Positive Tumors Research Articles

GCT-05. UPDATED REPORT ON TREATMENT MODALITIES IN METASTATIC GERMINOMA IN CHILDREN: A MULTI-INSTITUTIONAL ANALYSIS

Abstract BACKGROUND Primary intracranial germ cell tumors (GCTs) are rare heterogeneous tumors; germinoma accounts for two-thirds of cases. While neoadjuvant chemotherapy followed by response-based reduced radiotherapy dose and field is the established approach for managing localized CNS germinomas, controversy persists regarding the treatment of primary metastatic disease. Additionally, limited research exists on the utilization of neoadjuvant chemotherapy in primary metastatic germinoma. METHODS A retrospective multi-institutional analysis was conducted to assess overall survival (OS) and event-free survival (EFS) among patients diagnosed with metastatic germinoma who were treated with various modalities. RESULTS We identified 88 patients, including 63 males and 25 females. The median age at presentation was 13.5 years. All patients, who had undergone both brain and spine MRIs, had their diagnoses confirmed through a biopsy, positive CSF cytology, and/or positive CSF tumor markers at presentation. Primary Tumor location was pineal (n=37), suprasellar (n=27), bifocal (n=14) and others (n=9). Eight patients underwent subtotal resection. Craniospinal irradiation (CSI; 21-24 Gy) was administered to 71 patients (81%), while eight patients (9%) received whole ventricular irradiation (WVI; 23.4-30 Gy). Whole brain radiation was given to four patients (5%; 24 Gy), and two patients (2%) had unknown fields. Boosts to primary and/or metastatic sites were administered in all but seven patients. Notably, thirty patients (34%) received CSI without neoadjuvant chemotherapy. At the end of therapy, 69 patients had complete response, 10 partial response and the response was unknown in six. Three patients did not receive irradiation, all died of disease progression. The median follow-up was 64 months (range 6-159 months), yielding an OS of 96.6%. Ongoing multi-institutional data collection and analysis will be presented at the meeting. CONCLUSION Our study is one of the largest studies to date in metastatic germinoma and may provide insight into the role of neoadjuvant chemotherapy with lower CSI doses.

Endometrial Tumors with “Shadow Cells” Intimate a Neoplastic Potential for Morules or Their Progenitors in β-Catenin Mutated Endometrial Adenocarcinomas.

Background : Several features are shared by endometrial morules and pilomatrixoma-like endometrial carcinomas including CDX-2 and β-catenin nuclear staining, absence of p63 and p40 nuclear staining, and a unique form of endepithelial differentiation that produces so-called shadow cells. Both endometrial morules and pilomatrixoma-like endometrial carcinomas may be associated with low-grade endometrioid adenocarcinoma. Methods : We present 11 fully staged endometrioid endometrial adenocarcinomas that showed extrauterine metastases (Stages III and IV), morules, shadow cell differentiation, and nuclear β-catenin positive immunohistochemical staining (both in morules and in adjacent malignant glandular cells). Results : All intrauterine adenocarcinomas had at least focal components of grade 1 endometrial adenocarcinoma and morules and showed nuclear β-catenin immunostaining in morules and in adjacent malignant glandular cells. 10 cases were stages III and IV endometrial cancers, and one, initially diagnosed as grade 1 stage II endometrioid endometrial adenocarcinoma, rapidly recurred in the retroperitoneum as a nuclear β-catenin positive pilomatrixoma-like tumor without an obvious glandular component. Two positive lymph node dissections showed metastatic adenocarcinoma with malignant glands, morules and shadow cells. Five cases showed at least focal components of morphologically divergent high-grade tumor with foci resembling malignant pilomatrixoma. Extrauterine “shadow cell granulomas” were detected in 8 cases. Conclusion : Metastatic nuclear β-catenin positive endometrial adenocarcinomas with morules can metastasize and show pilomatrixoma-like tumor foci. This highlights the ability of these cancers to evolve into “other-than-glandular” carcinomas. Furthermore, because of their shadow cell features, we speculate that endometrial morules are not simply inert “epitumoral” elements; but that either they or the population of progenitor cells from which they eventuate harbors an abnormal β-catenin gene that may endow endometrial adenocarcinomas with morules the capacity for progressive, divergent differentiation into a higher-grade matrix-producing tumor.

Fetal gut cell-like differentiation in esophageal adenocarcinoma defines a rare tumor subtype with therapeutically relevant claudin-6 positivity and SWI/SNF gene alteration

Esophageal adenocarcinoma (EAC) is one of the deadliest tumor entities worldwide, with a 5-year survival rate of less than 25%. Unlike other tumor entities, personalized therapy options are rare, partly due to the lack of knowledge about specific subgroups. In this publication, we demonstrate a subgroup of patients with EAC in a large screening cohort of 826 patients, characterized by specific morphological and immunohistochemical features. This subgroup represents approximately 0.7% (6/826) of the total cohort. Morphological features of this subgroup show a striking clear cytoplasm of the tumour cells and the parallel existence of rare growth patterns like yolk sac-like differentiation and enteroblastic differentiation. Immunohistochemistry reveals expression of the fetal gut cell-like proteins Sal-like protein 4 (SALL4), claudin-6, and glypican 3. Interestingly, we find a correlation with alterations of SWI/SNF-complex associated genes, which are supposed to serve as tumor suppressor genes in various tumour entities. Our results suggest a possible implication of rare tumour subtypes in the WHO classification for EACs according to the classification for gastric cancer. Furthermore, claudin-6 positive tumors have shown promising efficacy of CAR T cell therapy in the recently published BNT-211-01 trial (NCT04503278). This represents a personalized therapeutic option for this tumor subtype.

