How to develop new systemic treatments in ultra-rare cancers with high unmet needs? The case of alveolar soft-part sarcoma

Developing new drugs or generating evidence for existing drugs in new indications for ultra-rare cancers is complex and carries a high-risk of failure. This gets even harder in ultra-rare tumours, which have an annual incidence of 1 per 1,000,000 population or less. Here, we illustrate the problem of adequate evidence generation in ultra-rare tumours, using Alveolar Soft-Part Sarcomas (ASPS) - an ultra-rare sarcoma newly diagnosed in approximately 60 persons a year in the European Union - as an exemplar case showing challenges in development despite being potentially relevant for classes of agents. We discuss some possible approaches for addressing such challenges, especially focussing on constructive collaboration between academic groups, patients and advocates, drug manufacturers, and regulators to optimise drug development in ultra-rare cancers. This article, written by various European stakeholders, proposes a way forward to ultimately get better options for patients with ultra-rare cancers.

Atezolizumab as the First Systemic Therapy Approved for Alveolar Soft Part Sarcoma

OBJECTIVE

The objective was to review the pharmacology, efficacy, and safety of atezolizumab (Tecentriq) for the treatment of adult and pediatric patients aged 2 years and older with unresectable or metastatic alveolar soft part sarcoma (ASPS).

DATA SOURCES

A literature search was conducted using PubMed and MEDLINE databases, published abstracts, and ongoing studies from ClinicalTrials.gov between January 1, 1981, and May 31, 2023. Keywords included atezolizumab, Tecentriq, MPDL3280, immunotherapy, PD-L1, PD-1, pediatrics, sarcoma, and ASPS.

STUDY SELECTION AND DATA EXTRACTION

All English-language studies involving atezolizumab for ASPS were included and discussed.

DATA SYNTHESIS

Atezolizumab is an anti-programmed death-ligand 1 (PD-L1) monoclonal antibody designed to block the interaction between PD-L1 and the programmed cell death protein 1 (PD-1) receptor. Atezolizumab was granted approval by the FDA specifically for ASPS based on a phase II clinical trial in adult and pediatric patients (n = 49), which reported an overall response rate of 24% and a durable response rate at 6 and 12 months of 67% and 42%, respectively. Common grade 3/4 adverse reactions include musculoskeletal pain (8%), followed by hypertension (6%), weight gain (6%), headache (4%), and dizziness (4%).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON WITH EXISTING DRUGS

Advanced ASPS is a high-risk disease with limited treatment options. Atezolizumab appears to be a viable treatment option in ASPS demonstrating clinical efficacy and a manageable toxicity profile.

CONCLUSIONS

With no other treatments that are FDA approved specifically for ASPS, and few demonstrating efficacy in the advanced setting, the approval of atezolizumab, including the first approval for pediatric patients, represents a landmark improvement to the therapeutic arsenal against this rare disease.

Mimicking angiogenic microenvironment of alveolar soft-part sarcoma in a microfluidic coculture vasculature chip

Alveolar soft-part sarcoma (ASPS) is a slow-growing soft tissue sarcoma with high mortality rates that affects adolescents and young adults. ASPS resists conventional chemotherapy; thus, decades of research have elucidated pathogenic mechanisms driving the disease, particularly its angiogenic capacities. Integrated blood vessels that are rich in pericytes (PCs) and metastatic potential are distinctive of ASPS. To mimic ASPS angiogenic microenvironment, a microfluidic coculture vasculature chip has been developed as a three-dimensional (3D) spheroid composed of mouse ASPS, a layer of PCs, and endothelial cells (ECs). This ASPS-on-a-chip provided functional and morphological similarity as the in vivo mouse model to elucidate the cellular crosstalk within the tumor vasculature before metastasis. We successfully reproduce ASPS spheroid and leaky vessels representing the unique tumor vasculature to assess effective drug delivery into the core of a solid tumor. Furthermore, this ASPS angiogenesis model enabled us to investigate the role of proteins in the intracellular trafficking of bioactive signals from ASPS to PCs and ECs during angiogenesis, including Rab27a and Sytl2. The results can help to develop drugs targeting the crosstalk between ASPS and the adjacent cells in the tumoral microenvironment.

Efficacy of immune checkpoint inhibitors in alveolar soft-part sarcoma: results from a retrospective worldwide registry

BACKGROUND

Conventional cytotoxic drugs are not effective in alveolar soft-part sarcoma (ASPS). Immune checkpoint (programmed cell death protein 1/programmed death-ligand 1) inhibitors (ICIs) are promising drugs in ASPS. A worldwide registry explored the efficacy of ICI in ASPS.

