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.

Axitinib in patients with advanced/metastatic soft tissue sarcoma (Axi-STS): an open-label, multicentre, phase II trial in four histological strata.

BACKGROUND: Axitinib is an oral vascular endothelial growth factor receptor inhibitor with anti-tumour activity in renal, thyroid, and pancreatic cancer. METHODS: Axi-STS was a pathologically-stratified, non-randomised, open-label, multi-centre, phase II trial of continuous axitinib treatment in patients ≥16 years, performance status ≤2, with pathologically-confirmed advanced/metastatic soft tissue sarcoma (STS). Patients were recruited within four tumour strata, each analysed separately: angiosarcoma, leiomyosarcoma, synovial sarcoma, or other eligible STSs. The primary outcome was progression-free survival at 12 weeks (PFS12). A Simon's two-stage design with activity defined as PFS12 rate of 40% determined a sample size of 33 patients per strata. RESULTS: Between 31-August-2010 and 29-January-2016, 145 patients were recruited: 38 angiosarcoma, 37 leiomyosarcoma, 36 synovial sarcoma, and 34 other subtypes. PFS12 rate for each stratum analysed was 42% (95% lower confidence interval (LCI); 29), 45% (95% LCI; 32), 57% (95% LCI; 42), and 33% (95% LCI; 21), respectively. There were 74 serious adverse events including two treatment-related deaths of pulmonary haemorrhage and gastrointestinal bleeding. Fatigue and hypertension were the most common grade 3 adverse events. CONCLUSIONS: Axitinib showed clinical activity in all STS strata investigated. The adverse event profile was acceptable, supporting further investigation in phase III trials. CLINICAL TRIAL REGISTRATION: ISRCTN 60791336.

A phase II study of gemcitabine and docetaxel combination in relapsed metastatic or unresectable locally advanced synovial sarcoma.

Synovial sarcoma (SS) is one of the commonest non-rhabdomyosarcoma soft tissue sarcoma with limited treatment options in the relapsed and advanced settings. The combination of gemcitabine and docetaxel has demonstrated its role predominantly in leiomyosarcoma and pleomorphic sarcomas but has not been prospectively studied in SS. This trial assesses the efficacy, tolerability and quality of life (QoL) with this regimen in metastatic/unresectable locally advanced relapsed SS.Patients and methods This was a single-arm, two-stage, phase II, investigator-initiated interventional study among patients with metastatic or unresectable locally advanced SS who had progressed after at least one line of chemotherapy. Gemcitabine 900 mg/m2 on days 1 and 8 and docetaxel 75 mg/m2 on day 8 were administered intravenously every 21 days. The primary endpoint was 3-month progression-free rate (PFR); overall survival (OS), progression-free survival (PFS), overall response rate (ORR), safety and quality of life (QoL) constituted the secondary endpoints.Results Twenty-two patients were enrolled between March 2020 and September 2021 and the study had to be closed early due to slow accrual. The study population comprised of 18 (81.8%) patients with metastatic disease and 4 (18.2%) patients with locally advanced, unresectable disease. The most common primary sites of disease were extremity in 15 (68%) and the median number of lines of prior therapies received was 1 (range 1-4). 3-month PFR was 45.4% (95% CI 24.8-66.1) and ORR was 4.5%. Median progression-free survival (PFS) was 3 months (95% CI 2.3-3.6) and median OS was 14 months (95% CI 8.9-19.0). 7 (31.8%) patients experienced grade 3 or worse toxicities, including anemia (18%), neutropenia (9%) and mucositis (9%). QoL analysis demonstrated significant decline in certain functional and symptom scales, while financial and global health scales remained stable.Conclusion This is the first prospective study on the combination of gemcitabine and docetaxel performed specifically in patients with advanced, relapsed SS. Although the accrual of patients could not be completed as planned, the therapy did produce clinically meaningful outcomes and met its primary endpoint of 3-month PFR. This result, along with the manageable toxicity profile and stable global health status on QoL analysis, should encourage further studies.Trial registration This trial was prospectively registered under the Clinical Trials Registry of India on 26/02/2020 (Registration number: CTRI/2020/02/023612).