Outcome of Patients with Locally Advanced Rectal Cancer Pursuing Non-Surgical Strategy in National Cancer Database

Background: Survival data on patients with locally advanced rectal cancer (LARC) undergoing non-operative management (NOM) in a real-world setting are lacking. Methods: We analyzed LARC patients from the National Cancer Database with the following features: treated between 2010 and 2020, age 18–65 years, Charlson comorbidity index (CCI) ≤ 1, received neoadjuvant multiagent chemotherapy plus radiation ≥ 45 Gray, and underwent surgery or NOM. Patients were stratified into two groups: (A) clinical T1-3 tumors with positive nodes (cT1-3N+) and (B) clinical T4 tumors, N+/− (cT4N+/−). We performed a comparative analysis of overall survival (OS) with NOM versus surgery by the Kaplan–Meier method and propensity score matching. Additionally, a multivariable analysis explored the association between NOM and OS. Results: NOM exhibited significantly lower OS than surgery in both groups. In cT1-3N+ patients, NOM resulted in a 5-year OS of 73.9% (95% confidence interval [CI] = 69.7–77.6%) versus 84.5% (95% CI = 83.6–85.3%) with surgery (p < 0.001). In the cT4N+/− group, NOM yielded a 5-year OS of 44.5% (95% CI = 37.0–51.8%) versus 72.5% (95% CI = 69.9–74.8%) with surgery (p < 0.001). Propensity score matching and multivariable analyses revealed similar conclusions. Conclusion: Patients with LARC undergoing NOM versus surgery in real-world settings appear to have inferior survival.

Clinicopathological parameters associated with cervical lymph node metastases in differentiated thyroid cancer.

Lymph node metastasis (LNM) has an important role for the prognosis of diferentiated thyroid cancer (DTC). The aim of the study was to investigate the efect of clinicopathologic parameters on cervical LNM in DTC. The patients who underwent thyroidectomy along with neck dissection were analyzed retrospectively. Of the 150 patients diagnosed with DTC who underwent neck dissection, 1 had follicular thyroid carcinoma and 149 had papillary thyroid carcinoma (PTC). The median tumor size was 14.0 mm. The tumor diameter with the highest specificity and sensitivity for the detection of LNM was >11.5 mm. Extrathyroidal extension (ETE) was observed in 35.3% of the patients. The rate of multifocality in tumors with extrathyroidal spread was significantly higher than in tumors without ETE. LNM was observed in 60.0% of the patients. ETE was present in 28.9% of the tumors that had LNM. Lymphovascular invasion (LVI), perineural invasion (PNI), and positive surgical margin were observed in 13.3%, 2.7%, and 14% of the patients respectively. A significant positive correlation was found between LNM and tumor diameter, ETE, positive tumor margin and LVI (Pp=.006, P=.031, P = .002, and P=.014, respectively). In this study, ETE, LVI, positive tumor margin, and tumor diameter greater than 11.5 mm were significantly correlated with the presence of LNM. These findings may be useful in bringing to mind the possibility of lymph node metastases that have not been able to be detected before surgery and in monitoring these patients more closely.

InVivo PET Imaging of 89Zr-Labeled Natural Killer Cells and the Modulating Effects of a Therapeutic Antibody.

Natural killer (NK) cells can kill cancer cells via antibody-dependent cell-mediated cytotoxicity (ADCC): a tumor-associated IgG antibody binds to the Fcγ receptor CD16 on NK cells via the antibody Fc region and activates the cytotoxic functions of the NK cell. Here, we used PET imaging to assess NK cell migration to human epidermal growth factor receptor 2 (HER2)-positive HCC1954 breast tumors, examining the influence of HER2-targeted trastuzumab antibody treatment on NK cell tumor accumulation. Methods: Human NK cells from healthy donors were expanded ex vivo and labeled with [89Zr]Zr-oxine. In vitro experiments compared the phenotypic markers, viability, proliferation, migration, degranulation, and ADCC behaviors of both labeled (89Zr-NK) and unlabeled NK cells. Female mice bearing orthotopic human breast HCC1954 tumors were administered 89Zr-NK cells alongside trastuzumab treatment or a sham treatment and then scanned using PET/CT imaging over 7 d. Flow cytometry and γ-counting were used to analyze the presence of 89Zr-NK cells in liver and spleen tissues. Results: 89Zr cell radiolabeling yields measured 42.2% ± 8.0%. At an average specific activity of 16.7 ± 4.7 kBq/106 cells, 89Zr-NK cells retained phenotypic and functional characteristics including CD56 and CD16 expression, viability, migration, degranulation, and ADCC capabilities. In vivo PET/CT studies indicated predominant accumulation of 89Zr-NK cells in the liver and spleen. Ex vivo analyses of liver and spleen tissues indicated that the administered human 89Zr-NK cells retained their radioactivity invivo and that 89Zr did not transfer to cells of murine soft tissues, thus validating this 89Zr PET method for NK cell tracking. Notably, 89Zr-NK cells migrated to HER2-positive tumors, both with and without trastuzumab treatment. Trastuzumab treatment was associated with an increased 89Zr-NK cell signal at days 1 and 3 after injection. Conclusion: In vitro, 89Zr-NK cells maintained key cellular and cytotoxic functions. In vivo, 89Zr-NK cells trafficked to HER2-postive tumors, with trastuzumab treatment correlating with enhanced 89Zr-NK infiltration. This study demonstrates the feasibility of using PET to image 89Zr-NK cell infiltration into solid tumors.

