Afamitresgene autoleucel for advanced synovial sarcoma and myxoid round cell liposarcoma (SPEARHEAD-1): an international, open-label, phase 2 trial.

BACKGROUND: Afamitresgene autoleucel (afami-cel) showed acceptable safety and promising efficacy in a phase 1 trial (NCT03132922). The aim of this study was to further evaluate the efficacy of afami-cel for the treatment of patients with HLA-A*02 and MAGE-A4-expressing advanced synovial sarcoma or myxoid round cell liposarcoma. METHODS: SPEARHEAD-1 was an open-label, non-randomised, phase 2 trial done across 23 sites in Canada, the USA, and Europe. The trial included three cohorts, of which the main investigational cohort (cohort 1) is reported here. Cohort 1 included patients with HLA-A*02, aged 16-75 years, with metastatic or unresectable synovial sarcoma or myxoid round cell liposarcoma (confirmed by cytogenetics) expressing MAGE-A4, and who had received at least one previous line of anthracycline-containing or ifosfamide-containing chemotherapy. Patients received a single intravenous dose of afami-cel (transduced dose range 1·0 × 109-10·0 × 109 T cells) after lymphodepletion. The primary endpoint was overall response rate in cohort 1, assessed by a masked independent review committee using Response Evaluation Criteria in Solid Tumours (version 1.1) in the modified intention-to-treat population (all patients who received afami-cel). Adverse events, including those of special interest (cytokine release syndrome, prolonged cytopenia, and neurotoxicity), were monitored and are reported for the modified intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT04044768; recruitment is closed and follow-up is ongoing for cohorts 1 and 2, and recruitment is open for cohort 3. FINDINGS: Between Dec 17, 2019, and July 27, 2021, 52 patients with cytogenetically confirmed synovial sarcoma (n=44) and myxoid round cell liposarcoma (n=8) were enrolled and received afami-cel in cohort 1. Patients were heavily pre-treated (median three [IQR two to four] previous lines of systemic therapy). Median follow-up time was 32·6 months (IQR 29·4-36·1). Overall response rate was 37% (19 of 52; 95% CI 24-51) overall, 39% (17 of 44; 24-55) for patients with synovial sarcoma, and 25% (two of eight; 3-65) for patients with myxoid round cell liposarcoma. Cytokine release syndrome occurred in 37 (71%) of 52 of patients (one grade 3 event). Cytopenias were the most common grade 3 or worse adverse events (lymphopenia in 50 [96%], neutropenia 44 [85%], leukopenia 42 [81%] of 52 patients). No treatment-related deaths occurred. INTERPRETATION: Afami-cel treatment resulted in durable responses in heavily pre-treated patients with HLA-A*02 and MAGE-A4-expressing synovial sarcoma. This study shows that T-cell receptor therapy can be used to effectively target solid tumours and provides rationale to expand this approach to other solid malignancies. FUNDING: Adaptimmune.

A Single Arm Phase 2 Trial of Trametinib in Patients With Locally Advanced or Metastatic Epithelioid Hemangioendothelioma.

PURPOSE: Epithelioid hemangioendothelioma (EHE) is a rare vascular cancer with pathogenic TAZ-CAMTA1 operating as an oncogenic driver through activation of MAPK pathway. Trametinib is an inhibitor of MEK, a critical kinase in the MAPK pathway. We sought to evaluate the effect of trametinib in patients with EHE. PATIENTS AND METHODS: A phase 2 trial of trametinib was conducted in patients with locally advanced or metastatic EHE. Eligibility requirements included evidence of tumor progression or presence of EHE-related pain requiring opiates for management prior to enrollment. The primary endpoint was objective response rate (ORR) per RECIST1.1 in cases with TAZ-CAMTA1 confirmed by fusion-FISH. Secondary objectives were to estimate ORR for all patients, median PFS, 2-year OS rate, patient safety, and change in patient-reported global health and pain scores per PROMIS questionnaires. RESULTS: 44 patients enrolled and 42 started trametinib. TAZ-CAMTA1 was detected in 27 tumor samples. The ORR was 3.7% (95% CI: 0.094, 19.0), median PFS was 10.4 months (95% CI: 7.1, NA), and 2-year OS rate was 33.3% (95% CI: 19.1, 58.2) in the target population. Median pain intensity and interference scores improved significantly after 4 weeks of trametinib in patients using opiates. Common AEs related to trametinib were rash, fatigue, nausea/vomiting, diarrhea/constipation, alopecia and edema; one Grade 5 ARDS/pneumonitis was related to trametinib. CONCLUSIONS: Trametinib was associated with reduction in EHE-related pain and median PFS of more than 6 months providing palliative benefit in patients with advanced EHE, but the trial did not meet the ORR goal.