Clinical analysis of multimodal treatment for localized synovial sarcoma: A multicenter retrospective study.

INTRODUCTION: Several prognostic factors for survival in synovial sarcoma have been proposed, but the role of adjuvant chemotherapy and radiotherapy is a matter of debate. The study aim was to clarify the effect of high-dose ifosfamide-containing chemotherapy and adjuvant radiotherapy for patients with localized synovial sarcoma. MATERIALS AND METHODS: Five tertiary musculoskeletal oncology hospitals participated in this retrospective study. The records of the patient diagnosed with synovial sarcoma without metastasis at diagnosis from 1990 to 2011 have been collected and reviewed. Overall, distant failure-free, and local failure-free survivals were calculated, and prognostic factors for each survival were evaluated by performing univariate and multivariate analyses. RESULTS: A total of 162 patients were enrolled in this study with a median follow-up period of 67 months (range, 5-267 months) for all surviving patients. The 5-year overall, distant failure-free, and local failure-free survival rates were 79.7%, 66.3%, and 98.4%, respectively. Univariate analyses demonstrated that high-dose ifosfamide-containing chemotherapy was significantly associated with better overall (p = 0.014) and distant failure-free survival (p = 0.0043) than that of low-dose or no ifosfamide-containing chemotherapy if we analyzed only patients with tumors >5 cm in size. Addition of radiotherapy was not a significant prognostic factor for overall survival in the univariate and multivariate analyses, but it did improve the overall survival of the patients with R1 resection (p = 0.053). CONCLUSION: Patients with localized synovial sarcoma >5 cm in size had better overall and distant failure-free survival after receiving adjuvant chemotherapy containing high-dose ifosfamide comparing to low-dose or no ifosfamide-containing chemotherapy. The addition of adjuvant radiotherapy was beneficial for the patients who received R1 resection. Alternatively, adjuvant radiotherapy could be avoided for patients who achieved an R0 margin.

[Efficacy and safety of Anlotinib in the treatment of advanced sarcoma].

Objective: Patients with advanced sarcomas have a dismal prognosis with few effective therapies. The purpose of this study was to evaluate the efficacy and safety of anlotinib in the treatment of advanced sarcoma and to explore the relationship between adverse events (AEs) and efficacy. Methods: Data from 45 advanced sarcoma patients who received anlotinib monotherapy at Affiliated Cancer Hospital of Zhengzhou University between June 2018 and August 2021 were retrospectively analyzed. According to Response Evaluation Criteria In Solid Tumors (RECIST) Version 1.1, the objective remission rate (ORR) and disease control rate (DCR) were calculated, and the progression free survival (PFS) and treatment-related AEs were recorded and analyzed. Survival analysis was conducted using the Kaplan-Meier survival rates were compared using the Log rank test. Results: Forty patients were treated for more than 1.5 months and received efficacy evaluation. The ORR and DCR after 3 months were 7.5%(3/40) and 80.0%(32/40), respectively. The overall ORR was 2.5%(1/40), the total DCR was 27.5%(11/40), and the median progression-free survival (m-PFS) was 6.70 months; The m-PFS of alveolar soft tissue sarcoma (ASPS) was 10.27 months, which was significantly longer than that of other subtypes of sarcoma (P=0.048). In addition, the DCR of ASPS and synovial sarcoma (SS) was significantly better than that of osteosarcoma (P<0.05). The most common AEs were elevated thyroid stimulating hormone (17.8%, 8/45), anemia (15.6%, 7/45), fatigue (11.1%, 5/45). Five patients developed grade 3 AEs after treatment; The PFS of patients with hand-foot syndrome after treatment was significantly longer than that of patients without hand-foot syndrome (14.10 vs 6.00, P=0.024). Conclusions: The efficacy of anlotinib in the treatment of ASPS and SS is better than that of other subtypes. The PFS in the group with hand-foot syndrome was significantly longer than that of the group without hand-foot syndrome.

Poor Treatment Outcomes with Second-Line Chemotherapy in Advanced Synovial Sarcoma.