Synthesis and Characterization of a Novel PET Tracer for Noninvasive Evaluation of FGL1 Status in Tumors.

Fibrinogen-like protein 1 (FGL1) is a potential novel immune checkpoint target for malignant tumor diagnosis and therapy. Accurate detection of FGL1 levels in tumors via noninvasive PET imaging might be beneficial for managing the disease. To achieve this, multiple FGL1-targeting peptides (FGLP) were designed, and a promising candidate, 68Ga-NOTA-FGLP2, was identified through a high-throughput screening approach using microPET imaging of 68Ga-labeled peptides. Subsequent in vitro cell experiments showed that uptake values of 68Ga-NOTA-FGLP2 in FGL1 positive Huh7 tumor cells were significantly higher than those in FGL1 negative U87 MG tumor cells. Further microPET imaging showed that the Huh7 xenografts were clearly visualized with a favorable contrast. ROI analysis showed that the uptake values of the tracer in Huh7 xenografts were 2.63 ± 0.07% ID/g at 30 min p.i.. After treatment with an excess of unlabeled FGLP2, the tumor uptake significantly decreased to 0.54 ± 0.05% ID/g at 30 min p.i.. Moreover, the uptake in U87 MG xenografts was 0.44 ± 0.06% ID/g at the same time point. The tracer was excreted mainly through the renal system. 18F-FDG PET imaging was also performed in mice bearing Huh7 and U87 MG xenografts, respectively. However, there was no significant difference in the uptake between the tumors with different FGL1 expressions. Preclinical data indicated that 68Ga-NOTA-FGLP2 might be a suitable radiotracer for in vivo noninvasive visualization of tumors with abundant expression of FGL1. Further investigation of 68Ga-NOTA-FGLP2 for tumor diagnosis and therapy is undergoing.

HyperGCN: an effective deep representation learning framework for the integrative analysis of spatial transcriptomics data

BackgroundAdvances of spatial transcriptomics technologies enabled simultaneously profiling gene expression and spatial locations of cells from the same tissue. Computational tools and approaches for integration of transcriptomics data and spatial context information are urgently needed to comprehensively explore the underlying structure patterns. In this manuscript, we propose HyperGCN for the integrative analysis of gene expression and spatial information profiled from the same tissue. HyperGCN enables data visualization and clustering, and facilitates downstream analysis, including domain segmentation, the characterization of marker genes for the specific domain structure and GO enrichment analysis.ResultsExtensive experiments are implemented on four real datasets from different tissues (including human dorsolateral prefrontal cortex, human positive breast tumors, mouse brain, mouse olfactory bulb tissue and Zabrafish melanoma) and technologies (including 10X visium, osmFISH, seqFISH+, 10X Xenium and Stereo-seq) with different spatial resolutions. The results show that HyperGCN achieves superior clustering performance and produces good domain segmentation effects while identifies biologically meaningful spatial expression patterns. This study provides a flexible framework to analyze spatial transcriptomics data with high geometric complexity.ConclusionsHyperGCN is an unsupervised method based on hypergraph induced graph convolutional network, where it assumes that there existed disjoint tissues with high geometric complexity, and models the semantic relationship of cells through hypergraph, which better tackles the high-order interactions of cells and levels of noise in spatial transcriptomics data.

Prognostic implications of preoperative, postoperative, and dynamic changes of alpha-fetoprotein and des-gamma (γ)-carboxy prothrombin expression pattern for hepatocellular carcinoma after hepatic resection: a multicenter observational study.

The utility of pre- and post-operative alpha-fetoprotein (AFP) and des-gamma (γ)-carboxy prothrombin (DCP) expression patterns and their dynamic changes as predictors of the outcome of hepatic resection for hepatocellular carcinoma (HCC) has yet to be well elucidated. From a multicenter database, AFP and DCP data during the week prior to surgery and the first post-discharge outpatient visit (within 1-2 months after surgery) were collected from patients with HCC who underwent hepatectomy. AFP-DCP expression patterns were categorized according to the number of positive tumor markers (AFP ≥ 20ng/mL, DCP ≥ 40mAU/mL), including double-negative, single-positive, and double-positive. Changes in the AFP-DCP expression patterns were delineated based on variations in the number of positive tumor markers when comparing pre- and post-operative patterns. Preoperatively, 53 patients (8.3%), 337 patients (52.8%), and 248 patients (38.9%) exhibited double-negative, single-positive, and double-positive AFP-DCP expression patterns, respectively. Postoperatively, 463 patients (72.6%), 130 patients (20.4%), and 45 patients (7.0%) showed double-negative, single-positive, and double-positive AFP-DCP expression patterns, respectively. Survival analysis showed a progressive decrease in recurrence-free (RFS) and overall survival (OS) as the number of postoperative positive tumor markers increased (both P < 0.001). Multivariate analysis showed that postoperative AFP-DCP expression pattern, but not preoperative AFP-DCP expression pattern, was an independent risk factor for RFS and OS. Further analysis showed that for patients with positive preoperative markers, prognosis gradually improves as positive markers decrease postoperatively. In particular, when all postoperative markers turned negative, the prognosis was consistent with that of preoperative double-negative patients, regardless of the initial number of positive markers. AFP-DCP expression patterns, particularly postoperative patterns, serve as vital sources of information for prognostic evaluation following hepatectomy for HCC. Moreover, changes in AFP-DCP expression patterns from pre- to post-operation enable dynamic prognostic risk stratification postoperatively, aiding the development of individualized follow-up strategies.