Outcome of Patients With Malignant Peripheral Nerve Sheath Tumors Enrolled on Sarcoma Alliance for Research Through Collaboration (SARC) Phase II Trials.

BACKGROUND: Evaluation of prior phase II trials for malignant peripheral nerve sheath tumors (MPNST) may help develop more suitable trial endpoints in future studies. METHODS: We analyzed outcomes of patients with recurrent or unresectable/metastatic MPNST enrolled on prior Sarcoma Alliance for Research through Collaboration (SARC) phase II trials and estimated the progression-free survival (PFS). PFS from SARC006 (NCT00304083), the phase II trial of upfront chemotherapy in chemotherapy naïve patients, was analyzed separately. Impact of baseline enrollment characteristics on PFS was evaluated. RESULTS: Sixty-four patients (29 male, 35 female, median age 39 years (range 15-81)) with MPNST were enrolled on 1 of 5 trials of single agent or combination therapy that were determined to be inactive. Patients had received a median of 1 (range 0-5) prior systemic therapy, and most had undergone prior surgery (77%) and radiation (61%). Seventy-three percent had metastatic disease at enrollment. Median PFS was 1.77 months (95% CI, 1.61-3.45), and the PFS rate at 4 months was 15%. Greater number of prior systemic therapies and worse performance status were associated with inferior PFS. There was no significant difference in PFS based on age at enrollment, treatment trial, response criteria, presence of metastatic disease, disease site at enrollment, and prior surgery or radiation. In comparison, on the SARC006 trial the PFS rate at 4 months was 94% in 40 patients. CONCLUSION: These data provide a historical baseline PFS that may be used as a comparator in future clinical trials for patients with MPNST.

OER-073: A multicenter phase 2 study evaluating the role of pazopanib in angiosarcoma.

BACKGROUND: Angiosarcomas are rare mesenchymal sarcomas that can present as primary cutaneous or noncutaneous disease. They express a variety of vascular endothelial growth factor receptors. The authors hypothesized that the treatment of angiosarcoma with pazopanib, a multikinase inhibitor with activity against vascular endothelial growth factor receptors, would result in disease response and prolonged disease stabilization. METHODS: This was an open-label, phase 2 trial of pazopanib in patients who had incurable angiosarcoma. The co-primary end points were response according to the Response Evaluation Criteria in Solid Tumors and progression-free survival (PFS) at 3 months. The starting dose of pazopanib was 800 mg daily. RESULTS: Twenty-nine patients were accrued between 2011 and 2018, and 22 patients were evaluable for response. Toxicities were similar to those identified in prior reports. There was one partial response (3%), and the clinical benefit rate (including complete responses, partial responses, and stable disease) was 48%, which was observed more frequently in patients who had cutaneous disease. The median PFS was 14.4 weeks, and the 3-month PFS rate determined by Kaplan-Meier estimate was 54.6% (95% CI, 36.0%-82.9%), meeting the primary study objective. The Kaplan-Meier overall survival estimate was 16.1 months. CONCLUSIONS: Pazopanib therapy in patients who had incurable angiosarcoma was associated with meaningful disease control, especially in those who had cutaneous disease with limited objective responses. LAY SUMMARY: Angiosarcoma is a rare cancer that can be found on the skin or in internal organs. This study tested pazopanib, an oral targeted medication, to determine its benefit in patients with angiosarcoma who could not undergo the removal of their tumors by surgery. Pazopanib treatment was safe, and no new side effects were reported. The study showed that pazopanib controlled tumor growth in one half of patients at 3 months and was more common in angiosarcomas of the skin; it led to tumor shrinkage in a minority of patients (1 of 29).

Giant Cell Tumor of Bone: Effect of Longer Dosing Intervals of Denosumab on Tumor Control and Bone-related Complications.

BACKGROUND: Denosumab is an effective treatment for giant cell tumor of the bone (GCTB) but can cause clinically significant adverse effects. Current approved dosing is every 4 weeks after 3 weekly loading doses. We assessed whether alternative, longer dosing intervals are associated with differences in efficacy or bone toxicity. METHODS: Single institution retrospective chart review was conducted on patients with GCTB over 18 years old who received at least 1 year of standard denosumab dosing. Patients identified using a free-text search engine with keywords "giant cell tumor" and "denosumab" from January 1998 to August 2020. RESULTS: Approximately 37 patients with GCTB (19F, 18M) were identified with median age of 37 years (range 22-73). Dosing interval was increased in 38% (n = 14), with the most common final dosing interval 12 weeks (n = 8). Six patients (16%) had bone complications: osteonecrosis of the jaw (n =5), atypical fracture (n = 1), and nonhealing dental wounds (n = 2). All patients with bone complications were on the monthly dosing schedule, but there was no statistically significant difference compared to longer dosing intervals (P = .22). No statistically significant difference in median PFS was noted (P = .97). However, 5-year PFS was superior in patients treated with less frequent versus standard dosing of denosumab (P = .036). CONCLUSIONS: Increasing the interval of denosumab dosing for GCTB provided similar tumor control compared to standard dosing and lower absolute number of bone toxicity events. Larger studies are needed to better define the optimal interval of denosumab administration and the effect on efficacy, toxicity, and associated healthcare expense.