INTRODUCTION: Synovial sarcoma (SS) predominantly affects adolescents and young adults. Doxorubicin with or without ifosfamide therapy is the standard first-line treatment for unresectable or metastatic SS. However, there is no standard second-line chemotherapy regimen. The purpose of the current study was to evaluate the outcomes of second-line chemotherapy for patients with SS. METHODS: We retrospectively evaluated the outcomes of 61 patients with unresectable or metastatic SS who had received first-line chemotherapy at our institution between 1997 and 2017. Patients who received second-line chemotherapy were included in the analysis. Outcomes of the chemotherapy were evaluated. RESULTS: Among the 61 patients treated with first-line chemotherapy, we identified 32 patients who received second-line chemotherapy. Most patients (62.5%) were under 40 years of age. Regarding second-line chemotherapy regimens, 6 (18.8%) patients were treated with doxorubicin with/without ifosfamide, 6 (18.8%) with ifosfamide and etoposide, 4 (12.5%) with docetaxel and gemcitabine, 5 (15.6%) with pazopanib, 2 (6.2%) with trabectedin, and 1 (3.1%) with eribulin. The overall response rate according to the Response Evaluation Criteria in Solid Tumors for all patients was 9.4%. Eleven patients (34.3%) achieved disease-control for >6 months. The median follow-up duration was 15.2 months. The 1-year progression-free and overall survival rates were 33.1% and 67.1%, respectively. CONCLUSION: Our exploratory study revealed that the response rate of second-line chemotherapy regimens for patients with SS was 9.4%. Therefore, there is an urgent need to develop more active therapeutic regimens for SSs.

Meta-analysis of pazopanib and trabectedin effectiveness in previously treated metastatic synovial sarcoma (second-line setting and beyond).

Background: This study examined the efficacy/effectiveness of pazopanib and trabectedin in previously treated metastatic synovial sarcoma (mSS). Materials & methods: A literature search identified studies (2002-2019) reporting outcomes of pazopanib and trabectedin in previously treated mSS, including median overall survival (mOS) and overall response rate (ORR). A meta-analysis was conducted and sensitivity analyses examined outcomes by agent (pazopanib/trabectedin), study type (clinical trial [CT] or real-world [RW]) and sample size. Results: Sixteen studies were included (pazopanib: n = 7; trabectedin: n = 9). Pooled mOS was 10.4 months and was consistent across agents and in RW and CT (pazopanib: 10.3; trabectedin: 10.4; CT: 10.8; RW: 9.9). ORR results were more variable (pooled ORR: 14.7%). ORR was consistently higher for RW (17.7%) than for CT (9.5%) and for pazopanib (18.9%) compared with trabectedin (12.3%). Conclusion: Poor outcomes across agents and settings highlight a need for novel treatments with improved efficacy. This study serves as a benchmark for efficacy estimates in this rare disease.

Synovial sarcoma (SS) is a rare and aggressive type of soft tissue sarcoma. SS frequently spreads to other locations, referred to as metastatic SS (mSS) and is associated with a high death rate. Patients treated with first-line chemotherapy (1L setting), may need further lines of treatment (≥2L setting), which commonly involve the drugs pazopanib and trabectedin. This study assessed how well pazopanib and trabectedin work in people with ≥2L mSS, by examining both clinical trial (CT) and real-world (RW) studies. Overall, findings across 16 studies showed that mSS patients lived approximately 10 months after treatment with pazopanib or trabectedin in the ≥2L setting, and this was similar across both agents (10.3 months for pazopanib; 10.4 months for trabectedin) and between the CT (10.8 months) and the RW (9.9 months) settings. In terms of response to treatment, a higher percentage of people appeared to respond in RW settings (17.7%) than in CTs (9.5%), and to pazopanib (18.9%) compared with trabectedin (12.3%). These results show there is a need for better treatments for patients with previously treated mSS. These findings are useful benchmarks for the development of future treatment approaches for this rare disease.

Formulation, Characterization, and In Vitro/In Vivo Efficacy Studies of a Novel Liposomal Drug Delivery System of Amphiphilic Jaspine B for Treatment of Synovial Sarcoma.

