Combination treatment with PD1/PDL-1 inhibitors for sarcomas: state of the art, next questions.

PURPOSE OF REVIEW: Only a small fraction of sarcomas exhibit recognized parameters of immune sensitivity, such as tumor mutational burden, PDL-1 expression, or microsatellite instability. Combined strategies aimed to modulate tumor microenvironment to increase the efficacy of PD1/PDL-1 inhibitors in sarcoma. Most explored prospective studies were based on combinations of PD1/PDL-1 inhibitors with antiangiogenics, other immune checkpoints, or chemotherapy. RECENT FINDINGS: Results on 6-month PFS rate, median PFS, and ORR in trials using PD1/PDL-1 inhibitors plus antiangiogenics ranged respectively as 46.9-55%, 4.7-7.8 months and 21-36.7%. In combination with other immune checkpoint inhibitors, the results of median PFS and ORR ranged from 2.8-4.1 months and 10-16%, respectively. In combination with chemotherapy, the best results were obtained with doxorubicin-based regimens compared to other agents. Duplet-based chemotherapy plus anti-PD1/PDL-1 obtained the highest ORR (56.2%) compared with doxorubicin (19-36.7%). Currently, the most robust predictive biomarker for anti-PD1/PDL-1 efficacy is the presence of tertiary lymphoid structures (TLS) with mature dendritic cells. SUMMARY: Even when direct comparisons between PD1/PDL-1 inhibitor-based combinations and single agents have not been performed yet in sarcoma, some combinations appear promising. Studies controlling heterogeneity by biomarker or histotype selection contribute to an increase in efficacy or knowledge crucial for future comparative trials.

Beyond Clinical Trials: Understanding Neurotrophic Tropomyosin Receptor Kinase Inhibitor Challenges and Efficacy in Real-World Pediatric Oncology.

PURPOSE: Our study aimed to explore real-world treatment scenarios for children and adolescents with neurotrophic tropomyosin receptor kinase (NTRK)-fused tumors, emphasizing access, responses, side effects, and outcomes. PATIENTS AND METHODS: Pooled clinical data from 17 pediatric cases (11 soft-tissue sarcomas, five brain tumors, and one neuroblastoma) treated with larotrectinib and radiologic images for 14 patients were centrally reviewed. Testing for gene fusions was prompted by poor response to treatment, tumor progression, or aggressiveness. RESULTS: Six different NTRK fusion subtypes were detected, and various payment sources for testing and medication were reported. Radiologic review revealed objective tumor responses (OR) in 11 of 14 patients: Complete responses: two; partial responses: nine; and stable disease: three cases. Grades 1 or 2 Common Terminology Criteria for Adverse Events adverse effects were reported in five patients. Regarding the entire cohort's clinical information, 15 of 17 patients remain alive (median observation time: 25 months): four with no evidence of disease and 11 alive with disease (10 without progression). One patient developed resistance to the NTRK inhibitor and died from disease progression while another patient died due to an unrelated cause. CONCLUSION: This real-world study confirms favorable agnostic tumor OR rates to larotrectinib in children with NTRK-fused tumors. Better coordination to facilitate access to medication remains a challenge, particularly in middle-income countries like Brazil.

Therapeutic Drug Monitoring of Pazopanib in Renal Cell Carcinoma and Soft Tissue Sarcoma: A Systematic Review.