Selinexor in Advanced, Metastatic Dedifferentiated Liposarcoma: A Multinational, Randomized, Double-Blind, Placebo-Controlled Trial.

PURPOSE: Antitumor activity in preclinical models and a phase I study of patients with dedifferentiated liposarcoma (DD-LPS) was observed with selinexor. We evaluated the clinical benefit of selinexor in patients with previously treated DD-LPS whose sarcoma progressed on approved agents. METHODS: SEAL was a phase II-III, multicenter, randomized, double-blind, placebo-controlled study. Patients age 12 years or older with advanced DD-LPS who had received two-five lines of therapy were randomly assigned (2:1) to selinexor (60 mg) or placebo twice weekly in 6-week cycles (crossover permitted). The primary end point was progression-free survival (PFS). Patients who received at least one dose of study treatment were included for safety analysis (ClinicalTrials.gov identifier: NCT02606461). RESULTS: Two hundred eighty-five patients were enrolled (selinexor, n = 188; placebo, n = 97). PFS was significantly longer with selinexor versus placebo: hazard ratio (HR) 0.70 (95% CI, 0.52 to 0.95; one-sided P = .011; medians 2.8 v 2.1 months), as was time to next treatment: HR 0.50 (95% CI, 0.37 to 0.66; one-sided P < .0001; medians 5.8 v 3.2 months). With crossover, no difference was observed in overall survival. The most common treatment-emergent adverse events of any grade versus grade 3 or 4 with selinexor were nausea (151 [80.7%] v 11 [5.9]), decreased appetite (113 [60.4%] v 14 [7.5%]), and fatigue (96 [51.3%] v 12 [6.4%]). Four (2.1%) and three (3.1%) patients died in the selinexor and placebo arms, respectively. Exploratory RNA sequencing analysis identified that the absence of CALB1 expression was associated with longer PFS with selinexor compared with placebo (median 6.9 v 2.2 months; HR, 0.19; P = .001). CONCLUSION: Patients with advanced, refractory DD-LPS showed improved PFS and time to next treatment with selinexor compared with placebo. Supportive care and dose reductions mitigated side effects of selinexor. Prospective validation of CALB1 expression as a predictive biomarker for selinexor in DD-LPS is warranted.

A Multicenter Phase II Trial of Ipilimumab and Nivolumab in Unresectable or Metastatic Metaplastic Breast Cancer: Cohort 36 of Dual Anti-CTLA-4 and Anti-PD-1 Blockade in Rare Tumors (DART, SWOG S1609).

PURPOSE: Metaplastic breast cancer (MpBC) is a rare aggressive subtype that responds poorly to cytotoxics. Median survival is approximately 8 months for metastatic disease. We report results for advanced MpBC treated with ipilimumab + nivolumab, a cohort of S1609 for rare cancers (DART: NCT02834013). PATIENTS AND METHODS: Prospective, open-label, multicenter phase II (two-stage) trial of ipilimumab (1 mg/kg i.v. every 6 weeks) plus nivolumab (240 mg i.v. every 2 weeks) for advanced MpBC. Primary endpoint was objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity. RESULTS: Overall, 17 evaluable patients enrolled. Median age was 60 years (26-85); median number of prior therapy lines was 2 (0-5). ORR was 18%; 3 of 17 patients achieved objective responses (1 complete, 2 partial responses; 2 spindle cell, 1 chondromyxoid histology), which are ongoing at 28+, 33+, and 34+ months, respectively. Median PFS and OS were 2 and 12 months, respectively. Altogether, 11 patients (65%) experienced adverse events (AE), including one grade 5 AE. Eight patients (47%) developed an immune-related AE (irAE), with adrenal insufficiency observed in all 3 responders. Responses occurred in tumors with low tumor mutational burden, low PD-L1, and absent tumor-infiltrating lymphocytes. CONCLUSIONS: The ipilimumab and nivolumab combination showed no new safety signals and met its primary endpoint with 18% ORR in advanced, chemotherapy-refractory MpBC. All responses are ongoing at >2 to almost 3 years later. The effect of ipilimumab and nivolumab was associated with exceptional responses in a subset of patients versus no activity. This combination warrants further investigation in MpBC, with special attention to understanding mechanism of action, and carefully designed to weigh against the significant risks of irAEs.