MATERIALS AND METHODS

Data from adult patients diagnosed with ASPS and treated with ICI for advanced disease in expert sarcoma centers from Europe, Australia and North America were retrospectively collected, including demographics and data related to treatments and outcome.

RESULTS

Seventy-six ASPS patients, with a median age at diagnosis of 25 years (range 3-61 years), were registered. All patients received ICI for metastatic disease. Immunotherapy regimens consisted of monotherapy in 38 patients (50%) and combination in 38 (50%) (23 with a tyrosine kinase inhibitor). Among the 68 assessable patients, there were 3 complete responses and 34 partial responses, translating into an overall response rate of 54.4%. After a median follow-up of 36 months [95% confidence interval (CI) 32-40 months] since the start of immunotherapy, 45 (59%) patients have progressed on ICI, with a median progression-free survival (PFS) of 16.3 months (95% CI 8-25 months). Receiving ICI in first line (P = 0.042) and achieving an objective response (P = 0.043) correlated with a better PFS. Median estimated overall survival (OS) from ICI initiation has not been reached. The 12-month and 24-month OS rates were 94% and 81%, respectively.

CONCLUSIONS

This registry constitutes the largest available series of ASPS treated with ICI. Our results suggest that the ICI treatment provides long-lasting disease control and prolonged OS in patients with advanced ASPS, an ultra-rare entity with limited active therapeutic options.

Severe immediate hypersensitivity to gadolinium contrast agent after targeted treatment in a patient with alveolar soft part sarcoma: A case report and review of literature

RATIONALE

Gadolinium-based contrast agents (GBCAs), benefiting from good tolerance and safety, become the priority contrast agents in magnetic resonance imaging. Serious hypersensitivity reactions caused by GBCAs are rare, but occur occasionally. The "immune surveillance" theory proposes that lowered immune function exists in patients with malignance, which decrease the occurrence of atopy. Natural immunosurveillance that enhanced by effective treatment of malignance may increase the risk of hypersensitivity.

PATIENT CONCERNS

A 29-year-old female patient suffering from intensive pain with left leg mass was admitted in our hospital.

DIAGNOSES

The patient was diagnosed with alveolar soft part sarcoma by histopathology and revealed destruction of the left fibula and lung metastasis by computed tomography scan, and treated with anlotinib hydrochloride, a multi-targeted tyrosine kinase inhibitor. After 4 cycles of effective targeted therapy, the patient developed severe immediate hypersensitivity due to gadopentetate dimeglumine-enhanced magnetic resonance imaging.

INTERVENTIONS AND OUTCOMES

The vital signs of the patient returned to normal after rescue. Since then, the patient has not used gadolinium contrast agent again, and currently the condition is stable and still alive.

LESSONS

Severe immediate hypersensitivity might be occurred by gadolinium contrast agent in patients with malignance after effective treatment. We explored the potential mechanism of GBCA-inducing hypersensitivity in detail, by especially focusing on the changes of immune environment. Furthermore, we propose new ideas for the safe use of GBCAs in patients with malignancies.

Exploratory study of an anti-PD-L1/TGF-β antibody, TQB2858, in patients with refractory or recurrent osteosarcoma and alveolar soft part sarcoma: a report from Chinese sarcoma study group (TQB2858-Ib-02)

BACKGROUND

Novel and effective immunotherapies are required for refractory or recurrent sarcomas. Transforming growth factor-beta (TGF-β) is a diverse regulatory and fibrogenic protein expressed in multiple sarcoma tumors that promotes epithelial-mesenchymal transition and excessive deposition of extracellular matrix. This study evaluated the efficacy and safety of the anti-PD-L1/TGF-β antibody TQB2858 in patients with refractory osteosarcoma and alveolar soft part sarcoma (ASPS).

METHODS

This single-arm phase 1b exploratory study included patients with refractory osteosarcoma or ASPS who had previously undergone at least two lines of systemic therapy. Patients were administered 1200 mg of TQB2858 once every 3 weeks. The primary endpoint was objective response rate (ORR), with null and alternative hypotheses of ORR ≤5% and ≥20%, respectively. Exploratory biomarker analyses using immunohistochemistry (IHC) staining (for PD-L1 and TGF-β) were performed on pre-treatment tumor samples.

