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Figure S1. shows total epirubicin concentrations (mean {plus minus} SD) at the end of infusion of 170 mg/m2 NC-6300 across cycles.

Table S1. shows progression Free Survival in individual subjects. Table S2. show exposures to epirubicinol in subjects who received infusion of NC-6300. Figure S1. shows total epirubicin concentrations (mean {plus minus} SD) at the end of infusion of 170 mg/m2 NC-6300 across cycles. Figure S2. shows mean Change in EORTC QLQ-C30 Score from Baseline.

Purpose:NC-6300 is a novel nanoparticle formulation of epirubicin that has a pH-sensitive linker conjugated to epirubicin. It exhibits selective tumor accumulation owing to enhanced permeability and retention effect. We conducted a phase 1b trial to determine MTD and recommended phase II dose (RP2D) of NC-6300 monotherapy in advanced, metastatic, or unresectable solid tumors, including soft-tissue sarcomas.Patients and Methods:This phase 1b dose-escalation trial of NC-6300 monotherapy employed a Bayesian continuous reassessment method design. NC-6300 was administered on day 1 of every 21-day cycle, with epirubicin-equivalent dose increments from 125 to 215 mg/m2. Safety, efficacy, quality of life, and pharmacokinetic profile of NC-6300 monotherapy were evaluated.Results:Twenty-nine subjects (16 male) were enrolled: 17 with soft-tissue sarcoma, one with osteosarcoma, and 11 with other solid tumors. Observed dose-limiting toxicities included thrombocytopenia, stomatitis, lung infection, and febrile neutropenia. The most common grade 3/4 adverse events were neutropenia (59%), anemia (24%), thrombocytopenia (24%), and febrile neutropenia (21%). MTD and RP2D were determined to be 185 mg/m2 and 150 mg/m2, respectively. The objective response rate in the evaluable population was 11%. Partial response was observed in angiosarcoma and endometrial stromal sarcoma. A dose-dependent increase was observed in both total and released epirubicin concentrations.Conclusions:NC-6300 was well tolerated with a manageable side effect profile, despite the MTD and RP2D being higher than conventional epirubicin doses. A signal of preliminary activity was observed in angiosarcoma. NC-6300 warrants further investigation in patients with advanced solid tumors, including sarcoma.

Supplementary Table S4 PDF file 59K, Relative gene copy number determined by qPCR analysis (ratio to adjacent normal tissue) of selected eight genes located on chromosome 12q13-15 of individual UHGPS

Supplementary Table Legend PDF file 58K, Legend for Supplementary Tables S1-S5

Adamantinoma-like Ewing sarcoma typically shows t(11;22) EWSR1::FLI1 translocation and complex epithelial differentiation. It poses a diagnostic challenge, especially in the head and neck region, due to its under-recognition and significant histologic overlap with other malignancies. Neoadjuvant and adjuvant treatment information on head and neck Adamantinoma-like Ewing sarcoma is limited. Herein, we report a case of a 78-year-old female with Adamantinoma-like Ewing sarcoma of the parotid gland, including the imaging findings and clinical response to neoadjuvant therapy followed by surgery. The efficacy of neoadjuvant therapy in the treatment of Adamantinoma-like Ewing sarcoma is discussed in the context of a review of pertinent literature. Adamantinoma-like Ewing sarcoma in the head and neck is frequently misdiagnosed as poorly differentiated squamous cell carcinoma or a basaloid salivary gland carcinoma. Adamantinoma-like Ewing sarcoma is a EWS1::FLI1 translocation driven tumor; frequently misdiagnosed on head and neck biopsies as poorly differentiated carcinoma, or squamous cell carcinoma. Ewing sarcoma-specific chemoregimen appears effective for this entity. If diagnosed early, patient may be amenable to neoadjuvant therapy, which may improve surgical and cosmetic outcomes. This is especially important in head and neck regions.

Background Gene-modified autologous T cells expressing NY-ESO-1c259, an affinity-enhanced T-cell receptor (TCR) reactive against the NY-ESO-1-specific HLA-A*02-restricted peptide SLLMWITQC (NY-ESO-1 SPEAR T-cells; GSK 794), have demonstrated clinical activity in patients with advanced synovial sarcoma (SS). The factors contributing to gene-modified T-cell expansion and the changes within the tumor microenvironment (TME) following T-cell infusion remain unclear. These studies address the immunological mechanisms of response and resistance in patients with SS treated with NY-ESO-1 SPEAR T-cells. Methods Four cohorts were included to evaluate antigen expression and preconditioning on efficacy. Clinical responses were assessed by RECIST v1.1. Engineered T-cell persistence was determined by qPCR. Serum cytokines were evaluated by immunoassay. Transcriptomic analyses and immunohistochemistry were performed on tumor biopsies from patients before and after T-cell infusion. Gene-modified T-cells were detected within the TME via an RNAish assay. Results Responses across cohorts were affected by preconditioning and intra-tumoral NY-ESO-1 expression. Of the 42 patients reported (data cut-off 4June2018), 1 patient had a complete response, 14 patients had partial responses, 24 patients had stable disease, and 3 patients had progressive disease. The magnitude of gene-modified T-cell expansion shortly after infusion was associated with response in patients with high intra-tumoral NY-ESO-1 expression. Patients receiving a fludarabine-containing conditioning regimen experienced increases in serum IL-7 and IL-15. Prior to infusion, the TME exhibited minimal leukocyte infiltration; CD163+ tumor-associated macrophages (TAMs) were the dominant population. Modest increases in intra-tumoral leukocytes (≤5%) were observed in a subset of subjects at approximately 8 weeks. Beyond 8 weeks post infusion, the TME was minimally infiltrated with a TAM-dominant leukocyte infiltrate. Tumor-associated antigens and antigen presentation did not significantly change within the tumor post-T-cell infusion. Finally, NY-ESO-1 SPEAR T cells trafficked to the TME and maintained cytotoxicity in a subset of patients. Conclusions Our studies elucidate some factors that underpin response and resistance to NY-ESO-1 SPEAR T-cell therapy. From these data, we conclude that a lymphodepletion regimen containing high doses of fludarabine and cyclophosphamide is necessary for SPEAR T-cell persistence and efficacy. Furthermore, these data demonstrate that non-T-cell inflamed tumors, which are resistant to PD-1/PD-L1 inhibitors, can be treated with adoptive T-cell based immunotherapy. Trial registration ClinicalTrials.gov, NCT01343043, Registered 27 April 2011.

Background This single-arm, multicenter, phase 2 study evaluated the safety and antitumor activity of pazopanib in patients with unresectable or metastatic conventional chondrosarcoma. Methods Eligible patients had conventional chondrosarcoma of any grade with measurable tumors that were unresectable or metastatic. Patients with mesenchymal, dedifferentiated, and extraskeletal myxoid chondrosarcoma subtypes and patients who received prior tyrosine kinase inhibitor therapy were excluded. Pazopanib at 800 mg once daily was administered for 28-day cycles. Tumor responses were evaluated by local radiology assessments every 2 cycles. The primary endpoint was the disease control rate (DCR) at week 16 (4 cycles). Results Forty-seven patients were enrolled. The DCR at 16 weeks was 43% (95% confidence interval [CI], 28%-58%), which was superior to the null hypothesis rate of 30%, but the 2-sided P value (exact test) was .09 (1-sided P = .045). One patient had a partial response. The median overall survival was 17.6 months (95% CI, 11.3-35.0 months), and the median progression-free survival was 7.9 months (95% CI, 3.7-12.6 months). Grade 3 or higher adverse events were infrequent; hypertension (26%) and elevated alanine aminotransferase (9%) were most common. Conclusions This study provides evidence of positive drug activity for pazopanib in conventional chondrosarcoma.

Small-molecule chemotherapeutics are potent and effective against a variety of malignancies, but common and severe side effects restrict their clinical applications. Nanomedicine approaches represent a major focus for improving chemotherapy, but have met limited success. To overcome the limitations of chemotherapy drugs, we have developed a novel Single Protein Encapsulation (SPE)-based drug formulation and delivery platform and tested its utility in improving doxorubicin (DOX) treatment. Using this methodology, a series of SPEDOX complexes were generated by encapsulating various numbers of DOX molecules into a single human serum albumin (HSA) molecule. UV/fluorescence spectroscopy, membrane dialysis, and dynamic light scattering techniques showed that SPEDOXs are stable and uniform as monomeric HSA and display unique properties distinct from those of DOX and DOX-HSA mixture. Furthermore, detailed procedures to precisely monitor and control both DOX payload and binding strength to HSA were established. Breast cancer xenograft tumor studies revealed that SPEDOX-6 treatment displays improved pharmacokinetic profiles, higher antitumor efficacy, and lower DOX accumulation in the heart tissue compared with unformulated DOX. This SPE technology, which does not involve nanoparticle assembly and modifications to either small-molecule drugs or HSA, may open up a new avenue for developing new drug delivery systems to improve anticancer therapeutics.

