Post-treatment Biopsies Research Articles

Abstract I008: Antisense Oligonucleotides as Therapeutics for Difficult-to-Drug Targets in Oncology

Abstract Many potential oncology targets are difficult to modulate by conventional classes of agents. Interfering with these targets at the level of RNA is a novel approach for difficult-to target proteins, as well as for non-coding RNAs, emerging targets that are part of the “dark matter’ of the genome. Antisense oligonucleotide (ASO) therapeutics are short sequences of 12- 30 DNA/RNA residues, designed to bind the cognate transcribed RNA. The ASO is chemically modified to increase stability, improve binding affinity, optimize pharmacokinetic properties and reduce immunostimulatory potential. The hybridization of ASO to cognate RNA results in cleavage of bound RNA by RNAse H1 and subsequent degradation. Several ASOs are marketed for treatment of rare diseases, but to date none have been approved for oncology indications. The long-noncoding RNA (lncRNA) MALAT1 is an example of an oncology target uniquely suited for an ASO therapeutic. This lncRNA is not translated and resides mostly in the nucleus, limiting access for most therapeutic approaches. MALAT1 is highly upregulated in various cancers, appears to play a role in epithelial to mesenchymal transition, and is associated with disease progression in patients. Inhibition of MALAT1 in preclinical breast cancer models, either genetic or pharmacologic using a murine ASO, leads to changes in tumor architecture and reduction in metastasis. FLM-7523 is a 16-mer ASO designed to bind to human MALAT1. It is a generation 2.5 design based on the constrained ethyl (cEt) modification to the 3 residues on the 3’ and 5’ ends of the ASO, and administered in a saline solution without any delivery vehicle. Preclinical studies have shown that FLM-7523 effectively inhibits MALAT1 expression in in vitro and in vivo models, and GLP toxicology studies have been completed to support a First-in-Human clinical trial. The signal transduction molecule STAT3 is another oncology target of interest that has, to date, been difficult to modulate. Danvatirsen is a 16-mer generation 2.5 ASO targeting human STAT3 mRNA and is currently in clinical trials. Preclinical in vivo studies in murine tumor models have demonstrated a reduction in STAT3 mRNA and protein following treatment with a STAT3 targeting ASO, along with tumor growth inhibition. Combination treatments with immune checkpoint inhibitors, including anti-PD-1 and anti-PD-L1, demonstrate improved tumor growth inhibition relative to monotherapy. In clinical trials, tumor uptake of danvatirsen is observed in post-treatment biopsies, with corresponding reduction in STAT3 protein. Danvatirsen is generally well tolerated with the most common adverse events being increased liver function tests and decreased myeloid hematologic parameters, both of which are easily monitored, manageable, and reversible. Clinical responses have been observed with the most robust being in combination with a PD-L1 inhibitor in recurrent/metastatic head and neck squamous cell carcinoma. In conclusion, ASOs are novel therapies that can inhibit oncology targets not tractable by traditional approaches. Citation Format: Andrew Denker. Antisense Oligonucleotides as Therapeutics for Difficult-to-Drug Targets in Oncology [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr I008.

TMIC-78. CHEMOTHERAPY INDUCED IMMUNOGENIC RESPONSE IN GLIOMA AND IMPLICATIONS FOR THERAPEUTIC STRATEGIES

Abstract INTRODUCTION Many glioblastoma (GBM) treatments fail because they treat tumor cells in isolation and ignore the surrounding microenvironment. In our phase 1b clinical trial of delivery of Topotecan (TPT) via Convection Enhanced Delivery (CED) in glioma, we demonstrated effective tumor cell elimination accompanied by a robust inflammatory response. We hypothesized that TPT induces an immunogenic response resulting in an unfavorable inflammatory landscape. METHODS To characterize chemotherapy’s effect on myeloid cells, we analyzed pre- and post-treatment biopsies from our trial using bulk RNA sequencing to measure canonical myeloid markers. We validated survival benefit of CED in vivo in our tumor model and characterized post-treatment tissue using single cell RNA sequencing (scRNA seq) after 7 days of treatment. We treated slice cultures generated from surgical samples of GBM with TPT and performed scRNA seq and histologic analysis to assess microenvironment changes after 24 hours of treatment. We used several in vitro assays to characterize the direct and indirect mechanisms of myeloid activation. RESULTS Bulk RNA sequencing of post treatment biopsies demonstrates upregulation of markers associated with activated and exhausted immune cell populations such as IBA1, CD68, MSR1, MARCO and loss of markers associated with homeostatic microglia such as P2RY12 and TMEM119. Similar results are found within 7 days of treatment in vivo, however, are not found in human derived samples treated acutely. Treatment of in vitro mono and co-culture systems demonstrate a tumor cell death dependent activation of myeloid cell populations via immunogenic molecules. CONCLUSIONS Chemotherapies eliminate proliferating glioma cells but also induce inflammation. While many investigators have tried to leverage this activation, our results suggest that chronic inflammation contributes to poor prognosis and recurrence. The identification of molecules responsible for this activation point to new therapeutic targets aimed at controlling treatment-induced inflammation, as part of a combinatorial approach to treat GBM.

