Clinical activity of checkpoint inhibitors in angiosarcoma: A retrospective cohort study.

BACKGROUND: Systemic treatments for angiosarcoma remains an area of unmet clinical need. The authors conducted this retrospective study to assess the clinical activity of checkpoint inhibitors in patients with angiosarcoma. The primary objective was to assess the objective response rate, and the secondary objective was to assess the progression-free and overall survival durations and disease control rate. METHODS: Patient data were obtained using The University of Texas MD Anderson Cancer Center Tumor Registry database. The final study population was refined to only include patients who had undergone pembrolizumab monotherapy. The objective response rate was evaluated using RECIST/irRECIST version 1.1. Progression-free survival and overall survival were defined as the time from the initiation of immunotherapy to disease progression or recurrence, death, or last follow-up and to death or last follow-up, respectively. RESULTS: The final cohort comprised 25 patients. Most patients had metastatic disease (72%) and had undergone at least two lines of systemic therapy (80%) before starting pembrolizumab. The objective response rate was 18%, whereas the disease control rate was 59%. The median progression-free survival duration was 6.2 months and was not significantly different between the cutaneous (4.7 months) and visceral angiosarcoma (6.2 months) groups (p = .42). The median overall survival duration was 72.6 months. Toxicities were recorded for eight patients, with fatigue, anemia, constipation, and rash being the most common. CONCLUSIONS: Pembrolizumab shows durable clinical activity in angiosarcoma. These findings suggest that checkpoint inhibition as monotherapy or combination therapy is likely to have a high probability of success.© 2022 American Cancer Society. LAY SUMMARY: This is the largest retrospective study to assess the clinical activity of checkpoint inhibitor monotherapy in angiosarcomas. The study includes an adequate number of patients with visceral angiosarcoma that enabled to obtain meaningful clinical insights that were previously unavailable. Our findings indicate an improvement in progression-free survival with pembrolizumab that is comparable to other active agents in angiosarcoma. Pembrolizumab monotherapy in angiosarcomas also has a favorable tolerability profile. Our findings emphasize the need for prospective studies to evaluate the activity of pembrolizumab monotherapy and combination therapy.

An updated review of the treatment landscape for advanced gastrointestinal stromal tumors.

Before the introduction of tyrosine kinase inhibitors (TKIs), the overall survival of patients with advanced or metastatic gastrointestinal stromal tumors (GISTs) was 10 to 20 months because of the lack of approved therapies. In the last 20 years, a treatment algorithm for patients with advanced GISTs, which includes imatinib, sunitinib, and regorafenib as first-, second-, and third-line therapies, respectively, has been established. Recently, 2 new TKIs have been approved: ripretinib for fourth-line therapy and avapritinib as first-line therapy in patients harboring platelet-derived growth factor receptor α (PDGFRA) exon 18 D842V mutations. Additionally, there are several experimental therapies under investigation that could advance individualized patient care. All of these therapies have varying efficacies and safety profiles that warrant an updated treatment landscape review. This review article summarizes the efficacy and safety data currently available for conventional TKIs along with recently approved and experimental therapies.

Real-world outcomes of patients with locally advanced or metastatic epithelioid sarcoma.

BACKGROUND: Limited data are available on the real-world effectiveness and safety of systemic therapies for advanced (surgically unresectable and/or metastatic) epithelioid sarcoma (ES). METHODS: A retrospective medical records review was conducted in patients with advanced ES who were initiating first-line or ≥2 lines of systemic therapy (2000-2017) at 5 US cancer centers. The real-world overall response rate (rwORR), the duration of response (rwDOR), the disease control rate (rwDCR) (defined as stable disease for ≥32 weeks or any duration of response), and progression-free survival (rwPFS) were assessed by radiology reports. Overall survival (OS), rwDOR, and rwPFS were estimated from the time therapy was initiated using the Kaplan-Meier method. Serious adverse events were assessed. RESULTS: Of 74 patients (median age at diagnosis, 33 years; range, 10.6-76.3 years), 72% were male, and 85% had metastatic disease. The median number of lines of therapy was 2 (range, 1-7 lines of therapy), and 46 patients (62%) received ≥2 lines of systemic therapy. First-line regimens were usually anthracycline-based (54%) or gemcitabine-based (24%). For patients receiving first-line systemic therapy, the rwORR was 15%, the rwDCR was 20%, the median rwDOR was 3.3 months (95% CI, 2.1-5.2 months), the median rwPFS was 2.5 months (95% CI, 1.7, 6.9 months), and the median OS was 15.2 months (95% CI, 11.4-21.7 months). For those who received ≥2 lines of systemic therapy, the rwORR was 9%, the rwDCR was 20%, the median rwDOR was 4.5 months (95% CI, 0.7-5.6 months), and the median rwPFS was 6.0 months (95% CI, 3.2-7.4 months). Over one-half of patients (51.4%) experienced an adverse event, most frequently febrile neutropenia (14%), pain (10%), anemia, dyspnea, fever, thrombocytopenia, or transaminitis (5% each). CONCLUSIONS: Systemic therapies demonstrate limited efficacy in patients with advanced ES and have associated toxicities.