Purpose: Most gastrointestinal stromal tumors (GIST) are driven by KIT/PDGFRa mutations. Tyrosine kinase inhibitor benefit is progressively less after imatinib failure. This phase II trial analyzed the efficacy of nivolumab (N) or nivolumab + ipilimumab (N + I) in patients with refractory GIST. Patients and Methods: Patients with advanced/metastatic GIST refractory to at least imatinib were randomized 1:1 in a noncomparative, parallel group, unblinded phase II trial of N (240 mg every 2 weeks) or N + I (240 mg every 2 weeks + 1 mg/kg every 6 weeks). The primary endpoint was the objective response rate of N alone or N+I by RECIST 1.1 in the intent-to-treat population. Results: A total of 36 patients with a median of 3 (1–6) prior lines of therapies were enrolled. Ten of 19 (52.6%) patients had stable disease (SD) for a clinical benefit rate (CBR) of 52.6% in the N arm and the median progression-free survival (PFS) was 11.7 weeks [95% confidence interval (CI), 7.0–17.4]. In the N+I arm, 1 of 16 (6.7%) patients had a complete response (CR) and 4/16 (25.0%) had SD for a CBR of 31.3% and a median PFS of 8.3 weeks (95% CI, 5.6–22.2). The 4- and 6-month PFS were 42.1% and 26.3%, respectively for N, and 31.3% and 18.8%, respectively for N+I. The most common adverse events (AE) attributed to N and N+I were fatigue: 13.9% and 22.2%, respectively. There were nine total attributable grade 3–4 AEs. Conclusions: The primary endpoint of response rate > 15% was not observed for N or N + I. In a heavily pretreated GIST population, responses and long-term disease control with both N and N+I were observed. No new safety signals have been observed.

Background NY-ESO-1–specific T cells (letetresgene autoleucel [lete-cel]; GSK3377794) are autologous CD4+ and CD8+ T cells transduced to express a high-affinity T-cell receptor that recognizes NY-ESO-1 antigen in complex with HLA-A*02. NY-ESO-1 is a cancer testis antigen that is expressed in many cancers, including synovial sarcoma (SS). Study 208466 (NCT01343043) is a Phase I clinical trial that assessed the safety and efficacy of lete-cel in patients with advanced SS (presented in complementary abstract). This abstract presents correlations of transduced cell kinetics and biomarkers with response. Methods Patients with unresectable, metastatic, or recurrent SS were enrolled to 4 cohorts based on NY-ESO-1 expression levels and received different lymphodepleting regimens (LDR) prior to lete-cel infusion (N=45) (table 1). Response was assessed per RECIST v1.1. Transduced cell kinetics (persistence) were measured by quantitative PCR of transgene vector copies in DNA extracted from peripheral blood mononuclear cells. Serum cytokines were measured by Meso Scale Discovery (MSD) immunoassay. Gene expression within tumor biopsies was evaluated by Nanostring. Post hoc analyses were evaluated in a hypothesis-driven manner using logistic and linear regression. Potential determinants of peak persistence and clinical response were tested using generalized linear models. Results Higher peak persistence (Pmax) was associated (p=0.012) with response across cohorts. Higher weight-normalized cell dose (p=0.00421) and LDR (p=0.000910) were associated with Pmax according to the generalized linear model: Pmax ~ cell dose + LDR. These relationships allowed for accurate retrospective prediction of probability of response. Low LDR resulted in higher endogenous lymphocyte counts on the day of dosing, which trended with lack of response within and across cohorts. While the impact of fludarabine on IL-15 levels has been previously reported, data presented here show a novel, positive correlation between IL-15 levels pre-infusion and response (p=0.0332). Post lete-cel infusion, the concentrations of IFNγ, IL-6, and IL-2RA within the first week were increased in responders vs non-responders. The peak expression of IL-2RA within the first week showed a linear correlation to Pmax. Analysis of tumor biopsies showed good correlation between NY-ESO-1 mRNA and protein expression. Conclusions Exposure–response analysis of study 208466 reveals that efficacy appears to be driven by weight-normalized cell dose and LDR via Pmax. Biomarker correlation analysis indicates that LDR impacts the level of IL-15 pre-infusion, which correlates with response directly. IFNγ, IL-6, and IL-2RA levels appear to be promising pharmacodynamic markers. Optimizing dose and LDR may offer opportunities to maximize antitumor efficacy. Acknowledgements This study (208466) was funded by GlaxoSmithKline (GSK). Trial Registration Clinicaltrials. gov NCT01343043 Ethics Approval This study was approved by the appropriate institutional review boards and independent ethics committees.

Background NY-ESO-1–specific T cells (letetresgene autoleucel [lete-cel]; GSK3377794) are autologous T cells transduced with a self-inactivating lentiviral vector to express an engineered NY-ESO-1–specific TCR that recognizes HLA-A*02–presented peptides derived from NY-ESO-1, a cancer/testis antigen expressed in 70%–80% of SS. NCT01343043 was a Phase I, open-label trial assessing safety, efficacy, and pharmacokinetics of lete-cel in patients with SS; activity was evaluated after different lymphodepletion conditioning regimens and in patients with differing levels of NY-ESO-1 expression. Methods Patients with unresectable, metastatic, or recurrent SS who were intolerant/nonresponsive to standard first-line chemotherapy enrolled in 4 cohorts based on NY-ESO-1 tumor expression were lymphodepleted and received lete-cel infusion (table 1). Primary endpoint was investigator-assessed overall response rate (ORR) per RECIST v1.1; secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. Transduced cell persistence was measured by qPCR of transgene vector copies in DNA extracted from PBMCs. Study was not designed/powered to compare cohorts. Results Overall, 50 patients enrolled; 45 received lete-cel infusion (modified intent-to-treat population). Demographics were similar between cohorts. Median time in study was 480/278/605/643 days in Cohorts 1/2/3/4, respectively. At study completion, ORR ranged from 20%–50% between cohorts, with 1 complete (lasting 34 weeks) and 14 partial responses (table 1). In Cohorts 1/2/3/4, respectively, median DoR was 31.0/8.6/32.1/16.4 weeks; median PFS was 15.4/13.1/8.6/22.4 weeks (table 1). As of 27Jan2020, median OS for Cohorts 1/2/3 was 24.3/9.9/19.9 months; Cohort 4 median OS was immature (table 1). Across cohorts, Grade ≥3 adverse events (AEs) in ≥40% of patients were mostly hematologic in nature; Grade ≥3 serious AEs (SAEs) were most frequently febrile neutropenia, dyspnea, and neutropenia (table 2). AEs of special interest included cytokine release syndrome in 44% of patients (n=20; maximum Grade 1/2/3/4 in 9/7/3/1 patients, respectively; 5 patients had SAEs [Grade ≥3 in 2 patients]; all AEs/SAEs resolved); Guillain-Barre syndrome in 2 patients (Grade 3 SAEs; resolved with sequalae); and multilineage cytopenias in 96% of patients (n=43; maximum Grade 5 in 1 patient, Grade 3/4 in others). Peak persistence of transduced cells was generally higher in responders vs non-responders (table 1); time to peak persistence was similar between these groups (median 8 days). No patients tested positive for replication-competent lentivirus. Conclusions In patients with advanced SS who need effective treatment, lete-cel had a manageable safety profile; responses occurred in all cohorts, but patients with high NY-ESO-1 expression and more intensive lymphodepletion regimen received greatest benefit. Acknowledgements This study (208466) was funded by GlaxoSmithKline. Medical writing assistance was provided by Gemma Corr, DPhil, and Tiffany Brake, PhD, of Fishawack Indicia, UK, and funded by GlaxoSmithKline. We thank Ran Ji for contributions to statistical analysis. Trial Registration Clinicaltrials. gov NCT01343043 Ethics Approval This study was approved by the appropriate institutional review boards and independent ethics committees.