IMMU-31. DAMAGE RESPONSE FROM SYSTEMIC RNA VACCINATION RESTORES HUMORAL IMMUNITY IN GLIOBLASTOMA

Abstract Therapies against glioblastoma (GBM) remain stymied by poor penetration across the blood-brain barrier (BBB) and systemic immunotolerance. These outcomes necessitate development of therapies simultaneously targeted to tumors while engineering peripheral immunity to co-localize for synergistic responses. We developed RNA loaded lipid particles (LPs) to simultaneously function as inducers of cytotoxic responses in the GBM tumor microenvironment (TME) and as systemic activators of peripheral immunity. RNA-LP mediated response was studied in mice bearing KR158b tumors and in canines and humans with spontaneous glioma and glioblastoma respectively. We found that RNA-LPs could localize to the brain TME of animals bearing murine gliomas and rapidly upregulate damage associated signaling pathways including p53-CDKN2A. This correlates with increased gene signatures for complement and proteosome processing. Simultaneously, in the periphery, RNA-LPs increase integrin expression on activated T cells and ICAM expression in brain tumors helping steer T cell translocation across the BBB. In canines with malignant gliomas, response to RNA-LPs correlated with increasing tumor size suggesting pseudoprogression. Similar to murine glioma, canine gliomas harvested within 48h of vaccine administration demonstrated rapid increases in complement and p53 pathway activation. In one human patient treated with RNA-LPs per NCT04573140 (PNOC020 trial), we demonstrate biopsy confirmed pseudoprogression with increases in p53 pathway signaling and complement activation. In post-treatment tumor biopsy samples, there was increased hyperexpanded post-infusion intratumoral IgH clones. Systemic administration of RNA-LP elicits damage response in the TME that predisposes complement activation and humoral immunity. Coupled with peripheral recruitment of T cells that can translocate across the BBB, RNA-LPs elicit potent bi-directional adaptive immunotherapy against GBM.

Single intravenous administration of oncolytic adenovirus TILT-123 results in systemic tumor transduction and immune response in patients with advanced solid tumors

BackgroundA limitation of approved oncolytic viruses is their requirement for intratumoral (i.t.) injection. TILT-123 (igrelimogene litadenorepvec, Ad5/3-E2F-D24-hTNFα-IRES-hIL-2) is a chimeric oncolytic adenovirus suitable for intravenous (i.v.) delivery due to its capsid modification and dual selectivity devices. It is armed with tumor necrosis alpha and interleukin-2 for promoting T-cell activation and lymphocyte trafficking to tumors, thereby enhancing the antitumor immune response. Here, we present the findings after a single i.v. administration of TILT-123 in three phase I dose escalation clinical trials.MethodsPatients with advanced solid tumors initially received a single i.v. dose of TILT-123 ranging from 3 × 109 to 4 × 1012 viral particles (VP). Blood was collected at baseline, 1, 16, and 192 h (7 days) post-treatment for bioavailability and serum analysis. Tumor biopsies were collected prior to treatment and 7 days post-treatment for analysis of viral presence and immunological effects. Patients did not receive any other cancer therapies during this period.ResultsAcross all three trials (TUNIMO, TUNINTIL, and PROTA), 52 total patients were treated with i.v. TILT-123. Overall, TILT-123 was found to be well-tolerated, with no dose-limiting toxicities observed. Post-treatment tumor biopsies showed expression of viral genes, presence of TILT-123 adenovirus proteins or DNA, and changes in immune cell infiltration from baseline. Increased virus dose did not lead to increased virus detection in tumors. Median overall survival was longer in patients with confirmed presence of TILT-123 in post-treatment biopsies (280 versus 190 days, p = 0.0405).ConclusionTILT-123 demonstrated safety and significant intratumoral immunomodulation following a single i.v. administration, warranting further investigation.Trial registrationsTUNIMO—NCT04695327. Registered 4 January 2021, https://clinicaltrials.gov/study/NCT04695327. TUNINTIL—NCT04217473. Registered 19 December 2019, https://clinicaltrials.gov/study/NCT04217473. PROTA—NCT05271318. Registered 4 February 2022, https://clinicaltrials.gov/study/NCT05271318.

Incidence of acute cellular and antibody mediated rejection in heart transplantation from a tertiary care center

