Types Of Advanced Cancer Research Articles

Cellular liquid biopsy provides unique chances for disease monitoring, preclinical model generation and therapy adjustment in rare salivary gland cancer patients.

While cell-free liquid biopsy (cfLB) approaches provide simple and inexpensive disease monitoring, cell-based liquid biopsy (cLB) may enable additional molecular genetic assessment of systemic disease heterogeneity and preclinical model development. We investigated 71 blood samples of 62 patients with various advanced cancer types and subjected enriched circulating tumor cells (CTCs) to organoid culture conditions. CTC-derived tumoroid models were characterized by DNA/RNA sequencing and immunohistochemistry, as well as functional drug testing. Results were linked to molecular features of primary tumors, metastases, and CTCs; CTC enumeration was linked to disease progression. Of 52 samples with positive CTC counts (≥1) from eight different cancer types, only CTCs from two salivary gland cancer (SGC) patients formed tumoroid cultures (P = 0.0005). Longitudinal CTC enumeration of one SGC patient closely reflected disease progression during treatment and revealed metastatic relapse earlier than clinical imaging. Multiomics analysis and functional invitro drug testing identified potential resistance mechanisms and drug vulnerabilities. We conclude that cLB might add a functional dimension (to the genetic approaches) in the personalized management of rare, difficult-to-treat cancers such as SGC.

Non-canonical olfactory pathway activation induces cell fusion of cervical cancer cells

Multinucleation occurs in various types of advanced cancers and contributes to their malignant characteristics, including anticancer drug resistance. Therefore, inhibiting multinucleation can improve cancer prognosis; however, the molecular mechanisms underlying multinucleation remain elusive. Here, we introduced a genetic mutation in cervical cancer cells to induce cell fusion-mediated multinucleation. The olfactory receptor OR1N2 was heterozygously mutated in these fused cells; the same OR1N2 mutation was detected in multinucleated cells from clinical cervical cancer specimens. The mutation-induced structural change in the OR1N2 protein activated protein kinase A (PKA), which, in turn, mediated the non-canonical olfactory pathway. PKA phosphorylated and activated furin protease, resulting in the cleavage of the fusogenic protein syncytin-1. Because this cleaved form of syncytin-1, processed by furin, participates in cell fusion, furin inhibitors could suppress multinucleation and reduce surviving cell numbers after anticancer drug treatment. The improved anticancer drug efficacy indicates a promising therapeutic approach for advanced cervical cancers.

Infliximab for Immune Checkpoint Inhibitor Therapy-Related Toxicities

What Is the Issue? Immune checkpoint inhibitor (ICI) therapy has become a treatment option for various types of advanced cancer, resulting in significant improvement in disease outcomes. However, ICIs can overstimulate the immune system leading to various side effects known as immune-related adverse events (irAEs) that can occur in any organ system. Administration of corticosteroids is the initial mainstay treatment of irAEs. However, there is little evidence of how to treat steroid-resistant irAEs. Treatment of steroid-resistant irAEs includes holding ICI and starting immunosuppressive therapy. Decision-makers are interested in understanding the use of infliximab, a selective immunosuppressive drug, for the treatment of steroid-resistant irAEs affecting various organs. What Did We Do? We identified and summarized the literature regarding the efficacy and safety of infliximab for the treatment of steroid-resistant irAEs. Due to the limitation of evidence, we included studies of any design, including case reports and case series. A research information specialist conducted a literature search of peer-reviewed and grey literature sources published between January 1, 2019 and April 8, 2024. One reviewer screened citations for inclusion based on predefined criteria, critically appraised the included studies, and narratively summarized the findings. What Did We Find? The evidence presented in this report was based on 2 systematic reviews of case reports and case series, 1 retrospective cohort study, and 40 additional publications consisting of 29 case reports and 11 case series. We identified 4 main irAEs, which were colitis, hepatitis, pneumonitis, and myocarditis. Very low-quality evidence, which was mainly derived from case reports and case series, suggests that infliximab may be effective for the treatment of steroid-resistant immune-induced colitis, while there are concerns regarding its use for the treatment of hepatitis due to potential hepatotoxicity and infectious complications. There is mixed evidence regarding the use of infliximab for the treatment of immune-induced pneumonitis and myocarditis. Recent consensus guidelines recommend the use of infliximab as first-line treatment for steroid-resistant immune-induced colitis, while its use for hepatitis is not recommended due to potential hepatotoxicity and infectious complications. The use of infliximab for the treatment of pneumonitis is an option, while its use for myocarditis remains to be determined. The usual dose of infliximab was 5 mg/kg, administered by IV. A higher dose of 10 mg/kg was seen in some cases. The number of infusions, the period between infusions and the length of treatment varied depending on the responsiveness of infliximab and the type and severity of irAEs. Treatment with infliximab as compared with vedolizumab resulted in comparable immune-induced colitis response rates, higher recurrent rate of colitis, and more hospitalizations despite a shorter time to clinical response. What Does This Mean? The very low-quality evidence identified suggests the potential benefits of infliximab in the management of immune-induced colitis due to its efficacy and fast response. When using the clinical evidence and recommendations summarized in this report to inform decisions, decision-makers should consider that the evidence is of very low quality, mainly derived from case reports and case series. Large prospective and comparative studies are needed to verify the findings and to determine the role of infliximab in the treatment of other irAEs.