BACKGROUND: Pazopanib, an anti-angiogenic multitarget tyrosine kinase inhibitor, has been approved for the treatment of metastatic renal cell carcinoma and soft tissue sarcoma. However, its recommended dose does not always produce consistent outcomes, with some patients experiencing adverse effects or toxicity. This variability is due to differences in the systemic exposure to pazopanib. This review aimed to establish whether sufficient evidence exists for the routine or selective therapeutic drug monitoring of pazopanib in adult patients with approved indications. METHODS: A systematic search of the PubMed and Web of Science databases using search terms related to pazopanib and therapeutic drug monitoring yielded 186 and 275 articles, respectively. Ten articles associated with treatment outcomes or toxicity due to drug exposure were selected for review. RESULTS: The included studies were evaluated to determine the significance of the relationship between drug exposure/Ctrough and treatment outcomes and between drug exposure and toxicity. A relationship between exposure and treatment outcomes was observed in 5 studies, whereas the trend was nonsignificant in 4 studies. A relationship between exposure and toxicity was observed in 6 studies, whereas 2 studies did not find a significant relationship; significance was not reported in 3 studies. CONCLUSIONS: Sufficient evidence supports the therapeutic drug monitoring of pazopanib in adult patients to improve its efficacy and/or safety in the approved indications.

The bispecific B7H3xCD3 antibody CC-3 induces T cell immunity against bone and soft tissue sarcomas.

Sarcomas are rare and heterogeneous malignancies that are difficult to treat. Approximately 50% of patients diagnosed with sarcoma develop metastatic disease with so far very limited treatment options. The transmembrane protein B7-H3 reportedly is expressed in various malignancies, including different sarcoma subtypes. In several cancer entities B7-H3 expression is associated with poor prognosis. In turn, B7-H3 is considered a promising target for immunotherapeutic approaches. We here report on the preclinical characterization of a B7-H3xCD3 bispecific antibody in an IgG-based format, termed CC-3, for treatment of different sarcoma subtypes. We found B7-H3 to be expressed on all sarcoma cells tested and expression on sarcoma patients correlated with decreased progression-free and overall survival. CC-3 was found to elicit robust T cell responses against multiple sarcoma subtypes, resulting in significant activation, release of cytokines and effector molecules. In addition, CC-3 promoted T cell proliferation and differentiation, resulting in the generation of memory T cell subsets. Finally, CC-3 induced potent target cell lysis in a target cell restricted manner. Based on these results, a clinical trial evaluating CC-3 in soft tissue sarcoma is currently in preparation.

HMGA1 regulates trabectedin sensitivity in advanced soft-tissue sarcoma (STS): A Spanish Group for Research on Sarcomas (GEIS) study.

HMGA1 is a structural epigenetic chromatin factor that has been associated with tumor progression and drug resistance. Here, we reported the prognostic/predictive value of HMGA1 for trabectedin in advanced soft-tissue sarcoma (STS) and the effect of inhibiting HMGA1 or the mTOR downstream pathway in trabectedin activity. The prognostic/predictive value of HMGA1 expression was assessed in a cohort of 301 STS patients at mRNA (n = 133) and protein level (n = 272), by HTG EdgeSeq transcriptomics and immunohistochemistry, respectively. The effect of HMGA1 silencing on trabectedin activity and gene expression profiling was measured in leiomyosarcoma cells. The effect of combining mTOR inhibitors with trabectedin was assessed on cell viability in vitro studies, whereas in vivo studies tested the activity of this combination. HMGA1 mRNA and protein expression were significantly associated with worse progression-free survival of trabectedin and worse overall survival in STS. HMGA1 silencing sensitized leiomyosarcoma cells for trabectedin treatment, reducing the spheroid area and increasing cell death. The downregulation of HGMA1 significantly decreased the enrichment of some specific gene sets, including the PI3K/AKT/mTOR pathway. The inhibition of mTOR, sensitized leiomyosarcoma cultures for trabectedin treatment, increasing cell death. In in vivo studies, the combination of rapamycin with trabectedin downregulated HMGA1 expression and stabilized tumor growth of 3-methylcholantrene-induced sarcoma-like models. HMGA1 is an adverse prognostic factor for trabectedin treatment in advanced STS. HMGA1 silencing increases trabectedin efficacy, in part by modulating the mTOR signaling pathway. Trabectedin plus mTOR inhibitors are active in preclinical models of sarcoma, downregulating HMGA1 expression levels and stabilizing tumor growth.

