cross-sectional survey (July-September 2023) was sent to Spanish Multidisciplinary Melanoma Group (GEM Group) members to assess access to new drugs. Fifty physicians from 15 Spanish AaCc responded to the survey. Access for drug with approved public reimbursement, Hedgehog inhibitors in basal-cell carcinoma and anti PD-L1 antibody in Merkel carcinoma, was observed in 84% and 86% of centers, respectively. For other EMA-approved treatments, but without reimbursement in Spain access decreased to 78% of centers. Heterogeneity in access was mainly observed intra regions. Unequal financial support for drugs for NMSC with creates a patchwork of access across Spanish hospitals, with variations even within the same AaCc.

A-BRAVE trial: A phase III randomized trial with avelumab in early triple-negative breast cancer with residual disease after neoadjuvant chemotherapy or at high risk after primary surgery and adjuvant chemotherapy.

LBA500 Background: Prognosis of pts with early triple negative breast cancer (TNBC) is still poor and new effective treatments are needed. TNBC is the most immunogenic BC subtype, and this may account for sensitivity to immune checkpoint inhibitors. The A-BRAVE trial was designed to evaluate the efficacy of avelumab, an anti PD-L1 antibody, as adjuvant treatment for pts with early TNBC at high risk. Methods: This is a phase III, multicentric, randomized adjuvant study comparing 1 year of treatment with the anti PD-L1 avelumab vs observation for TNBC pts considered at high risk of relapse. Pts were enrolled after they completed standard treatment with curative intent including surgery and neoadjuvant/adjuvant chemotherapy. High risk was defined as: 1) invasive residual disease (breast and/or nodes) after neoadjuvant chemotherapy (Stratum A), 2) >pN2/any pT, pN1/pT2, or pN0/pT3 after primary surgery (Stratum B). Pts were randomly assigned (1:1, balanced for strata A and B) to Avelumab 10 mg/kg I.V. q2w for 1 year or observation. Co-primary endpoints were disease free survival (DFS) in the total population and in Stratum A. 474 pts were needed to detect, in the total population, an improvement from 60% to 73.6% 3-year DFS rate (HR 0.6; 90% power, 1-sided test, alfa 2%). 172 DFS events were required to perform the event-driven analysis. Assuming a proportion of 70-80% pts enrolled in Stratum A, the expected power to detect an HR 0.6 at alpha allocated in this subgroup is 70-79%. Overall survival was a secondary endpoint. Results: From June 2016 to October 2020, 477 pts were randomly assigned from 64 Italian and 6 UK centers. 11 pts (3 avelumab, 8 control) withdrew consent immediately after randomisation and are excluded from further analyses. 378 pts entered Stratum A (83%), of whom 99 (57 avelumab, 42 control) received further chemotherapy after surgery prior to enrollment in the trial. Efficacy results for the two co-primary DFS endpoints and the secondary OS endpoints are reported in the table. Conclusions: One year adjuvant avelumab versus control does not significantly improve DFS in high-risk TNBC patients. Nevertheless, the secondary enpoind OS was significanlty improved with avelumab vs control. RFS and DMFS will also be reported. A centralised collection of tumor tissue, plasma and feces has been performed and will allow a number of correlative studies. Clinical trial information: NCT02926196 . [Table: see text]

A three-arm randomized phase II study of dostarlimab alone or with bevacizumab versus nonplatinum chemotherapy in recurrent gynecological clear cell carcinoma: DOVE (APGOT-OV7/ENGOT-ov80 study).

TPS5627 Background: Recurrent gynecological clear cell carcinoma (rGCCC) is known for low objective response rates to chemotherapy. Prior preclinical and clinical data suggests potential synergy of immune checkpoint inhibitor adding bev in rGCCC. Dostarlimab, a humanized monoclonal antibody targeting PD-1, combined with the anti-angiogenic bevacizumab, presents a novel therapeutic approach. The aim of the present study is to investigate the efficacy of dostarlimab +/- bevacizumab in rGCCC. Methods: DOVE is a global, multicenter, international, open-label, randomized phase 2 study of dostarlimab +/- bevacizumab with standard chemotherapy in patients with rGCCC. It enrolls 198 patients with rGCCC, assigning them to one of three groups in a 1:1:1 ratio: Group A (dostarlimab monotherapy), Group B (dostarlimab + bevacizumab), Group C: investigator’s choice chemotherapy. Patients with PD on Group A or Group C were allowed to crossover to Group B. Stratification factors are prior bevacizumab use, prior lines of therapy (1 vs. >1), and primary site (ovarian vs. non-ovarian). Key inclusion criteria are histologically proven confirmed recurrent or persistent clear cell carcinoma of the ovary, endometrium, cervix, vagina and vulva, up to 5 prior lines of therapies, disease progression within 12 months after platinum-based chemotherapy, and measurable disease. Key exclusion criteria are prior treatment with an anti PD-1, anti PD-L1, or anti PD-L2 agent. The primary endpoint is progression-free survival by investigator. The secondary endpoints include ORR, DCB, DCR, PFS2, OS, and toxicity. Exploratory objectives include immune biomarker. The study, commencing in Jan 2024, is registered with Clinicaltrials.gov (NCT06023862). Clinical trial information: NCT06023862 .

Fasting mimicking diet reduces anti-OX40/anti PD-L1 and anti-PD-1/anti-CTLA-4 cardiovascular side effects in preclinical melanoma models.