Development of a prediction model for suicidal ideation in patients with advanced cancer: A multicenter, real-world, pan-cancer study in China.

Patients diagnosed with advanced stage cancer face an elevated risk of suicide. We aimed to develop a suicidal ideation (SI) risk prediction model in patients with advanced cancer for early warning of their SI and facilitate suicide prevention in this population. We consecutively enrolled patients with multiple types of advanced cancers from 10 cancer institutes in China from August 2019 to December 2020. Demographic characteristics, clinicopathological data, and clinical treatment history were extracted from medical records. Symptom burden, psychological status, and SI were assessed using the MD Anderson Symptom Inventory (MDASI), Hospital Anxiety and Depression Scale (HADS), and Patient Health Questionnaire-9 (PHQ-9), respectively. A multivariable logistic regression model was employed to establish the model structure. In total, 2814 participants were included in the final analysis. Nine predictors including age, sex, number of household members, history of previous chemotherapy, history of previous surgery, MDASI score, HADS-A score, HADS-D score, and life satisfaction were retained in the final SI prediction model. The model achieved an area under the curve (AUC) of 0.85 (95% confidential interval: 0.82-0.87), with AUCs ranging from 0.75 to 0.95 across 10 hospitals and higher than 0.83 for all cancer types. This study built an easy-to-use, good-performance predictive model for SI. Implementation of this model could facilitate the incorporation of psychosocial support for suicide prevention into the standard care of patients with advanced cancer.

Comprehensive molecular profiling identifies actionable biomarkers for patients from Thailand and the United Arab Emirates with advanced malignancies.

Comprehensive molecular profiling of tissue samples that can help guide therapy management is not widely available across the globe. Comprehensive molecular profiling through Caris Molecular Intelligence involves the analysis of DNA through next-generation sequencing, chromogenic or fluorescent in situ hybridization, pyrosequencing, and copy number alterations; RNA through whole-transcriptome sequencing and multiplex PCR of RNA; and protein through immunohistochemistry. Here we describe the experience of molecular profiling of tumor tissue samples from patients diagnosed with advanced solid tumors and treated in two countries, the United Arab Emirates and Thailand. Tumor cancer cases submitted to Caris Life Sciences (Phoenix, Arizona, USA) for molecular profiling from the UAE and Thailand were retrospectively analyzed (data accessed between 2019 and 2020) for their molecular alterations and clinical biomarkers, without regard to ethnicity. A total of 451 samples from 35 distinct types of advanced cancers were examined for mutations, amplifications, overexpression, exon copy number alterations, microsatellite instability, deficient mismatch repair, tumor mutational burden, and fusions. Interrogating each step of the biological pathway, from DNA to RNA to distinct protein, identified an alteration with an associated therapy for 75% of these tumor samples. The most common alterations identified included elevated PDL-1 that can be targeted with an immune checkpoint inhibitors and amplification of HER2 for which a variety of anti HER2 therapies are available. Comprehensive molecular profiling in patients with advanced malignancies can help optimize therapeutic management allowing for improved prognostic outcome.