Cardiac safety of trabectedin monotherapy or in combination with pegylated liposomal doxorubicin in patients with sarcomas and ovarian cancer.

BACKGROUND: As with other alkylating agents, cardiac dysfunction can occur with trabectedin therapy for advanced soft tissue sarcomas (STS) or recurrent ovarian cancer (ROC) where treatment options for advanced disease are still limited. Cardiac safety for trabectedin monotherapy (T) for STS or in combination with pegylated liposomal doxorubicin (T+PLD) for ROC was evaluated in this retrospective postmarketing regulatory commitment. METHODS: Patient data for multiple cardiac-related treatment-emergent adverse events (cTEAEs) were evaluated in pooled analyses of ten phase 2 trials, one phase 3 trial in STS (n = 982), and two phase 3 trials in ROC (n = 1231). RESULTS: Multivariate analyses on pooled trabectedin data revealed that cardiovascular medical history (risk ratio [RR (95% CI)]: 1.90 [1.24-2.91]; p = 0.003) and age ≥65 years (RR [95% CI]: 1.78 [1.12-2.83]; p = 0.014) were associated with increased risk for cTEAEs. Multivariate analyses showed increased risk of experiencing cTEAEs with T+PLD compared to PLD monotherapy (RR [95% CI]: 2.70 [1.75-4.17]; p < 0.0001) and with history of prior cardiac medication (RR [95% CI]: 1.88 [1.16-3.05]; p = 0.010). CONCLUSIONS: For patients with STS or ROC who still have limited treatment options, trabectedin may be initiated after carefully considering benefit versus risk. Trial Registration (ClinicalTrials.gov): NCT01343277; NCT00113607; NCT01846611.

Health-related quality of life and pain with selinexor in patients with advanced dedifferentiated liposarcoma.

Objective: Compare health-related quality of life (HRQoL) of selinexor versus placebo in patients with dedifferentiated liposarcoma. Materials & methods: HRQoL was assessed at baseline and day 1 of each cycle using the European Organization for Research and Treatment of Cancer 30-item core quality of life questionnaire. Results were reported from baseline to day 169 (where exposure to treatment was maximized while maintaining adequate sample size). Results: Pain scores worsened for placebo versus selinexor across all postbaseline visits, although differences in HRQoL at some visits were not significant. Other domains did not exhibit significant differences between arms; however, scores in both arms deteriorated over time. Conclusion: Patients treated with selinexor reported lower rates and slower worsening of pain compared with patients who received placebo.

Lay abstract The goal of this study was to compare the health-related quality of life (HRQoL) of patients with advanced unresectable dedifferentiated liposarcoma treated with selinexor compared with those treated with placebo. HRQoL was measured prior to treatment initiation and at the first day of each cycle of their treatment using the European Organization for Research and Treatment of Cancer 30-item core quality of life questionnaire. Pain scores worsened for placebo compared with selinexor across all visits after treatment, but differences at some visits were not significant. Other domains did not exhibit significant differences between arms; however, scores in both arms worsened over time reflecting the progressive disease burden in this patient population. As pain is one of the most devastating symptoms associated with advanced and progressing cancers, the significant reduction in pain in the selinexor arm, according to patient perception, represent a relevant added value of this drug in dedifferentiated liposarcoma.

Unmet Medical Needs and Future Perspectives for Leiomyosarcoma Patients-A Position Paper from the National LeioMyoSarcoma Foundation (NLMSF) and Sarcoma Patients EuroNet (SPAEN).

As leiomyosarcoma patients are challenged by the development of metastatic disease, effective systemic therapies are the cornerstone of outcome. However, the overall activity of the currently available conventional systemic treatments and the prognosis of patients with advanced or metastatic disease are still poor, making the treatment of this patient group challenging. Therefore, in a joint effort together with patient networks and organizations, namely Sarcoma Patients EuroNet (SPAEN), the international network of sarcoma patients organizations, and the National LeioMyoSarcoma Foundation (NLMSF) in the United States, we aim to summarize state-of-the-art treatments for leiomyosarcoma patients in order to identify knowledge gaps and current unmet needs, thereby guiding the community to design innovative clinical trials and basic research and close these research gaps. This position paper arose from a leiomyosarcoma research meeting in October 2020 hosted by the NLMSF and SPAEN.

Assessment of Clinical Benefit of Integrative Genomic Profiling in Advanced Solid Tumors.