Sphingomyelin is a cell membrane sphingolipid that is upregulated in synovial sarcoma (SS). Jaspine B has been shown to inhibit sphingomyelin synthase, which synthesizes sphingomyelin from ceramide, a critical signal transducer; however, jaspine B's low bioavailability limits its application as a promising treatment option. To address this shortcoming, we used microfluidics to develop a liposomal delivery system with increased anticancer efficacy. The nano-liposome size was determined by transmission electron microscopy. The jaspine B liposome was tested for its tumor inhibitory efficacy compared to plain jaspine B in in vitro and in vivo studies. The human SS cell line was tested for cell viability using varying jaspine B concentrations. In a mouse model of SS, tumor growth suppression was evaluated during four weeks of treatment (3 times/week). The results show that jaspine B was successfully formulated in the liposomes with a size ranging from 127.5 ± 61.2 nm. The MTT assay and animal study results indicate that jaspine B liposomes dose-dependently lowers cell viability in the SS cell line and effectively suppresses tumor cell growth in the SS animal model. The novel liposome drug delivery system addresses jaspine B's low bioavailability issues and improves its therapeutic efficacy.

Efficacy of perioperative chemotherapy for synovial sarcoma: a retrospective analysis of a Nationwide database in Japan.

BACKGROUND: Synovial sarcoma is an aggressive but chemosensitive soft-tissue tumor. We retrospectively analyzed the efficacy of perioperative chemotherapy for synovial sarcoma with data from the nationwide database, Bone and Soft Tissue Tumor Registry in Japan. METHODS: This study included 316 patients diagnosed with synovial sarcoma between 2006 and 2012. Oncologic outcomes were analyzed using a Cox-hazard regression model. Moreover, the effects of perioperative chemotherapy on outcomes were evaluated using a matched-pair analysis. The oncologic outcomes of patients who did or did not receive chemotherapy were compared (cx + and cx-). RESULTS: Multivariate analysis revealed significant correlations of age (over 40, hazard ratio [HR] = 0.61, p = 0.043), margin status (marginal resection, HR = 0.18, p < 0.001 and intralesional resection, HR = 0.30, p = 0.013 versus wide resection) with overall survival; surgical margin type (marginal resection, HR = 0.14, p = 0.001 and intralesional resection, HR = 0.09, p = 0.035 versus wide resection) with local recurrence; and postoperative local recurrence (HR = 0.30, p = 0.027) and surgical margin (marginal resection, HR = 0.31, p = 0.023 versus wide resection) with distant relapse-free survival. Before propensity score matching, perioperative chemotherapy was mainly administered for young patients and patients with deeper tumor locations, larger tumors, more advanced-stage disease, and trunk location. The 3-year overall survival, local control, and distant relapse-free survival rates were 79.8%/89.3% (HR = 0.64, p = 0.114), 89.6%/93.0% (HR = 0.37, p = 0.171) and 71.4%/84.5% (HR = 0.60, p = 0.089) in the cx+/cx- groups, respectively. After propensity score matching, 152 patients were selected such that the patient demographics were nearly identical in both groups. The 3-year overall survival, local control, and distant relapse-free survival rates were 71.5%/86.0% (HR = 0.48, p = 0.055), 92.5%/93.3% (HR = 0.51, p = 0.436) and 68.4%/83.9% (HR = 0.47, p = 0.046) in the cx+/cx- groups, respectively. CONCLUSION: This large-sample study indicated that the margin status and postoperative disease control were associated directly or indirectly with improved oncologic outcomes. However, the efficacy of perioperative chemotherapy for survival outcomes in synovial sarcoma patients was not proven in this Japanese database analysis.

Pediatric Locally Advanced Synovial Sarcoma: What Would Be the Best Treatment Option?

KEY POINTS • Synovial sarcomas are often mistreated with unplanned tumor resection. • Attention from specialists early in the course of SS can minimize the risk of recurrence, metastases, and the necessity for resurgery, all of which are increased with unplanned tumor resection. • Chemotherapy alone does not provide sufficient local control of the tumor. • Resurgery, in conjunction with radiotherapy and chemotherapy, is the best choice of management for this patient.