Fasting mimicking diet reduces anti-OX40/anti PD-L1 and anti-PD-1/anti-CTLA-4 cardiovascular side effects in preclinical melanoma models.

COMBINATORIAL IMMUNE CHECKPOINT BLOCKADE INCREASES MYOCARDIAL SECRETION OF H–FABP, NT–PRO–BNP, NLRP–3 INFLAMMASOME, INTERLEUKIN–1Β AND INTERLEUKIN–6: BIOCHEMICAL IMPLICATIONS IN CARDIO–IMMUNO–ONCOLOGY

Abstract Background Immune checkpoint blockade have become an integral part of oncology in recent years. Monoclonal antibodies against CTLA–4 or PD–1 or PDL–1 are the most studied ICIs in randomized clinical trials, however, more recently, an anti–LAG3 monoclonal antibody, Relatlimab, has been approved by FDA for combinatorial treatment with Nivolumab for metastatic melanoma. Moreover, anti PD–L1 blocking agent Atezolizumab is actually under study in association with Ipilimumab as innovative thearpy for metastatic lung cancer. Myocarditis, vasculitis and endothelitis are rarely observed in these patients on monotherapy, however new combination therapies and the use of new targets in immunotherapy could expose patients to more adverse cardiovascular events. Purpose In this study, we highlighted the cardiotoxic properties of new Combinatorial immune checkpoint blockade therapies. Methods Human cardiomyocytes co–cultured with human peripheral blood lymphocytes (hPBMCs) were exposed to monotherapy and combinatorial ICIs (PD–L1 and CTLA–4 or PD–1 and LAG–3 blocking agents, at 100 nM) for 48 h. After treatments, cardiac cell lysis and secretion of biomarkers of cardiotoxicity (H–FABP, NT–Pro–BNP), NLRP3–inflammasome and Interleukin 1 and 6 were determined through colorimetric and enzymatic assays. Results Both combinations of immune checkpoint inhibitors exert more potent cardiotoxic side effects compared to monotherapies against human cardiac cells co–cultured with human lymphocytes. LDH release from cardiac cells was 43% higher in PD–L1/CTLA–4 blocking agents, and 35.7% higher in PD–1/LAG–3 blocking agents compared to monotherapies. NT–Pro–BNP and H–FABP, were also strongly increased in combination therapy with respect to monotherapies. NLRP3, IL–6 and IL–1β levels were also increased by PDL–1/CTLA–4 and PD–1/LAG–3 combined blocking agents compared to untreated cells and monotherapies. Conclusion Data of the present study, although in vitro, indicate that combinatorial immune checkpoint blockade, induce a pro– inflammatory phenotype, thus indicating that these therapies should be closely monitored by the multidisciplinary team consisting of oncologists, cardiologists and immunologists.

Immune checkpoint inhibitors induce acute interstitial nephritis in mice with increased urinary MCP1 and PD-1 glomerular expression

IntroductionImmune checkpoint inhibitors (ICIs) induce acute interstitial nephritis (AIN) in 2–5% of patients, with a clearly higher incidence when they are combined with platinum derivatives. Unfortunately, suitable disease models and non-invasive biomarkers are lacking. To fill this gap in our understanding, we investigated the renal effects of cisplatin and anti-PD-L1 antibodies in mice, assessing PD-1 renal expression and cytokine levels in mice with AIN, and then we compared these findings with those in AIN-diagnosed cancer patients.MethodsTwenty C57BL6J mice received 200 µg of anti-PD-L1 antibody and 5 mg/kg cisplatin intraperitoneally and were compared with those receiving cisplatin (n = 6), anti-PD-L1 (n = 7), or saline (n = 6). After 7 days, the mice were euthanized. Serum and urinary concentrations of TNFα, CXCL10, IL-6, and MCP-1 were measured by Luminex. The kidney sections were stained to determine PD-1 tissue expression. Thirty-nine cancer patients with AKI were enrolled (AIN n = 33, acute tubular necrosis (ATN) n = 6), urine MCP-1 (uMCP-1) was measured, and kidney sections were stained to assess PD-1 expression.ResultsCisplatin and anti PD-L1 treatment led to 40% AIN development (p = 0.03) in mice, accompanied by elevated serum creatinine and uMCP1. AIN-diagnosed cancer patients also had higher uMCP1 levels than ATN-diagnosed patients, confirming our previous findings. Mice with AIN exhibited interstitial PD-1 staining and stronger glomerular PD-1 expression, especially with combination treatment. Conversely, human AIN patients only showed interstitial PD-1 positivity.ConclusionsOnly mice receiving cisplatin and anti-PDL1 concomitantly developed AIN, accompanied with a more severe kidney injury. AIN induced by this drug combination was linked to elevated uMCP1, consistently with human AIN, suggesting that uMCP1 can be potentially used as an AIN biomarker.