RESULTS

Eleven eligible patients were included in this study. TQB2858 did not demonstrate evidence of efficacy as 0/5 osteosarcomas had any objective response, while 2/6 ASPS showed a partial response. The median progression-free survivals were 1.51 (1.38, Not Evaluable) and 2.86 (1.38, Not Evaluable) months for the osteosarcoma and ASPS groups, respectively. None of the administered cycles met the criteria for unacceptable toxicity. Other Grade 3 toxicities included abnormal liver function and elevation of γ-glutamyl transferase. IHC analysis revealed that functional enrichment in the TGF-β pathway or PD-L1 was not associated with treatment outcomes.

CONCLUSIONS

The combination of PD-L1 and TQB2858 did not significantly improve the ORR in patients with recurrent osteosarcoma. However, it improved immunogenic responses in ASPS, even after progression upon anti-PD-1/PD-L1 therapy, with an acceptable safety profile. IHC profiling with pathway enrichment analysis may not have any predictive value for survival outcomes.

TRIAL REGISTRATION

Prospectively registered in the Ethical Review Committee of Peking University People's Hospital. The trial registration number is 2021PHA105-001 and 2021PHA140-001 and the registration date was March 2, 2022.

CLINICALTRIALS

gov Identifier CTR20213001 and CTR20220390.

Atezolizumab for Advanced Alveolar Soft Part Sarcoma

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a rare soft-tissue sarcoma with a poor prognosis and no established therapy. Recently, encouraging responses to immune checkpoint inhibitors have been reported.

METHODS

We conducted an investigator-initiated, multicenter, single-group, phase 2 study of the anti-programmed death ligand 1 (PD-L1) agent atezolizumab in adult and pediatric patients with advanced ASPS. Atezolizumab was administered intravenously at a dose of 1200 mg (in patients ≥18 years of age) or 15 mg per kilogram of body weight with a 1200-mg cap (in patients <18 years of age) once every 21 days. Study end points included objective response, duration of response, and progression-free survival according to Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, as well as pharmacodynamic biomarkers of multistep drug action.

RESULTS

A total of 52 patients were evaluated. An objective response was observed in 19 of 52 patients (37%), with 1 complete response and 18 partial responses. The median time to response was 3.6 months (range, 2.1 to 19.1), the median duration of response was 24.7 months (range, 4.1 to 55.8), and the median progression-free survival was 20.8 months. Seven patients took a treatment break after 2 years of treatment, and their responses were maintained through the data-cutoff date. No treatment-related grade 4 or 5 adverse events were recorded. Responses were noted despite variable baseline expression of programmed death 1 and PD-L1.

CONCLUSIONS

Atezolizumab was effective at inducing sustained responses in approximately one third of patients with advanced ASPS. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT03141684.).

Pembrolizumab in patients with rare and ultra-rare sarcomas (AcSé Pembrolizumab): analysis of a subgroup from a non-randomised, open-label, phase 2, basket trial

BACKGROUND

Sarcoma is a heterogeneous group of diseases with few treatment options. Immunotherapy has shown little activity in studies including unselected sarcomas, but immune checkpoint blockers have shown activity in specific histotypes. We evaluated the activity of pembrolizumab in rare and ultra-rare sarcomas.

METHODS

AcSé Pembrolizumab is an ongoing phase 2, basket, multitumour study investigating the activity of pembrolizumab monotherapy in rare cancers. Here, we report the results obtained in patients with selected histotypes of rare sarcomas (incidence of less than one case per 1 000 000 people per year) recruited at 24 French hospitals. Key inclusion criteria were age 15 years or older, Eastern Cooperative Oncology Group performance status of 0-1, and advanced disease that was untreated and resistant to treatment. Patients were given pembrolizumab 200 mg intravenously on day 1 of every 21-day cycle for a maximum of 24 months. The primary endpoint was objective response rate at week 12 using Response Evaluation Criteria in Solid Tumours version 1.1, assessed by local investigators. The primary endpoint and safety were analysed in the intention-to-treat population. The AcSé Pembrolizumab study is registered with ClinicalTrials.gov, NCT03012620.