Trial Information Click here to access other published clinical trials. Lessons Learned The results from the liposarcoma cohort of SARC024 confirm previously published data and do not support the routine use of regorafenib in this patient population. Continued exploration of novel therapies, including combination approaches, is warranted for a patient population in whom limited treatment options exist. Background Regorafenib is a multitargeted kinase inhibitor with a kinase profile overlapping, but distinct from, pazopanib, an agent approved for recurrent and metastatic non-gastrointestinal stromal tumor (GIST), non-adipocytic soft tissue sarcoma. We conducted a randomized, phase II study of regorafenib versus placebo in refractory liposarcoma patients. Methods Patients with advanced or metastatic, treatment-refractory liposarcoma were randomized 1:1 to receive regorafenib 160 mg or placebo once daily (3 weeks on, 1 week off). Patients with well-differentiated liposarcoma only were excluded. Crossover for placebo was allowed upon progression. The primary endpoint was progression-free survival (PFS), according to RECIST version 1.1. Results Forty-eight subjects with liposarcoma (34 dedifferentiated, 12 myxoid/round cell, 2 pleomorphic) were enrolled. Median PFS was 1.87 (95% confidence interval [CI], 0.92–3.67) months for regorafenib versus 2.07 (95% CI, 1.64–3.44) months for placebo; stratified hazard ratio [HR], 0.85 (95% CI, 0.46, 1.58), p = .62. No responses were seen on regorafenib. One PR was observed on placebo. Median overall survival was 6.46 (95% CI, 4.16–23.48) months for regorafenib and 4.89 (95% CI, 3.02–9.77) months for placebo, stratified HR, 0.66 (95% CI, 0.31–1.40), p = .28). Treatment-related adverse events were similar to the known safety profile of regorafenib. Conclusion Regorafenib did not appear to improve PFS in treatment-refractory liposarcoma. No new significant safety signals were observed.

Purpose: NC-6300 is a novel nanoparticle formulation of epirubicin that has a pH-sensitive linker conjugated to epirubicin. It exhibits selective tumor accumulation owing to enhanced permeability and retention effect. We conducted a phase 1b trial to determine MTD and recommended phase II dose (RP2D) of NC-6300 monotherapy in advanced, metastatic, or unresectable solid tumors, including soft-tissue sarcomas. Patients and Methods: This phase 1b dose-escalation trial of NC-6300 monotherapy employed a Bayesian continuous reassessment method design. NC-6300 was administered on day 1 of every 21-day cycle, with epirubicin-equivalent dose increments from 125 to 215 mg/m2. Safety, efficacy, quality of life, and pharmacokinetic profile of NC-6300 monotherapy were evaluated. Results: Twenty-nine subjects (16 male) were enrolled: 17 with soft-tissue sarcoma, one with osteosarcoma, and 11 with other solid tumors. Observed dose-limiting toxicities included thrombocytopenia, stomatitis, lung infection, and febrile neutropenia. The most common grade 3/4 adverse events were neutropenia (59%), anemia (24%), thrombocytopenia (24%), and febrile neutropenia (21%). MTD and RP2D were determined to be 185 mg/m2 and 150 mg/m2, respectively. The objective response rate in the evaluable population was 11%. Partial response was observed in angiosarcoma and endometrial stromal sarcoma. A dose-dependent increase was observed in both total and released epirubicin concentrations. Conclusions: NC-6300 was well tolerated with a manageable side effect profile, despite the MTD and RP2D being higher than conventional epirubicin doses. A signal of preliminary activity was observed in angiosarcoma. NC-6300 warrants further investigation in patients with advanced solid tumors, including sarcoma.

BACKGROUND AND OBJECTIVES:Primary liver sarcomas (PLS) are rare. Published series are limited by small numbers of patients. METHODS:We reviewed the National Cancer Database (2004-2014) for patients who underwent surgical resection of PLS. RESULTS:Of 237 patients identified, the majority were female (60.8%), with median age of 52 years. Histologies were: epithelioid hemangioendothelioma (n = 67), angiosarcoma (n = 64), leiomyosarcoma (n = 33), embryonal rhabdomyosarcoma (n = 31), carcinosarcoma (n = 16), giant cell sarcoma (n = 14), spindle cell sarcoma (n = 12). Ninety-seven (40.9%) patients underwent lobectomies or extended lobectomies, 41 patients (17.3%) underwent transplantation. Surgical margins were negative in 82.9%. Tumors were well differentiated in 11.3%. Histology type correlated with outcome with the best prognosis for epithelioid hemangioendothelioma (OS: not reached, similar for resection and transplantation) and the worst for angiosarcoma (OS:16.6 mo with resection; 6 mo with transplantation; P = 0.04). Resections with microscopically negative margins were associated with improved survival (58.7 vs 11.3 mo for positive margins; P

11532 Background: Ewing Sarcoma (ES) is an aggressive, translocation-associated, bone cancer associated with a poor prognosis in the recurrent or metastatic setting. ES is identified by the canonical balanced reciprocal chromosomal translocation involving EWSR1 and ETS transcription factors. Secondary somatic alterations in ES are rarely described and genomic alterations (GA) affecting various molecular pathways may work synergistically with ETS-FL1 translocations to promote oncogenesis. Alterations in fibroblast growth factor receptor 4 (FGFR4), a receptor tyrosine kinase protein that functions in cellular processes, have been observed to affect carcinogenesis. Moreover, the FGFR4-Gly388Arg (G388R) single nucleotide polymorphism (SNP) is found to increase the risk of cancer with mouse embryonic fibroblasts derived from knock-in strain of homologous Fgfr4 G385R mice exhibiting a transformed phenotype. We sought to further evaluate the frequency of FGFR4 G388R SNP in relation to other identifiable pathway alterations observed with Comprehensive Genomic Profiling (CGP). Methods: Next generation sequencing (NGS) analysis was obtained in the context of clinical care with clinical status, outcomes, and source acquisition (primary tumor, metastasis, or recurrence) unknown to Foundation Medicine. CGP, FoundationOne Heme, evaluated GAs including base substitutions, indels, amplifications, copy number alterations, gene fusions and rearrangements. 189 samples were assayed by hybrid-capture based CGP, including 406 DNA-sequenced genes in addition to 265 RNA-sequenced genes commonly reported to be rearranged in cancer, as previously described. Tumor mutational burden was assessed from a minimum 1.4 Mb sequenced DNA. Microsatellite instability (MSI) status was determined by a novel algorithm analyzing 114 specific loci. Results: The median age of evaluated patients was 20 (range 0-70) with the number of alterations averaging 7 per patient. Pathways noted to be altered in the presence of FGFR388R SNP occurred frequently with the following pathways most observed: MAPK (33%), WNT (32%), NOTCH1 (20%), HRR (19%), Histone/chromatin remodeling (18%). FGFR388R SNP was observed in more than half (51%) of evaluated samples. Most affected pathways irrespective of FGFR388R SNP status included: MAPK (n = 89), HRR (n = 75), and PIK3 (n = 64). All evaluated samples were TMB low ( < 10 mut/mb) and Microsatellite Stable. Conclusions: Secondary GAs affecting major pathways were observed in high frequency, often co-occurring with the FGFR4 G388R SNP. Secondary alteration of known oncogenic pathways may contribute to sarcoma formation in ES potentially informing further therapeutic strategies in the future.

TPS11578 Background: Conventional chondrosarcoma (cCS) accounts for ̃25% of primary bone cancers and is the second most common primary bone tumor after osteosarcoma. Surgical resection is the primary treatment for localized disease. No FDA approved therapy exists for advanced disease and chemotherapy has marginal efficacy with ORR < 12%. IDH1/2 mutation is seen in 50% of cases. Epigenetic dysregulation is central to oncogenesis in both IDH1/2 mutant and wild-type CS. Pre-clinical studies from our group show that combination treatment with HDAC and DNMT inhibitors is significantly more effective at suppressing the growth of CS models in vitro and in vivo compared to either therapy alone. The combination regimen mediates anti-tumor effects on CS by induction of apoptosis, induction of tumor suppressor genes (eg. E-cadherin), the induction of interferon responsive genes (eg. IRF7, OASL, ISG15, DDX58) and reversal of global hypomethylated state. Based on these findings we have designed a phase 2 clinical trial with an HDAC inhibitor (belinostat) and a DNMT inhibitor (guadecitabine) in patients with advanced cCS. Methods: NCI # 10330 is a single-arm, multi-center, Simon 2-stage, phase 2 clinical trial evaluating belinostat and guadecitabine in patients with advanced cCS. Eligible patients will have biopsy proven cCS which is measurable by RECIST v1.1 and amenable to biopsy, ECOG PS ≤ 2, any number of prior treatments (including none). Patients will receive guadecitabine 45 mg/m2 SC followed by belinostat 1000 mg/m2 IV once daily on days 1-5 of a 28-day cycle. A safety lead-in and continuous toxicity monitoring rule will be applied. The primary endpoint will be ORR. Since chemotherapy is associated with an ORR of 8-12% and targeted agents have shown an ORR of 0% in cCS, we will consider an ORR of 8% as inactive while an ORR of 28% will suggest promising activity. A Simon 2-stage design is employed. The design calls for 26 patients. If ≥ 2 responses are observed among 13 patients in stage I, the study will proceed to full accrual. If ≥ 5 responses are seen among 26 patients, the study treatment is considered promising. This design has 85% power with α of 0.054 to test for a response rate of 8% vs 28%. Secondary objectives include safety, tolerability and PFS. All patients will undergo pre-treatment and on-treatment tumor biopsies. Paired tissue will be used for correlative analysis including: 1) whole exome sequencing/RNAseq to evaluate changes in gene expression in response to treatment, 2) multiplex IHC to interrogate the effect of combination therapy on tumor immune microenvironment and 3) a global DNA methylation assay to better understand the changes in epigenetic landscape in response to treatment. This study is open throughout the ETCTN (NCT04340843). Six of the planned 26 patients in the safety lead-in have been enrolled without DLT. Further accrual is on hold pending completion of the safety lead-in. Clinical trial information: 04340843.