Abstract PO1-19-10: Durvalumab + datopotamab deruxtecan in patients with PD-L1 positive advanced/metastatic triple-negative breast cancer: Arm 8 of the phase 1b/2, open label, platform BEGONIA study

Abstract Background: Patients (pts) with advanced/metastatic triple-negative breast cancer (a/mTNBC) have limited treatment options and poor prognosis. Immune checkpoint inhibitors combined with chemotherapy is the standard of care for pts with PD-L1 positive tumors; still, most pts progress within a year, highlighting a need for new treatments. BEGONIA is an ongoing Simon 2-stage, multicenter, multi-arm platform study evaluating the safety and efficacy of durvalumab (D), an anti–PD-L1 monoclonal antibody, with or without paclitaxel, in combination with novel oncology therapies as first-line treatment for a/mTNBC (NCT03742102). Datopotamab deruxtecan (Dato-DXd) is an antibody-drug conjugate (ADC) consisting of a humanized anti-trophoblast cell surface antigen 2 (TROP2) IgG1 monoclonal antibody linked to a topoisomerase I inhibitor payload via a plasma stable, tumor selective, tetrapeptide-based cleavable linker. TROP2 is broadly expressed on breast and other epithelial tumors and Dato-DXd monotherapy showed antitumor activity in heavily pretreated mTNBC pts (Bardia SABCS 2022 P6-10-03). Pts treated with Dato-DXd+D in Arm 7 of BEGONIA showed a 74% objective response rate (ORR) with median 7.2 months follow-up (Schmid SABCS 2022 PD11-09). Although responses were observed in both PD-L1–high and –low-expressing tumors, most pts (87%) had PD-L1–low-expressing tumors. In Arm 8 of BEGONIA, pts determined to have PD-L1 positive tumors by pre-existing/local testing will be recruited and treated with Dato-DXd+D to evaluate efficacy and safety in a PD-L1–high population. Methods: Eligible female pts are aged ≥18 years with untreated unresectable, locally advanced or mTNBC; ≥6 months between completion of treatment for earlier-stage breast cancer and recurrence of distant disease; ≥12 months since prior taxane therapy; ECOG PS 0/1; adequate organ function; and ≥1 nonirradiated measurable lesion. For inclusion in Arm 8, a PD-L1 positive tumor as determined by local immunohistochemistry (IHC) testing is required (either pre-existing or obtained during prescreening). Exclusion criteria for Arm 8 are clinically significant corneal disease; history or suspicion of interstitial lung disease/pneumonitis; underlying pulmonary disorder; prior exposure to immune-mediated therapy; or prior treatment with an ADC containing a topoisomerase I inhibitor. Arm 8 will evaluate Dato-DXd (6 mg/kg) + D (1120 mg) given intravenously every 3 weeks until disease progression or unacceptable toxicity. Tumors will be assessed per RECIST v1.1 every 6 weeks for 48 weeks, then every 12 weeks thereafter. A safety run-in will not occur for Arm 8, as Dato-DXd+D was evaluated in Arm 7 and was tolerable with no DLTs reported. Part 1 of Arm 8 will enroll 30 pts. The primary endpoint of Part 1 is safety and tolerability. A futility analysis will be performed with an option to expand Arm 8 to Part 2, where an additional 27 pts will be enrolled if expansion criteria are met. The primary endpoint for Part 2 is ORR. Secondary endpoints include ORR (Part 1 only), testing for antidrug antibodies and treatment pharmacokinetics (Part 1 only), duration of response (DoR), progression-free survival (PFS), and overall survival (OS). ORR will be summarized with descriptive statistics and 95% Clopper-Pearson confidence intervals. Kaplan-Meier analysis will be used for DoR, PFS, and OS. All tumor response and survival endpoints will be based on investigator assessments. Additional PD-L1 testing with the VENTANA PD-L1 (SP263) Assay will be performed on pretreatment tumor samples; high expression is defined as ≥10% of the tumor area populated by PD-L1–expressing tumor or immune cells. TROP2 expression will be assessed by IHC. Enrollment is ongoing. Funding: AstraZeneca/Daiichi Sankyo Citation Format: Peter Schmid, Cynthia Ma, Robert Huisden, Ross Stewart, Katrin Heider, Petra Vuković, Neelima Denduluri. Durvalumab + datopotamab deruxtecan in patients with PD-L1 positive advanced/metastatic triple-negative breast cancer: Arm 8 of the phase 1b/2, open label, platform BEGONIA study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-19-10.

Abstract PO1-25-12: Metformin enhances response to chemotherapy combined with immunotherapy in a triple negative breast cancer in vivo model