Optimized new Shengmai powder inhibits myocardial fibrosis in heart failure by regulating the rat sarcoma/rapidly accelerated fibrosarcoma/mitogen-activated protein kinase kinase/extracellular regulated protein kinases signaling pathway.

OBJECTIVE: Exploring the effect of Optimized New Shengmai powder (, ONSMP) on myocardial fibrosis in heart failure (HF) based on rat sarcoma (RAS)/rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase kinase (MEK)/extracellular regulated protein kinases (ERK) signaling pathway. METHODS: Randomized 70 Sprague-Dawley rats into sham (n = 10) and operation (n = 60) groups, then established the HF rat by ligating the left anterior descending branch of the coronary artery. We randomly divided the operation group rats into the model, ONSMP [including low (L), medium (M), and high (H) dose], and enalapril groups. After the 4-week drug intervention, echocardiography examines the cardiac function and calculates the ratios of the whole/left heart to the rat's body weight. Finally, we observed the degree of myocardial fibrosis by pathological sections, determined myocardium collagen (COL) I and COL Ⅲ content by enzyme-linked immunosorbent assay, detected the mRNA levels of COL I, COL Ⅲ, α-smooth muscle actin (α-SMA), and c-Fos proto-oncogene (c-Fos) by universal real-time, and detected the protein expression of p-RAS, p-RAF, p-MEK1/2, p-ERK1/2, p-ETS-like-1 transcription factor (p-ELK1), p-c-Fos, α-SMA, COL I, and COL Ⅲ by Western blot. RESULTS: ONSMP can effectively improve HF rat's cardiac function, decrease cardiac organ coefficient, COL volume fraction, and COL I/Ⅲ content, down-regulate the mRNA of COL I/Ⅲ, α-SMA and c-Fos, and the protein of p-RAS, p-RAF, p-MEK1/ 2, p-ERK1/2, p-ELK1, c-Fos, COL Ⅰ/Ⅲ, and α-SMA. CONCLUSIONS: ONSMP can effectively reduce myocardial fibrosis in HF rats, and the mechanism may be related to the inhibition of the RAS/RAF/MEK/ERK signaling pathway.

Tislelizumab combined with GT chemotherapy for intimal sarcoma of inferior vena cava: A case report.

RATIONALE: Intimal sarcoma of inferior vena cava (IVC) is a rare soft tissue sarcoma with no typical symptoms and specific imaging features in the early stage, and there is a lack of standardized treatment and methods. PATIENT CONCERNS: A 54-year-old female patient presented to Fenghua District People's Hospital with a post-active cough and hemoptysis and was subsequently referred to our hospital. DIAGNOSES: The patient was pathologically diagnosed as intimal sarcoma of IVC complicating multiple intrapulmonary metastases. Chest CT revealed left lung malignant tumor with multiple intrapulmonary metastases; while enhanced upper abdominal CT showed cancer embolus of IVC with extension to right atrium and bilateral renal veins. Besides, hematoxylin and eosin staining suggested intimal sarcoma of veins. Immunohistochemical staining showed positivity for PD-L1, Ki-67, CD31, Desmin and ERG. INTERVENTIONS: The patient initially received GT chemotherapy (gemcitabine injection + docetaxel). Then, immunotherapy (tislelizumab) was added based on the results of genetic testing (TP53 gene mutation). OUTCOMES: The disease was stabilized after receiving the treatment. LESSONS: Given the lack of characteristic clinical manifestations in patients with intimal sarcoma of IVC, imaging examination combined with immunohistochemical index were helpful for diagnosis of intimal sarcoma of IVC. Furthermore, the combination of tislelizumab and GT chemotherapy was feasible in such patients with positive PD-L1 expression and TP53 mutation.

Evaluation of the efficacy and safety of immunotherapy in sarcoma: a two-center study.