Differential expression of NAT1 pharmacogene in hormone receptor positive vs. negative female breast tumors may affect drug treatment.

Studies have reported overexpression of NAT1 gene for xenobiotic metabolizing arylamine N -acetyltransferase type 1 in estrogen receptor positive breast tumors, and this association has been linked to patient chemoresistance and response to tamoxifen. We probed the expression of NAT1 , using quantitative reverse transcription PCR to screen clinically characterized breast cancer tissue cDNA arrays. Primers detecting all NAT1 alternative transcripts were used, and the protocol and results are reported according to consensus guidelines. The clinical information about 166 tumor samples screened is provided, including tumor stage, estrogen and progesterone receptor status and HER2 expression. NAT1 was found to be significantly ( P < 0.001) upregulated in hormone receptor positive vs. negative tumors. No correlation was apparent between NAT1 and tumor stage or HER2 expression. Our findings demonstrate a strong correlation between the expression of NAT1 and steroid hormone receptors in breast tumors, supporting its possible utility as a pharmacogenetic biomarker or drug target. Of the two polymorphic NAT genes, NAT1 is the one primarily expressed in breast tissue, and is subjected to regulation by two differential promoters and more than one polyadenylation signal. Hormonal factors may enhance NAT1 gene expression at the transcriptional or epigenetic level, and tamoxifen has additionally been shown to inhibit NAT1 enzymatic activity. The outcome of tamoxifen treatment is also more favorable in patients with NAT1 overexpressing tumors. The study adds to the growing body of evidence implicating NAT1 in breast cancer and its pharmacological treatment.

Association of mammographic breast density measurements and hormone receptor status of breast cancer.

Breast cancer is the most frequent cancer in women, with significant mortality. Mammography is a routine investigation for breast disease. A known risk factor for breast cancer is increased breast density. Here, we tried to observe if mammographic density also affects the hormone receptor status of breast cancer, which will help in the understanding of the biological mechanisms of breast cancer development. Suspected breast cancer patients at Lok Nayak Hospital, Delhi, underwent mammography in the Department of Radiodiagnosis. The density of breast contralateral to the mass was assessed using Hologic Quantra software version 2.1.1 [Area Breast Density(ABD)]. The hormone receptor status of all the tumours was recorded on histopathology. Of these, 100 confirmed cases were included in the study. ER-positive, PR-positive, and HER2-positive tumours were seen in 41%, 33%, and 34% patients, respectively. Regarding ER receptor status, the mean ABD for positive and negative tumours was 27% and 23%, respectively, p-value = 0.01, showing significant relation between them. Mean ABD for HER2-positive and -negative tumours was 25% and 24%, respectively, p-value = 0.75. Mean ABD for PR-positive and PR-negative tumours was 23% and 25%, respectively, p-value = 0.42 (not significant). We found that ER-positive tumours were common in dense breasts, which was statistically significant. However, this was not true for PR and HER2 receptor status. Limited studies have been done to study MD using computerised software and its effect on hormone receptor status, with conflicting results. Further, large, multicentric studies can be useful in understanding the mechanism and providing better treatment for breast cancer patients.

Clinical update related to the first-in-human trial of SYS6002 (CRB-701), a next-generation nectin-4 targeting antibody drug conjugate.