TPS11582 Background: Letetresgene autoleucel (lete-cel; GSK3377794) is an autologous T-cell product using a genetically modified T-cell receptor to target cancer cells expressing the cancer testis antigen New-York esophageal squamous cell carcinoma 1 (NY-ESO-1). Lete-cel is currently being investigated alone and in combination in multiple tumor types [1,2]. NY-ESO-1 is expressed in 70‒80% of synovial sarcoma (SS) and 80‒90% of myxoid/round cell liposarcoma (MRCLS) tumors [3,4], suggesting these tumors may be prime lete-cel targets. This master protocol design (IGNYTE-ESO; NCT03967223) enables evaluation of multiple cell therapies in multiple tumor types and treatment stages in separate substudies, beginning with lete-cel in Substudies 1 and 2 for SS and MRCLS. Methods: Substudy 1 is a single-arm study assessing lete-cel in treatment-naïve patients (pts; ie, anthracycline therapy-naïve for metastatic disease) with advanced (metastatic/unresectable) NY-ESO-1+ SS or MRCLS as a first line of therapy (n=10 planned). Substudy 2 is a pivotal, single-arm study assessing lete-cel in pts with NY-ESO-1+ SS or MRCLS who progressed after anthracycline therapy (n=70 planned). Key eligibility criteria are age ≥10 y and NY-ESO-1 and HLA-A*02 positivity. Exclusion criteria include prior NY-ESO-1–specific/gene therapy, allogeneic stem cell transplant, and central nervous system metastases. Screened pts undergo leukapheresis for lete-cel manufacture, lymphodepletion, lete-cel infusion, and follow-up (FU). Long-term FU (15 y) may be done under a separate protocol. The Substudy 2 primary endpoint is overall response rate (ORR) per RECIST v1.1 assessed by central independent review. Substudy 1 is not testing any formal hypotheses; statistical analysis will be descriptive. Substudy 2 is comparing ORR with the historical control assuming at least 90% power with 0.025 one-sided type I error. Secondary endpoints include efficacy (time to/duration of response, disease control rate, progression-free survival), safety (adverse event [AE] frequency/severity, serious AEs, AEs of special interest), and pharmacokinetic (maximum transgene expansion [Cmax], time to Cmax, area under the time curve from zero to time t as data permit). Enrollment began in December 2019. References: 1. Reckamp KL, et al. Ann Oncol 2019;30(Suppl_5):v602–v660. 2. Rapoport A, et al. J Clin Oncol 2020 38:15_suppl, TPS8555. 3. D’Angelo SP, et al. Cancer Discov 2018;8(8):944–957. 4. D’Angelo SP, et al. J Clin Oncol 2018 36:15_suppl, 3005. Funding: GSK. Editorial support was provided by Eithne Maguire, PhD, of Fishawack Indicia, part of Fishawack Health, and funded by GSK. Previously presented at BSG 2021 (P914542). Clinical trial information: NCT03967223.

11562 Background: Sarcoma cells are most immunogenic earlier in the disease course and before treatment when the immune system can recognize and destroy them. Hypothesis: Immune checkpoint inhibitors would be most effective when given to previously untreated patients with metastatic soft tissue sarcoma. Methods: Eligible patients for this Phase 2 study are previously untreated patients ≥ 18 years of age with unresectable or metastatic soft tissue sarcoma, with measurable disease by RECIST v1.1. Immune checkpoint inhibitors Ipilimumab (I) and Nivolumab (N) were given with Trabectedin (T), a marine derived alkaloid with defined doses of I (1 mg/kg i.v. q 12 weeks), N (3 mg/kg i.v. q 2 weeks), and T (1.2 mg/m2 i.v. q 3 weeks). Primary endpoints: (1) Objective response rate by RECIST v1.1 via CT scan or MRI, (2) Progression-free survival (PFS): from first day of treatment to disease progression or death due to any cause; otherwise, it is censored at the time of last follow-up, and (3) Overall survival: from first day of treatment to death due to any cause; otherwise, it is censored at the time of last follow-up. Results: There were eighty-two evaluable subjects, having completed the first cycle of I, N, and T and have had a CT or MRI scan at the 6-week follow-up period. Best Overall Response by RECIST v1.1 = 7 CR (2 surgical CR), 9 PR, 54 SD, and 12 PD. Disease control rate was 85.4%. The median PFS was >6.4 (range: 0-32) months; 6-month PFS rate: 57.3%. The median OS was >12.0 (0-38) months; 6-month OS rate: 78.8%. Safety analysis: The most common Grade 3 TRAEs include increased ALT (26), anemia (11), increased AST (9), and fatigue (8). Common Grade 4 TRAEs include thrombocytopenia (2), increased AST (2), increased ALT (2), and increased CPK (2). There was one Grade 5 TRAE of rhabdomyolysis (1). Conclusions: Taken together, these results suggest that first-line combinatorial therapy with I, N, and T are (1) synergistic, and (2) may be equal or superior to, and safer than, standard first line therapy for advanced/metastatic soft tissue sarcoma. Clinical trial information: NCT03138161.

BACKGROUND Alveolar soft part sarcoma (ASPS), chondrosarcoma (CS), chordoma, epithelioid sarcoma, and solitary fibrous tumor (SFT) are malignant tumors that are relatively resistant to chemotherapy and for which more effective drug therapy is needed. METHODS The 5 listed subtypes were enrolled into a single indolent sarcoma cohort in a phase 2 study of dasatinib using a Bayesian continuous monitoring rule for enrollment. The primary objective was to estimate the 6-month progression-free survival (PFS) rate according to the Choi criteria with a target of ≥50%. Cross-sectional imaging was performed before the start of treatment, every 2 months for 6 months, and then every 3 months during treatment. The 2- and 5-year survival rates were determined. RESULTS One hundred sixteen patients were enrolled within 45 months, and 109 began treatment with dasatinib. The 6-month PFS rate and the median PFS were 48% and 5.8 months, respectively. The PFS rate at 6 months was highest with ASPS (62%) and lowest with SFT (30%). More than 10% of the patients with ASPS, CS, or chordoma had stable disease for more than 1 year. Collectively, for all 5 subtypes, the 2- and 5-year overall survival rates were 44% and 13%, respectively. An objective response was observed in 18% of the patients with CS or chordoma. CONCLUSIONS Dasatinib failed to achieve control of sarcoma growth for at least 6 months in more than 50% of the patients in this trial according to the Choi tumor response criteria. An objective tumor response and prolonged stable disease was observed in >10% of patients with CS or chordoma. Cancer 2016. © 2016 American Cancer Society.