Abstract Background Triple-negative breast cancer (TNBC) is a heterogeneous group comprising several well-defined molecular subtypes. Classical chemotherapy remains the standard of care for advanced TNBC, although blockade of the PD-1/PD-L1 axis has emerged as a promising therapeutic option to enhance antitumor immunity. Atezolizumab is an immune checkpoint inhibitor targeting PD-L1 that has been approved for use in combination with paclitaxel for the treatment of advanced TNBC. Metformin (MTF) is a prescribed drug for type 2 diabetes with well-tolerated side-effects and has been reported to have anticancer effects. Xenograft mouse models studies of breast, lung and prostate cancer, have reveal a synergistic effect of MTF when combined with paclitaxel, carboplatin or doxorubicin and has been reported to enhance the efficacy of immunotherapy. In this work we want to explore the effect of including MTF in a chemo-immunotherapy scheme using an in vivo model. Methods 1x106 EMT6 TNBC cell line (ATCC® CRL-2755™) were implanted subcutaneously in the back of immunocompetent BALB/c mice. Treatment began when tumours reached a volume size of 30-100 mm3. At that moment, mice received the drug, or drugs combinations, for 21 days. All drugs were administered intraperitoneally, except for MTF, which was given orally in drinking water at a concentration of 1g/L. The anti PD-L1 drug anti-hPD-L1-mIgG1 (mATZ, 300 mg/week) was administered twice per week and doxorubicin (DOXO) every three days (0.3 mg/Kg or 6 mg/kg). The primary outcome will be tumour response. Tumour size was measured using a digital caliper every day until mice were euthanized. For tumour volume determination (mm3), two measures were taken (length and width). Volume was calculated as (length x wide2)/2. We tested three different arms: DOXO(0,3mg/Kg)+m-ATZ, DOXO(0,3mg/Kg)+m-ATZ+MTF, and DOXO(6mg/Kg)+m-ATZ. Each arm included 10 mice. Differences in tumour volume and mice weight were assessed by Kruskall-Wallis analysis. Results EMT6 cells produced a tumour mass in twenty seven out of thirty mice. Follow-up in mice in the DOXO(0.3mg/Kg)+m-ATZ and DOXO(6mg/Kg)+m-ATZ arms was interrupted in two weeks due to extended tumour growth and quality of live criteria, respectively. Mice in the DOXO(0.3mg/Kg)+m-ATZ+MTF arm were followed for three weeks. Increase of tumoral volume was assessed at 14 days. Mean increase was 205, 1096 and 365 mm3in the DOXO(6mg/Kg)+m-ATZ, DOXO(0,3mg/Kg)+m-ATZ, and DOXO(0,3mg/Kg)+m-ATZ+MTF arms respectively, being the volume increase between DOXO(0,3mg/Kg)+m-ATZ treated mice significantly higher. Regarding mice, mean weight at the beginning of the treatments was 19.8 gr for the complete mice population, whereas mean weight after 14 days of treatment was 15.4, 20.9 and 21.7 gr in the DOXO(6mg/Kg)+m-ATZ, DOXO(0,3mg/Kg)+m-ATZ, and DOXO(0,3mg/Kg)+m-ATZ+MTF arms respectively, showing a significant decrease of body weight in mice receiving a high dose of DOX, while no differences associated to the inclusion of MTF in the treatment scheme was found. Conclusions MTF addition to a combination of chemotherapy and immunotherapy in the treatment of TNBC increased therapy efficacy, with no added side effects. These result paves the way to explore treatment schemes with lower chemotherapy doses, decreasing toxicity side effects. Citation Format: Pilar Zamora, Angelo Gamez Pozo, Luz Vega-Clemente, Elena Lopez-Camacho, Lucia Trilla-Fuertes, David Alonso-Martin, Juan Angel Fresno Vara, Mariano Garcia-Arranz, Enrique Espinosa. Metformin enhances response to chemotherapy combined with immunotherapy in a triple negative breast cancer in vivo model [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-25-12.

In Silico Transcriptomic Expression of MSR1 in Solid Tumors Is Associated with Responses to Anti-PD1 and Anti-CTLA4 Therapies.

Immuno-oncology has gained momentum with the approval of antibodies with clinical activities in different indications. Unfortunately, for anti-PD (L)1 agents in monotherapy, only half of the treated population achieves a clinical response. For other agents, such as anti-CTLA4 antibodies, no biomarkers exist, and tolerability can limit administration. In this study, using publicly available genomic datasets, we evaluated the expression of the macrophage scavenger receptor-A (SR-A) (MSR1) and its association with a response to check-point inhibitors (CPI). MSR1 was associated with the presence of macrophages, dendritic cells (DCs) and neutrophils in most of the studied indications. The presence of MSR1 was associated with macrophages with a pro-tumoral phenotype and correlated with TIM3 expression. MSR1 predicted favorable overall survival in patients treated with anti-PD1 (HR: 0.56, FDR: 1%, p = 2.6 × 10-5), anti PD-L1 (HR: 0.66, FDR: 20%, p = 0.00098) and anti-CTLA4 (HR: 0.37, FDR: 1%, p = 4.8 × 10-5). When specifically studying skin cutaneous melanoma (SKCM), we observed similar effects for anti-PD1 (HR: 0.65, FDR: 50%, p = 0.0072) and anti-CTLA4 (HR: 0.35, FDR: 1%, p = 4.1 × 10-5). In a different dataset of SKCM patients, the expression of MSR1 predicted a clinical response to anti-CTLA4 (AUC: 0.61, p = 2.9 × 10-2). Here, we describe the expression of MSR1 in some solid tumors and its association with innate cells and M2 phenotype macrophages. Of note, the presence of MSR1 predicted a response to CPI and, particularly, anti-CTLA4 therapies in different cohorts of patients. Future studies should prospectively explore the association of MSR1 expression and the response to anti-CTLA4 strategies in solid tumors.