Abstract Background Heart transplant greatly increases the survival in patients with end stage heart failure. However, cardiologists and cardiothoracic surgeons face difficulty in detecting rejection at times. Post-cardiac transplant surveillance biopsy remains the gold standard for diagnosing rejection and therapeutic intervention. Purpose The objective is to report our experience of monitoring rejection by endomyocardial biopsy (EMB). Methods The index study is an ambispective one where we evaluated all the patients who underwent heart transplant at our center from 1994 to 2021. Results Heart transplant were carried out in 72 patients within a period of 28 years, with majority being done after 2016. The patients mean age was 31.6 years (10-59 years). The commonest indication was dilated cardiomyopathy (67%) followed by ischemic cardiomyopathy (2.5%), congenital heart disease (7%) and other miscellaneous causes (5%). The mean age of donors was 31.8 years (14-55 years). Eight of the 72 patients died without any post cardiac transplant endomyocardial biopsy. The remaining 64 patients underwent cumulatively a total of 271 endomyocardial biopsy procedures. Majority of endomyocaridal biopsies contained three cores (range 1-7). First EMB procedure was performed in 17 (26.6%) patients within first seven days, 35(53.1%) within the second week and 12(20.3%) after 14 days. Histologically rejection was identified in 42 (66%) patients. Thirty-nine (61%) had only acute cellular rejection (ACR), one (1.6%) had only antibody mediated rejection (AMR) and two (3.1%) had mixed ACR and AMR. These 42 patients with rejection had a total of 90 (33.2%) episodes of ACR detected in 271 endomyocardial biopsies. Out of 90 ACR, 44 (48.9%) occurred in less than six months; seventeen (18.9% of 90 ACR) episodes occurred between six and 12 months and 29 (32.2%) after one year. The mean of presentation of first ACR episode was 36 weeks (range 5 days to 3.6 years). There were 172 endomyocardial procedures within one year of transplantation of which 61 (35%) showed rejection. Ninety-nine endomyocardial procedures were performed one year of transplantation of which 29 (29%) showed rejection. Most common grade in both the time period was ACR grade 1R (International Society for Heart and Lung Transplantation (ISHLT) 2004) (72.1% in ≤1 year and 65.5% in >1 year) followed by 2R and 3R. Thirty-eight (90.4%) of 42 patients expired in less than five years since transplantation. Two (4.8%) patients survived between five to ten years post transplantation and two (4.8%) survived more than ten years. The longest cardiac transplant recipient had completed 23 years since cardiac transplant and is alive till date. Conclusions EMB being the gold standard for cardiac allograft rejection, the cardiac pathologists need to be aware of the various grades of rejection including mixed rejection.Acute cellular rejection (ISHLT 2004)

Role of artificial intelligence in staging and assessing of treatment response in MASH patients.

The risk of disease progression in MASH increases proportionally to the pathological stage of fibrosis. This latter is evaluated through a semi-quantitative process, which has limited sensitivity in reflecting changes in disease or response to treatment. This study aims to test the clinical impact of Artificial Intelligence (AI) in characterizing liver fibrosis in MASH patients. The study included 60 patients with clinical pathological diagnosis of MASH. Among these, 17 received a medical treatment and underwent a post-treatment biopsy. For each biopsy (n = 77) a Sirius Red digital slide (SR-WSI) was obtained. AI extracts >30 features from SR-WSI, including estimated collagen area (ECA) and entropy of collagen (EnC). AI highlighted that different histopathological stages are associated with progressive and significant increase of ECA (F2: 2.6% ± 0.4; F3: 5.7% ± 0.4; F4: 10.9% ± 0.8; p: 0.0001) and EnC (F2: 0.96 ± 0.05; F3: 1.24 ± 0.06; F4: 1.80 ± 0.11, p: 0.0001); disclosed the heterogeneity of fibrosis among pathological homogenous cases; revealed post treatment fibrosis modification in 76% of the cases (vs 56% detected by histopathology). AI characterizes the fibrosis process by its true, continuous, and non-categorical nature, thus allowing for better identification of the response to anti-MASH treatment.

Modulation of the tumor microenvironment in non-muscle-invasive bladder cancer by OncoTherad® (MRB-CFI-1) nanoimmunotherapy: effects on tumor-associated macrophages, tumor-infiltrating lymphocytes, and monoamine oxidases.

Non-muscle-invasive bladder cancer (NMIBC) presents management challenges due to its high recurrence rate and a complex tumor microenvironment (TME). This study investigated the effects of OncoTherad® (MRB-CFI1) nanoimmunotherapy on the TME of BCG-unresponsive NMIBC, focusing on alterations in monoamine oxidases (MAO-A and MAO-B) and immune markers: CD163, FOXP3, CD8, and CX3CR1. A comparative analysis of immunoreactivities was made before and after OncoTherad® treatment and an immune score (IS) was established to evaluate the correlation between immunological changes and clinical outcomes. Forty bladder biopsies of twenty patients were divided into 2 groups (n = 20/group): 1 (pre-treatment biopsies); and 2 (post-treatment biopsies). Our results showed stable MAO-A levels but a significant (p < 0.05) decrease in MAO-B immunoreactivity after treatment, suggesting OncoTherad®'s efficacy in targeting the tumor-promoting and immunosuppressive functions of MAO-B. Significant (p < 0.05) reductions in CD163 and FOXP3 immunoreactivities were seen in post-treatment biopsies, indicating a decreased presence of M2 macrophages and Tregs. Corroborating with these results, we observed reductions in tumor histological grading, focality and size, factors that collectively enhanced recurrence-free survival (RFS) and pathological complete response (PCR). Moreover, elevated IFN-γ immunoreactivities in treated biopsies correlated with increased counts of CD8+ T cells and higher CX3CR1 expression, underscoring OncoTherad®'s enhancement of cytotoxic T cell functionality and overall antitumor immunity. The IS revealed improvements in immune responses post-treatment, with higher scores associated with better RFS and PCR outcomes. These findings validate OncoTherad®'s capability to modify the bladder cancer microenvironment favorably, promoting effective immune surveillance and response.