Background Oral metronomic chemotherapy, which has low toxicity, has demonstrated promising anti-tumor and anti-angiogenic properties that may lead to prolonged progression-free survival and improved response rates in patients with recurrent epithelial ovarian cancer (EOC). These effects may be enhanced by the co-administration of anti-angiogenic agents. Methods We conducted a randomized phase II clinical trial to evaluate the therapeutic benefit of oral metronomic cyclophosphamide (CTX) alone and with the anti-angiogenic drug celecoxib in patients with gynecological malignancies. 52 patients were randomly assigned to two treatments arms: 50 mg oral CTX daily alone (Arm A) or with 400 mg celecoxib twice daily (Arm B). The primary endpoint was response rate. Secondary endpoints included toxicity, time to treatment failure, and overall survival. Results In Arm A (n = 26), 3 patients (12%) had stable disease >6 months and 1 (4%) had a partial response. In Arm B, 5 (19%) had stable disease >6 months and 1 patient (4%) had a partial response. There were no significant between-group differences in overall survival (9.69 months [95% CI 3.84–13.18] vs. 12.55 months [6.67–17.61]) or in median time to treatment failure (1.84 months [1.68–2.76] vs. 1.92 months [1.64–5.22]). The most common adverse events were nausea, vomiting, and abdominal pain. Conclusions Oral metronomic CTX has activity with no major toxicities in heavily pretreated recurrent gynecological cancers and may be considered in patients with indolent disease. We did not observe any additional benefit of celecoxib treatment, though this may be due to small sample sizes.

BACKGROUND Dasatinib exhibited activity in preclinical models of sarcoma. The Sarcoma Alliance for Research through Collaboration (SARC) conducted a multicenter, phase 2 trial of dasatinib in patients with advanced sarcoma. METHODS Patients received dasatinib twice daily. The primary objective was to estimate the clinical benefit rate (CBR) (complete response or partial response within 6 months or stable disease duration of ≥6 months) with a target of ≥25%. Patients were enrolled into 1 of 7 different cohorts and assessed by imaging every 8 weeks using Choi criteria tumor response and a Bayesian hierarchical design. For each subtype, enrollment was stopped after a minimum of 9 patients were treated if there was a

TPS11571 Background: T cells modified to target NY-ESO-1 have shown encouraging activity in HLA-A*02+ patients with NY-ESO-1–positive synovial sarcoma. NY-ESO-1 is a cancer/testis antigen that is expressed across multiple tumor types and highly expressed in synovial sarcoma. NY-ESO-1 TCR T (GSK3377794) are autologous polyclonal T cells transduced by a self-inactivating lentiviral vector to express an affinity-enhanced TCR able to recognize NY-ESO-1 epitope in complex with HLA-A*02. Ongoing trials are evaluating GSK3377794 in multiple solid tumors and multiple myeloma. Methods: This study (NCT03967223) uses a Master Protocol design that allows investigation of GSK3377794 in multiple tumor types under the same protocol in separate substudies. The first two are single-arm substudies in patients with advanced metastatic or unresectable synovial sarcoma: treatment-naïve (1st line [1L], substudy 1; n = 10 planned) and progressing after anthracycline-based chemotherapy (2L+, substudy 2; n = 55 planned). Patients must be aged ≥10 years, have adequate organ function, ECOG performance status 0–1, measurable disease, and no central nervous system metastases. Excluded prior treatments include gene therapy with an integrating vector or NY-ESO-1–specific T cells, vaccine or targeting antibody, or allogeneic stem cell transplant. Patients will undergo leukapheresis and manufacture of GSK3377794; lymphodepletion then GSK3377794 infusion, followed by safety and disease assessments; and long-term follow-up for 15 years (under a separate protocol). The primary objective of substudy 2 is overall response rate per RECIST v1.1 by central independent review. Secondary objectives include time to response, duration of response, disease control rate, progression-free survival, overall survival, plus safety and tolerability. Exploratory objectives include assessment of the correlation of T-cell persistence with safety, clinical responses, and infused T-cell phenotype. Evaluation of quality of life and daily functioning of patients will also be assessed. Enrollment began in December 2019. These data are presented on behalf of the original authors with their permission. A similar presentation (P453) was presented at the SITC Annual Meeting, National Harbor, MD, USA, Nov 6–10, 2019. Funding: GlaxoSmithKline (208467) Clinical trial information: NCT03967223 .

Importance Gastrointestinal stromal tumors (GISTs) are life-threatening when metastatic or not amenable to surgical removal. In a few patients with advanced GISTs refractory to imatinib mesylate, treatment with sunitinib malate followed by regorafenib provides tumor control; however, additional active treatments are needed for most patients. Objective To evaluate the 6-month progression-free survival (PFS), tumor objective response, and overall survival rates in patients with GISTs treated with dasatinib. Design, Setting, and Participants This single-arm clinical trial used a Bayesian design to enroll patients 13 years or older with measurable imatinib-refractory metastatic GISTs treated at 14 sarcoma referral centers from June 1, 2008, through December 31, 2009. A control group was not included. Patients were followed up for survival for a minimum of 5 years from date of enrollment. Tumor imaging using computed tomography or magnetic resonance imaging was performed every 8 weeks for the first 24 weeks and every 12 weeks thereafter. Tumor response was assessed by local site using the Choi criteria. Treatment was continued until tumor progression, unacceptable toxic effects after reduction in drug dose, or patient or physician decision. Archival tumor tissue was evaluated for expression of the proto-oncogene tyrosine-protein kinase Src (SRC), phosphorylated SRC (pSRC), and succinate dehydrogenase complex iron sulfur subunit B (SDHB) proteins and for mutation in the V-Kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog ( KIT ) and platelet-derived growth factor receptor α ( PDGFRA ) genes. Data analysis was performed from May 19, 2017, through December 20, 2017. Interventions Dasatinib, 70 mg orally twice daily. Main Outcomes and Measures The primary end point was the 6-month PFS estimate using greater than 30% as evidence of an active drug and less than 10% as evidence of inactive treatment. Results In this study, 50 patients were enrolled (median age, 60 years; age range, 19-78 years; 31 [62%] male and 19 [38%] female; 41 [82%] white), and 48 were evaluable for response. The estimated 6-month PFS rate was 29% in the overall population and 50% in a subset of 14 patients with pSRC in GISTs. Objective tumor response was observed in 25%, including 1 patient with an imatinib-resistant mutation in PDGFRA exon 18. Conclusions and Relevance Dasatinib may have activity in a subset of patients with imatinib-resistant GISTs. Further study is needed to determine whether pSRC is a prognostic biomarker.

Chondrosarcomas constitute a heterogeneous group of primary bone cancers characterized by hyaline cartilaginous neoplastic tissue. They are the second most common primary bone malignancy. The vast majority of chondrosarcomas are conventional chondrosarcomas, and most conventional chondrosarcomas are low- to intermediate-grade tumors (grade 1 or 2) which have indolent clinical behavior and low metastatic potential. Recurrence augurs a poor prognosis, as conventional chondrosarcomas are both radiation and chemotherapy resistant. Recent discoveries in the biology, genetics, and epigenetics of conventional chondrosarcomas have significantly advanced our understanding of the pathobiology of these tumors and offer insight into potential therapeutic targets.

Hospital cancer registries are only required to report gastrointestinal stromal tumors (GISTs) if labeled malignant or metastatic, leading to potential loss of cases in national cancer registries. Our objective was to determine whether GISTs are underreported in the US. Retrospective review of pathology reports between 2010 and 2013 with diagnosis of GIST was performed at two academic medical centers. Recurrent GISTs were excluded. Pathology reports were cross-referenced to cases reported by each cancer registry. Risk for metastasis/death was determined according to National Comprehensive Cancer Network (NCCN) guidelines. Forty-nine cases of non-recurrent GIST were identified. Only 19/49 (38.8 %) cases were reported. None of the 30 non-reported cases were labeled malignant/metastatic on final pathology. To illustrate malignant potential, these tumors were risk stratified. Most (60 %) of the non-reported cases were low risk, but there were 4 (13.3 %) cases each in the intermediate, high, and unknown risk groups. Additionally, 7/30 (23.0 %) cases were treated with tyrosine kinase inhibitors, highlighting clinical concern of malignant GIST. Our results show that nearly two thirds of GIST cases have been underreported, suggesting that current reporting practices underestimate its true incidence. Revision of reporting guidelines may result in a more accurate estimation of the US disease burden of GIST.