IMPORTANCE: Use of next-generation sequencing (NGS) to identify clinically actionable genomic targets has been incorporated into routine clinical practice in the management of advanced solid tumors; however, the clinical utility of this testing remains uncertain. OBJECTIVE: To determine which patients derived the greatest degree of clinical benefit from NGS profiling. DESIGN, SETTING, AND PARTICIPANTS: Patients in this cohort study underwent fresh tumor biopsy and blood sample collection for genomic profiling of paired tumor and normal DNA (whole-exome or targeted-exome capture with analysis of 1700 genes) and tumor transcriptome (RNA) sequencing. Somatic and germline genomic alterations were annotated and classified according to degree of clinical actionability. Results were returned to treating oncologists. Data were collected from May 1, 2011, to February 28, 2018, and analyzed from May 1, 2011, to April 30, 2020. MAIN OUTCOMES AND MEASURES: Patients' subsequent therapy and treatment response were extracted from the medical record to determine clinical benefit rate from NGS-directed therapy at 6 months and exceptional responses lasting 12 months or longer. RESULTS: During the study period, NGS was attempted on tumors from 1138 patients and was successful in 1015 (89.2%) (MET1000 cohort) (538 men [53.0%]; mean [SD] age, 57.7 [13.3] years). Potentially clinically actionable genomic alterations were discovered in 817 patients (80.5%). Of these, 132 patients (16.2%) received sequencing-directed therapy, and 49 had clinical benefit (37.1%). Exceptional responses were observed in 26 patients (19.7% of treated patients). Pathogenic germline variants (PGVs) were identified in 160 patients (15.8% of cohort), including 49 PGVs (4.8% of cohort) with therapeutic relevance. For 55 patients with carcinoma of unknown primary origin, NGS identified the primary site in 28 (50.9%), and sequencing-directed therapy in 13 patients resulted in clinical benefit in 7 instances (53.8%), including 5 exceptional responses. CONCLUSIONS AND RELEVANCE: The high rate of therapeutically relevant PGVs identified across diverse cancer types supports a recommendation for directed germline testing in all patients with advanced cancer. The high frequency of therapeutically relevant somatic and germline findings in patients with carcinoma of unknown primary origin and other rare cancers supports the use of comprehensive NGS profiling as a component of standard of care for these disease entities.

A randomized, open-label, phase 2, multicenter trial of gemcitabine with pazopanib or gemcitabine with docetaxel in patients with advanced soft-tissue sarcoma.

BACKGROUND: Therapeutic options for patients with advanced soft-tissue sarcoma (STS) are limited. The goal of the current phase 2 study was to examine the clinical activity and safety of the combination of gemcitabine plus pazopanib, a multityrosine kinase inhibitor with activity in STS. METHODS: The current randomized, phase 2 trial enrolled patients with advanced nonadipocytic STS who had received prior anthracycline-based therapy. Patients were assigned 1:1 to receive gemcitabine at a dose of 1000 mg/m2 on days 1 and 8 with pazopanib at a dose of 800 mg daily (G+P) or gemcitabine at a dose of 900 mg/m2 on days 1 and 8 and docetaxel at a dose of 100 mg/m2 on day 8 (G+T) every 3 weeks. Crossover was allowed at the time of disease progression. The study used a noncomparative statistical design based on the precision of 95% confidence intervals for reporting the primary endpoints of median progression-free survival (PFS) and rate of grade ≥3 adverse events (AEs) for these 2 regimens based on the intent-to-treat patient population (AEs were graded using version 4.0 of the National Cancer Institute Common Terminology Criteria for Adverse Events). RESULTS: A total of 90 patients were enrolled: 45 patients on each treatment arm. The median PFS was 4.1 months for each arm (P = .3, log-rank test). The best overall response of stable disease or better (complete response + partial response + stable disease) was the same for both treatment arms (64% for both the G+T and G+P arms). The rate of related grade ≥3 AEs was 82% for the G+T arm and 78% for the G+P arm. Related grade ≥3 AEs occurring in ≥10% of patients in the G+T and G+P arms were anemia (36% and 20%, respectively), fatigue (29% and 13%, respectively), thrombocytopenia (53% and 49%, respectively), neutropenia (20% and 49%, respectively), lymphopenia (13% and 11%, respectively), and hypertension (2% and 20%, respectively). CONCLUSIONS: The data from the current study have demonstrated the safety and efficacy of G+P as an alternative to G+T for patients with nonadipocytic STS.

Results of a Randomized, Double-Blinded, Placebo-Controlled, Phase 2.5 Study of Saracatinib (AZD0530), in Patients with Recurrent Osteosarcoma Localized to the Lung.