MGMT METHYLATION AND ITS PROGNOSTIC SIGNIfiCANCE IN INOPERABLE IDH WILDTYPE GLIOBLASTOMA: A SIX-YEAR REVIEW AT A TERTIARY NEURO-ONCOLOGY CENTER

Abstract AIMS IDH wild-type glioblastoma has the worst prognosis among glioma patients. The methylation of the O6- Methylguanine-DNA Methyltransferase (MGMT) gene is a valid biomarker for predicting response to therapy with alkylating agents and, independently, prognosis. Patients undergoing biopsy only without subsequent treatment have poor prognosis. We aimed to study the survival impact of MGMT methylation in this subset of patients. METHOD We collected six-year retrospective (2017-2023) data at a tertiary neuro-oncology center for patients undergoing biopsy as the only surgical procedure for an unresectable IDH wildtype glioblastoma. Data was collected from patient records including neuro-oncology MDT documentation. Patients were grouped into four categories according to different types of treatment received after biopsy (biopsy only, Biopsy + chemotherapy(CT), biopsy + radiotherapy(RT), biopsy + complete/incomplete STUPP, biopsy + STUPP + 2nd Line). Analysis was performed in python and R statistical software. Survival analysis was performed with Kaplan-Meier Analysis in python. RESULTS 166 glioblastoma IDH wildtype patients were included in the study with mean age of 62.5 years (M: F = 1.5: 1). 50% (n=83) patients had unmethylated MGMT status (0-5%), 29.5% (n=49) patients had methylated MGMT status (&amp;gt;15%) and 19.2% (n=32) patients had borderline methylated MGMT status (5-15%). 21%(n=35) patients did not receive any treatment post biopsy,, 6.6% (n=11) received CT only, 15% (n=25) RT only, 27% (n= 45) complete/incomplete STUPP therapy, whereas 13.2% (n=22) received STUPP therapy along with second line treatment. In biopsy only group, there was no notable difference in survival outcomes among the different methylation statuses. For biopsy and any-other-form-of-treatment groups showed a distinct trend of better survival compared to the borderline or unmethylated groups. Overall, methylated patients had better survival as compared to unmethylated or borderline groups. CONCLUSION Methylated MGMT status is a predictor for better overall survival in unresectable IDH wildtype glioblastoma patients undergoing biopsy and treatment.

Histological Improvement and Cytokine Levels Reduction in Patients with Oral Lichen Planus after Photobiomodulation Therapy.

Background: Oral lichen planus (OLP) is a mucocutaneous disease associated with the formation of symptomatic lesions in the mouth that are often refractory to treatment. An as-yet-unknown antigen triggers an inflammatory reaction in which various immune and non-immune cells release multiple cytokines that contribute to disease progression. The ability of photobiomodulation (PBM) to reduce the symptoms and signs of the disease has been shown, but little is known about its molecular and cellular effects. The aim of this study was to evaluate changes in pro-inflammatory cytokine levels and in histological findings in OLP patients treated with photobiomodulation therapy. Methods: Twenty OLP patients underwent PBM with diode laser (810 nm), (0.50 W, 30 s, 1.2 J/cm2), 3 times weekly for a month. Pain level and clinical scores of lesions were recorded before and after therapy. Salivary levels of IL-1β, IL-6, and TNF-α in OLP patients were measured before and after PBM and compared with those of 10 healthy controls. Biopsies were taken at the beginning and end of treatment to assess pathomorphological changes. Results: PBM significantly reduced the level of pain and clinical scores of the lesions. Salivary levels of IL-1β, IL-6, and TNF-α in OLP patients were significantly higher compared to those in healthy controls and decreased after therapy. 60% of the post-treatment OLP biopsies demonstrated histological improvement, characterized by inflammatory infiltrate reduction (50%), epithelial hyperplasia reduction (30%), epithelial thickening (15%), or epidermal-dermal attachment repair (5%). Conclusion: The effectiveness of PBM therapy in OLP patients was confirmed at the clinical, molecular, and histomorphological levels.

MGMT methylation and its prognostic significance in inoperable IDH-wildtype glioblastoma: the MGMT-GBM study

IntroductionThe methylation of the O6-Methylguanine-DNA Methyltransferase (MGMT) promoter is a valid biomarker for predicting response to therapy with alkylating agents and, independently, prognosis in IDH-wildtype(IDH-w) glioblastoma. We aim to study the impact of its methylation in overall survival of the unresectable IDH-w glioblastoma undergoing biopsy and systemic treatment.MethodsWe collected six-year retrospective (2017–2023) data at a quaternary neurosurgery center for patients undergoing biopsy as the only surgical procedure for an unresectable IDH wildtype glioblastoma. Data was collected from patient records including neuro-oncology multidisciplinary team meeting (MDT) documentation. Patients were grouped into categories according to different types of treatment received after biopsy (no treatment, chemotherapy (CT), radiotherapy (RT), chemoradiotherapy (CRT), chemoradiotherapy with adjuvant temozolomide (CRT with adjuvant TMZ), EORTC-NCIC protocol followed by second line treatment) and according to methylation status (unmethylated (< 5%), borderline methylated (5–15%) and strongly methylated (> 15%)). Survival analysis was performed.Results166 glioblastoma IDH wildtype patients were included in the study with mean age of 62.5 years (M: F = 1.5: 1). 70 (49.3%) patients had unmethylated MGMT status (< 5%), 29 (20.4%) patients had borderline methylated MGMT status (5–15%) and 43 (30.2%) patients had methylated MGMT status (> 15%). 36 (25.3%) patients did not receive any treatment post biopsy, 13 (9.1%) received CT only, 27 (19%) RT only, 12 (8.4%) CRT, 33 (23.2%) CRT with adjuvant TMZ, whereas 21 (14.7%) received EORTC-NCIC protocol along with second line treatment.In biopsy only group, there was no notable difference in survival outcomes among the different methylation statuses. For biopsy and any-other-form-of-treatment methylated groups showed a distinct trend of better survival compared to the borderline or unmethylated groups. Overall, methylated patients had better survival as compared to unmethylated or borderline groups.ConclusionMethylated MGMT status are predictors for better overall survival in unresectable IDH wildtype glioblastoma patients undergoing biopsy and treatment regardless of the treatment modality.