Background: The MEK inhibitor, selumetinib, suppresses soft-tissue sarcoma (STS) cell proliferation in vitro. Mammalian target of rapamycin inhibitors possess modest activity against STS; however, resistance develops via MAPK pathway feedback activation. The combination of selumetinib and temsirolimus synergistically inhibits STS cell line growth. Therefore, a randomized phase II trial of selumetinib vs selumetinib plus temsirolimus was conducted. Methods: Seventy-one adults with advanced STS who received ⩽2 prior chemotherapeutics were randomized to selumetinib 75 mg p.o. bid and allowed to crossover upon progression, or to selumetinib 50 mg p.o. bid plus temsirolimus 20 mg i.v. weekly, with primary endpoint of progression-free survival (PFS). Results: There was no difference in PFS between the two arms for the overall cohort (median 1.9 vs 2.1 months); an improved median PFS was observed in the combination arm (N=11) over single agent (N=10) in the prespecified leiomyosarcoma stratum (median 3.7 vs 1.8 months; P=0.01). Four-month PFS rate was 50% (95% confidence interval 0.19–0.81) with the combination vs 0% with selumetinib alone in the leiomyosarcoma cohort. Most common grade 3/4 adverse events with the combination were mucositis (29%), lymphopenia (26%), neutropenia and anaemia (20% each). Conclusions: While single-agent selumetinib has no significant activity in STS, the combination may be active for leiomyosarcomas.

The NCCN Guidelines for Bone Cancer provide interdisciplinary recommendations for treating chordoma, chondrosarcoma, giant cell tumor of bone, Ewing sarcoma, and osteosarcoma. These NCCN Guidelines Insights summarize the NCCN Bone Cancer Panel's guideline recommendations for treating Ewing sarcoma. The data underlying these treatment recommendations are also discussed.

SK-UT-1 uterine leiomyosarcomas (Ut-LMS) cells were transduced with a fatty acid synthase (FASN)-containing retroviral vector to recapitulate the "lipogenic phenotype of cancer." Consistent with this model, forced expression of FASN enhanced SK-UT-1 proliferation, migration, and cellular motion. Further investigation showed FASN promotes trimethylation of H3K9 (H3K9me3) and acetylation of H3K27 (H3K27ac) in SK-UT-1 cells. In contrast, siRNA targeting of FASN in high endogenous FASN expressing SK-LMS-1 Ut-LMS cells inhibits trimethylation of H3K9 and acetylation of H3K27. Palmitate, the predominant fatty acid product of FASN, increased H3K9me3, H3K27ac and H3K27me3 detection in SK-UT-1 cells. FASN promoted histone 3 methylation and acetylation through alteration of histone 3-modifying enzymatic activities (HDAC, HDM, HMT and HAT). ChIP-seq in SK-UT-1-FASN cells with anti-H3K9me3 antibody identified regions of enriched binding compared to vector-only cells. One differentially-enriched gene, CRISP1, was investigated further by ChIP-PCR. The transcriptionally repressive function of H3K9me3 was confirmed in CRISP1. Our results provide mechanistic insight into the pathobiology of the "lipogenic phenotype of cancer." Here, FASN reprograms the Ut-LMS epigenome through chromatin remodeling to promote the "malignant phenotype."

11024 Background: Ewing sarcoma (ES) is the second most common bone cancer in children and young adults. The prognosis of recurrent or metastatic ES is poor, with a 5-year overall survival

11017 Background: Most GISTs are driven by mutations in KIT and PDGFRa and secondary mutations are felt to confer resistance to TKIs. In advanced/metastatic GIST, the benefit of second line TKIs and beyond is progressively less after imatinib failure. As such, novel non-TKI approaches are important to explore. Here we report interim analyses of safety and efficacy in advanced GIST patients treated with immunotherapy. Methods: Patients with advanced/metastatic GIST refractory to at least imatinib were enrolled on a randomized, parallel group, unblinded Phase 2 trial of either nivo (240 mg Q2wks) or nivo (240 mg Q2wks) with ipi (1mg/kg Q6wks) for up to 2 years. The primary endpoint was the objective response rate(ORR) of nivo alone or nivo + ipi by RECIST 1.1 criteria. Imaging was assessed by investigator and 3 independent radiologists. Patients were randomized 1:1 and were restaged every 8 weeks. With a sample size of 20 per group, an exact binomial test with a nominal 0.050 one-sided significance level will have 82% power to detect the difference between the null hypothesis response rate 1.5% and the alternative response rate of 15%. Secondary objectives are to ascertain the PFS, CBR, RR by Choi criteria and safety. Blood and biopsies are also being collected. Results: At cutoff, 29 patients (27 evaluable) with a median of 3 (1-7) lines of prior therapies have started on trial. In the nivo only arm, 7/15 pts had a best response of SD for a CBR of 46.7% with the median PFS being 8.57 wks. In the nivo + ipi arm, 1/12 patients had a PR and 2/12 have SD for a CBR of 25.0% (95% exact C.I. 5.5%-57.2%) with a median PFS of 9.1 wks. 8 patients have been on therapy for more than 6 months and two patients with a KIT Exon 17 mutation had radiographic disease shrinkage. Most AEs were grades 1-2 with fatigue (37%) being the most common. 4 Grade 3/4 AEs occurred in the nivo and ipi arm (hyperglycemia, weakness, diarrhea x 2) and 4 grade 3/4AEs occurred in the nivo arm (DKA, hyperglycemia, rash, fatigue). Pretreatment biopsies have been obtained in all patients and blood has been collected on all patients for correlative analysis. Conclusions: In a heavily pretreated GIST population, responses and disease control with both nivo and nivo + ipi were observed. To date, the drugs have been well tolerated and no new safety signals have been observed in this disease state. Clinical trial information: NCT02880020.

Background: NY-ESO-1c259T-cells recognizing an NY-ESO-1 derived peptide complexed with HLA-A*02 (SPEAR T-cells) are being studied in an ongoing multi-cohort clinical trial in synovial sarcoma (NCT01343043). We compared safety, efficacy and cell persistence between two cohorts using different doses of lymphodepleting chemotherapy. Methods: There are four cohorts separated by differing antigen expression levels and lymphodepletion regimens, and this assessment compares cohorts 1 (closed) and 4 (ongoing). In both, ≥50% patient tumor cells expressed NY-ESO-1 at 2+/3+ levels by immunohistochemistry. Following apheresis, T-cells are isolated, activated, transduced to express NY-ESO-1c259T and expanded. Lymphodepletion in cohort 1 consists of fludarabine 30 mg/m2/d × 4 d and cyclophosphamide 1800 mg/m2/d × 2d, and in cohort 4 consists of fludarabine 30 mg/m2/d × 3d and cyclophosphamide 600 mg/m2/d × 3d. Target dose is 1–6 × 109 transduced cells. Disease is assessed at weeks 4, 8 and 12 and every 3 months until disease progression. Results: 12 patients were treated in cohort 1 and 14 patients in cohort 4 (as of 23Nov17). Median transduced cell dose was 3.6 × 109 cells in cohort 1 and 2.6 × 109 cells in cohort 4. Treatment-related adverse events (AEs) were observed in 100% of patients in cohort 1 and 86% in cohort 4; related serious adverse events (SAEs) were reported in 50% of cohort 1 and 14% of cohort 4. There were no fatal AEs. Overall response rate (ORR) in cohort 4 is 29% vs 50% in cohort 1, and duration of response is in cohort 4 is 16 weeks vs 31 weeks in cohort 1. The best overall response of stable is 50% in cohort 1 and 64% in cohort 4. Median peak expansion of transduced T-cells in peripheral blood in responders is lower in cohort 4 (40,137 copies/μg DNA) vs cohort 1 (106,174 copies/μg DNA). Median absolute lymphocyte counts following lymphodepletion were 1×107/L (range 0-3) in cohort 1 and 9×107/L (0-40) in cohort 4. Conclusions: The greater ORR and higher peak expansion in cohort 1 may be attributable to the dose intensity of the lymphodepleting regimen. Although related SAEs were reported in a higher proportion in cohort 1 than 4, the safety and tolerability are acceptable in both, and cell doses were similar. The data and overall benefit:risk considerations support utilizing higher doses of preconditioning chemotherapy in future trials. Citation Format: Sandra P. D'Angelo, Dejka Araujo, Brian Van Tine, George Demetri, Mihaela Dutra, John Glod, Warren Chow, Stephen Grupp, Alibiruni Abdul Razak, William Tap, Breelyn Wilky, Erin Van Winkle, Elliott Norry, Samik Basu, Karen Chagin, Malini Iyengar, Trupti Trivedi, Rafael Amado, Crystal Mackall. Comparison of pretreatment conditioning on efficacy in two cohorts of a pilot study of genetically engineered NY-ESO-1c259T-cells in patients with synovial sarcoma [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A007.