Ultra-rare sarcomas: A consensus paper from the Connective Tissue Oncology Society community of experts on the incidence threshold and the list of entities.

BACKGROUND: Among sarcomas, which are rare cancers, many types are exceedingly rare; however, a definition of ultra-rare cancers has not been established. The problem of ultra-rare sarcomas is particularly relevant because they represent unique diseases, and their rarity poses major challenges for diagnosis, understanding disease biology, generating clinical evidence to support new drug development, and achieving formal authorization for novel therapies. METHODS: The Connective Tissue Oncology Society promoted a consensus effort in November 2019 to establish how to define ultra-rare sarcomas through expert consensus and epidemiologic data and to work out a comprehensive list of these diseases. The list of ultra-rare sarcomas was based on the 2020 World Health Organization classification, The incidence rates were estimated using the Information Network on Rare Cancers (RARECARENet) database and NETSARC (the French Sarcoma Network's clinical-pathologic registry). Incidence rates were further validated in collaboration with the Asian cancer registries of Japan, Korea, and Taiwan. RESULTS: It was agreed that the best criterion for a definition of ultra-rare sarcomas would be incidence. Ultra-rare sarcomas were defined as those with an incidence of approximately ≤1 per 1,000,000, to include those entities whose rarity renders them extremely difficult to conduct well powered, prospective clinical studies. On the basis of this threshold, a list of ultra-rare sarcomas was defined, which comprised 56 soft tissue sarcoma types and 21 bone sarcoma types. CONCLUSIONS: Altogether, the incidence of ultra-rare sarcomas accounts for roughly 20% of all soft tissue and bone sarcomas. This confirms that the challenges inherent in ultra-rare sarcomas affect large numbers of patients.

Safety and efficacy of trabectedin when administered in the inpatient versus outpatient setting: Clinical considerations for outpatient administration of trabectedin.

BACKGROUND: The results of the randomized, phase 3 ET743-SAR-3007 trial demonstrated that trabectedin had a significantly longer progression-free survival (PFS) compared with dacarbazine in patients with advanced leiomyosarcoma/liposarcoma after the failure of prior chemotherapy. Patients randomized to trabectedin received a 24-hour intravenous infusion either in an inpatient or outpatient setting. Herein, the authors reported the safety, efficacy, and patient-reported outcomes based on first infusion site of care. METHODS: Patients were randomized 2:1 to trabectedin (at a dose of 1.5 mg/m2 ) or dacarbazine (1 g/m2 over 20-120 minutes) with overall survival (OS) as the primary endpoint and PFS, time to disease progression, objective response rate, duration of response, safety, and patient-reported symptom scoring as secondary endpoints. The setting of the trabectedin infusion was based on institutional preference and categorized based on the setting of the first infusion. RESULTS: Of the 378 patients who were treated with trabectedin, 100 (27%) and 277 (73%), respectively, first received trabectedin in the inpatient and outpatient setting. No differences were observed with regard to PFS or OS based on site of care. The median PFS was 4.1 months versus 4.2 months (hazard ratio, 0.90; P = .49) for inpatients versus outpatients, respectively, and the median OS was 14.3 months versus 13.7 months (hazard ratio, 0.89; P = .40), respectively. Grade 3/4 adverse events (classified according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]) were reported in 87 inpatients (87%) compared with 219 outpatients (79%); grade 3/4 serious adverse events were reported in 43 inpatients (43%) and 92 outpatients (33%). Extravasation occurred in 0 inpatients and 5 outpatients (2%), whereas the incidence of catheter-related complications was similar between groups (16% vs 15%). CONCLUSIONS: Although the majority of patients who were randomized to trabectedin received outpatient therapy, the outcomes of the current study suggested equivalent safety and efficacy in either setting.

Outcome of First-Line Systemic Treatment for Unresectable Conventional, Dedifferentiated, Mesenchymal, and Clear Cell Chondrosarcoma.