3151 Background: SYS6002 (CRB-701) is a novel, nectin-4 targeting antibody drug conjugate (ADC) that take advantage of a third generation, site-specific cleavable linker with novel conjugation chemistry. This technology is designed to establish a stable linker across antibody and payload, to produce an ADC with a homogenous drug antibody ratio of 2.0, with the additional aim to reduce the concentration of free-MMAE and thereby improve known payload related toxicities. SYS6002 (CRB-701) also contains a novel monoclonal antibody with a prolonged half-life that can support Q3W dosing. Methods: This is a multicenter, open-label, single-arm, phase I study using Bayesian optimal interval design. Eligible patients were aged ≥18 years with histologically confirmed Nectin-4 positive solid tumors (no Nectin-4 testing was required for urothelial carcinoma [UC]) who had failed or were intolerant to standard of care options. In the dose escalation, patients were given SYS6002 (dose level 0.2, 0.6, 1.2, 1.8, 2.7, 3.6, and 4.5 mg/kg) administered Q3W by intravenous infusion. The primary endpoints were safety, tolerability, and the recommended phase 2 dose. Results: As of January 2024, SYS6002 (CRB-701) has established a differentiated safety profile across a broad dose range (0.2-3.6 mg/kg) with no dose limiting toxicities and the majority of adverse events representing grade 1 or 2. No low-grade peripheral neuropathy, skin rash or fatigue, known toxicities that rate limit the usage of enfortumab vedotin (EV) have occurred. Herein, we report the anti-tumor activity of SYS6002 (CRB-701) in patients with nectin-4 positive solid tumors with a median of 4 prior therapies. The first confirmed stable disease was observed at 0.6 mg/kg and the first confirmed partial response was at 1.2 mg/kg. Anti-tumor activity in nectin-4 positive patients at doses ≥ 2.7 mg/kg ( n=6) would suggest an overall unconfirmed objective response rate of 50%, and among them, the ORR of patients with UC was 50% (1/2), and that of patients with cervical cancer reached 67% (2/3). Across this group of patients, 4/6 had moderate to high nectin-4 expression (H-score ≥ 150) and 3 achieved a partial response, suggesting SYS6002 (CRB-701) could achieve a highly differentiated ORR of 75% in patients with moderate to high Nectin-4 expression. After single IV infusion of SYS6002 0.2-3.6 mg/kg, the exposure of TAb, ADC and MMAE generally increased in a dose proportional manner. The half-lives of TAb, ADC and MMAE were 4-6 days, 4-5 days and 5-10 days, respectively. SYS6002 (CRB-701) exhibited a longer ADC half-life and lower free-MMAE exposures relative to EV at comparable dose levels. Conclusions: SYS6002 (CRB-701) demonstrates promising anti-tumor activity with a well-tolerated safety profile in patients with advanced nectin-4 positive solid tumors. Dose escalation at 4.5 mg/kg Q3W and dose expansion at 3.6 mg/kg Q3W are ongoing. Clinical trial information: ChiCTR2200066256.

Concordance of PD-L1 combined positive score (CPS) analysis between primary gastric cancer and matched peritoneal metastasis.

e16068 Background: Peritoneum represents one of the most common metastatic sites of gastroesophageal adenocarcinoma (GEA) and is associated with poor prognosis. Programmed death-ligand 1 (PD-L1) expression is a recognized predictive biomarker of response to immune checkpoint inhibitors (ICIs) in the first-line setting. However, data from pivotal trials showed poorer clinical efficacy of ICIs in the sub-set of patients with peritoneal involvement, regardless of PD-L1 score magnitude. Here, we investigated the temporal and spatial heterogeneity of PD-L1 expression between primary tumor and matched peritoneal metastasis. Methods: PD-L1 expression according to CPS was determined by immunohistochemistry using VENTANA PD-L1 (SP263) assays on formalin-fixed paraffin-embedded (FFPE) tumor tissues derived from 22 patients treated at our institution for advanced GEA from September 2015 to August 2023. Concordance rate of PD-L1 expression between primary tumor and matched peritoneal metastasis using PD-L1 CPS cut-off of 1 and 5 was reported (spatial heterogeneity); additionally, concordance between PD-L1 value before and after the administration of systemic treatments was analyzed (temporal heterogeneity). Results: 12(54.5%)/5(22.7%) primary tumor samples and 12(54.5%)/1(4.5%) peritoneal metastases showed PD-L1 CPS ≥ 1/ ≥ 5, respectively. Concordance of PD-L1 CPS between primary and peritoneal specimens was 54.5% and 72.7% according to CPS cuts-off of 1 and 5, respectively, highlighting marked spatial heterogeneity. High concordance rate (94%) was reported between negative PD-L1 CPS primary tumor samples and matched peritoneal metastases, against the cut-off of CPS ≥ 5; in contrast, none of the positive primary tumor samples retained PD-L1 expression in the peritoneum. Evident temporal heterogeneity of PD-L1 expression was also observed, with 56% concordance against CPS ≥ 5 in the pre- versus post-treatment comparison. Conclusions: PD-L1 expression in GEA is characterized by spatial and temporal heterogeneity which is more prominent for lower CPS cut-offs values. This evidence could hamper its role as predictive biomarker for ICIs. The high intra-patient discordance rate of PD-L1 CPS expression between positive primary tumor samples and matched peritoneal metastases suggests that peritoneal specimens should not be recommended as the preferred source for PD-L1 assessment.

PD-L1 immunohistochemistry in gastric cancer: Comparison of combined positive score and tumor area positivity across 28-8, 22C3, and SP263 assays.