Background: NY-ESO-1c259 is an affinity optimized TCR recognizing an NY-ESO-1-derived peptide complexed with HLA-A*02 (SPEAR T-cells). NY-ESO-1c259TCR therapy induced responses in ~50% of patients whose tumors express high level NY-ESO-1 (NCT01343043). Here we report on preclinical studies of TCR activity and results from a cohort of patients whose tumors express low NY-ESO-1 levels. Methods: T-cell response against tumor-derived cell lines with differential NY-ESO-1 expression levels was assessed by ELISA. Patients had selected HLA subtypes (HLA-A*02:01, 02:05, 02:06) and advanced NY-ESO-1+ SS. In this cohort, tumors express NY-ESO-1 at ≥ 1+ in > 1% but < 2+ or 3+ in ≥ 50% cells by immunohistochemistry (IHC). Following apheresis, T-cells are isolated, activated, transduced to express NY-ESO-1c259T and expanded. Lymphodepletion is with fludarabine 30 mg/m2/d × 4d and cyclophosphamide 1800 mg/m2/d × 2d. Target dose is 1–6 × 10e9 transduced cells. Disease is assessed at weeks 4, 8 and 12 and then every 3 months until disease progression. Results: NY-ESO-1c259T-cells produce IFNγ responses across a spectrum of NY-ESO-1 expressing tumor cell lines. A threshold for activation was observed at ~1×10e4 mRNA copies/10e6 reference gene transcripts. The IHC clinical trial assay was tested in FFPE tumor-derived cell lines, and staining was observed in cell lines expressing >1×10e4 mRNA copies/10e6 reference gene transcripts. Ten patients in this cohort have been treated (as of 23Nov17). One died due to disease progression 2 days post infusion. Four have had a partial response (ORR 40%), and median duration of response was 8.5 weeks (range, 8-13). Antigen expression level by IHC (% 1+, 2+, and/or 3+), best overall response (BOR) by RECIST v1.1, and transduced cell expansion (copies/microgram DNA) are listed below for the 9 evaluable patients: Pt 264, 30% 1+/2+, PR, 86320; Pt 313, 90% 1+, PR, 45430; Pt 325, 10% 2+, PR, 13365; Pt 331, 40% 1+, 10% 2+, 10% 3+, PR, 197546; Pt 324, 50% 1+, 10% 2+, SD, 133334; Pt 305, 5% 1+, 5% 2+, 5% 3+, SD, 74855; Pt 322, 50% 1+, 10% 2+, SD, 54569; Pt 323, 20% 1+, 10% 2+, SD, 50912; Pt 211, 10% 1+, 20% 2+, 20% 3+, PD, 22627. Conclusions: In vitro assays can assess mRNA levels and protein expression of target antigen required for T-cell activation and cytotoxicity, predicting expression levels required for anti-tumor activity in vivo. The patient data suggest that affinity optimized TCRs can be used to treat tumors with low target antigen expression. Citation Format: Dejka Araujo, Sandra D'Angelo, George Demetri, Mihaela Druta, John Glod, Warren Chow, William Tap, Joana Senra, Rachel Abbott, Erin Van Winkle, Karen Chagin, Miguel Maroto, Elliot Norry, Malini Iyengar, Trupti Trivedi, Andrew Gerry, Rafael Amado, Crystal Mackall. Autologous Tcells transduced with the affinity enhanced NY-ESO-1c259TCR in patients with synovial sarcoma expressing low levels of the NY-ESO-1 antigen [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A002.

Fibroblast growth factor (FGF) receptor (FGFR) substrate 2 (FRS2) is an adaptor protein that plays a critical role in FGFR signaling. FRS2 is located on chromosome 12q13-15 that is frequently amplified in liposarcomas. The significance of FRS2 and FGFR signaling in high-grade liposarcomas is unknown. Herein, we first comparatively examined the amplification and expression of FRS2 with CDK4 and MDM2 in dedifferentiated liposarcoma (DDLS) and undifferentiated high-grade pleomorphic sarcoma (UHGPS). Amplification and expression of the three genes were identified in 90% to 100% (9–11 of 11) of DDLS, whereas that of FRS2, CDK4, and MDM2 were observed in 55% (41 of 75), 48% (36 of 75), and 44% (33/75) of clinically diagnosed UHGPS, suggesting that these “UHGPS” may represent DDLS despite lacking histologic evidence of lipoblasts. Immunohistochemical analysis of phosphorylated FRS2 protein indicated that the FGFR/FRS2 signaling axis was generally activated in about 75% of FRS2-positive high-grade liposarcomas. Moreover, we found that FRS2 and FGFRs proteins are highly expressed and functional in three high-grade liposarcoma cell lines: FU-DDLS-1, LiSa-2, and SW872. Importantly, the FGFR selective inhibitor NVP-BGJ-398 significantly inhibited the growth of FU-DDLS-1 and LiSa-2 cells with a concomitant suppression of FGFR signal transduction. Attenuation of FRS2 protein in FU-DDLS-1 and LiSa-2 cell lines decreased the phosphorylated extracellular signal–regulated kinase 1/2 and AKT and repressed cell proliferation. These findings indicate that analysis of FRS2 in combination with CDK4 and MDM2 will more accurately characterize pathologic features of high-grade liposarcomas. Activated FGFR/FRS2 signaling may play a functional role in the development of high-grade liposarcomas, therefore, serve as a potential therapeutic target. Cancer Res; 73(4); 1298–307. ©2012 AACR.

Patients with advanced solid malignancies were enrolled to an open-label, single-arm, dose-escalation study, in which CRLX101 was administered intravenously over 60 min among two dosing schedules, initially weekly at 6, 12, and 18 mg/m(2) and later bi-weekly at 12, 15, and 18 mg/m(2). The maximum tolerated dose (MTD) was determined at 15 mg/m(2) bi-weekly, and an expansion phase 2a study was completed. Patient samples were obtained for pharmacokinetic (PK) and pharmacodynamic (PD) assessments. Response was evaluated per RECIST criteria v1.0 every 8 weeks. Sixty-two patients (31 male; median age 63 years, range 39-79) received treatment. Bi-weekly dosing was generally well tolerated with myelosuppression being the dose-limiting toxicity. Among all phase 1/2a patients receiving the MTD (n = 44), most common grade 3/4 adverse events were neutropenia and fatigue. Evidence of systemic plasma exposure to both the polymer-conjugated and unconjugated CPT was observed in all treated patients. Mean elimination unconjugated CPT Tmax values ranged from 17.7 to 24.5 h, and maximum plasma concentrations and areas under the curve were generally proportional to dose for both polymer-conjugated and unconjugated CPT. Best overall response was stable disease in 28 patients (64 %) treated at the MTD and 16 (73 %) of a subset of NSCLC patients. Median progression-free survival (PFS) for patients treated at the MTD was 3.7 months and for the subset of NSCLC patients was 4.4 months. These combined phase 1/2a data demonstrate encouraging safety, pharmacokinetic, and efficacy results. Multinational phase 2 clinical development of CRLX101 across multiple tumor types is ongoing.

Background: While aromatase inhibitors are effective for ER/PR positive breast cancer, resistance frequently develops. EXE is a steroidal AI and has a weak hormone-like activity. Long-term EXE treatment up-regulated amphiregulin-mediated EGFR activation and EXE resistance could result from ER-EGFR cross-talk. In cell culture and animal studies, acquired resistance to EXE was significantly delayed with intermittent use, associated with decreased production of amphiregulin. For first line therapy in MBC, EXE had a median progression free survival (PFS) of 10 mos. As second and third line therapies, PFS decreased to 4.7 mos and 2 mos, respectively. After ≥ 2 of prior endocrine therapy, PFS to EXE ranged between 3.4 mos to 3.7 mos. The rationale for this study was that after long-term estrogen deprivation clinically equivalent to long-term exposure to AI, estrogen may induce apoptosis. With intermittent EXE use, we hope to delay the acquired AI resistance. Methods: Aims were to: 1) assess the PFS and 2) compete response (CR), partial response (PR) and clinical benefit rate [CBR=CR +PR + Stable disease (SD)≥ 6 mos], assessment of toxicity, compliance with medication adherence, and quality of life with assessment of bone health. The study included: 1) ER/PR positive MBC in first, second line/third line hormonal therapy, and one prior chemotherapy for MBC with no prior EXE allowed. EXE was given 25 mg daily × 14 days then 7 days off treatment, each 21-day cycle, imaging was done after every three cycles. Correlatives with estradiol level were drawn at day 1 and day 15 in each cycle. Results: From June 2008 to 2012 we enrolled 33 MBC patients ER/PR positive MBC with a median age of 60 yrs (42–79). At this cut off data date, 2 were inevaluable due to incidental colon cancer and change in treatment choice. 17 patients received treatment as first line (52%), 10 as second or third line hormonal therapy (30%), and 6 who received chemotherapy for MBC (18%). Median PFS and (95% CI) was 6.2 mos (1.9–12.2), 4.2 mos (2.1–10.1), and 3.2 mos (2.1-NR), respectively. For first line patients, there were 3 PRs and 4 with SD>6 mos for a CBR of 7/14 (50%). For second/third line, there were 3 with SD>6 mos for a CBR of 3/9(33%), no response seen in the prior chemotherapy group. The major metastatic sites included bone, liver, lung. 4 patients were Her2+ (13%). Adverse effects including hot flashes (62%), insomnia (31%), nausea (24%), bone pain (17%), fatigue (41%), joint pain (31%) were observed. Median number of cycles delivered is 6 (2–24) for first line, 5.5 (1–15) for second/third line, and 5 (2–9) for prior chemotherapy. Correlatives and QOL assessments are ongoing. Conclusions: Compared to the standard continuous EXE, PFS and CBR is inferior in the intermittent EXE as first line therapy, as second and third line therapy, the median PFS was 4.2 comparable to reported 3.7 mos with the CBR was 33% to 31.5% observed in the EFFECT trial. Interestingly, hot-flash rate was much higher at 62% compared to 11.2% in the EFFECT trial. Arthralgia is comparable at 31%. Patients who already received chemotherapy do not appear to respond favorably to intermittent hormonal therapy. Full response data with correlatives regarding the estradiol levels will be presented. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-14-08.