Abstract 1187: Sensitization to chemo-immunotherapy by targeting TGF-β in preclinical triple negative breast cancer models

Abstract Metastatic triple-negative breast cancer (mTNBC) is refractory to anti-PD-(L)1 immunotherapy. In order to sensitize it, preclinical data show the value of adding chemotherapy treatment for its ability to induce immunogenic cancer cell death (Kroemer et al, 2013). This would enable the recruitment of cytotoxic T-CD8+ lymphocytes (CTL) and thus initiate an antitumor immune response to sensitize tumors to immunotherapy. Nevertheless, the results of clinical trials using chemo-immunotherapy combinations are divergent (IMpassion 130 and 131). The IMpassion 130 trial demonstrated the efficacy of nab-paclitaxel and atezolizumab (anti-PD-L1) in PD-L1+ patients, but unfortunately, IMpassion 131 with paclitaxel did not replicate these results. The choice of chemotherapy to combine with immunotherapy appears to be crucial for inducing an antitumor immune response. Optimizing chemo-immunotherapy combinations is a major challenge in the management of TNBC. The initial aim of this project was to evaluate the immune effects of an experimental chemotherapy doublet, based on two drugs used in mTNBC: cisplatin (CDDP) and eribulin. The idea was to find an alternative to the use of taxanes in combination with anti-PD-(L)1.The effect of the two molecules, alone or in combination, was evaluated on immunogenic death stigmata, modulation of effector or immunosuppressive immune populations and stromal populations, and sensitization to anti-PD-L1 immunotherapy in the immunologically "cold" model: 4T1. The in vivo studies has been realized by generation of orthotopic 4T1 tumors, the analysis of the immune infiltration was performed by RT-qPCR, IHC and flow cytometry. In vitro, our results indicate that CDDP, and more intensely in combination with eribulin, significantly induces the various immunogenic death stigmas. In vivo, the therapeutic effect of chemotherapies is limited, with a superior effect of CDDP and the combination. Nevertheless, CTL recruitment and functionality induced by CDDP are significantly enhanced by eribulin. Despite these data pointing to a potential therapeutic synergy with anti PD-L1 immunotherapy, chemo-immunotherapy treatment fails to induce a superior treatment effect. The significant increase in a TGF-β signature induced by the combination in parallel with CTL recruitment explains this resistance. The results show that inhibition of TGF-β, combined with chemo-immunotherapy in the 4T1 model, leads to a reduction in tumor immunosuppression and intratumoral fibrosis, as well as an increase in CTL infiltration and cytotoxicity, enabling tumor sensitization. Overall, this project highlights the benefits of using an experimental doublet of CDDP and eribulin-based chemotherapies. This project demonstrates that management of chemo-induced immunosuppression mechanisms is necessary to overcome tumor resistance to immunotherapy. Citation Format: Laura Kalfeist, Fanny Ledys, Stacy Petit, Samia Kada-Mohammed, Mickael Rialland, François Ghiringhelli, Emeric Limagne, Sylvain Ladoire. Sensitization to chemo-immunotherapy by targeting TGF-β in preclinical triple negative breast cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1187.

First exploration of the on-treatment changes in tumor and organ uptake of a radiolabeled anti PD-L1 antibody during chemoradiotherapy in patients with non-small cell lung cancer using whole body PET

BackgroundIn patients with locally advanced unresectable non-small cell lung cancer (NSCLC), durvalumab, an anti-programmed cell death ligand-1 (PD-L1) antibody, has shown improved overall survival when used as consolidation therapy following...

Zanzalintinib (XL092) plus atezolizumab versus regorafenib in previously treated MSS/MSI-low metastatic colorectal cancer (mCRC): The randomized phase 3 STELLAR-303 study.

TPS229 Background: Patients with microsatellite stable/microsatellite instability-low (MSS/MSI-low) mCRC account for ~95% of mCRC cases, and there is a significant unmet need in patients with treatment-refractory MSS/MSI-low mCRC. Although immune checkpoint inhibitors (ICIs) have shown limited activity in this patient population, the addition of tyrosine kinase inhibitors (TKIs) may increase sensitivity to ICIs by promoting an immune-permissive tumor microenvironment. Furthermore, TKI-ICI combinations have demonstrated encouraging clinical activity in patients with mCRC, particularly in subgroups of patients without liver metastases (LM). Most recently, in the phase 3 LEAP-017 study of patients with non–MSI-high/mismatch repair deficient (dMMR) mCRC, although pembrolizumab + lenvatinib did not improve overall survival (OS) vs standard of care, subgroup analysis suggested the potential for clinical benefit in patients without LM (Kawazoe et al, ESMO-WCGI 2023). Zanzalintinib is a novel multi-kinase inhibitor targeting VEGFR, MET, and the TAM kinases (TYRO3, AXL, MER). In a phase 1 study, zanzalintinib alone and in combination with atezolizumab (an anti–PD-L1 ICI) showed preliminary anti-tumor activity and a manageable safety profile across multiple tumor types (Sharma et al, ESMO 2022). Methods: STELLAR-303 (NCT05425940) is a global, randomized, open-label phase 3 study to assess the efficacy and safety of zanzalintinib + atezolizumab versus regorafenib in adult patients with MSS/MSI-low mCRC. Patients must have documented MSI/MMR status (non–MSI-high/dMMR) and RAS status by tissue-based analysis, measurable disease per RECIST v1.1, ECOG PS 0 or 1, and radiographic progression during/after or intolerance to standard of care treatments for mCRC. Prior regorafenib, trifluridine/tipiracil, or PD-L1/PD-1 ICIs are not allowed. Patients with or without active LM at baseline are eligible; those with definitively treated LM (includes surgical resection, microwave/radiofrequency ablation, or stereotactic body radiation therapy, but not yttrium-90 or chemoembolization alone) are considered to have non-active LM if treated ≥6 months before enrollment with no evidence of radiologic progression on subsequent imaging. Patients are randomized 1:1 to receive zanzalintinib + atezolizumab or regorafenib. Planned enrollment is 874 patients; number of patients with LM will be capped to ensure results of the study are relevant to the real-world mCRC population. Primary endpoint is OS in patients without LM. The key secondary efficacy endpoint is OS in all randomized patients. A hierarchical testing strategy will be employed for primary and key secondary endpoints. Safety will also be assessed. Enrollment is ongoing in the US, Europe, and Asia-Pacific region. Clinical trial information: NCT05425940 .