Background: Sarcoma is a highly heterogeneous malignancy with a poor prognosis. Although chemotherapy and targeted therapy have improved the prognosis to some extent, the efficacy remains unsatisfactory in some patients. The efficacy and safety of immunotherapy in sarcoma need further evaluation. Methods: We conducted a two-center study of sarcoma patients receiving PD-1 immunotherapy at Tianjin Medical University Cancer Institute and Hospital and Henan Provincial Cancer Hospital. The treatment regimens included PD-1 inhibitor monotherapy and combination therapy based on PD-1 inhibitors. The observed primary endpoints were median progression-free survival (mPFS) and median overall survival (mOS). Survival curves were compared using the Kaplan-Meier method. Results: A total of 43 patients were included from the two centers. The median follow-up time for all patients was 13 months (range, 1-48 months). In the group of 37 patients with advanced or unresectable sarcoma, the mPFS was 6 months (95%CI: 5-12 months), and the mOS was 16 months (95%CI: 10-28 months). The ORR was 10.8% (4/37), and the DCR was 18.9% (7/37). Subgroup analysis showed no significant differences in mPFS (p=0.11) and mOS (p=0.88) between patients with PD-L1 negative/positive expression. There were also no significant differences in mPFS (p=0.13) or mOS (p=0.72) between PD-1 inhibitor monotherapy and combination therapy. Additionally, there were no significant differences in mPFS (p=0.52) or mOS (p=0.49) between osteogenic sarcoma and soft tissue sarcoma. Furthermore, the results showed no significant differences in mPFS (p=0.66) or mOS (p=0.96) between PD-1 inhibitors combined with targeted therapy and PD-1 inhibitors combined with AI chemotherapy. Among the 6 patients receiving adjuvant therapy after surgery, the mPFS was 15 months (95%CI: 6-NA months), and the mOS was not reached. In terms of safety, most adverse events were mild (grade 1-2) and manageable. The most severe grade 4 adverse events were bone marrow suppression, which occurred in 4 patients but resolved after treatment. There was also one case of a grade 4 adverse event related to hypertension. Conclusion: Immunotherapy is an effective treatment modality for sarcoma with manageable safety. Further inclusion of more patients or prospective clinical trials is needed to validate these findings.

Predicting Trabectedin Efficacy in Soft Tissue Sarcoma: Inflammatory Biomarker Analysis.

BACKGROUND/AIM: Trabectedin is used as a treatment for advanced-stage soft tissue sarcomas (STSs), particularly liposarcoma and leiomyosarcoma. Aside from its direct effect on tumor cells, trabectedin can affect the immune system in the tumor microenvironment. This study aimed to evaluate whether inflammatory biomarkers predict trabectedin efficacy in STSs. PATIENTS AND METHODS: We retrospectively reviewed the clinical features and outcomes of patients with STS treated with trabectedin at our institution between 2016 and 2020. The neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelet-to-lymphocyte ratio (PLR), and systemic inflammation response index (SIRI=neutrophil × monocyte/lymphocyte) were calculated based on the blood samples obtained prior to trabectedin treatment initiation. Analyses of overall survival (OS) and progression-free survival (PFS) were performed according to various factors. RESULTS: Of the 101 patients identified, 54 had L-sarcoma (leiomyosarcoma: 30; liposarcoma: 24), and 47 had other types of STSs. Elevated SIRI, NLR, PLR, LMR, and C-reactive protein (CRP) were associated with worse PFS (p<0.001, p=0.008, p=0.027, p=0.013, and p<0.001, respectively) according to the results of the univariate analysis. Multivariate analysis showed that elevated SIRI, other histology, and CRP were associated with poor PFS (p=0.007, p=0.008, and p=0.029, respectively). In addition, the multivariate analysis of OS showed that SIRI was an independent prognostic factor (hazard ratio=2.16, p=0.006). CONCLUSION: Pretreatment SIRI can be considered a biomarker for the prognostic prediction of patients with STS treated with trabectedin.

Reclassification of a spindle cell sarcoma after identification of a TFG-ROS1 fusion: A case demonstrating the clinical benefit of next-generation sequencing in sarcoma.