Spatial profiling of METex14-altered NSCLC under tepotinib treatment: Shifting the immunosuppressive landscape

MET inhibitors have demonstrated efficacy in treating patients with non-small cell lung cancer (NSCLC) harboring METex14 skipping alterations. Advancements in spatial profiling technologies have unveiled the complex dynamics of the tumor microenvironment (TME), a crucial factor in cancer progression and therapeutic response.This study uses spatial profiling to investigate the effects of the MET inhibitor tepotinib on the TME in a case of locally advanced NSCLC with a METex14 skipping alteration. A patient with resectable stage IIIB NSCLC, unresponsive to neoadjuvant platinum-based chemotherapy, received tepotinib following the detection of a METex14 skipping alteration. Paired pre- and post-treatment biopsies were subjected to GeoMx Digital Spatial Profiling using the Cancer Transcriptome Atlas and immune-related protein panels to evaluate shifts in the immune TME.Tepotinib administration allowed for a successful lobectomy and a pathological downstaging to stage IA1. The TME was transformed from an immunosuppressive to a more permissive state, with upregulation of antigen-presenting and pro-inflammatory immune cells. Moreover, a marked decrease in immune checkpoint molecules, including PD-L1, was noted. Spatial profiling identified discrete immune-enriched clusters, indicating the role of tepotinib in modulating immune cell trafficking and function. Tepotinib appears to remodel the immune TME in a patient with METex14 skipping NSCLC, possibly increasing responsiveness to immunotherapy.Our study supports the integration of genetic profiling into the management of early and locally advanced NSCLC to guide personalized, targeted interventions. These findings underscore the need to further evaluate combinations of MET inhibitors and immunotherapies.

CRYO-VATE: A Pilot Study of Lung Cancer Cryoactivation in Combination With Immunotherapy in Advanced NSCLC

IntroductionNSCLC is the leading cause of cancer-related mortality. Although immune-checkpoint inhibitors (ICIs) have improved survival in patients with advanced NSCLC, treatment resistance remains a challenge. Cryoactivation, a technique inducing cell death by cycles of freezing/thawing, has the potential to augment tumor responses when combined with ICIs. MethodsThis single-arm phase 1 clinical trial enrolled patients with previously untreated advanced NSCLC and 50% or higher programmed cell death ligand 1. Patients underwent cryoactivation followed by ICI monotherapy initiated 5 days later. The primary end point was the objective response rate. Co-secondary end points included the safety and feasibility of the procedure and overall survival. Immune cell infiltration by immunohistochemistry was performed on paired pre- and post-treatment samples, with patients dichotomized according to clinical benefit (CB) rate (CB versus no CB [NCB]). ResultsEight patients were enrolled. Two patients achieved a partial response, yielding an objective response rate of 25%. Median progression-free survival and overall survival were 3.8 and 13.0 months, respectively. The cryoactivation procedure was well tolerated, without grade 3 to 4 adverse events. Post-hoc analysis reported a CB rate of 50%. Immunohistochemistry analysis reported a numerical difference in the cluster of differentiation 8–positive (CD8+) T cell infiltration in CB versus NCB in the pre- and post-treatment biopsies (p = 0.09) and an increase in CD8+ T cells in the post-treatment biopsies of CB versus NCB (p = 0.03). ConclusionsAlthough cryoactivation combined with pembrolizumab was safe and well tolerated in patients with NSCLC, therapeutic benefits were not evident compared with historical cohorts of ICI monotherapy. Correlative analyses validated CD8+ T cell recruitment in patients deriving CB.