PURPOSE: Osteosarcoma is a rare cancer and a third of patients who have completed primary treatment will develop osteosarcoma recurrence. The Src pathway has been implicated in the metastatic behavior of osteosarcoma; about 95% of samples examined express Src or have evidence of downstream activation of this pathway. Saracatinib (AZD0530) is a potent and selective Src kinase inhibitor that was evaluated in adults in Phase 1 studies. The primary goal of this study was to determine if treatment with saracatinib could increase progression-free survival (PFS) for patients who have undergone complete resection of osteosarcoma lung metastases in a double-blinded, placebo-controlled trial. Patients and Methods. Subjects with recurrent osteosarcoma localized to lung and who had complete surgical removal of all lung nodules were randomized within six weeks after complete surgical resection. Saracatinib, or placebo, was administered at a dose of 175 mg orally, once daily, for up to thirteen 28-day cycles. RESULTS: Thirty-seven subjects were included in the analyses; 18 subjects were randomized to receive saracatinib and 19 to receive placebo. Intent-to-treat analysis demonstrated a median PFS of 19.4 months in the saracatinib treatment group and 8.6 months in the placebo treatment group (p=0.47). Median OS was not reached in either arm. CONCLUSIONS: Although saracatinib was well tolerated in this patient population, there was no apparent impact of the drug in this double-blinded, placebo-controlled trial on OS, and Src inhibition alone may not be sufficient to suppress metastatic progression in osteosarcoma. There is a suggestion of potential clinical benefit as evidenced by longer PFS in patients randomized to saracatinib based on limited numbers of patients treated.

Correlative Analyses of the SARC028 Trial Reveal an Association Between Sarcoma-Associated Immune Infiltrate and Response to Pembrolizumab.

PURPOSE: We recently reported a 17.5% objective RECIST 1.1 response rate in a phase II study of pembrolizumab in patients with advanced sarcoma (SARC028). The majority of responses occurred in undifferentiated pleomorphic sarcoma (UPS) and dedifferentiated liposarcoma (DDLPS). We sought to determine whether we can identify immune features that correlate with clinical outcomes from tumor tissues obtained pre- and on-treatment. PATIENTS AND METHODS: Pretreatment (n = 78) and 8-week on-treatment (n = 68) tumor biopsies were stained for PD-L1 and multiplex immunofluorescence panels. The density of positive cells was quantified to determine associations with anti-PD-1 response. RESULTS: Patients that responded to pembrolizumab were more likely to have higher densities of activated T cells (CD8+ CD3+ PD-1+) and increased percentage of tumor-associated macrophages (TAM) expressing PD-L1 pre-treatment compared with non-responders. Pre-treatment tumors from responders also exhibited higher densities of effector memory cytotoxic T cells and regulatory T cells compared with non-responders. In addition, higher density of cytotoxic tumor-infiltrating T cells at baseline correlated with a better progression-free survival (PFS). CONCLUSIONS: We show that quantitative assessments of CD8+ CD3+ PD-1+ T cells, percentage of TAMs expressing PD-L1, and other T-cell densities correlate with sarcoma response to pembrolizumab and improved PFS. Our findings support that multiple cell types present at the start of treatment may enhance tumor regression following anti-PD-1 therapy in specific advanced sarcomas. Efforts to confirm the activity of pembrolizumab in an expansion cohort of patients with UPS/DDLPS are underway.

Linsitinib (OSI-906) for the Treatment of Adult and Pediatric Wild-Type Gastrointestinal Stromal Tumors, a SARC Phase II Study.

PURPOSE: Most gastrointestinal stromal tumors (GIST) have activating mutations of KIT, PDGFRA, or uncommonly BRAF. Fifteen percent of adult and 85% of pediatric GISTs are wild type (WT), commonly having high expression of IGF-1R and loss of succinate dehydrogenase (SDH) complex function. We tested the efficacy of linsitinib, an oral TKI IGF-1R inhibitor, in patients with WT GIST. PATIENTS AND METHODS: A multicenter phase II trial of linsitinib was conducted. The primary endpoint was objective response rate. Secondary endpoints were clinical benefit rate: complete response, partial response, and stable disease (SD) ≥ 9 months, and quantitative 2[18F]fluoro-2-deoxy-D-glucose (FDG) metabolic response (MR) at week 8. Serum levels for glucose, insulin, IGF-1R ligand IGF1, and binding proteins were obtained to explore correlations to patient outcomes and FDG-PET results. RESULTS: Twenty patients were accrued in a 6-month period. Grade 3-4 toxicities possibly related to linsitinib were uncommon (8.5%). No objective responses were seen. Clinical benefit rate (CBR) at 9 months was 40%. Intense FDG uptake was observed at baseline, with partial MR of 12% and stable metabolic disease of 65% at week 8; these patients had RECIST 1.1 SD as their best response. Progression-free survival (PFS) and overall survival Kaplan-Meier estimates at 9 months were 52% and 80%, respectively. SDHA/B loss determined by IHC was seen in 35% and 88% of cases, respectively. CONCLUSIONS: Linsitinib is well tolerated in patients with WT GIST. Although the 9-month CBR was 40%, and PFS at 9 months was 52%, no objective responses were observed. Rapid accrual to this study demonstrates that clinical trials of experimental agents in selected subtypes of GIST are feasible.