Organ preservation with durvalumab-based immunotherapy in combination with chemoradiation as definitive therapy for early stage, cT1, and cT2N0 esophageal adenocarcinoma with indication for radical surgery: A prospective, multicenter study of the FLOT-AIO Gastric Cancer Group (IKF-t057/PRESTO trial).

TPS431 Background: The outcome of patients (pts) with adenocarcinomas of stomach and esophagogastric junction (GEJ) remains unsatisfactory (5-year survival rates of 24-84%), whereby surgical resection is considered as cornerstone of the curative treatment for pts with early stage esophageal adenocarcinoma (EGA), however, it is associated with mortality, morbidity and an impact on the patient’s quality of life. Recent investigations showed that in locally advanced stage EGA surgery with neoadjuvant chemoradiotherapy (CROSS trial) is beneficial over surgery alone. Further benefit was achieved for locally advanced EGA by perioperative treatment with FLOT acc. to FLOT4- trial data. Immuno-oncology (IO) therapy by using checkpoint inhibitors is approved in the palliative and adjuvant EGA situation. In this trial we aim for the organ preservation treatment of EGA pts with a combination of the anti PD-L1 antibody durvalumab- FLOT - and chemoradio-therapy. Methods: This is a multicenter, single arm, open-label, phase II trial including a total of 32 pts with T1-T2N0 EGA (including GEJ) with indication for radical surgery. Enrolled pts will receive immunotherapy with durvalumab (1500 mg Q4W) in parallel to 2 cycles FLOT (50 mg/m2 docetaxel, 85 mg/m2 oxaliplatin, 200 mg/m2 calcium folinate and 2600 mg/m2 5FU, Q2W) induction followed by 3 cycles of mFOLFOX (85 mg/m2 oxaliplatin, 200 mg/m2 calcium folinate, 400 mg/m2 5FU bolus and 1600 mg/m2 5FU over 48h, Q2W) plus concomitant radiation (25 daily fractions with 2.0 Gy = Σ50Gy). 8 weeks after last treatment, pts will undergo tumor assessment by esophagogastroduodenoscopy with biopsies, endoscopic ultrasonography, and CT- or MRI-scans. Surgical resection would be offered only to pts in whom a locoregional persistence is confirmed. Pts with complete remission will enter the maintenance phase and will receive durvalumab monotherapy (1500 mg, Q4W) for a maximum of 12 cycles accompanied by regular tumor re-evaluation. Primary endpoint is the rate of cCR/pCR at time of re-evaluation. Secondary endpoints include rate of cCR/pCR at 1, 2 and 3 years, rate of salvage surgery, 90 day and 1 year mortality after start of treatment, safety and quality of life. In this exploratory trial a cCR/pCR rate of ≥75% would indicate that the study treatment should be further investigated, whereas a rate < 55% indicates no further investigation. First patient was enrolled on 2023-08-28. Currently one patient is recruited. Clinical trial information: NCT05713838 .

β-Glucan–conjugated anti–PD-L1 antibody enhances antitumor efficacy in preclinical mouse models

The use of immune checkpoint blockade (ICB) is a promising approach for clinical cancer treatment. However, most of cancer patients do not respond to anti–PD-1/PD-L1 antibody. In this study, we proposed a novel strategy of antibody–β-glucan conjugates (AGC) to enhance the antitumor immune response to ICB therapy. The AGC were constructed by conjugating an anti–PD-L1 antibody with a β-glucan via click chemistry. This design facilitates the delivery of β-glucan into the tumor microenvironment (TME). Furthermore, the bridging effect mediated by AGC can promote the interaction between tumor cells and dendritic cells (DCs), thereby enhancing immunotherapeutic benefits. In the MC38 tumor-bearing mouse model, AGC demonstrated powerful tumor suppression, achieving a tumor suppression rate of 86.7 %. Immunophenotyping, cytokine analysis, RNA sequencing, and FTY720-treated models were combined to elucidate the mechanism underlying AGC function. Compared with anti–PD-L1 antibody, AGC induced an earlier immune response, infiltration of DCs, and activation of preexisting T cells in the TME, with T cells predominantly proliferating locally rather than migrating from other organs. In conclusion, these data suggest that AGC could serve as a promising strategy to improve ICB therapy with prospects for clinical utilization.