Evaluating the efficacy and safety of nivolumab and ipilimumab combination therapy compared to nivolumab monotherapy in advanced cancers (excluding melanoma): a systemic review and meta-analysis

BackgroundNivolumab (Nivo) and ipilimumab (Ipi) have revolutionized cancer treatment by targeting different pathways. Their combination shows promising results in various cancers, including melanoma, but not all studies have demonstrated significant benefits. A meta-analysis was performed to assess the effectiveness and safety of Nivo-Ipi compared to Nivo alone in advanced cancer types (excluding melanoma).MethodsFollowing PRISMA guidelines, we conducted a meta-analysis up to September 30, 2023, searching databases for randomized controlled trials (RCTs). We focused on advanced solid malignancies (excluding melanoma) with specific Nivo and Ipi dosing. Primary outcomes were overall survival (OS), progression-free survival (PFS), grades 3–4 adverse events (AEs), and treatment-related discontinuations. Secondary outcomes included specific adverse events. Statistical analysis in Review Manager included hazard ratio (HR) and risk ratio (RR), assessing heterogeneity (Higgins I2).ResultsNine RCTs, involving 2152 patients covering various malignancies, were analyzed. The Nivo plus Ipi group exhibited a median OS of 12.3 months and a median PFS of 3.73 months, compared to monotherapy with 11.67 months and 3.98 months, respectively. OS showed no significant difference between Nivo and Ipi combination and Nivo alone (HR = 0.97, 95% CI: 0.88 to 1.08, p = 0.61). PFS had a slight improvement with combination therapy (HR = 0.91, 95% CI: 0.82 to 1.00, p = 0.04). Treatment-related cumulative grades 3–4 adverse events were higher with Nivo and Ipi (RR = 1.52, 95% CI: 1.30 to 1.78, p < 0.00001), as were treatment-related discontinuations (RR = 1.99, 95% CI: 1.46 to 2.70, p < 0.0001). Hepatotoxicity (RR = 2.42, 95% CI: 1.39 to 4.24, p = 0.002), GI toxicity (RR = 2.84, 95% CI: 1.44 to 5.59, p = 0.002), pneumonitis (RR = 2.29, 95% CI: 1.24 to 2.23, p = 0.008), dermatitis (RR = 2.96, 95% CI: 1.08 to 8.14, p = 0.04), and endocrine dysfunction (RR = 6.22, 95% CI: 2.31 to 16.71, p = 0.0003) were more frequent with Nivo and Ipi.ConclusionsCombining nivolumab and ipilimumab did not significantly improve overall survival compared to nivolumab alone in advanced cancers (except melanoma). However, it did show slightly better PFS at the cost of increased toxicity, particularly grades 3–4 adverse events. Specific AEs occurred more frequently in the combination group. Further trials are needed to fully assess this combination in treating advanced cancers.

Abstract 7040: Mutations in cytoskeleton genes SPTAN1/SPTBN1 serve as novel predictive markers for immunotherapy against bladder cancer

Abstract Cancer progression is often driven by somatic mutations. Despite several well-known driver mutations, more evidence has shown that genetic alterations in cytoskeleton organization enhance tumor aggressiveness and promote cancer progression, suggesting their roles as potential drivers. In this study, pan-cancer genetic analyses by using TCGA cohorts, more frequent mutation events were found in cytoskeleton-related genes as compared to total annotated genes, especially in cancers derived from hollow organs. High-dimensional analysis of molecular alterations in cancer (HD-MAC) suggested gene mutations in SPTAN1 and its partner SPTBN1 as potential prognostic biomarkers for clinical outcomes of patients with bladder cancer. Gene knockdown in either SPTAN1 or SPTBN1, mimicking silencing mutations in cancer tissues, caused cell morphology changes, DNA breaks, and alternations in cytokine profiles via activating cGAS-STING mediated interferon signaling. Xenograft tumor models also indicate accelerated tumor growth in SPTAN1- or SPTBN1-silenced cells, suggesting a more advanced cancer type. Based on immune staining in both human and mouse samples, increased CD8+ T cell infiltration was in tumor lesions with mutations or truncations in SPTAN1/SPTBN1 genes. In addition, several known substitution mutations were found as potent neo-antigens based on MHC II binding prediction, which could be utilized as targets for immune checkpoint therapy. This study provides a novel insight into how the cytoskeleton can contribute to cancer progression and find out predictive biological indicators with therapeutic values. Citation Format: Brian Yu-Ting Kuo. Mutations in cytoskeleton genes SPTAN1/SPTBN1 serve as novel predictive markers for immunotherapy against bladder cancer [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 7040.