BACKGROUND: Inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal soft tissue sarcomas that often present diagnostic challenges due to their wide and varied morphology. A subset of IMTs have fusions involving ALK or ROS1. The role of next-generation sequencing (NGS) for classification of unselected sarcomas remains controversial. METHODS AND RESULTS: We report a case of a metastatic sarcoma in a 34-year-old female originally diagnosed as an unclassified spindle cell sarcoma with myofibroblastic differentiation and later reclassified as IMT after NGS revealed a TFG-ROS1 rearrangement. Histologically, the neoplasm had spindle cell morphology with a lobulated to focally infiltrative growth pattern with scant inflammatory cell infiltrate. Immunohistochemistry demonstrated focal desmin and variable smooth muscle actin staining but was negative for SOX10, S100, and CD34. Fluorescence in situ hybridization was negative for USP6 or ALK gene rearrangements. NGS revealed a TFG-ROS1 rearrangement and the patient was treated with crizotinib with clinical benefit. CONCLUSIONS: We discuss the role of NGS as well as its potential benefit in patients with unresectable, ALK-negative metastatic disease. Considering this case and previous literature, we support the use of NGS for patients requiring systemic treatment.

Stabilizing Tumor-Resident Mast Cells Restores T-Cell Infiltration and Sensitizes Sarcomas to PD-L1 Inhibition.

PURPOSE: To explore the cellular cross-talk of tumor-resident mast cells (MC) in controlling the activity of cancer-associated fibroblasts (CAF) to overcome tumor microenvironment (TME) abnormalities, enhancing the efficacy of immune-checkpoint inhibitors in sarcoma. EXPERIMENTAL DESIGN: We used a coculture system followed by further validation in mouse models of fibrosarcoma and osteosarcoma with or without administration of the MC stabilizer and antihistamine ketotifen. To evaluate the contribution of ketotifen in sensitizing tumors to therapy, we performed combination studies with doxorubicin chemotherapy and anti-PD-L1 (B7-H1, clone 10F.9G2) treatment. We investigated the ability of ketotifen to modulate the TME in human sarcomas in the context of a repurposed phase II clinical trial. RESULTS: Inhibition of MC activation with ketotifen successfully suppressed CAF proliferation and stiffness of the extracellular matrix accompanied by an increase in vessel perfusion in fibrosarcoma and osteosarcoma as indicated by ultrasound shear wave elastography imaging. The improved tissue oxygenation increased the efficacy of chemoimmunotherapy, supported by enhanced T-cell infiltration and acquisition of tumor antigen-specific memory. Importantly, the effect of ketotifen in reducing tumor stiffness was further validated in sarcoma patients, highlighting its translational potential. CONCLUSIONS: Our study suggests the targeting of MCs with clinically administered drugs, such as antihistamines, as a promising approach to overcome resistance to immunotherapy in sarcomas.

Acquired NF2 mutation confers resistance to TRK inhibition in an ex vivo LMNA::NTRK1-rearranged soft-tissue sarcoma cell model.

Genomic rearrangements of the neurotrophic receptor tyrosine kinase genes (NTRK1, NTRK2, and NTRK3) are the most common mechanism of oncogenic activation for this family of receptors, resulting in sustained cancer cell proliferation. Several targeted therapies have been approved for tumours harbouring NTRK fusions and a new generation of TRK inhibitors has already been developed due to acquired resistance. We established a patient-derived LMNA::NTRK1-rearranged soft-tissue sarcoma cell model ex vivo with an acquired resistance to targeted TRK inhibition. Molecular profiling of the resistant clones revealed an acquired NF2 loss of function mutation that was absent in the parental cell model. Parental cells showed continuous sensitivity to TRK-targeted treatment, whereas the resistant clones were insensitive. Furthermore, resistant clones showed upregulation of the MAPK and mTOR/AKT pathways in the gene expression based on RNA sequencing data and increased sensitivity to MEK and mTOR inhibitor therapy. Drug synergy was seen using trametinib and rapamycin in combination with entrectinib. Medium-throughput drug screening further identified small compounds as potential drug candidates to overcome resistance as monotherapy or in combination with entrectinib. In summary, we developed a comprehensive model of drug resistance in an LMNA::NTRK1-rearranged soft-tissue sarcoma and have broadened the understanding of acquired drug resistance to targeted TRK therapy. Furthermore, we identified drug combinations and small compounds to overcome acquired drug resistance and potentially guide patient care in a functional precision oncology setting. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Radical resection and hyperthermic intraperitoneal chemotherapy (HIPEC) in the treatment of high risk recurrent retroperitoneal sarcoma-A pilot study in a tertiary Asian centre.