Denosumab in patients with giant-cell tumour of bone: a multicentre, open-label, phase 2 study.

BACKGROUND: Giant-cell tumour of bone (GCTB) is a rare, locally aggressive osteoclastogenic stromal tumour of the bone. This phase 2 study aimed to assess the safety and activity of denosumab in patients with surgically salvageable or unsalvageable GCTB. METHODS: In this multicentre, open-label, phase 2 study done at 30 sites in 12 countries we enrolled adults and skeletally mature adolescents (aged ≥12 years) weighing at least 45 kg with histologically confirmed and radiographically measurable GCTB, Karnofsky performance status 50% or higher (Eastern Cooperative Oncology Group status 0, 1, or 2), and measurable active disease within 1 year of study enrolment. Patients had surgically unsalvageable GCTB (cohort 1), had surgically salvageable GCTB with planned surgery expected to result in severe morbidity (cohort 2), or were enrolled from a previous study of denosumab for GCTB (cohort 3). Patients received 120 mg subcutaneous denosumab once every 4 weeks during the treatment phase, with loading doses (120 mg subcutaneously) administered on study days 8 and 15 to patients in cohorts 1 and 2 (patients in cohort 3 did not receive loading doses). The primary endpoint was safety in terms of the type, frequency, and severity of adverse events; secondary endpoints included time to disease progression from cohort 1 and the proportion of patients without surgery at month 6 for cohort 2. The safety analysis set included all enrolled patients who received at least one dose of denosumab. This study is registered with ClinicalTrials.gov, number NCT00680992, and has been completed. FINDINGS: Between Sept 9, 2008, and Feb 25, 2016, 532 patients were enrolled: 267 in cohort 1, 253 in cohort 2, and 12 in cohort 3. At data cutoff on Feb 24, 2017, median follow-up was 58·1 months (IQR 34·0-74·4) in the overall patient population, and 65·8 months (40·9-82·4) in cohort 1, 53·4 months (28·2-64·1) in cohort 2, and 76·4 months (61·2-76·5) in cohort 3. During the treatment phase, the most common grade 3 or worse adverse events were hypophosphataemia (24 [5%] of 526 patients), osteonecrosis of the jaw (17 [3%], pain in extremity (12 [2%]), and anaemia (11 [2%]). Serious adverse events were reported in 138 (26%) of 526 patients; the most common were osteonecrosis of the jaw (17 [3%]), anaemia (6 [1%]), bone giant cell tumour (6 [1%]), and back pain (5 [1%]). 28 (5%) patients had positively adjudicated osteonecrosis of the jaw, four (1%) had atypical femur fracture, and four (1%) had hypercalcaemia occurring 30 days after denosumab discontinuation. There were four cases (1%) of sarcomatous transformation, consistent with historical data. Ten (2%) treatment-emergent deaths occurred (two of which were considered treatment-related; bone sarcoma in cohort 2 and sarcoma in cohort 1). Median time to progression or recurrence for patients in cohort 1 during the first treatment phase was not reached (28 [11%] of 262 patients had progression or recurrence). 227 (92%; 95% CI 87-95) of 248 patients who received at least one dose of denosumab in cohort 2 had no surgery in the first 6 months of the study. INTERPRETATION: The types and frequencies of adverse events were consistent with the known safety profile of denosumab, which showed long-term disease control for patients with GCTB with unresectable and resectable tumours. Our results suggest that the overall risk to benefit ratio for denosumab treatment in patients with GCTB remains favourable. FUNDING: Amgen.

Primary Cardiac Sarcoma: A Rare, Aggressive Malignancy with a High Propensity for Brain Metastases.