FINDINGS

Between Sept 4, 2017, and Dec 29, 2020, 98 patients were enrolled, of whom 97 received treatment and were included in analyses (median age 51 years [IQR 35-65]; 53 [55%] were male; 44 [45%] were female; no data were collected on race or ethnicity). 34 (35%) patients had chordomas, 14 (14%) had alveolar soft part sarcomas, 12 (12%) had SMARCA4-deficient sarcomas or malignant rhabdoid tumours, eight (8%) had desmoplastic small round cell tumours, six (6%) had epithelioid sarcomas, four (4%) had dendritic cell sarcomas, three (3%) each had clear cell sarcomas, solitary fibrous tumours, and myxoid liposarcomas, and ten (10%) had other ultra-rare histotypes. As of data cutoff (April 11, 2022), median follow-up was 13·1 months (range 0·1-52·8; IQR 4·3-19·7). At week 12, objective response rate was 6·2% (95% CI 2·3-13·0), with no complete responses and six partial responses in the 97 patients. The most common grade 3-4 adverse events were anaemia (eight [8%] of 97), alanine aminotransferase and aspartate aminotransferase increase (six [6%]), and dyspnoea (five [5%]). 86 serious adverse events were reported in 37 patients. Five deaths due to adverse events were reported, none of which were determined to be related to treatment (two due to disease progression, two due to cancer, and one due to unknown cause).

INTERPRETATION

Our data show the activity and manageable toxicity of pembrolizumab in some rare and ultra-rare sarcoma histotypes, and support the PD-1/PD-L1 pathway as a potential therapeutic target in selected histotypes. The completion of the basket study will provide further evidence regarding the activity and toxicity of pembrolizumab in identified rare types of cancer.

FUNDING

The Ligue contre le cancer, INCa, MSD.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

Randomized Phase II Trial of Sunitinib or Cediranib in Alveolar Soft Part Sarcoma

PURPOSE

Alveolar soft part sarcoma (ASPS) is a rare, highly vascular tumor with few treatment options. We designed a phase II randomized trial to determine the activity and tolerability of single-agent cediranib or sunitinib in patients with advanced metastatic ASPS.

PATIENTS AND METHODS

Patients 16 years of age and older were randomized to receive cediranib (30 mg) or sunitinib (37.5 mg) in 28-day cycles. Patients could cross over to the other treatment arm at disease progression. The primary endpoint was to measure the objective response rate (ORR) for each agent. Median progression-free survival (mPFS) for the two arms was also determined.

RESULTS

Twenty-nine of 34 enrolled patients were evaluable for response. One patient on each of the initial two treatment arms had a partial response (ORR: 6.7% and 7.1% for cediranib and sunitinib, respectively). Twenty-four patients had a best response of stable disease (86.7% and 78.6% for cediranib and sunitinib, respectively). There were no significant differences in mPFS for the two treatment arms. Clinical benefit (i.e., objective response or stable disease for a minimum of four or six cycles of therapy) on the first-line tyrosine kinase inhibitor (TKI) therapy did not predict benefit on the second-line TKI. Both drugs were well tolerated. As of August 2021, 1 patient (unevaluable for ORR) remains on study.

CONCLUSIONS

The study did not meet its endpoints for ORR. Although both TKIs provided clinical benefit, the outcomes may have been attenuated in patients who had progressed ≤6 months before enrollment, potentially accounting for the low response rates. See related commentary by Wilky and Maleddu, p. 1163.

Correlation of Immunological and Molecular Profiles with Response to Crizotinib in Alveolar Soft Part Sarcoma: An Exploratory Study Related to the EORTC 90101 "CREATE" Trial

Alveolar soft part sarcoma (ASPS) is a rare subtype of soft tissue sarcoma characterized by an unbalanced translocation, resulting in ASPSCR1-TFE3 fusion that transcriptionally upregulates MET expression. The European Organization for Research and Treatment of Cancer (EORTC) 90101 “CREATE” phase II trial evaluated the MET inhibitor crizotinib in ASPS patients, achieving only limited antitumor activity. We performed a comprehensive molecular analysis of ASPS tissue samples collected in this trial to identify potential biomarkers correlating with treatment outcome. A tissue microarray containing 47 ASPS cases was used for the characterization of the tumor microenvironment using multiplex immunofluorescence. DNA isolated from 34 available tumor samples was analyzed to detect recurrent gene copy number alterations (CNAs) and mutations by low-coverage whole-genome sequencing and whole-exome sequencing. Pathway enrichment analysis was used to identify diseased-associated pathways in ASPS sarcomagenesis. Kaplan–Meier estimates, Cox regression, and the Fisher’s exact test were used to correlate histopathological and molecular findings with clinical data related to crizotinib treatment, aiming to identify potential factors associated with patient outcome. Tumor microenvironment characterization showed the presence of PD-L1 and CTLA-4 in 10 and 2 tumors, respectively, and the absence of PD-1 in all specimens. Apart from CD68, other immunological markers were rarely expressed, suggesting a low level of tumor-infiltrating lymphocytes in ASPS. By CNA analysis, we detected a number of broad and focal alterations. The most common alteration was the loss of chromosomal region 1p36.32 in 44% of cases. The loss of chromosomal regions 1p36.32, 1p33, 1p22.2, and 8p was associated with shorter progression-free survival. Using whole-exome sequencing, 13 cancer-associated genes were found to be mutated in at least three cases. Pathway enrichment analysis identified genetic alterations in NOTCH signaling, chromatin organization, and SUMOylation pathways. NOTCH4 intracellular domain dysregulation was associated with poor outcome, while inactivation of the beta-catenin/TCF complex correlated with improved outcome in patients receiving crizotinib. ASPS is characterized by molecular heterogeneity. We identify genetic aberrations potentially predictive of treatment outcome during crizotinib therapy and provide additional insights into the biology of ASPS, paving the way to improve treatment approaches for this extremely rare malignancy.