Is perioperative chemotherapy recommended in childhood and adolescent patients with synovial sarcoma? A systematic review.

OBJECTIVE: Synovial sarcoma is the most common soft tissue sarcomas among childhood and adolescents, accounting for 8-10% of all soft tissue sarcoma. Synovial sarcoma is considered a relatively chemosensitive tumor compared with other soft tissue sarcomas. However, the role of perioperative chemotherapy in synovial sarcoma remains controversial. The purpose of this systematic review is to evaluate the role of perioperative chemotherapy in childhood and adolescent patients with synovial sarcoma. METHODS: We evaluated studies published between 1 January 1990 and 31 December 2017. The following databases were searched: MEDLINE, Cochrane database (via PubMed) and Ichushi (in Japanese). RESULTS: The search yielded 216 articles in English and Japanese. After the initial screening, based on the title and abstract, 160 articles were excluded. As a second screening, we then assessed the full text of the remaining 56 articles for eligibility. Finally, 10 articles were included in the systematic review. Surgical resection with R0 margin alone was recommended because of the excellent results of two prospective studies. Meta-analysis was performed using data from two retrospective studies of 261 patients. Perioperative chemotherapy did not have a significant effect on survival and event-free survival. CONCLUSIONS: We weakly do not recommend perioperative chemotherapy in patients with non-metastatic synovial sarcoma ≤ 5 cm when R0 resection is acquired. There was no consensus concerning the role of perioperative chemotherapy in patients with synovial sarcoma > 5 cm or those with ≤5 cm who undergo R1 or R2 resection.

Marine Antimicrobial Peptide TP4 Exerts Anticancer Effects on Human Synovial Sarcoma Cells via Calcium Overload, Reactive Oxygen Species Production and Mitochondrial Hyperpolarization.

Synovial sarcoma is a rare but aggressive soft-tissue sarcoma associated with translocation t(X;18). Metastasis occurs in approximately 50% of all patients, and curative outcomes are difficult to achieve in this group. Since the efficacies of current therapeutic approaches for metastatic synovial sarcoma remain limited, new therapeutic agents are urgently needed. Tilapia piscidin 4 (TP4), a marine antimicrobial peptide, is known to exhibit multiple biological functions, including anti-bacterial, wound-healing, immunomodulatory, and anticancer activities. In the present study, we assessed the anticancer activity of TP4 in human synovial sarcoma cells and determined the underlying mechanisms. We first demonstrated that TP4 can induce necrotic cell death in human synovial sarcoma AsKa-SS and SW982 cells lines. In addition, we saw that TP4 initiates reactive oxygen species (ROS) production and downregulates antioxidant proteins, such as uncoupling protein-2, superoxide dismutase (SOD)-1, and SOD-2. Moreover, TP4-induced mitochondrial hyperpolarization is followed by elevation of mitochondrial ROS. Calcium overload is also triggered by TP4, and cell death can be attenuated by a necrosis inhibitor, ROS scavenger or calcium chelator. In our experiments, TP4 displayed strong anticancer activity in human synovial sarcoma cells by disrupting oxidative status, promoting mitochondrial hyperpolarization and causing calcium overload.

Glycogen synthase kinase 3ß as a potential therapeutic target in synovial sarcoma and fibrosarcoma.