Abstract 7160: Germline predictors for bevacizumab induced hypertensive crisis in ECOG-ACRIN 5103 and BEATRICE

Abstract Introduction: Bevacizumab is a beneficial therapy in several advanced cancer types. Predictive biomarkers to better understand which patients are destined to benefit or experience toxicity are needed. Associations between bevacizumab induced hypertension and survival have been reported but with conflicting conclusions. Methods: We performed post-hoc analyses to evaluate the association in 3,124 patients from two phase III adjuvant breast cancer trials, E5103 and BEATRICE. Differences in invasive disease-free survival (IDFS) and overall survival (OS) between patients with hypertension and those without were compared. Hypertension was defined as systolic blood pressure (SBP) ≥ 160 mmHg (n=346) and SBP ≥ 180 mmHg (hypertensive crisis) (n=69). Genomic analyses were performed to evaluate germline genetic predictors for the hypertensive crisis. Results: Hypertensive crisis was significantly associated with superior IDFS (p = 0.015) and OS (p = 0.042), but only IDFS (p = 0.029; HR = 0.28) remained significant after correction for prognostic factors. SBP ≥ 160 mmHg was not associated with either IDFS or OS. A common single-nucleotide polymorphism, rs6486785, was significantly associated with hypertensive crisis (p = 8.4 × 10−9; OR = 5.2). Conclusion: Bevacizumab-induced hypertensive crisis is associated with superior outcomes and rs6486785 predicted an increased risk of this key toxicity. Citation Format: Fei Shen, Guanglong Jiang, Santosh Philips, Erica Cantor, Laura Gardner, Gloria Xue, Geneva Cunningham, Nawal Kassem, Anne Oneil, David Cameron, Thomas Suter, Kathy Miller, George Sledge, Bryan Schneider. Germline predictors for bevacizumab induced hypertensive crisis in ECOG-ACRIN 5103 and BEATRICE [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 7160.

PARP Inhibitors in Metastatic Castration-Resistant Prostate Cancer: Unraveling the Therapeutic Landscape.

The treatment landscape of metastatic prostate cancer (mPCa) is rapidly evolving with the recent approvals of poly-ADP ribose polymerase inhibitors (PARPis) as monotherapy or as part of combination therapy with androgen receptor pathway inhibitors in patients with metastatic castration-resistant prostate cancer (mCRPC). Already part of the therapeutic armamentarium in different types of advanced cancers, these molecules have shaped a new era in mPCa by targeting genomic pathways altered in these patients, leading to promising responses. These agents act by inhibiting poly-ADP ribose polymerase (PARP) enzymes involved in repairing single-strand breaks in the DNA. Based on the PROfound and TRITON3 trials, olaparib and rucaparib were respectively approved as monotherapy in pretreated patients with mCRPC and alterations in prespecified genes. The combinations of olaparib with abiraterone (PROpel) and niraparib with abiraterone (MAGNITUDE) were approved as first-line options in patients with mCRPC and alterations in BRCA1/2, whereas the combination of talazoparib with enzalutamide (TALAPRO-2) was approved in the same setting in patients with alterations in any of the HRR genes, which are found in around a quarter of patients with advanced prostate cancer. Additional trials are already underway to assess these agents in an earlier hormone-sensitive setting. Future directions will include refining the treatment sequencing in patients with mCRPC in the clinic while taking into account the financial toxicity as well as the potential side effects encountered with these therapies and elucidating their mechanism of action in patients with non-altered HRR genes. Herein, we review the biological rationale behind using PARPis in mCRPC and the key aforementioned clinical trials that paved the way for these approvals.

Therapeutic potential of hedgehog signaling in advanced cancer types.

In this chapter, we have made an attempt to elucidate the relevance of hedgehog signaling pathway in tumorigenesis. Here, we have described different types of hedgehog signaling (canonical and non-canonical) with emphasis on the different mechanisms (mutation-driven, autocrine, paracrine and reverse paracrine) it adopts during tumorigenesis. We have discussed the role of hedgehog signaling in regulating cell proliferation, invasion and epithelial-to-mesenchymal transition in both local and advanced cancer types, as reported in different studies based on preclinical and clinical models. We have specifically addressed the role of hedgehog signaling in aggressive neuroendocrine tumors as well. We have also elaborated on the studies showing therapeutic relevance of the inhibitors of hedgehog signaling in cancer. Evidence of the crosstalk of hedgehog signaling components with other signaling pathways and treatment resistance due to tumor heterogeneity have also been briefly discussed. Together, we have tried to put forward a compilation of the studies on therapeutic potential of hedgehog signaling in various cancers, specifically aggressive tumor types with a perspective into what is lacking and demands further investigation.