Cediranib phase-II study in children with metastatic alveolar soft-part sarcoma (ASPS)

BACKGROUND

Alveolar soft-part sarcoma (ASPS), a rare vascular sarcoma with a clinically indolent course, frequently presents with metastases. Vascular endothelial growth factor (VEGF) is a promising therapeutic target. In a phase-II trial of the VEGF receptor inhibitor cediranib for adults with ASPS, the partial response (PR) rate (response evaluation criteria in solid tumors [RECIST] v1.0) was 35% (15/43; 95% confidence interval: 21-51%). We evaluated cediranib in the pediatric population.

PROCEDURE

Patients <16 years old with metastatic, unresectable ASPS received cediranib at the pediatric maximum tolerated dose of 12 mg/m² (≈70% of the fixed adult phase-II dose orally daily). Tumor response was assessed every two cycles (RECIST v1.0). A Simon two-stage optimal design (target response rate 35%, rule out 5%) was used.

RESULTS

Seven patients (four females), with a median age of 13 years, (range 9-15), were enrolled on stage 1. The most frequent grade 2 or 3 adverse events were neutropenia, diarrhea, hypertension, fatigue, and proteinuria. The best response was stable disease (SD) (median cycle number = 34). Three patients were removed from the study treatment for disease progression (cycles 4, 5, and 36). Five of seven patients had SD for ≥14 months. Two patients with SD remain on study (34-57+ cycles).

CONCLUSIONS

Cediranib did not reach the target response rate in this small pediatric cohort, in contrast to the adult 35% PR rate. The pediatric dosing was 30% lower compared to the adult dosing, which may have contributed to response differences. Prolonged SD was observed in five patients, but given the indolent nature of ASPS, SD cannot be clearly attributed to cediranib. Cediranib has an acceptable safety profile.

Brain Metastases and Place of Antiangiogenic Therapies in Alveolar Soft Part Sarcoma: A Retrospective Analysis of the French Sarcoma Group

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a rare sarcoma characterized by a slow evolution, brain metastasis (BM), and resistance to doxorubicin. Antiangiogenic therapies (AAT) have shown clinical activity, but little is known about the optimal therapeutic strategy, specifically considering BM.

SUBJECTS, MATERIALS, AND METHODS

We performed a retrospective analysis of all patients with ASPS treated in three referral centers of the French Sarcoma Group. We aimed to describe factors associated with overall survival (OS) and the impact of BM on outcome of patients treated by AAT.

RESULTS

We identified 75 patients between 1971 and 2012 (median age = 23, range: 5-96 years). Median follow-up was 74 months. Patients with localized (n = 44, 59%) and metastatic (n = 31, 41%) diseases had a 10-year OS of 69% and 25%, respectively. Only surgical incomplete resection was associated with shorter OS in localized disease (hazard ratio [HR] = 5.2, 95% confidence interval [CI] 1.2-22.4, p = .02). Fifty-two (69%) patients developed lung metastasis (LM; baseline: n = 31, [41%]; de novo: n = 21, [28%]). Thirteen patients developed BM, all occurring after LM. Tumor size ≥5 cm was associated with poorer BM-free survival (HR = 8.4, 95% CI 2.1-33.9, p = .002). Median OS post-BM was 17 months (95% CI 15 to not assessable). Overall, 12 patients were treated with AAT (sunitinib n = 10): 5 patients had BM and achieved poor outcomes compared with patients without, with median progression-free-survivals of 2 versus 11 months, respectively.

CONCLUSION

Baseline larger tumors were associated with increased risk of brain metastasis in patients with ASPS. Patients with BM seem to have little benefit from AAT, suggesting the need to develop antineoplastic agents with high central nervous system penetrance in this setting.