Timing of anti–PD-L1 antibody initiation affects efficacy/toxicity of CD19 CAR T-cell therapy for large B-cell lymphoma

AbstractMore than half of the patients treated with CD19-targeted chimeric antigen receptor (CAR) T-cell immunotherapy for large B-cell lymphoma (LBCL) do not achieve durable remission, which may be partly due to PD-1/PD-L1–associated CAR T-cell dysfunction. We report data from a phase 1 clinical trial (NCT02706405), in which adults with LBCL were treated with autologous CD19 CAR T cells (JCAR014) combined with escalating doses of the anti–PD-L1 monoclonal antibody, durvalumab, starting either before or after CAR T-cell infusion. The addition of durvalumab to JCAR014 was safe and not associated with increased autoimmune or immune effector cell–associated toxicities. Patients who started durvalumab before JCAR014 infusion had later onset and shorter duration of cytokine release syndrome and inferior efficacy, which was associated with slower accumulation of CAR T cells and lower concentrations of inflammatory cytokines in the blood. Initiation of durvalumab before JCAR014 infusion resulted in an early increase in soluble PD-L1 (sPD-L1) levels that coincided with the timing of maximal CAR T-cell accumulation in the blood. In vitro, sPD-L1 induced dose-dependent suppression of CAR T-cell effector function, which could contribute to inferior efficacy observed in patients who received durvalumab before JCAR014. Despite the lack of efficacy improvement and similar CAR T-cell kinetics early after infusion, ongoing durvalumab therapy after JCAR014 was associated with re-expansion of CAR T cells in the blood, late regression of CD19+ and CD19– tumors, and enhanced duration of response. Our results indicate that the timing of initiation of PD-L1 blockade is a key variable that affects outcomes after CD19 CAR T-cell immunotherapy for adults with LBCL.

1068P Fasting mimicking diet reduces anti-OX40/anti PD-L1 and anti-PD-1/anti-CTLA-4 cardiovascular side effects in melanoma and lung cancer models

1068P Fasting mimicking diet reduces anti-OX40/anti PD-L1 and anti-PD-1/anti-CTLA-4 cardiovascular side effects in melanoma and lung cancer models

Photo-induced crosslinked and anti-PD-L1 peptide incorporated liposomes to promote PD-L1 multivalent binding for effective immune checkpoint blockade therapy

Immune checkpoint blockade (ICB) therapy targeting PD-L1 via monoclonal antibody (mAb) has shown extensive clinical benefits in the diverse types of advanced malignancies. However, most patients are completely refractory to ICB therapy owing to the PD-L1 recycling mechanism. Herein, we propose photo-induced crosslinked and anti-PD-L1 peptide incorporated liposomes (immune checkpoint blockade liposomes; ICB-LPs) to promote PD-L1 multivalent binding for inducing lysosomal degradation of PD-L1 in tumor cells. The ICB-LPs are prepared by formulation of DC8,9PC with photo-polymerized diacetylenic moiety, 1,2-dipalmitoylphosphatidylcholine (DPPC) and anti-PD-L1 peptide (D-form NYSKPTDRQYHF)-conjugated DSPE-PEG2k (anti-PD-L1-DSPE-PEG2k) in a molar ratio of 45:45:10, followed by cross-linking of liposomal bilayer upon UV irradiation. The 10 mol% anti-PD-L1-DSPE-PEG2k incorporated ICB-LPs have a nano-sized lipid bilayer structure with an average diameter of 137.7 ± 1.04 nm, showing a high stability in serum condition. Importantly, the ICB-LPs efficiently promote the multivalent binding with PD-L1 on the tumor cell membrane, which are endocytosed with aim to deliver PD-L1 to the lysosomes, wherein the durable PD-L1 degradation is observed for 72 h, in contrast to anti PD-L1 mAbs showing the rapid PD-L1 recycling within 9 h. The in vitro co-culture experiments with CD8+ T cells show that ICB-LPs effectively enhance the T cell-mediated antitumor immune responses against tumor cells by blocking the PD-L1/PD-1 axis. When ICB-LPs are intravenously injected into colon tumor-bearing mice, they efficiently accumulate within the targeted tumor tissues via both passive and active tumor targeting, inducing a potent T cell-mediated antitumor immune response by effective and durable PD-L1 degradation. Collectively, this study demonstrates the superior antitumor efficacy of crosslinked and anti-PD-L1 peptide incorporated liposome formulation that promotes PD-L1 multivalent binding for trafficking of PD-L1 toward the lysosomes instead of the recycling endosomes.

CXCR5 and TIM-3 expressions define distinct exhausted T cell subsets in experimental cutaneous infection with Leishmania mexicana.

T-cell exhaustion is a key stage in chronic infections since it limits immunopathology, but also hinders the elimination of pathogens. Exhausted T (Tex) cells encompass dynamic subsets, including progenitor cells that sustain long-term immunity through their memory/stem like properties, and terminally-differentiated cells, resembling the so-called Tex cells. The presence of Tex cells in chronic leishmaniasis has been reported in humans and murine models, yet their heterogeneity remains unexplored. Using flow cytometry, we identified Tex cells subtypes based on PD-1, CXCR5 and TIM-3 expressions in draining lymph nodes (dLNs) and lesion sites of C57BL/6 mice infected with L. mexicana at 30-, 60- and 90-days post-infection. We showed that infected mice developed a chronic infection characterized by non-healing lesions with a high parasite load and impaired Th1/Th2 cytokine production. Throughout the infection, PD-1+ cells were observed in dLNs, in addition to an enhanced expression of PD-1 in both CD4+ and CD8+ T lymphocytes. We demonstrated that CD4+ and CD8+ T cells were subdivided into PD-1+CXCR5+TIM-3- (CXCR5+), PD-1+CXCR5+TIM-3+ (CXCR5+TIM-3+), and PD-1+CXCR5-TIM-3+ (TIM-3+) subsets. CXCR5+ Tex cells were detected in dLNs during the whole course of the infection, whereas TIM-3+ cells were predominantly localized in the infection sites at day 90. CXCR5+TIM-3+ cells only increased at 30 and 60 days of infection in dLNs, whereas no increase was observed in the lesions. Phenotypic analysis revealed that CXCR5+ cells expressed significantly higher levels of CCR7 and lower levels of CX3CR1, PD-1, TIM-3, and CD39 compared to the TIM-3+ subset. CXCR5+TIM-3+ cells expressed the highest levels of all exhaustion-associated markers and of CX3CR1. In agreement with a less exhausted phenotype, the frequency of proliferating Ki-67 and IFN-γ expressing cells was significantly higher in the CXCR5+ subset within both CD4+ and CD8+ T cells compared to their respective TIM-3+ subsets, whereas CD8+CXCR5+TIM-3+ and CD8+TIM-3+ subsets showed an enhanced frequency of degranulating CD107a+ cells. In summary, we identified a novel, less-differentiated CXCR5+ Tex subset in experimental cutaneous leishmaniasis caused by L. mexicana. Targeting these cells through immune checkpoint inhibitors such as anti-PD-1 or anti PD-L1 might improve the current treatment for patients with the chronic forms of leishmaniasis.