North American Adult T-Cell Leukemia/Lymphoma Has Frequent Mutations in CCR4 and Responds in Vitro to a Small Molecule CCR4 Antagonist, CCR4-351

Adult T-cell leukemia/lymphoma (ATLL) is a rare and aggressive disease of malignant CD4+ T cells that develops in human T-lymphotropic virus-1 (HTLV-1) carriers. Patients diagnosed with ATLL have the worst survival among all peripheral T-cell lymphomas. There is an urgent need for in-depth understanding of its pathogenesis and development of new treatment strategies. We and others have shown that ATLLs diagnosed in the Japanese (J-ATLL) and North American (NA-ATLL) patients have differences in clinical characteristics and immune-genetic landscape. Among the most frequently mutated genes in J-ATLL cohorts is CCR4, a chemokine receptor that is targeted by C-terminal truncation mutations in one third of the cases. These mutations result in a more stabilized surface CCR4 and have been reported to cause elevated Akt activation following chemokine stimulation. Since our previous targeted exon sequencing study did not include CCR4, this work was initiated to assess CCR4 mutation frequency in NA-ATLL cases and to evaluate the preclinical activity of a small molecule CCR4 antagonist. This is because, although an anti-CCR4 mAb, mogamulizumab, has been approved in Japan to treat ATLL, this therapy failed in a Phase 2 trial among patients outside of Japan. Thus, mogamulizumab is not available as a routine treatment for NA-ATLL patients. We compiled CCR4 gene status data from bulk RNA-seq (n=10) and whole genome sequencing (WGS) analysis (n = 10). Out of a total of 17 NA-ATLL cases, 8 (47.1%) carried CCR4 gene alterations that included in-frame and frameshift indels, as well as nonsense mutations targeted to the C-terminus cytoplasmic tail and also the trans-membrane domain. In subtype analysis, 6 out 14 acute cases (42.9%) and 2 out of 3 (66.7%) of chronic cases carried at least one copy of mutated CCR4 gene, indicating that the mutation frequency in NA-ATLL is possibly even higher than that reported for the Japanese cohorts ( Figure 1). We then evaluated cell surface CCR4 expression using flow cytometry. The primary ATLL cells (CD4 +CD7 -CD8 -) from all 7 diagnostic samples uniformly express markedly increased levels of CCR4 relative to healthy control CD4 T cells. Interestingly, CCR4 expression among 8 ATLL cell lines is highly variable, implying that in vivo, tumor microenvironment factors may also contribute to sustained CCR4 upregulation in addition to the influence from the HTLV-1 oncoprotein, HBZ. FLX475 is an orally active small molecule CCR4 antagonist that is currently in a Phase 1/2 study (NCT03674567) in several types of advanced cancer including EBV+ NK/T cell lymphoma. So far, favorable clinical antitumor activity has been observed that includes complete responses with FLX475 monotherapy and encouraging combination activity (Lin C.-C. et al ESMO-IO 2022 Dec; #187P). Using several CCR4-positive cell lines, we examined in vitro anti-ATLL activity of CCR4-351, a CCR4 antagonist that is a highly related analog of FLX475. CCR4 is the exclusive homing receptor for two chemokine molecules, CCL17 and CCL22. In a transwell assay, both chemokines can elicit strong chemotaxis activity in a J-ATLL cell line ED40515(+). However, only CCL22 but not CCL17 can induce significant chemotaxis in two NA-ATLL cell lines, ATL#13 and ATL#29. The exact cause of this difference between these cell lines awaits future studies. In these transwell-based assays, CCR4-351 exhibited potent chemotaxis inhibitory activity with IC 50 values ranging from 7-60 nM ( Figure 2). In addition, when the cell lines were cultured under growth factor-deprivation conditions, CCR4-351 treatment caused a mild reduction in total cell viability, suggesting an additional anti-ATLL mechanism of action. In summary, in this first study of the CCR4 pathway status in NA-ATLL, we found that nearly half of the cases in our ATLL cohort carried a mutated CCR4 gene. Contrary to primary ATLL cells, ATLL cell lines exhibit a wide variation in CCR4 expression. CCL22 but not CCL17 induced strong chemotaxis behavior in NA-ATLL cell lines, which was potently inhibited by a small molecule CCR4 antagonist, CCR4-351. Since extramedullary presentation is frequently seen in NA-ATLL and central nervous system involvement is an adverse prognostic feature, inhibiting chemotaxis with a CCR4 antagonist such as FLX475 may be an effective therapeutic approach.