IMPLICATIONS FOR PRACTICE

Alveolar soft part sarcoma (ASPS) is an extremely rare subtype of sarcoma that is particularly resistant to conventional therapies. Antiangiogenic therapies (AAT) have shown promising results. However, patients with ASPS still die of tumor evolution. This study highlights the prognostic shift induced by brain metastasis (BM), identifying this event as a major contributor to the death of patients with ASPS, and observes a striking lack of effectiveness of AAT in patients who had previously developed BM. This observation is of interest for the therapeutic development in ASPS, highlighting the need to develop strategies dedicated to BM, such as radiosurgery or high-central nervous system penetrance tyrosine kinase inhibitors.

Effective treatment of advanced alveolar soft part sarcoma with sunitinib: A case report

RATIONALE

Alveolar soft part sarcoma (ASPS) is a very rare soft tissue sarcoma. ASPS often occurs in deep soft tissues of the lower extremities, and develops into metastatic diseases. Chemotherapy is considered to be ineffective in patients with ASPS, which constitutes a very important clinical challenge. The strategy for ASPS treatment still requires clarification in order to improve survival outcome. Patients concerns: A 19-year-old female patient presented with a 5-year history of painless lump in the left knee and 4-day cough. Her previous medical history was unremarkable. Menstruation and family history were also normal in this patient, whose physical examination and laboratory test results showed no abnormalities.

DIAGNOSIS

ASPS was confirmed by clinical manifestations, radiological data and pathological diagnosis of the biopsy of left knee.

INTERVENTIONS AND OUTCOMES

This patient received circulating tumor DNA detection and only a mutation of the SMARCA4 gene was detected. The patient received sunitinib treatment (37.5 mg once daily) for 15 months and showed partial regression of lung metastatic lesions and stabilization of brain metastases. She achieved 15 months of progression free survival.

CONCLUSIONS

Sunitinib is effective for the treatment of advanced ASPS with lung and brain metastases. The current patient had long-term progression free survival under sunitinib administration.

A Phase II Trial of Pazopanib in Patients with Metastatic Alveolar Soft Part Sarcoma

Lessons Learned.

Pazopanib shows a modest efficacy in metastatic alveolar soft part sarcoma.

Clinical outcomes were comparable to those in previous studies using antiangiogenic drugs.

Further prospective studies evaluating the benefit of pazopanib in alveolar soft part sarcoma with a larger sample are warranted to validate results.

Background.

Alveolar soft part sarcoma (ASPS) is a rare mesenchymal malignant tumor characterized by an unbalanced translocation, t(X;17)(p11.2;q25), which leads to the fusion of ASPSCR1 to the TFE3 transcription factor. Because this results in the upregulation of angiogenesis‐related transcripts, antiangiogenic drugs have been used in ASPS patients.

Methods.

This open‐label, single‐arm, multicenter, investigator‐initiated phase II trial was designed to evaluate efficacy and safety of pazopanib 800 mg once daily in patients with metastatic ASPS. The primary endpoint was investigator‐assessed overall response rate (ORR), and secondary endpoints were toxicity, progression‐free survival (PFS), and overall survival (OS). ⁶⁸Ga‐RGD (Arg‐Gly‐Asp) positron emission tomography (PET) scan and gene expression profiling using NanoString platform were performed for biomarker analysis.

Results.

Six patients with histologically confirmed metastatic ASPS were enrolled between December 2013 and November 2014. Among six patients, one achieved a partial response (PR) (ORR 16.7%) and five patients showed stable disease (SD). With a median follow‐up of 33 months (range 18.7–39.3 months), median PFS was 5.5 months (95% confidence interval [CI] 3.4–7.6 months), and median OS was not reached. There were no severe toxicities except one patient with grade 3 diarrhea.

Conclusion.

Pazopanib showed modest antitumor activity with manageable toxicities for patients with metastatic ASPS.

Activity of Pazopanib and Trabectedin in Advanced Alveolar Soft Part Sarcoma

BACKGROUND

Alveolar soft part sarcoma (ASPS) is an exceedingly rare and orphan disease, without active drugs approved in the front line. Pazopanib and trabectedin are licensed for sarcoma treatment from second-line, but very little and contradictory data are available on their activity in ASPS. Lacking ongoing and/or planned clinical trials, we conducted a multi-institutional study involving the reference sites for sarcoma in Europe, U.S., and Japan, within the World Sarcoma Network, to investigate the efficacy of pazopanib and trabectedin.

MATERIALS AND METHODS

From May 2007, 14 of the 27 centers that were asked to retrospectively review their databases had identified 44 advanced ASPS patients treated with pazopanib and/or trabectedin. Response was evaluated by Response Evaluation Criteria in Solid Tumors 1.1. Progression-free survival (PFS) and overall survival (OS) were computed by Kaplan-Meier method.