Soft tissue sarcomas (STSs) are a rare cancer type. Almost half are unresponsive to multi-pronged treatment and might therefore benefit from biologically targeted therapy. An emerging target is glycogen synthase kinase (GSK)3ß, which is implicated in various diseases including cancer. Here, we investigated the expression, activity and putative pathological role of GSK3ß in synovial sarcoma and fibrosarcoma, comprising the majority of STS that are encountered in orthopedics. Expression of the active form of GSK3ß (tyrosine 216-phosphorylated) was higher in synovial sarcoma (SYO-1, HS-SY-II, SW982) and in fibrosarcoma (HT1080) tumor cell lines than in untransformed fibroblast (NHDF) cells that are assumed to be the normal mesenchymal counterpart cells. Inhibition of GSK3ß activity by pharmacological agents (AR-A014418, SB-216763) or of its expression by RNA interference suppressed the proliferation of sarcoma cells and their invasion of collagen gel, as well as inducing their apoptosis. These effects were associated with G0/G1-phase cell cycle arrest and decreased expression of cyclin D1, cyclin-dependent kinase (CDK)4 and matrix metalloproteinase 2. Intraperitoneal injection of the GSK3ß inhibitors attenuated the growth of SYO-1 and HT1080 xenografts in athymic mice without obvious detrimental effects. It also mitigated cell proliferation and induced apoptosis in the tumors of mice. This study indicates that increased activity of GSK3ß in synovial sarcoma and fibrosarcoma sustains tumor proliferation and invasion through the cyclin D1/CDK4-mediated pathway and enhanced extracellular matrix degradation. Our results provide a biological basis for GSK3ß as a new and promising therapeutic target for these STS types.

ADVL1522: A phase 2 study of lorvotuzumab mertansine (IMGN901) in children with relapsed or refractory wilms tumor, rhabdomyosarcoma, neuroblastoma, pleuropulmonary blastoma, malignant peripheral nerve sheath tumor, or synovial sarcoma-A Children's Oncology Group study.

BACKGROUND: Lorvotuzumab mertansine (IMGN901) is an antibody-drug conjugate linking an antimitotic agent (DM1) to an anti-CD56 antibody (lorvotuzumab). Preclinical efficacy has been noted in Wilms tumor, rhabdomyosarcoma, and neuroblastoma. Synovial sarcoma, malignant peripheral nerve sheath tumor (MPNST), and pleuropulmonary blastoma also express CD56. A phase 2 trial of lorvotuzumab mertansine was conducted to assess its efficacy, recommended phase 2 dose, and toxicities. METHODS: Eligible patients had relapsed after or progressed on standard therapy for their tumor type. Lorvotuzumab mertansine (110 mg/m2 per dose) was administered at the adult recommended phase 2 dose intravenously on days 1 and 8 of 21-day cycles. Dexamethasone premedication was used. Pharmacokinetic samples, peripheral blood CD56-positive cell counts, and tumor CD56 expression were assessed. RESULTS: Sixty-two patients enrolled. The median age was 14.3 years (range, 2.8-29.9 years); 35 were male. Diagnoses included Wilms tumor (n = 17), rhabdomyosarcoma (n = 17), neuroblastoma (n = 12), synovial sarcoma (n = 10), MPNST (n = 5), and pleuropulmonary blastoma (n = 1). Five patients experienced 9 dose-limiting toxicities: hyperglycemia (n = 1), colonic fistula (n = 1) with perforation (n = 1), nausea (n = 1) with vomiting (n = 1), increased alanine aminotransferase in cycle 1 (n = 2), and increased alanine aminotransferase in cycle 2 (n = 1) with increased aspartate aminotransferase (n = 1). Non-dose-limiting toxicities (grade 3 or higher) attributed to lorvotuzumab mertansine were rare. The median values of the maximum concentration, half-life, and area under the curve from zero to infinity for DM1 were 0.87 µg/mL, 35 hours, and 27.9 µg/mL h, respectively. Peripheral blood CD56+ leukocytes decreased by 71.9% on day 8. One patient with rhabdomyosarcoma had a partial response, and 1 patient with synovial sarcoma achieved a delayed complete response. CONCLUSIONS: Lorvotuzumab mertansine (110 mg/m2 ) is tolerated in children at the adult recommended phase 2 dose; clinical activity is limited.

BRAF V600E mutation is a potential therapeutic target for a small subset of synovial sarcoma.