Biomarker testing rates among metastatic cancer patients with receipt of anti-cancer systemic therapy: A real-world data analysis.

550 Background: Biomarker testing to direct individualized therapy options can optimize cancer patient outcomes, particularly for patients with advanced disease. Guideline-recommended molecular testing, comprehensive genomic profiling [CGP] and non-CGP testing, is covered by both Medicare and commercial private insurers (at least non-CGP).. This study examined real-world utilization of biomarker testing among cancer patients with metastatic disease who received anti-cancer systemic therapy. Methods: A retrospective analysis was conducted using de-identified administrative claims data from the Optum Labs Data Warehouse. Adults identified with 1 of 6 advanced cancer types from 1/2018 to 8/2021 were identified; index date was the first claim date for advanced disease. Patients with diagnosis codes indicating only lymph node involvement around the primary cancer were excluded. Continuous enrollment in a commercial (COM) or Medicare Advantage (MA) health plan with both medical and pharmacy benefits was required for 12 months prior to the index date (baseline), and ≥6 months after the index date (follow-up); patients with &lt;6 months follow-up due to death were included. Receipt of anti-cancer systemic therapy during the follow-up was required. Biomarker testing was captured using Current Procedural Terminology (CPT®) codes indicating CGP (&gt; 50 gene panels) or non-CGP (≤50 gene panels or single gene tests) during the study period. Rates of biomarker testing by cancer and insurance type, and receipt of targeted therapy and/ were assessed. Results: Result: There were 27,434 metastatic cancer patients meeting study criteria: 10,320 non-small cell lung (NSCLC), 5,525 breast (BC), 5,429 colorectal (CRC), 2,314 ovarian (OC), 872 gastric (GC) and 2,974 pancreatic (PC) cancer patients. 66% of patients were MA enrollees. The median age was 70 years and ranged from 67 years for BC patients to 71 years for NSCLC and PC patients. The median follow-up was 383 days, ranging from 246 days (for PC patients) to 564 days (for BC patients). Overall biomarker testing rates in the follow-up period were: 47% for NSCLC, 34% BC, 58% CRC, 61% OC, 48% GC, and 47% PC. Testing rates were lower among MA patients compared to COM patients (46% vs 53%). Receipt of targeted/monoclonal antibody therapy was higher (47% vs 33%, p&lt;0.01) among patients with biomarker testing compared to those without. Conclusions: Rates of biomarker testing across metastatic tumor types are far from optimal despite guideline recommendations and insurance coverage for testing, and may affect quality of care. To improve adherence to biomarker testing guidelines, interventions to help overcome obstacles to biomarker testing are needed. Future analysis with this cohort will examine patient management and outcomes by receipt of testing, timing of testing and type of therapy received.

L-carnitine prevents lenvatinib-induced muscle toxicity without impairment of the anti-angiogenic efficacy.

Lenvatinib is an oral tyrosine kinase inhibitor that acts on multiple receptors involved in angiogenesis. Lenvatinib is a standard agent for the treatment of several types of advanced cancers; however, it frequently causes muscle-related adverse reactions. Our previous study revealed that lenvatinib treatment reduced carnitine content and the expression of carnitine-related and oxidative phosphorylation (OXPHOS) proteins in the skeletal muscle of rats. Therefore, this study aimed to evaluate the effects of L-carnitine on myotoxic and anti-angiogenic actions of lenvatinib. Co-administration of L-carnitine in rats treated with lenvatinib for 2weeks completely prevented the decrease in carnitine content and expression levels of carnitine-related and OXPHOS proteins, including carnitine/organic cation transporter 2, in the skeletal muscle. Moreover, L-carnitine counteracted lenvatinib-induced protein synthesis inhibition, mitochondrial dysfunction, and cell toxicity in C2C12 myocytes. In contrast, L-carnitine had no influence on either lenvatinib-induced inhibition of vascular endothelial growth factor receptor 2 phosphorylation in human umbilical vein endothelial cells or angiogenesis in endothelial tube formation and mouse aortic ring assays. These results suggest that L-carnitine supplementation could prevent lenvatinib-induced muscle toxicity without diminishing its antineoplastic activity, although further clinical studies are needed to validate these findings.