RESULTS

Among 30 patients who received pazopanib, 18 were pretreated (13 with other antiangiogenics). Response was evaluable in 29/30 patients. Best responses were 1 complete response, 7 partial response (PR), 17 stable disease (SD), and 4 progressions. At a 19-month median follow-up, median PFS was 13.6 months (range: 1.6-32.2+), with 59% of patients progression-free at 1 year. Median OS was not reached.Among 23 patients treated with trabectedin, all were pretreated and evaluable for response. Best responses were 1 PR, 13 SD, and 9 progressions. At a 27-month median follow-up, median PFS was 3.7 months (range: 0.7-109), with 13% of patients progression-free at 1 year. Median OS was 9.1 months.

CONCLUSION

The value of pazopanib in advanced ASPS is confirmed, with durable responses, whereas the value of trabectedin appears limited. These results are relevant to defining the best approach to advanced ASPS.

IMPLICATIONS FOR PRACTICE

This retrospective study, conducted among the world reference centers for treatment of sarcoma, confirms the value of pazopanib in patients with advanced alveolar soft part sarcoma (ASPS), with dimensional and durable responses, whereas trabectedin shows a limited activity. Alveolar soft part sarcoma is resistant to conventional cytotoxic chemotherapy. Pazopanib and trabectedin are licensed for treatment of sarcoma from second line; in the lack of prospective clinical trials, these results are relevant to defining ASPS best management and strongly support initiatives aimed at obtaining the approval of pazopanib in the front line of the disease.

Lingual alveolar soft part sarcoma responsive to pazopanib: A case report

RATIONALE

The multi-targeted tyrosine kinase inhibitors such as cediranib, sunitinib and pazopanib have been reported to be effective for alveolar soft part sarcoma (ASPS). The efficacy of pazopanib for the patient with lingual ASPS has yet to be reported.

PATIENT CONCERNS

A 23-year old man presented with articulation disorder and swelling of the tongue. Diagnosis of lingual ASPS was made after incisional biopsy and complete excision of the mass was performed. Three months later, he presented with a protruding mental region.

DIAGNOSES

Computed tomography revealed mental region mass and lung metastasis.

INTERVENTIONS

After the failure of combination therapy of doxorubicin and ifosfamide, pazopanib was administered.

OUTCOMES

Shrinkage of both the mental region and lung mass continued for more than two months, but regrowth was confirmed at the fourth month.

LESSONS

Lingual ASPS is an exceedingly rare subset of ASPS with distinct molecular and histological characteristics and appropriate therapy remains to be established. Our findings suggest a possible therapeutic strategy for lingual ASPS.

Cabozantinib and dastinib exert anti-tumor activity in alveolar soft part sarcoma

Background

Alveolar soft part sarcoma (ASPS) is an extremely rare metastatic soft tissue tumor with a poor prognosis for which no effective systemic therapies have yet been established. Therefore, the development of novel effective treatment approaches is required. Tyrosine kinases (TKs) are being increasingly used as therapeutic targets in a variety of cancers. The purpose of this study was to identify novel therapeutic target TKs and to clarify the efficacy of TK inhibitors (TKIs) in the treatment of ASPS.

Experimental design

To identify novel therapeutic target TKs in ASPS, we evaluated the antitumor effects and kinase activity of three TKIs (pazopanib, dasatinib, and cabozantinib) against ASPS cells using an in vitro assay. Based on these results, we then investigated the phosphorylation activities of the identified targets using western blotting, in addition to examining antitumor activity through in vivo assays of several TKIs to determine both the efficacy of these substances and accurate targets.

Results

In cell proliferation and invasion assays using pazopanib, cabozantinib, and dasatinib, all three TKIs inhibited the cell growth in ASPS cells. Statistical analyses of the cell proliferation and invasion assays revealed that dasatinib had a significant inhibitory effect in cell proliferation assays, and cabozantinib exhibited marked inhibitory effects on cellular functions in both assays. Through western blotting, we also confirmed that cabozantinib inhibited c-MET phosphorylation and dasatinib inhibited SRC phosphorylation in dose-dependent fashion. Mice that received cabozantinib and dasatinib had significantly smaller tumor volumes than control animals, demonstrating the in vivo antitumor activity of, these substances.

Conclusions

Our findings suggest that cabozantinib and dasatinib may be more effective than pazopanib against ASPS cells. These in vitro and in vivo data suggest that c-MET may be a potential therapeutic target in ASPS, and cabozantinib may be a particularly useful therapeutic option for patients with ASPS, including those with pazopanib-resistant ASPS.