2625 Background: The clinical application of programmed death-ligand 1 (PD-L1) immunohistochemistry is complicated by multiple available assays and different testing platforms, scoring algorithms, and cut-offs applied. This study assessed the analytical comparability of three commercially available PD-L1 assays (28-8, 22C3, and SP263) and two scoring algorithms used in gastric cancer (GC). Methods: Serial sections of 100 commercially procured GC samples, selected by the 28-8 assay to represent the dynamic range of PD-L1 expression, were stained with the three in vitrodiagnostic (IVD)-grade PD-L1 assays. Stained slides were blindly and independently evaluated by three trained pathologists for intra- and inter-reader assessment. Scoring was performed using the combined positive score (CPS) and tumor area positivity (TAP) methods, followed by statistical analysis. Digital image analysis (DIA) was used to objectively assess the technical performance of each assay by simulating CPS and TAP scoring methods using the HALO platform. Results: Comparable, specific, staining patterns were observed with the three PD-L1 assays. Pathologist assessment of PD-L1 positivity was reproducible in GC sample cohorts despite discernible variability in the observed staining intensity. When the same PD-L1 cut-offs were applied, inter- and intra-assay assessments of all three assays, using either CPS or TAP scoring methods, demonstrated moderate to almost-perfect (inter-assay Cohen’s kappa [κ] ranged from 0.47 to 0.83) and substantial to almost-perfect (intra-assay κ ranged from 0.77 to 1.00) agreement, respectively. Moreover, inter-pathologist evaluation showed a significant level of reproducibility (intraclass correlation coefficient (ICC) ≥0.92). DIA confirmed no difference in technical performance when specific digital algorithms were applied. Conclusions: This GC study highlights analytical concordance in PD-L1 testing among three major PD-L1 assays when TAP and CPS scoring algorithms are prospectively applied. Independently, DIA further supports the comparability of the technical performance of the assays. These observations support flexibility in cross-application of the different PD-L1 assays and scoring algorithms currently used to characterize PD-L1–positive GC samples.

Multicentric retrospective study on the treatment characteristics, efficacy and safety of eribulin in Slovenian patients with breast cancer.

e13123 Background: Eribulin mesylate (eribulin) is a microtubule inhibitor and a synthetic analog of halichondrin B, a natural product isolated from the marine sponge Halichondria okadai. Eribulin was approved based on the randomized Phase 3 EMBRACE clinical trial, which showed an improvement in survival compared to chemotherapy (CT) of the physician's choice. The efficacy and safety of eribulin treatment in real-world settings has been reported in several studies: Korean and Chinese multicenter retrospective studies and a meta-analysis from 2020. Methods: We included all patients treated with eribulin between January 24, 2013 and September 14, 2022 at the Institute of Oncology Ljubljana (85.4% of patients) and University Medical Centre Maribor (14.6%). Clinical data were collected retrospectively from paper and electronic patient records. The primary endpoints were median progression-free survival (PFS), overall survival (OS), response rates and safety. We performed a descriptive statistical analysis and a survival analysis using the Kaplan-Meier method. Results: 205 patients, whose average age was 58.6 (29-88) years, were included in the study. The majority (79%) had a hormone receptor (HR+) positive tumor, 12.2% were HER2 positive and 16.6% were triple negative. 32/205 (15.6%) were primary metastatic. Of the remaining 173 patients, 160/173 (92.4%) received adjuvant therapy, of which 15% received hormone therapy, 23.1% received CT and 61.9% received both. At the start of treatment with eribulin, 84.9% had visceral tumors and 14.6% had tumors in the CNS. The median number of all treatment lines was 6 (range 2–15) and the median number of CT lines was 4 (0–13). The ECOG performance status was: 0 in 4.9%, 1 in 53.2%, 2 in 35.1% and 3 in 4.9% and 4 in 0.5% of patients. The objective response rate was 7.3% and clinical benefit was achieved in 27.3%. The median CT line in which eribulin was used was the fourth (1–10). Eribulin was used as the last CT line in half of the patients. The median PFS was 3.01 months (95% confidence interval 2.56–3.47) and the median OS was 6.68 months (95% confidence interval 5.60–7.77). Patients who received eribulin in the first 3 lines of treatment had a better OS than those who received eribulin in later lines. Adverse events (AEs) occurred in 52.7%. Eribulin therapy was discontinued due to AEs in 18.5% of patients. The most common AE was fatigue (25.9%), followed by neuropathy and neutropenia (22.9% and 18%). Conclusions: In our retrospective analysis, we found significantly worse results of treatment with eribulin than in previous studies. In our population, eribulin was used in the late stages of treatment and in older patients with poorer performance status. The proportion of patients with visceral and CNS tumors was higher. The side effects were comparable.

Phase 1 study of ZV0203, a first in class pertuzumab ADC, in patients with HER2 positive advanced solid tumors.