Abstract 2481: Human osteoclast assays for studying the effects of bone metastasis treatments with different mechanisms of action

Abstract Metastasis to bone is one of the common complications associated with different types of advanced cancer. Zoledronic acid, a third generation nitrogen containing bisphosphonate, accumulates in bones where it binds to hydroxyapatite crystals. For years, zoledronic acid has been regarded as the standard of care for patients with advanced cancer and bone metastasis to prevent skeletal complications. As an alternative therapeutic option, denosumab has also been found to be effective in delaying skeletal-related events in advanced cancer. Denosumab, a human monoclonal antibody against receptor activator of nuclear factor kappa-B ligand (RANKL), blocks the RANKL/RANK signalling pathway. In addition to the skeletal effects, both zoledronic acid and denosumab have shown direct effect on cancer cells. In this study, effects of zoledronic acid and denosumab on osteoclast differentiation and bone resorption activity were studied using human CD34+ osteoclast precursor cells that were cultured on bovine bone slices in 96-well plates for 7 days in the presence of RANKL and M-CSF, allowing them to differentiate into mature osteoclasts. In the osteoclast differentiation assay, zoledronic acid (0.0001 - 1 000 µM) and denosumab (0.01 - 10 µg/ml) were added into the culture medium at day 0. Tartrate-resistant acid phosphatase 5b (TRACP 5b) activity was measured in the culture medium at day 7 as an index of osteoclast differentiation. In the osteoclast activity assay, the test compounds were added into the culture medium at day 7, and the formed osteoclasts were allowed to resorb bone for 3 days. C-terminal crosslinked telopeptides of type I collagen (CTX-I) was measured in the culture medium at day 10 as an index of bone resorption. Denosumab and zoledronic acid showed strong concentration dependent inhibition of osteoclast differentiation and resorption activity. We conclude that this osteoclast culture system can be used for identifying new potential compounds affecting the disease process of bone metastases with different mechanisms of action. The manifold effects of zoledronic acid and denosumab on cancer cells remain to be studied in more detail. Citation Format: Katja M. Fagerlund, Mervi Ristola, Mari I. Suominen, Jenni H. Mäki-Jouppila, Jukka P. Rissanen. Human osteoclast assays for studying the effects of bone metastasis treatments with different mechanisms of action [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2481.

Extracellular vesicles released from ganglioside GD2-expressing melanoma cells enhance the malignant properties of GD2-negative melanomas

Exosomes (small extracellular vesicles: EVs) have attracted increasing attention from basic scientists and clinicians since they play important roles in cell-to-cell communication in various biological processes. Various features of EVs have been elucidated regarding their contents, generation and secretion mechanisms, and functions in inflammation, regeneration, and cancers. These vesicles are reported to contain proteins, RNAs, microRNAs, DNAs, and lipids. Although the roles of individual components have been rigorously studied, the presence and roles of glycans in EVs have rarely been reported. In particular, glycosphingolipids in EVs have not been investigated to date. In this study, the expression and function of a representative cancer-associated ganglioside, GD2, in malignant melanomas was investigated. Generally, cancer-associated gangliosides have been shown to enhance malignant properties and signals in cancers. Notably, EVs derived from GD2-expressing melanomas enhanced the malignant phenotypes of GD2-negative melanomas, such as cell growth, invasion, and cell adhesion, in a dose-dependent manner. The EVs also induced increased phosphorylation of signaling molecules such as EGF receptor and focal adhesion kinase. These results suggest that EVs released from cancer-associated ganglioside-expressing cells exert many functions that have been reported as a function of these gangliosides and regulate microenvironments, including total aggravation of heterogeneous cancer tissues, leading to more malignant and advanced cancer types.

187P Phase I/II study of the oral CCR4 antagonist, FLX475, as monotherapy and in combination with pembrolizumab in advanced cancer

Preclinical studies with oral CCR4 antagonists have demonstrated inhibition of suppressive regulatory T cell (Treg) migration into the tumor microenvironment and antitumor efficacy. The FLX475-02 trial is a phase 1/2, open-label, dose-escalation and cohort expansion study to determine the safety and antitumor activity of the oral CCR4 antagonist FLX475 as monotherapy and in combination with pembrolizumab in subjects with several types of advanced cancer.