Long-Term Kidney Outcome of Lupus Nephritis by Renal Response Status

IntroductionLimited evidence exists that clinical trial treatment response criteria predict long-term outcomes in Asian patients with lupus nephritis (LN). MethodsThis retrospective analysis of prospectively collected data from the Hong Kong Queen Mary Hospital Cohort categorized adults with biopsy-proven LN (Class III, IV, V, or mixed [III±V, IV±V]) after standard treatment for 2 years (2Y) post biopsy and immunosuppression induction according to modified primary efficacy renal response (mPERR: estimated glomerular filtration rate [eGFR] ≥60 ml/min/1.73 m2 or ≤20% below biopsy value AND urine protein:creatinine ratio [uPCR] ≤0.7) and modified complete renal response (mCRR; eGFR ≥90 ml/min/1.73 m2 or ≤10% below biopsy value AND uPCR ≤0.5). Associations between 2Y mPERR/mCRR status and long-term kidney survival and mild chronic kidney disease (CKD) or worse (Stage ≥3) were assessed. ResultsOf the 176 Chinese patients, 64.2% achieved mPERR and 43.8% achieved mCRR at 2Y post biopsy. After mean follow-up of 15.3 years, significantly higher proportions of mPERR and mCRR responders versus non-responders achieved long-term kidney survival (mPERR: 85.8% vs 71.4%; p=0.029; mCRR: 92.2% vs 71.7%; p<0.001). mPERR and mCRR achievement was associated with adjusted risk reductions for kidney non-survival of 60% (p=0.034) and 86% (p<0.001), respectively. Adjusted risk for mild CKD or worse (Stage ≥3) was 82% (p=0.013) and 87% (p=0.012) lower for mPERR and mCRR responders, respectively, versus non-responders. ConclusionsIn Chinese patients with LN, mPERR and mCRR at 2Y post biopsy predict superior long-term kidney outcomes and lower CKD progression risk.

CAR T-cells for pediatric solid tumors: where to go from here?

Despite the great success that chimeric antigen receptor (CAR) T-cells have had in patients with B-cell malignancies and multiple myeloma, they continue to have limited efficacy against most solid tumors. Especially in the pediatric population, pre- and post-treatment biopsies are rarely performed due to ethical reasons, and thus, our understanding is still very limited regarding the mechanisms in the tumor microenvironment by which tumor cells exclude effectors and attract immune-suppressive cells. Nevertheless, based on the principles that are known, current T-cell engineering has leveraged some of these processes and created more potent CAR T-cells. The recent discovery of new oncofetal antigens and progress made in CAR design have expanded the potential pool of candidate antigens for therapeutic development. The most promising approaches to enhance CAR T-cells are novel CAR gating strategies, creative ways of cytokine delivery to the TME without enhancing systemic toxicity, and hijacking the chemokine axis of tumors for migratory purposes. With these new modifications, the next step in the era of CAR T-cell development will be the clinical validation of these promising preclinical findings.

Abstract B078: A comprehensive spatial atlas of neoadjuvant chemoradiation therapy in resected pancreatic cancer identifies cellular &amp; microenvironmental determinants of persister populations

Abstract Background The molecular pathways involved in the response to radiation therapy (RT) in pancreatic ductal adenocarcinoma (PDAC) remain poorly understood. Despite extensive molecular stratification efforts, improvements in molecularly informed RT-based therapeutic strategies in the neoadjuvant setting have been limited. This study aims to elucidate the adaptive mechanisms and interactions within PDAC to identify new combinatorial therapeutic targets with RT. MethodsWe constructed a high-resolution molecular landscape of the cellular subtypes and spatial communities that constitute PDAC. Single-cell RNA sequencing (scRNA- seq) was performed on 16 PDAC biopsies of matched pre- and post-treatment samples from a Phase I/II dose-escalation clinical trial of pancreatic stereotactic body radiation therapy (SBRT). Additionally, Visium spatial transcriptomics (ST) was conducted on biopsies from primary PDAC patients collected at the time of surgery. These patients received either no neoadjuvant therapy (n = 8) or neoadjuvant chemoradiation (chemoRT) (n = 20). Cell type profiles were determined from scRNA-seq to compare changes in cell type proportions and signatures before and after RT. From these profiles, we employed robust cell type decomposition to analyze cell type signatures in our ST dataset. ResultsChemoRT induced several significant effects compared to controls within the tumor microenvironment, including an increase in the proportion of myofibroblasts, specifically senescent cancer-associated fibroblasts (CAFs), with signatures consistent with immune cell dysfunction. We observed an increase in CD8 and CD4 effector memory cells with RT; however, this occurred alongside a rise in immunosuppressive alternatively activated tumor-associated macrophages. Additionally, RT upregulated pathways related to HIF, cytokine production, B cell proliferation, and negative regulation of lymphocytes. Patients with increased infiltration of NK, memory B, and CD8 effector memory cells demonstrated improved overall survival outcomes. Inference of copy number variations enabled us to identify cancer subclones as either responsive or resistant in matched pre and post RT biopsies. Resistance was characterized by augmented hypoxia, KRAS activation, epithelial- mesenchymal transition, and interferon-gamma response signaling. Conversely, responders exhibited increased oxidative phosphorylation signaling and pathway enrichment associated with cell proliferation and cell cycle progression. Interestingly, RT induced a decrease in cancer cells characterized as harboring a chemoresistant basal-like molecular subtype. ConclusionThrough both longitudinal and therapy stratified tumor biopsies, we were able to observe significant selection pressures on stromal and cancer cells following RT. This includes upregulation of innate and adaptive immune pathways with a compensatory immunosuppressive response driven by myeloid cells and CAFs. This may provide opportunities for development of clinical trials to therapeutically target specific cellular phenotypes and their interactions. Citation Format: Vincent Bernard, Galia Jacobson, Kimal Rajapakshe, Jimin Min, Guangsheng Pei, Daniel Lin, Ayush Suresh, Dadi Jiang, Ching-Wei Tzeng, Manoop S Bhutani, Linghua Wang, Paola A Guerrero, Ethan B Ludmir, Albert C Koong, Anirban Maitra, Cullen M Taniguchi, Eugene J Koay. A comprehensive spatial atlas of neoadjuvant chemoradiation therapy in resected pancreatic cancer identifies cellular &amp; microenvironmental determinants of persister populations [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B078.