Synovial sarcoma (SS) is an aggressive tumor that most often affects the deep soft tissues in young adults. Intrathoracic SS is rare and is associated with poor outcome, highlighting the urgent need for a novel therapeutic strategy. In the process of clinical sequencing, we identified two patients with intrathoracic SS harboring the BRAF V600E mutation. The patients were women aged 32 and 23 years, and both presented with SS18-SSX2-positive monophasic SS in the thoracic cavity. BRAF V600E mutations were detected by next generation sequencing, and validated immunohistochemically by diffuse intense positivity to BRAF V600E mutation-specific antibodies. The phosphorylated ERK (pERK) immunohistochemistry result was also positive. One patient received a combination therapy of dabrafenib and trametinib, which led to tumor shrinkage. However, the tumor growth progressed 7.5 months later with an additional NRAS Q61K mutation. Immunohistochemical screening of 67 archival SS tumor samples failed to identify additional samples with BRAF V600E mutation. However, 32% of BRAF V600E-negative cases was positive for pERK, and one of the six tumors showing the highest pERK expression harbored an FGFR2-activating mutation. This is the first report of targetable BRAF mutation in a small subset of SS. Our study suggests involvement of the mitogen-activated protein kinase pathway and the potential clinical implication of BRAF mutation screening in SS.

Calcium-Dependent Calpain Activation-Mediated Mitochondrial Dysfunction and Oxidative Stress Are Required for Cytotoxicity of Epinecidin-1 in Human Synovial Sarcoma SW982 Cells.

Synovial sarcoma is a rare but highly malignant and metastatic disease. Despite its relative sensitivity to chemotherapies, the high recurrence and low 5-year survival rate for this disease suggest that new effective therapeutic agents are urgently needed. Marine antimicrobial peptide epinecidin-1 (epi-1), which was identified from orange-spotted grouper (Epinephelus coioides), exhibits multiple biological effects, including bactericidal, immunomodulatory, and anticancer activities. However, the cytotoxic effects and mechanisms of epi-1 on human synovial sarcoma cells are still unclear. In this study, we report that epi-1 exhibits prominent antisynovial sarcoma activity in vitro and in a human SW982 synovial sarcoma xenograft model. Furthermore, we determined that calcium overload-induced calpain activation and subsequent oxidative stress and mitochondrial dysfunction are required for epi-1-mediated cytotoxicity. Interestingly, reactive oxygen species (ROS)-mediated activation of extracellular signal-regulated kinase (ERK) plays a protective role against epi-1-induced cytotoxicity. Our results provide insight into the molecular mechanisms underlying epi-1-induced cell death in human SW982 cells.

A Phase II Trial of Sorafenib and Dacarbazine for Leiomyosarcoma, Synovial Sarcoma, and Malignant Peripheral Nerve Sheath Tumors.

BACKGROUND: Sorafenib and dacarbazine have low single-agent response rates in metastatic sarcomas. As angiogenesis inhibitors can enhance the efficacy of chemotherapy, we investigated the combination of sorafenib and dacarbazine in select sarcoma subtypes. MATERIALS AND METHODS: Patients with leiomyosarcoma (LMS), synovial sarcoma (SS), or malignant peripheral nerve sheath tumors (MPNST) with up to two previous lines of therapy and adequate hepatic, renal, and marrow function received 3-week cycles of sorafenib at 400 mg oral twice daily and dacarbazine 1,000 mg/m2 intravenously (later reduced to 850 mg/m2). Patients were evaluated for response every 6 weeks. The primary objective was to determine the disease control rate (DCR) of sorafenib plus dacarbazine in the selected sarcoma subtypes. RESULTS: The study included 37 patients (19 female); median age was 55 years (range 26-87); and histologies included LMS (22), SS (11), and MPNST (4). The DCR was 46% (17/37). Median progression-free survival was 13.4 weeks. The RECIST response rate was 14% (5/37). The Choi response rate was 51% (19/37). Median overall survival was 13.2 months. Of the first 25 patients, 15 (60%) required dacarbazine dose reductions for hematologic toxicity, with one episode of grade 5 neutropenic fever. After reducing the starting dose of dacarbazine to 850 mg/m2, only 3 of the final 12 (25%) patients required dose reduction. CONCLUSION: This phase II study met its primary endpoint with an 18-week DCR of 46%. The clinical activity of dacarbazine plus sorafenib in patients with these diagnoses is modest. IMPLICATIONS FOR PRACTICE: Metastatic soft tissue sarcomas are a heterogeneous group of relatively rare malignancies. Most patients are treated with cytotoxic chemotherapy or targeted therapy in the form of tyrosine kinase inhibitors. Response rates are relatively low, and there is a need for better therapies. This clinical trial demonstrates that combining a cytotoxic therapy (dacarbazine) with an antiangiogenic small molecule (sorafenib) is feasible and associated with favorable disease-control rates; however, it also increases the potential for significant toxicity.