HIV protease inhibitors are associated with HIV protease inhibitor-related lipodystrophy syndrome. We hypothesized that liposarcomas would be similarly susceptible to the apoptotic effects of an HIV protease inhibitor, nelfinavir.We conducted a phase I trial of nelfinavir for liposarcomas. There was no limit to prior chemotherapy. The starting dose was 1,250 mg twice daily (Level 1). Doses were escalated in cohorts of three to a maximally evaluated dose of 4,250 mg (Level 5). One cycle was 28 days. Steady-state pharmacokinetics (PKs) for nelfinavir and its primary active metabolite, M8, were determined at Levels 4 (3,000 mg) and 5.Twenty subjects (13 males) were enrolled. Median (range) age was 64 years (37-81). One subject at Level 1 experienced reversible, grade 3 pancreatitis after 1 week and was replaced. No other dose-limiting toxicities were observed. Median (range) number of cycles was 3 (0.6-13.5). Overall best responses observed were 1 partial response, 1 minor response, 4 stable disease, and 13 progressive disease. Mean peak plasma levels and AUCs for nelfinavir were higher at Level 4 (7.3 mg/L; 60.9 mg/L × h) than 5 (6.3 mg/L; 37.7 mg/L × h). The mean ratio of M8:nelfinavir AUCs for both levels was ~1:3.PKs demonstrate auto-induction of nelfinavir clearance at the doses studied, although the mechanism remains unclear. Peak plasma concentrations were within range where anticancer activity was demonstrated in vitro. M8 metabolite is present at ~1/3 the level of nelfinavir and may also contribute to the anticancer activity observed.

Nelfinavir induces apoptosis in liposarcoma by inhibiting site-2 protease (S2P) activity, which leads to suppression of regulated intramembrane proteolysis. We postulate similar effects in castration-resistant prostate cancer because it exhibits a lipogenic phenotype. Nelfinavir inhibited androgen receptor activation in androgen-sensitive prostate cancer and the nuclear translocation of the fusion proteins sterol regulatory element binding protein-1 (SREBP-1)-enhanced green fluorescence protein (EGFP) and activating transcription factor 6 (ATF6)-EGFP in castration-resistant prostate cancer cells, viewed under confocal microscopy. Nelfinavir and site-1 protease (S1P) and S2P small interfering RNAs (siRNAs) reduced the proliferation of castration-resistant prostate cancer and induced apoptosis, which was opposed by autophagy. Inhibition of autophagy with hydroxychloroquine was additive to the apoptotic effect of nelfinavir. Western blotting of S1P and S2P siRNA knockdown and/or nelfinavir-treated cells confirmed the accumulation of precursor SREBP-1 and ATF6. 3,4-Dichloroisocoumarin, an S1P inhibitor, did not affect SREBP-1 processing. In contrast, 1,10-phenanthroline, an S2P inhibitor, reproduced the nelfinavir-treated molecular and biological phenotype. Nelfinavir-mediated inhibition of regulated intramembrane proteolysis led to the accumulation of unprocessed SREBP-1 and ATF6. This resulted in sequential endoplasmic reticulum stress, inhibition of the unfolded protein response, reduced fatty acid synthase expression and apoptosis, which was countered by autophagy. Inhibition of autophagy was at least additive to this pro-apoptotic effect. These findings provide new insights into nelfinavir-induced endoplasmic reticulum stress and cancer cell death, and lead us to propose investigating its clinical activity in castration-resistant prostate cancer. This report validates S2P as a therapeutic target in castration-resistant prostate cancer.

The primary objective was to determine the maximum tolerated doses (MTDs) of the combination of bortezomib and temozolomide in patients with solid tumors. The secondary objective was to evaluate the pharmacokinetics (PK) of bortezomib with and without concurrent hepatic enzyme-inducing anticonvulsants (HEIAs).Bortezomib was administered on days 2, 5, 9, and 12; temozolomide on days 1-5 of a 28-day cycle. Dose escalation proceeded using a standard 3+3 design. Patients with primary or metastatic brain tumors were eligible and were stratified based on whether they were taking HEIAs or not.Of the 25 patients enrolled, 22 were not taking HEIAs. MTDs were only given to patients not receiving HEIAs. Dose-limiting toxicities (DLTs) consisted of grade-3 constipation, hyponatremia, fatigue, elevated hepatic enzymes, and grade-4 neutropenia, thrombocytopenia, constipation, and abdominal pain. Stable disease (8 weeks) was observed in 5 patients. Bortezomib systemic clearance (CL(sys)) on day 9 was 51% of the CL(sys) on day 2 (P 0.01) Similarly, the normalized area under the concentration-time curve (norm AUC) on day 9 was 1.9 times the norm AUC on day 2 (P 0.01). The median bortezomib CL(sys) on days 2 and 9 was significantly higher (P 0.04) in patients taking HEIAs, and the median norm AUC was correspondingly lower (P 0.04).The MTDs for the combination of bortezomib and temozolomide in patients not taking HEIAs are 1.3 and 200 mg/m(2), respectively. The rate of bortezomib elimination in patients taking HEIAs was increased twofold. Additional trials are needed to better define the optimal dosing in such patients.

Background The California Cancer Consortium has performed a Phase II trial of infusional bryostatin, a protein kinase C inhibitor isolated from the marine invertebrate bryozoan, Bugula Neritina, a member of the phylum Ectoprocta, in combination with cisplatin, in patients (pts) with recurrent platinum-sensitive or resistant ovarian cancer (OC). Methods Pts received bryostatin 45 mcg/m2 as a 72 h continuous infusion followed by cisplatin 50 mg/m2. Cycles were repeated every 3 weeks. Dosages were chosen based on phase I data obtained by the CCC in a population of pts with mixed tumor types. Results Eight pts with recurrent or persistent epithelial OC received 23 cycles of treatment. All pts had received previous platinum-based chemotherapy; two pts had received one prior course, five had received two prior courses, and one had received three prior courses of chemotherapy. The median age was 64 (range 32–72), and Karnofsky performance status 90 (range 80–100). A median of 3 cycles of chemotherapy were delivered (range: 1–5). The median progression-free and overall survivals were 3 and 8.2 months respectively. Best responses included two partial responses (one in a platinum-resistant pt), three pts with stable disease, and three progressions. All pts experienced Grade 3 or 4 toxicities including severe myalgias/pain/fatigue/asthenia in six pts, and severe nausea/vomiting/constipation in two other pts. One pt experienced a seizure and liver function tests were elevated in one other. Conclusions A modest response rate is observed in pts with recurrent or persistent ovarian cancer treated with the combination of bryostatin and cisplatin. The toxicity profile, however, observed in this pt population (primarily severe myalgias), precludes tolerability and prevents this combination from further investigation at this dose and schedule. It is possible that platinum pre-exposure in OC patients exacerbates observed toxicity. Phase II dosages of investigational agents in OC pts that are determined by phase I trials in pts with other tumor types should be chosen cautiously.

11505Background: Pazopanib, a multi-targeted tyrosine kinase inhibitor, has shown activity in various soft tissue sarcomas. Activity in liposarcoma, however, is limited. Regorafenib is a multi-kina...