e15004 Background: ZV0203, a first in class (FIC) pertuzumab antibody-drug conjugate (ADC), targets HER2 positive tumor cells with tubulin inhibitor DUO5 as its payload via a stable and protease-cleavable valine-citrulline linker. In preclinical studies, ZV0203 demonstrated superior antitumor activity compared to Kadcyla in multiple tumor cell line xenograft models with no noticeable toxicity. GLP toxicity studies indicated that ZV0203 was well tolerated with an estimated therapeutic index of 35. Methods: This was an open-label, multicenter, phase 1, dose-escalation study in patients (pts) with HER2+ advanced solid tumors. Primary objectives were safety, tolerability and RP2D. Secondary objectives included PK, immunogenicity and preliminary clinical efficacy. ZV0203 was administered intravenously Q3W on a 21-day cycle. An accelerated titration design was used for the 0.3 and 0.6 mg/kg doses, followed by a 3+3 design for 1.2, 1.8, 2.7 and 3.6 mg/kg dose levels. Results: As of January 18, 2024, 15 pts with solid tumors (breast [11], colorectal [2], gastric [1], lung [1]) were enrolled across doses of 0.3-3.6 mg/kg with a median age of 52 years old (range 35-65), of which 9 pts received prior HER2-targeted therapy (trastuzumab ± pertuzumab) and 14 pts completed 21-day DLT assessment (0.3 mg/kg and 0.6 mg/kg [1 each], 1.2 mg/kg, 1.8 mg/kg, 2.7 mg/kg and 3.6mg/kg [3 each]) with no DLT incidence. Treatment-related adverse events (TRAE) occurred in 14 (93.3%) pts. The most frequent TRAEs were corneal epitheliopathy [9], elevated liver enzymes [6], dry eyes [6], neutropenia [4], anemia [4], leukopenia [3], and proteinuria [3], and most were grade 1-2 in severity. 5 pts experienced grade 3 TRAEs: lymphocytopenia (1.8mg/kg [1]) , corneal epitheliopathy (3.6 mg/kg [1]) and blurred vision (2.7 mg/kg [2], 3.6 mg/kg [1]), which were manageable during treatment. No unexpected safety signals were reported. TRAEs led to 13.3% (2/15) treatment discontinuation. Among 14 pts evaluated, 5 pts achieved a best tumor response of PR; 4 pts had SD; 1 pt had Non-CR/Non-PD per RECIST v1.1. Thus, disease control rate was 71.4% (10/14). PK results demonstrated that the PK profile of total antibody was similar to that of ZV0203 ADC, whose systematic exposure increased in a dose-dependent manner and remained stable after repeated administration. Concentration of DUO5 remained scarce, suggesting good stability of ZV0203. Conclusions: ZV0203 was well tolerated and showed clinically encouraging anti-tumor activity in heavily pretreated pts with HER2 positive cancer. Clinical trial information: NCT05423977 .

A phase II randomized control trial of triapine plus lutetium 177 DOTATATE versus lutetium 177 DOTATATE alone for well-differentiated somatostatin receptor-positive neuroendocrine tumors.

TPS4202 Background: Radiolabeled somatostatin analogues provide a means of delivering targeted radiation with a high therapeutic index to NETs that express somatostatin receptors (SSTRs). Radiolabeled somatostatin analogue Lutetium 177 DOTATATE (Lutathera) is a beta-emitting radionuclide, FDA approved for use in SSTR positive gastroenteropancreatic neuroendocrine tumors (GEPNETS) in the US based on the NETTER-1 Phase III trial. Despite favorable PFS and safety profile, the drug has limited cytoreductive capability with a 14% ORR. Peptide receptor radionuclide therapy (PRRT) also doesn’t seem to be very effective in treating peritoneal disease. We hypothesize that addition of an effective radiation sensitizer could help improve antitumor activity of Lutathera. Radiation is a potent inducer of DNA double-strand breaks, and ribonucleotide reductase (RNR) is the rate-limiting enzyme in the synthesis and repair of DNA, making RNR-targeted therapy a rationale therapeutic strategy for radiosensitization. ETCTN 10388 (NCT04234568) evaluated safety and efficacy of the combination of lutetium 177 DOTATATE, a beta-emitting radionuclide in combination with triapine, a ribonucleotide reductase (RNR) inhibitor. The combination of triapine and Lu-177 DOTATATE was safe with preliminary efficacy signals. Methods: This study is an investigator initiated, NCI sponsored, multicenter randomized phase 2 trial of triapine and lutetium Lu 177 DOTATATE in well-differentiated somatostatin receptor-positive neuroendocrine tumor. A total of 94 patients will be equally randomized to either Lu-177 dotatate or Triapine + Lu-177 dotatate arm. The study will be open through the NCI ETCTN (National Cancer Institute Experimental Therapeutics Clinical Trials Network) program. Triapine will be administered orally from D1-14 with each dose of PRRT [200 mCi]. Primary endpoint is to evaluate overall response rate (ORR). Secondary endpoint is to evaluate median PFS. We are also evaluating triapine PK, plasma deoxyribonucleosides, circulating DNA and plasma hPG80, a novel blood based diagnostic biomarker. Clinical trial information: 05724108.

Preliminary results of phase I/II study to evaluate safety and efficacy of combination pucotenlimab with epidermal growth factor receptor-ADC (EGFR-ADC) MRG003 in patients with EGFR positive solid tumors.