Abstract A062: Neurotropic fibroblast population increases following exposure to chemotherapy in pancreatic adenocarcinoma

Abstract Introduction Pancreatic adenocarcinoma (PDA) will be the second leading cause of cancer related death by 2030 and patient response to chemotherapy is poor with a strong likelihood of cancer recurrence. While past studies have investigated pre- and post-chemotherapy patient samples, there is a paucity of studies looking at fresh, patient matched samples which allow us to observe interpatient heterogeneity in chemotherapy response. Methods Here, we study the effects of chemotherapy on five different patients using sc-RNA sequencing of matched treatment naïve and post treatment tissue biopsies to compare the effects of chemotherapy, not only on the tumor cells, but also on the tumor microenvironment – a key contributor to tumor survival and proliferation. We utilized the Seurat v4 pipeline and CellChat v2 to observe transcriptomic differences in epithelial cells, myeloid cells, t-Cells, and fibroblasts and their corresponding putative interactions in pre- and post- treatment states. Results Unsurprisingly, we found insufficient tumor epithelial cells post-treatment to perform further analysis on due to the intended cytotoxic effects of chemotherapy. Therefore, we turned our focus to the tumor microenvironment, where we had sufficient numbers of stromal and immune cells, to investigate the effects of chemotherapy. We identified that fibroblasts changed the most consistently across all patients in response to chemotherapy. The fibroblasts clustered into three distinct groups: an immunomodulatory group, a myofibroblastic and neurotropic group, as well as a mixed group expressing genes from all three categories. Interestingly, the neurotropic fibroblast signature was universally enriched after chemotherapy in all five patients, despite having a small and clinically heterogeneous cohort. Conclusions Through an analysis of each fibroblast group in the treatment naïve and post treatment categories, we observed that a specific set of fibroblasts become less myofibroblastic and increasingly neurotropic following treatment, leading us to posit that fibroblasts altered by exposure to chemotherapy may potentially contribute to a ‘pro-tumor’ environment that supports recurrence. To test this in vitro, we treated patient derived fibroblasts with Gemcitabine and used RTPCR to analyze their relative changes in gene expression. We specifically probed for genes that were definitive of myofibroblasts and neurotropic fibroblasts and saw that post-chemotherapy exposure, neurotropic genes such as NEGR1 and NFIA were upregulated. This validated our scRNA conclusions that fibroblasts become increasingly neurotropic following treatment and then differentially interact with their surrounding environment. In future studies, we will further analyze the role these neurotropic fibroblasts play in chemoresponse and tumor recurrence. Matched samples are critical to studies of chemotherapy effects on PDA due to the fact that they allow us to deconvolute one aspect of PDA heterogenity - interpatient heterogeneity - which is a large limitation in studies of this disease. Citation Format: Aylin Z Henstridge, Padma Kadiyala, Ahmed M Elhossiny, Jianhua Liu, Vaibhav Sahai, Nicole Peterson, Jorge Machicado, Richard Kwon, Allison Schulman, Erik Wamsteker, George Philips, Martin Fernandez-Zapico, Mark Truty, Costas Lyssiotis, Timothy Frankel, Filip Bednar, Marina Pasca di Magliano, Eileen S Carpenter. Neurotropic fibroblast population increases following exposure to chemotherapy in pancreatic adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A062.

PSV-4 Clodronate re-release in response to controlled exercise and bone stressors in juvenile horses