BACKGROUND: Peritoneal sarcomatosis (PS) is a difficult entity to treat with limited options and guarded prognosis. We aimed to determine if the addition of hyperthermic intraperitoneal chemotherapy (HIPEC) could offer superior local recurrence-free survival in patients with retroperitoneal sarcoma at high risk of developing PS as opposed to extended resection alone. METHODS: This is a single arm, phase II intervention study where all patients with recurrent localized retroperitoneal sarcoma considered at high risk of developing PS were considered for enrolment (ClinicalTrials.gov identifier: NCT03792867). Upon enrolment, patients underwent vigorous preoperative testing to ensure fitness for the procedure. During surgery, patients underwent extended resection and HIPEC with doxorubicin. Patients were followed-up every 2 weeks (± 10 days) for the first month and subsequently every three months (± 1 month) up to a year post-surgery, and were assessed for potential chemotherapy toxicity and post-treatment complications. After a year from resection and HIPEC, patients were followed-up either during routine clinic review or contacted via telephone every year (± 1 month) for 3 years. RESULTS: Six patients were recruited but one patient dropped out due to adverse and unexpected intraoperative events. The remaining patients completed the procedure uneventfully. Post-HIPEC, all patients recurred with a disease-free interval ranging from six to 24 months. Three patients died due to complications from recurrent disease whereas the remaining three patients are alive as of their last visit. The overall survival at time at reporting ranged between 22 to 56 months. CONCLUSION: The procedure is feasible with no major morbidity to patients. However, we are unable to recommend for it to be implemented as a routine procedure at this current stage due to lack of improved survival outcomes. Further multi-institutional studies may be conducted to yield better results.

Patient-reported outcomes in randomized clinical trials of systemic therapy for advanced soft tissue sarcomas in adults: A systematic review.

BACKGROUND: This systematic review evaluates reporting of patient-reported outcomes (PROs) within randomized clinical trials (RCTs) for advanced soft tissue sarcoma (STS) patients. METHODS: A systematic literature search from January 2000 - August 2022 was conducted for phase II/III RCTs evaluating systemic treatments in adult patients with advanced STS. Quality of PRO reporting was assessed using the CONSORT PRO extension. RESULTS: Out of 7294 abstracts, 59 articles were included; comprising 43 RCTs. Only 15 RCTs (35%) included PROs, none as primary endpoints. Only 10 of these RCTs reported PROs, either in the primary (6/10) or secondary publication (1/10) or in both (3/10), with a median time interval of 23 months. The median CONSORT PRO adherence score was 5.5/14, with higher scores in publications focusing exclusively on PROs. CONCLUSION: These results highlight the need for improved and more consistent PRO reporting to inform patient care in the setting of advanced STS.

Efficacy of tyrosine kinase inhibitors in patients with advanced or metastatic sarcomas after prior chemotherapy: A meta-analysis.