Standard treatment and emerging drugs for managing synovial sarcoma: adult's and pediatric oncologist perspective.

INTRODUCTION: in this review we discuss the standard of care for both pediatric and adult synovial sarcoma (SS), the prognostic differences between them, and the treatments available for localized and advanced diseases. We also overview the biology and the recent drugs under consideration in clinical trials on SS. Areas covered: we focus on new targeted therapies being investigated for advanced SS, especially anti-angiogenic drugs, and immunotherapy. We review all the published data and ongoing trials dedicated to SS or to soft tissue sarcoma in general, paying particular attention to the results obtained in SS patients. Expert opinion: we expect new treatment strategies to become available for SS in the near future. The ongoing and published trials on targeted therapies and immunotherapy mainly concern adult patients, but the somatic biology of pediatric SS has some similarities as in adult disease. A stronger cooperation between adult and pediatric oncologists in recent years has led to a more shared effort to find new treatment strategies for advanced SS patients, regardless of their age.

Surgical excision and not chemotherapy is the most powerful modality in treating synovial sarcoma: the UK's North East experience.

BACKGROUND AND PURPOSE: We reviewed our experience of synovial sarcoma to identify factors predictive of local recurrence and overall survival, the impact of chemotherapy and outcomes after surgical excision alone. MATERIALS AND METHODS: 81 patients were treated between 1997 and 2014 of mean age 39 years (8-78). Tumours were in the extremity in 55 (67%). 9 patients presented with metastases and 10 with unresectable disease. Mean follow-up was 3.7 years (SD 3.8). Treatment groups were palliative, surgery only, surgery and radiotherapy, or surgery with chemotherapy (with or without radiotherapy). RESULTS: Local recurrence-free survival (LRFS) was 73% at 5 years, and 68% at 10 and 15 years. In multivariate analysis, positive surgical margins were an independent predictor of LRFS. Overall survival (OS) was 50% at 5 years for all patients, and 62% at 5 years for those treated with curative intent. Larger tumour size and non-extremity locations were predictors of poorer OS. Patients who had chemotherapy did not have significantly better OS or LRS than others. INTERPRETATION: These results show that where feasible, curative resection should not be delayed for chemotherapy. Treatment with surgery only can be associated with good outcomes in selected patients with smaller extremity tumours; although our series is small.

Extracellular vesicle-encapsulated microRNA-761 enhances pazopanib resistance in synovial sarcoma.

The development of drug resistance in tumor cells leads to relapse and distant metastasis. Secreted microRNAs (miRNAs) enclosed in extracellular vesicles (EVs) can act as intercellular messengers. The objective of our study was to elucidate the role of secreted miRNAs to better understand the regulatory network underlying pazopanib-resistance in synovial sarcoma cells. We performed a comprehensive analysis of secreted miRNA abundance in pazopanib treated/untreated synovial sarcoma cells from four different cell lines (SYO-1, HS-SYII, 1273/99, and YaFuSS) using microarray technology, and discovered miR-761 in EVs as a potential biomarker of pazopanib-resistance in synovial sarcoma. Furthermore, we showed that miR-761 putatively targeted three proteins, thyroid hormone receptor interactor 6 (TRIP6), lamin A/C (LMNA), and NAD-dependent protein deacetylase sirtuin-3 (SIRT3). Knockdown of any of these proteins was shown in previous studies to confer increased resistance to chemotherapeutic agents. Our findings provide new insight into the potential role of miR-761, an EV-secreted miRNA from synovial sarcoma cells, making it a potential candidate for use in sarcoma therapy in the future.