Primary alveolar soft-part sarcoma of the liver: anomalous presentation of a rare disease

Alveolar soft-part sarcoma is a highly vascular soft-tissue tumor that is uniformly malignant. It comprises less than 1 per cent of all soft-tissue sarcomas. Patients with alveolar soft-part sarcoma most frequently are aged 15 to 35 years, and the soft tissues of the lower extremities typically are affected. In the pediatric population, it most frequently occurs in the head and neck and particularly affects the tongue and orbit. Alveolar soft-part sarcoma has been described as a primary lesion in the trunk, upper extremities, and retroperitoneum; more novel locations include the mediastinum, female genital tract, stomach, bone, and larynx. Numerous case reports describe alveolar soft-part sarcoma in diverse anatomic locations, but this report is, to our knowledge, the first documentation of primary alveolar soft-part sarcoma of the liver. We describe a 47-year-old woman with such a manifestation. Despite surgical resection and numerous chemotherapeutic regimens, this patient had widespread metastasis and died approximately 2 years after the diagnosis was established.

[Clinical features and prognosis of alveolar soft part sarcoma]

OBJECTIVE

To investigate the clinical feature, suitable treatment and prognosis of alveolar soft part sarcoma.

METHODS

The clinical data of 58 such patients treated at our hospital from 1967 to 2006 were retrospectively analyzed. Fifty-three patients except 6 with distant metastasis underwent surgical resection including 33 extensive resection and 19 local resection. Furthermore, 19 patients received postoperative adjuvant radiotherapy or chemotherapy.

RESULTS

Eleven of 50 patients who underwent complete resection developed local recurrence. Thirty-One (53.4%) was found to have lung metastasis. The overall 3-, 5-, 10-year survival rate was 89.5%, 74.1% and 57.7%, respectively. The median survival time of the patients was 125 months. The 3-, 5-, 10-year survival rate was 100.0%, 81.6% and 65.3% for female patients, but it was 79.6%, 67.2% and 49.7% for male patients, respectively.

CONCLUSION

Alveolar soft part sarcoma usually grows slowly. Though local recurrence is rarely seen, distant metastasis is frequently observed. Lung is the most common organ of metastasis. However, survival can still be long even with lung metastasis. To achieve microscopically complete resection is quite critical to localized alveolar soft part sarcoma. No survival advantage was observed when adding adjuvant radiotherapy and/or chemotherapy. The phenomena of female patient or patient with X chromosome translocation showing better prognosis than the male or other patients needs further investigation.

Chemotherapy in alveolar soft part sarcomas. What do we know?

Alveolar soft part sarcoma (ASPS) is a rare tumour. Published series about treatment and outcome are scarce. Conclusive data about the response to chemotherapy are not available. The aim of this study was to analyse the efficacy of palliative chemotherapeutic treatment options and the incidence and mode of presentation of brain metastases. We retrospectively analysed our own sarcoma data-base and reviewed the literature. From our registry containing 757 patients, we identified 8 patients with ASPS. From the literature, 47 cases of adult patients and 13 children with sufficient data about chemotherapy were identified. Response to first-line chemotherapy in 68 patients was: complete remission (CR) 4%, partial remission (PR) 3%, stable disease (SD) 41%, progressive disease (PD) 51%. 285 patients with stage IV disease were evaluable for the analysis of metastatic sites. The incidence of brain metastases was 30.5% (87/285). Brain metastases were detected at a median interval of 48 months (range 0-396 months) after the primary diagnosis. Median survival after the diagnosis of brain metastases was 12 months. The median survival for patients with stage IV disease treated by chemotherapy was 36+ months (range 10-132 months) (31 patients evaluable) with a median follow-up of 46 months (range 10-135 months). ASPS shows a high incidence of brain metastases, at least 3 times higher than that of other soft tissue sarcomas. Chemotherapeutic regimens used for the treatment of other soft tissue sarcomas lack efficacy in ASPS. Staging investigations for ASPS should routinely include imaging of the brain. ASPS patients should not be treated with chemotherapy outside of controlled clinical trials. New targets for specific biologically-directed therapies need to be developed.

Alveolar soft-part sarcoma of the orbit

Alveolar soft-part sarcoma is a malignant soft tissue neoplasm that involves mainly the deep soft tissues of the extremities, particularly the thighs and the buttock. Involvement of the orbit is uncommon. We describe a young child with such a tumor and illustrate the characteristic features.