BACKGROUND: Sarcoma is a heterogeneous malignancy arising from interstitial tissue. Anthracycline-based therapy is the first-line treatment recommended by guidelines for patients with locally advanced or metastatic unresectable sarcoma. Recently, targeted therapies, in particular tyrosine kinase inhibitors (TKIs), have made significant progress in the treatment of sarcoma, and their efficacy has been investigated in randomized controlled trials. The aim of this meta-analysis is to evaluate the efficacy of TKIs in patients with advanced or metastatic sarcoma who have previously received chemotherapy. METHODS: We completed a meta-analysis after conducting literature searches in PubMed, Embase, and Cochrane. The single-drug, placebo-controlled, randomized controlled clinical trials of TKIs in patients with advanced or progressive sarcoma who have previously received chemotherapy are available for inclusion in the study. The observation results were objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). The subgroup analysis was performed according to histological subtypes of sarcoma. RESULTS: This study included 6 studies, including 1033 patients. The ORR (OR: 7.99, 95% CI: 3.62-19.61, P < .00001), DCR (OR: 2.54, 95% CI: 1.27-5.08, P = .009), PFS (HR: 0.46, 95% CI: 0.34-0.62, P < .00001), and OS (HR: 0.80, 95% CI: 0.67-0.96, P = .02) of patients treated with TKIs were better than those in the placebo group. CONCLUSIONS: In patients with advanced sarcoma, TKIs have been shown to have advantages in terms of ORR, DCR and PFS and OS. Multi-targeted TKIs may be considered as one of the second-line treatment options for sarcoma patients who have received prior chemotherapy.

Characterisation of new in vitro models and identification of potentially active drugs in angiosarcoma.

Angiosarcoma is a rare soft tissue sarcoma originating from endothelial cells. Given that current treatments for advanced disease have shown limited efficacy, alternative therapies need to be identified. In rare diseases, patient-derived cell models are crucial for screening anti-tumour activity. In this study, cell line models were characterised in 2D and 3D cultures. The cell lines' growth, migration and invasion capabilities were explored, confirming them as useful tools for preclinical angiosarcoma studies. By screening a drug library, we identified potentially effective compounds: 8-amino adenosine impacted cell growth and inhibited migration and invasion at considerably low concentrations as a single agent. No synergistic effect was detected when combining with paclitaxel, gemcitabine or doxorubicin. These results suggest that this compound could be a potentially useful drug in the treatment of AGS.

Best Overall Response-Associated Signature to Doxorubicin in Soft Tissue Sarcomas: A Transcriptomic Analysis from ANNOUNCE.

PURPOSE: This exploratory analysis evaluated the tumor samples of the patients treated with doxorubicin (with or without olaratumab) in a negative phase III ANNOUNCE trial to better understand the complexity of advanced soft tissue sarcomas (STS) and to potentially identify its predictive markers. EXPERIMENTAL DESIGN: RNA sequencing was performed on pretreatment tumor samples (n = 273) from the ANNOUNCE trial to evaluate response patterns and identify potential predictive treatment markers for doxorubicin. A BOR-associated signature to doxorubicin (REDSARC) was created by evaluating tumors with radiographic response versus progression. An external cohort of doxorubicin-treated patients from the Spanish Group for Research on Sarcomas (GEIS) was used for refinement and validation. RESULTS: A total of 259 samples from the trial were considered for analysis. Comparative analyses by the treatment arm did not explain the negative trial. However, there was an association between the BOR signature and histologic subtype (χ2P = 2.0e-7) and grade (P = 0.002). There were no associations between the BOR signature and gender, age, ethnicity, or stage. Applied to survival outcomes, REDSARC was also predictive for progression-free survival (PFS) and overall survival (OS). Using the GEIS cohort, a refined 25-gene signature was identified and applied to the ANNOUNCE cohort, where it was predictive of PFS and OS in leiomyosarcoma, liposarcoma, and other sarcoma subtypes, but not in undifferentiated pleomorphic sarcoma. CONCLUSIONS: The refined REDSARC signature provides a potential tool to direct the application of doxorubicin in sarcomas and other malignancies. Validation and further refinement of the signature in other potentially subtype specific prospective cohorts is recommended.