Bone Metastasis of Breast Cancer: Molecular Mechanisms and Therapeutic Strategies.

Bone metastasis is a common complication of many types of advanced cancer, including breast cancer. Bone metastasis may cause severe pain, fractures, and hypercalcemia, rendering clinical management challenging and substantially reducing the quality of life and overall survival (OS) time of breast cancer patients. Studies have revealed that bone metastasis is related to interactions between tumor cells and the bone microenvironment, and involves complex molecular biological mechanisms, including colonization, osteolytic destruction, and an immunosuppressive bone microenvironment. Agents inhibiting bone metastasis (such as bisphosphate and denosumab) alleviate bone destruction and improve the quality of life of breast cancer patients with bone metastasis. However, the prognosis of these patients remains poor, and the specific biological mechanism of bone metastasis is incompletely understood. Additional basic and clinical studies are urgently needed, to further explore the mechanism of bone metastasis and develop new therapeutic drugs. This review presents a summary of the molecular mechanisms and therapeutic strategies of bone metastasis of breast cancer, aiming to improve the quality of life and prognosis of breast cancer patients and provide a reference for future research directions.

Role of PARP Inhibitors in Cancer Immunotherapy: Potential Friends to Immune Activating Molecules and Foes to Immune Checkpoints.

Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) induce cytotoxic effects as single agents in tumors characterized by defective repair of DNA double-strand breaks deriving from BRCA1/2 mutations or other abnormalities in genes associated with homologous recombination. Preclinical studies have shown that PARPi-induced DNA damage may affect the tumor immune microenvironment and immune-mediated anti-tumor response through several mechanisms. In particular, increased DNA damage has been shown to induce the activation of type I interferon pathway and up-regulation of PD-L1 expression in cancer cells, which can both enhance sensitivity to Immune Checkpoint Inhibitors (ICIs). Despite the recent approval of ICIs for a number of advanced cancer types based on their ability to reinvigorate T-cell-mediated antitumor immune responses, a consistent percentage of treated patients fail to respond, strongly encouraging the identification of combination therapies to overcome resistance. In the present review, we analyzed both established and unexplored mechanisms that may be elicited by PARPi, supporting immune reactivation and their potential synergism with currently used ICIs. This analysis may indicate novel and possibly patient-specific immune features that might represent new pharmacological targets of PARPi, potentially leading to the identification of predictive biomarkers of response to their combination with ICIs.

445P Development of a simple and objective prognostication model in patients with advanced solid malignant tumor treated with immune checkpoint inhibitors: A pan-cancer analysis

Recently, systemic therapy using immune checkpoint inhibitors (ICIs) has become prevalent for treatment of patients with various types of advanced cancer; however, it remains difficult to predict prognostic outcomes in patients receiving ICIs due to heterogenous response to these agents. The objective of this study was to develop a prognostic model for advanced cancer patients treated with ICIs.

Tissue factor-induced fibrinogenesis mediates cancer cell clustering and multiclonal peritoneal metastasis

Peritoneal metastasis is one of the most frequent causes of death in several types of advanced cancers; however, the underlying molecular mechanisms remain largely unknown. In this study, we exploited multicolor fluorescent lineage tracking to investigate the clonality of peritoneal metastasis in mouse xenograft models. When peritoneal metastasis was induced by intraperitoneal or orthotopic injection of multicolored cancer cells, each peritoneally metastasized tumor displayed multicolor fluorescence regardless of metastasis sites, indicating that it consists of multiclonal cancer cell populations. Multicolored cancer cell clusters form within the peritoneal cavity and collectively attach to the peritoneum. In vitro, peritoneal lavage fluid or cleared ascitic fluid derived from cancer patients induces cancer cell clustering, which is inhibited by anticoagulants. Cancer cell clusters formed in vitro and in vivo are associated with fibrin formation. Furthermore, tissue factor knockout in cancer cells abrogates cell clustering, peritoneal attachment, and peritoneal metastasis. Thus, we propose that cancer cells activate the coagulation cascade via tissue factor to form fibrin-mediated cell clusters and promote peritoneal attachment; these factors lead to the development of multiclonal peritoneal metastasis and may be therapeutic targets.