INTRODUCTION: Primary cardiac sarcoma (PCS) has a poor prognosis compared to other sarcomas due to late presentation, challenging resection, incidence of metastases, and limited efficacy of systemic therapies. METHODS: A medical record search engine was queried to identify patients diagnosed with PCS from 1992 to 2017 at the University of Michigan. RESULTS: Thirty-nine patients with PCS had a median age of 41 years (range 2-77). Common histologies were angiosarcoma (AS, 14), high-grade undifferentiated pleomorphic sarcoma (UPS, 10), and leiomyosarcoma (LMS, 5). Sites of origin were left atrium (18), right atrium (16), and pericardium (5). AS was the most common right-sided tumor; UPS was more common on the left. Eighteen patients presented with metastases involving lung (10), bone (7), liver (5), and brain (4). Twenty-five patients underwent resection, achieving 3 R0 resections. Patients received a median of 2 (1-6) systemic therapies. Median overall survival (OS) was 12.1 months (range 0-79). Median OS was 14.0 months and 8.2 months in patients who did or did not undergo resection, respectively (p=0.018). Brain metastases occurred in 12 (31%) patients, 9 (75%) of whom had left heart tumors, at a median of 8.5 months (range 0-75) from diagnosis. Median OS was 5.6 months (range 0-30) after the diagnosis of brain metastases. CONCLUSIONS: PCS portends a poor prognosis, because of difficulty in obtaining complete resection of sarcoma, advanced stage at diagnosis, and high risk of brain metastases. Providers should be aware of the increased risk of brain metastases and consider brain imaging at diagnosis and follow-up.

EWSR1-NFATC2 Translocation-associated Sarcoma Clinicopathologic Findings in a Rare Aggressive Primary Bone or Soft Tissue Tumor.

In recent years, a novel small round cell sarcoma harboring EWSR1-NFATC2 translocation with immunomorphologic overlap with Ewing sarcoma (ES), myoepithelial tumors, and extraskeletal myxoid chondrosarcoma has emerged. There has not been a case series devoted to describing its detailed clinicopathologic and immunohistochemical characteristics. Six sarcomas harboring EWSR1-NFATC2 fusion transcripts by reverse transcription polymerase chain reaction and amplification of the fusion gene by fluorescence in situ hybridization were identified. The patients were 5 adult men and 1 adult woman. Three were primary bone tumors of the radius and 3 were primary soft tissue tumors. Most tumors showed monomorphic round to epithelioid cells in anastomosing cords and abundant myxohyaline to collagenous extracellular matrix. Two tumors had large areas of a solid, matrix-poor histomorphology. All tumors stained for CD99 and NKX2.2; while EMA, dot-like cytokeratin, and focal WT-1 and SMA were present in some tumors. All but 1 tumor showed poor histologic and radiologic responses to neoadjuvant ES-specific chemotherapy. Local or distant recurrences happened in 4 cases. EWSR1-NFATC2 sarcoma is a novel translocation-associated sarcoma. It presents as either a primary bone or soft tissue tumor, usually exhibits distinctive histopathologic features, and has predilection for long bones of adult men. It consistently shows recurrent fusion gene amplification readily detectable by EWSR1 breakapart fluorescence in situ hybridization, which serves as a diagnostic surrogate. It has potential for local and distant recurrence and histologic progression, and is resistant to Ewing sarcoma-specific chemotherapy.

Differential Outcomes and Biologic Markers of Radiation-Associated vs. Sporadic Osteosarcoma: A Single-Institution Experience.

Background: Radiation-associated osteosarcoma (RAO) is a rare, life-threatening complication from radiation. Many physicians presume RAO has a worse prognosis than sporadic osteosarcoma (SO), although limited objective data exist. We conducted a retrospective study comparing these entities. Methods: We identified adults treated at our institution with osteosarcoma (1990-2016) and categorized tumors as SO or RAO based on location within a prior radiation field. We extracted data on demographics, treatment and primary malignancy and examined available tumor samples for MTA-1 and ezrin using immunohistochemistry (IHC). Results: Of 159 identified patients, 28 had RAO, diagnosed at a median interval from radiation of 11.5 years (1.5-28 years). Median follow-up was 2.8 years (0.1-19.6 years). Median progression free survival (PFS) and overall survival (OS) were not significantly different in the small population of patients with metastases, SO (n = 20) vs. RAO (n = 6): PFS 10.3 months vs. 4.8 months (p = 0.45) and OS 15.6 months vs. 6.1 months (p = 0.96), respectively. For the larger group with localized disease, median relapse-free survival (RFS) and OS were significantly different, NR vs. 12.2 months (p < 0.001) and NR vs. 27.6 months (p = 0.001) in SO (n = 111) vs. RAO (n = 22), respectively. On IHC, there were significant differences in distribution of high, intermediate or low MTA-1 (p = 0.015) and ezrin (p = 0.002) between RAO and SO tumors. Conclusions: Patients with metastases at diagnosis fared poorly irrespective of prior radiation. RAO patients with localized disease had worse outcomes without detectable differences in therapy rendered or treatment effect in resected specimens. Higher expression of MTA-1 in RAO patients may suggest an underlying difference in tumor biology to explain differences in outcomes.

Association of Dasatinib With Progression-Free Survival Among Patients With Advanced Gastrointestinal Stromal Tumors Resistant to Imatinib.

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.