Abstract Concerns over the extra-label use of bisphosphonates in skeletally immature horses has extended to include its likely re-release from bone into circulation in response to stressors. Therefore, the objective of this study was to be first to quantify the re-release of clodronate in response to controlled stressors. Yearling Quarter horses (n = 32) were stratified by age, body weight (BW), sex, and initial bone optical density into four treatment groups for a 168-d trial. Treatments consisted of control (CON; n = 8), single-dose (1X; d 84; n = 8), 2-dose (2X; d 0 and 84; n = 8), and four-dose groups (4X; d 0, 42, 84, and 126; n = 8). All horses received iso-volumetric intramuscular injections of either 1.8 mg/kg BW clodronate disodium (OSPHOSÒ) or saline (placebo) on d 0, 42, 84, and 126. Horses were housed in individual stalls (3.6 m × 7.2 m). Diets were formulated to meet nutrient requirements including concentrate offered every 12-h and ad libitum coastal bermudagrass (Cynodon dactylon) hay and water. Horses were exercised 5 d/wk with a progressive workload, and maximum exercise intensity was reached on d 120, verified via heart rate and blood lactate. On d 120, blood samples were collected prior to the start of the exercise bout (pre), and 0-, 0.5-, 1-, 3-, 12-, and 24-h post exercise. Both tuber coxae of each horse were biopsied on d 168 with blood samples collected prior to (pre), and 0, 12, 24, 48, 72, 168, and 336 h post biopsy. Clodronate was quantified in plasma from exercise and biopsy samples using liquid chromatography tandem mass spectrometry. Exercise and biopsy serum were analyzed for cortisol, a marker of stress, while biopsy serum was analyzed for substance P, a pain marker. Data were analyzed using SAS PROC MIXED. Exercise did not result in clodronate re-release as there was no treatment x time interaction or time effect (P ≥ 0.44), but clodronate was dose-dependently greater in treated groups throughout the exercise collection period (P &amp;lt; 0.01). A treatment x time interaction (P ≤ 0.01) was observed for clodronate concentrations surrounding bone biopsy in which concentrations decreased at 168 h post biopsy before increasing at 336 h in 4X horses. Substance P increased over time (P &amp;lt; 0.01) following biopsy, regardless of treatment. Despite decreasing over time (P ≤ 0.01), there were similarly no treatment differences (P ≥ 0.46) nor treatment ´ time interactions (P ≥ 0.78) for cortisol following either exercise or bone insult. In conclusion, submaximal exercise did not result in re-release of clodronate; however, direct bone insult disrupted clodronate concentrations in horses receiving 4 administrations of bisphosphonate despite no treatment impact on stress or pain indicators.

Dendritic cell effector mechanisms and tumor immune microenvironment infiltration define TLR8 modulation and PD-1 blockade.

The potent immunostimulatory effects of toll-like receptor 8 (TLR8) agonism in combination with PD-1 blockade have resulted in various preclinical investigations, yet the mechanism of action in humans remains unknown. To decipher the combinatory mode of action of TLR8 agonism and PD-1 blockade, we employed a unique, open-label, phase 1b pre-operative window of opportunity clinical trial ( NCT03906526 ) in head and neck squamous cell carcinoma (HNSCC) patients. Matched pre- and post-treatment tumor biopsies from the same lesion were obtained. We used single-cell RNA sequencing and custom multiplex staining to leverage the unique advantage of same-lesion longitudinal sampling. Patients receiving dual TLR8 agonism and anti-PD-1 blockade exhibited marked upregulation of innate immune effector genes and cytokines, highlighted by increased CLEC9A+ dendritic cell and CLEC7A/SYK expression. This was revealed via comparison with a previous cohort from an anti-PD-1 blockade monotherapy single-cell RNA sequencing study. Furthermore, in dual therapy patients, post-treatment mature dendritic cells increased in adjacency to CD8 + T-cells. Increased tumoral cytotoxic T-lymphocyte densities and expanded CXCL13 + CD8 + T- cell populations were observed in responders, with increased tertiary lymphoid structures (TLSs) across all three patients. This study provides key insights into the mode of action of TLR8 agonism and anti-PD-1 blockade immune targeting in HNSCC patients.

Eganelisib combined with immune checkpoint inhibitor therapy and chemotherapy in frontline metastatic triple-negative breast cancer triggers macrophage reprogramming, immune activation and extracellular matrix reorganization in the tumor microenvironment

BackgroundTriple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with a poor prognosis particularly in the metastatic setting. Treatments with anti-programmed cell death protein-1/programmed death-ligand 1 (PD-L1) immune...

COVID-19 epidemic investigation study of a follow-up cohort of patients with diabetic kidney disease.

The impact of coronavirus disease 2019 (COVID-19) on diabetic kidney disease (DKD) patients in China is not fully understood. This study aimed to investigate infection status in a DKD cohort post-renal biopsy and analyze vaccination and infection rates, as well as symptom severity, across various renal pathologies in DKD patients. This epidemiological survey, centered on COVID-19, employed a Chinese DKD and renal puncture follow-up cohort. A customized questionnaire enabled standardized data gathering. It collected data on clinical characteristics, vaccination and infection statuses, and diverse pathological types. The study analyzed the relationship between vaccination and infection statuses across various pathological types, evaluating characteristics and treatment outcomes in patients with infections. In total, 437 patients with DKD from 26 Chinese provinces were followed up for a median of 44.6 ± 20 months. COVID-19 infection, vaccination, and novel coronavirus pneumonia (NCP) rates were 73.68%, 59.3%, and 6.63%, respectively. Ten patients with NCP had severe pneumonia or died of COVID-19. Renal pathology revealed that 167 (38.22%) patients had diabetic nephropathy (DN), 171 (39.13%) had non-diabetic renal disease (NDRD), and 99 had DN and NDRD (22.65%). The DN group had the lowest vaccination (54.5%), highest all-cause mortality (3.6%), and highest endpoint rates (34.10%). Compared to patients who were not vaccinated pre-infection (117 cases), vaccinated patients (198 cases) had reduced NCP (6.6% vs. 13.7%), severity (1.0% vs. 3.4%), and endpoint (9.10% vs. 31.60%) rates. Vaccination can prevent infection and diminish COVID-19 severity in patients with DKD; therefore, increasing vaccination rates is particularly important. ClinicalTrails.gov, NCT05888909.