6013 Background: Pucotenlimab (HX008) is a recombinant humanized PD-1 inhibitor approved for marketing in China, and MRG003 is an EGFR-ADC which has shown promising anti-tumor activity in squamous cell carcinoma of the head and neck (SCCHN) and nasopharyngeal carcinoma (NPC) in multiple clinical studies. In the preclinical studies, the combination of them has demonstrated a synergistic antitumor effect. This study was aimed to assess the safety and efficacy of the combination therapy in patients (pts) with locally advanced or metastatic solid tumors known to express EGFR. Methods: In this Phase I/II dose escalation and expansion study, eligible pts were treated with 3.0 mg/kg HX008 combined with MRG003 every 3 weeks, with an escalated dosing ranging from 1.5 mg/kg to 2.3 mg/kg. The primary endpoints were maximum tolerated dose (MTD), recommended Phase II dose (RP2D) of combination and objective response rate (ORR). Secondary endpoints included duration of response (DOR), disease control rate (DCR), and progression-free survival (PFS). Results: As of 30 January 2024 (cut-off date), 33 pts (9 NPC, 1 SCCHN and 3 other solid tumors pts in Phase I, 14 NPC and 6 SCCHN pts in Phase II) were enrolled in this study with a median age of 52 (31,65), and 25 pts (76%) were male. 11 (33%) pts were ECOG PS 0. The most commonly reported treatment-related adverse events (TRAEs) included pruritus (46%), rash (33%), AST increased (30%), anemia (30%). Grade 3-4 TRAEs occurred in 4 pts (12%), and mainly was white blood cell count decreased (9%) and hypokalemia (6%). The only DLT event occurred in the 2.3mg/kg dose group, and the RP2D of MRG003 determined was 2.0mg/kg by SMC. Out of the 27 evaluable pts, 17 pts achieved PR and 7 pts achieved SD, thus the ORR and DCR were 63.0% (95%CI: 42.4, 80.6) and 88.9% (95%CI: 70.8, 97.7), respectively. In the Phase II, among 9 evaluable EGFR-positive NPC pts progression after first-line treatment of PD-1 plus platinum-based chemotherapy, 2 CR, 5 PR and 2 SD were observed, ORR and DCR were 77.8% (95%CI:40.0, 97.2) and 100% (95%CI:66.4, 100), respectively. Five evaluable systemic treatment naïve SCCHN pts with EGFR-positive, 3 PR and 1 SD were observed, ORR and DCR were 60% (95%CI:14.7, 94.7) and 80% (95%CI:28.4, 99.5), respectively. The DOR and PFS in the study were immature. The longest patient treated has had a DOR for more than 17 months and still ongoing. Conclusions: The Phase I/II study pts treated with HX008 in combination with MRG003 demonstrated good tolerability and encouraging antitumor activity in NPC and SCCHN, especially in PD-1 treatment failed NPC pts. The Phase II study is currently ongoing. Research Sponsor: Shanghai Miracogen Inc. Clinical trial information: NCT05688605.

Quality of life (QoL) benefits following 177Lu-DOTATATE therapy in patients (pts) with 68Ga-DOTATATE PET positive primary site agnostic neuroendocrine tumors (NET).

e16291 Background: The QoL experience during the 1st year of follow up for 68Ga-DOTATATE PET positive primary site agnostic pts with progressive metastatic NET enrolled in a prospective single arm clinical trial of 177Lu-DOTATATE therapy (OZM 067) is described here. Methods: Pts with progressive NET, Ki67 Index &lt; 30%, adequate organ function &amp; ECOG £2 were eligible. Only pts demonstrating positive disease (Krenning score 3-4) on 68Ga-DOTATATE PET were eligible to proceed to 177Lu-DOTATATE therapy (4 cycles at 8- to 12- week intervals. Primary outcome was progression free survival (PFS) at 12 mths. QoL (EORTC QLQ 30 and GINET21) at baseline, 6, 12, 18, 24, 30 months were recorded. Summary scores at time point of interest, and their change from baseline were estimated using a mixed model repeated measure, with baseline assessment included in the model as covariate. Data were normalized with a range of 0-100. A positive change score for Global Summary Status, Functioning Domains, and a negative change score for Symptom Scales and Items represent improvement. A ≥5 point change score is used as a threshold for Minimal Clinically Important Difference (MCID). Results: 195 pts were enrolled. 13 pts were 68Ga-DOTATATE PET negative while 5 pts withdrew consent. 177 pts received at least one dose of 177Lu-DOTATATE. All pts enrolled were eligible for a minimum of 12 mths follow up at time of data lock. The primary site was GEPNET in 143 (81%) and non GEPNET in 34 (19%). At 12 mths, the median follow-up was 33 (range 3-71) mths. PFS and OS were 81 (95% CI: 75-86)% and 92 (87-95)% respectively. QoL data at the following timepoints baseline, 6 &amp; 12 (±2) mths were available in 174,128 &amp; 111 pts respectively. The top three symptoms captured in EORTC QLQ 30 was Fatigue (32.5 SD 23.8) , Insomnia (26.7 SD 28.1) and Diarrhea (22.1 SD 29.4). At 12 mths, an improvement in mean score of ≥MCID in Global Health status (GHS) (+5.4), Role Fc Scale (+7,1), Social Fc Scale (+8.7) and multiple symptoms (Fatigue, Pain, Appetite, Constipation, Diarrhea, Financial Difficulties), Sexual fc, Social, Body image (Table 1) were captured. Conclusions: Patients with primary site agnostic 68Ga-DOTATATE PET positive NET experienced improvement in multiple quality of life domains including multiple symptoms post 177Lu-DOTATATE at 12 mths. Sexual fc and body image had the largest improvement. Clinical trial information: NCT02743741 . [Table: see text]

Open-label, dose-escalation phase 1a study of SPH5030, a tyrosine kinase inhibitor (TKI) targeting HER2, in patients with HER2 positive advanced solid tumors.

Open-label, dose-escalation phase 1a study of SPH5030, a tyrosine kinase inhibitor (TKI) targeting HER2, in patients with HER2 positive advanced solid tumors.