Wide-Range SPRi Sensors Based on Aptamer/sPD-L1/anti–PD-L1 Sandwich and AuNPs Enhancement for Ultrasensitive Detection of sPD-L1

Soluble programmed death-ligand 1 (sPD-L1) levels vary widely among different stages of tumor development, so the direct quantification of sPD-L1 as a cancer biomarker is useful in cancer diagnosis, prognosis and therapeutic assessment. There is an urgent need for an sPD-L1 detection method with a broad detection range and high sensitivity for monitoring cancer progression and evaluating the effectiveness of immunotherapy in real time. Herein, we have reported an enzyme-free, label-free surface plasmon resonance imaging (SPRi) sensor based on an aptamer/sPD-L1/anti–PD-L1 sandwich structure with gold nanoparticle (AuNP) signal enhancement for the ultrasensitive quantitative measurement of sPD-L1 for the first time. The gold chip of the SPRi sensing platform was modified by DNA aptamers, sPD-L1 was specifically adsorbed on the surface of a DNA aptamer-modified gold chip and then coupled with anti–PD-L1. Thus, the detection of sPD-L1 at different concentrations was realized through the formation of an aptamer/sPD-L1/anti–PD-L1 sandwich structure. We also enhanced the SPR signal via AuNPs to further improve sensor sensitivity. The SPRi sensor is able to measure sPD-L1 within a linear range of 50 pM–10 nM and 100 fM–50 pM, and the minimum detection limit is 19 fM. The sensor is designed to be widely applicable, with better accuracy and reliability for more application scenarios. The prepared SPRi sensor shows great potential in improving the sensitivity of detecting sPD-L1. The proposed method demonstrates the excellent performance of the SPRi sensor and provides a possibility for the establishment of effective clinical assay methods in the future.

Immunosensitivity mediated by downregulated AKT1-SKP2 induces anti-PD-1-associated thyroid immune injury.

Immune checkpoint inhibitors evoke the immune system, which may cause immune-related adverse effects. The predictors and mechanisms of anti-PD-1-associated thyroid immune injury remain unclear. A retrospective analysis is conducted on 518 patients treated with anti PD-1/PD-L1. Firstly, the differences between anti PD-1 and anti PD-L1 are compared on the risk of thyroid immune injury. Then, the predictors of the risk and thyroid function for anti PD-1 related thyroid immune injury are analyzed. Furthermore, the in vitro mechanism of normal thyroid cells (NTHY) is studied. First, the effect of anti PD-1 on the cell viability and immune sensitivity of thyroid cells is observed. Cell viability includes cell proliferation, apoptosis, cell cycle, T4 secretion, while immune sensitivity includes molecular expression and CD8+T cell aggregation and killing towards NTHY. Then the differentially expressed proteins (DEPs) are screened by protein mass spectrometry. Enrichment of KEGG pathway and annotation of GO function on DEPs are conducted. Human protein-protein interactions are obtained from STRING database. The network is constructed and analyzed using Cytoscape software. In vitro, key proteins and their pathways are validated through overexpression plasmids or inhibitors. The recovery experiment and the immuno-coprecipitation experiment are designed to support the results. In vivo, the key proteins are detected in the thyroid tissue of mice fed with anti PD-1, as well as in the thyroid tissue of patients with Hashimoto's thyroiditis. Thyroid irAE is associated with female, IgG, FT4, TPOAb, TGAb, TSHI, TFQI, and TSH. Peripheral lymphocytes are associated with thyroid function. In vitro, the NIVO group shows prologed G1 phase, decreased FT4, downregulated PD-L1, upregulated IFN-γ, and more CD8+T cell infiltration and cytotoxicity. AKT1-SKP2 is chosen as the key protein. AKT1 overexpression and SKP2 inhibitor replies to NIVO and AKT1 overexpression, respectively. Immunoprecipitation shows SKP2 and PD-L1 interaction. Female, impaired thyroid hormone sensitivity and IgG4 contribute to the risk of thyroid irAE, while peripheral blood lymphocyte characteristics affect thyroid function. Anti-PD-1 induces thyroid irAE by downregulating AKT1-SKP2 to enhance thyroid immunosensitivity.