BACKGROUND: Chondrosarcoma is a heterogeneous group of primary bone sarcoma with an excellent overall survival after local therapy. However, the small percentage of patients who have no surgical treatment options have a very poor prognosis. We retrospectively collected data from these patients in four sarcoma centers and compared the progression-free survival (PFS) for the different treatment regimens used for the four chondrosarcoma subtypes. MATERIALS AND METHODS: Patients diagnosed with unresectable chondrosarcoma in all four major sarcoma centers were included, and data on first-line systemic therapy were retrospectively collected for analysis. RESULTS: A total of 112 patients were enrolled in this retrospective analysis: 50 conventional, 25 mesenchymal, 34 dedifferentiated, and 3 clear cell chondrosarcoma patients. In conventional chondrosarcoma patients, the longest mean PFS (6.7 months) was found in the group treated with antihormonal therapy. Patients diagnosed with mesenchymal chondrosarcoma were all treated with multidrug chemotherapy, and the mean PFS was 6.7 months. Doxorubicin monotherapy seems to have an unexplained better PFS than doxorubicin-based combination therapy in patients with dedifferentiated chondrosarcoma (5.5 vs. 2.8 months, respectively; p = .275). CONCLUSION: Prospective studies need to be conducted based on preclinical work to develop a uniform regimen to treat advanced chondrosarcoma patients according to the diagnosed subtype and improve survival. IMPLICATIONS FOR PRACTICE: Currently, there are no uniform treatment lines for advanced chondrosarcoma patients, which results in a very diverse group of treatment regimens being used. In this study, the data of 112 patients was collected. It was concluded that some treatment regimens seem to have a better progression-free survival compared with others, and that these results also differ between the chondrosarcoma subtypes. Prospective studies need to be conducted based on preclinical work to develop a uniform regimen to treat advanced chondrosarcoma patients according to the diagnosed histological subtype to improve their survival.

Phase II study of neoadjuvant checkpoint blockade in patients with surgically resectable undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma.

BACKGROUND: Soft tissue sarcomas are a heterogeneous and rare group of solid tumors of mesenchymal origin that can arise anywhere in the body. Although surgical resection is the mainstay of treatment for patients with localized disease, disease recurrence is common and 5-year overall survival is poor (~ 65%). Both radiation therapy and conventional chemotherapy are used to reduce local and distant recurrence. However, the utility of radiation therapy is often limited by disease location (in the case of retroperitoneal sarcomas, for instance) while systemic therapy with conventional lines of chemotherapy offer limited efficacy and are often poorly tolerated and associated with significant toxicity. Within the past decade, major advances have been made in the treatment of other malignancies including melanoma, renal cell carcinoma, and non-small cell lung carcinoma with the advent of immune-checkpoint inhibitors such as ipilimumab (anti-CTLA4), pembrolizumab (anti-PD1), and nivolumab (anti-PD1). The recently published SARC028 (NCT02301039), an open label, phase II, multicenter trial of pembrolizumab in patients with advanced bone and soft tissue sarcomas reported promising activity in select histologic subtypes of advanced STS, including undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma. METHODS: There is a clear need for novel and effective adjuncts in the treatment of STS. We hypothesize that immune checkpoint blockade will be effective in patients with surgically resectable primary or locally recurrent dedifferentiated liposarcoma and undifferentiated pleomorphic sarcoma when administered in the neoadjuvant setting. The primary aim of this phase II, single-center, open label, randomized non-comparative trial is to determine the pathologic response to neoadjuvant nivolumab monotherapy and combination nivolumab/ipilimumab in patients with resectable dedifferentiated liposarcoma of the retroperitoneum or undifferentiated pleomorphic sarcoma of the trunk or extremity treated with concurrent standard of care neoadjuvant radiation therapy. DISCUSSION: This study will help define the role of single agent anti-PD1 and combination anti-CTLA4 and anti-PD1 therapy in patients with surgically resectable dedifferentiated liposarcoma and undifferentiated pleomorphic sarcoma. TRIAL REGISTRATION: ClinicalTrials.gov NCT03307616 , registered October 12, 2017.

Clinical trial enrollment of adolescents and young adults with sarcoma.

More than half of all sarcomas occur in adolescents and young adults (AYAs) aged 15 to 39 years. After the publication of the AYA series in the April 1, 2016 issue of Cancer, several leaders in the field of sarcoma across disciplines gathered to discuss the status of sarcoma clinical research in AYAs. They determined that a focused effort to include the underrepresented and understudied AYA population in current and future sarcoma clinical trials is overdue. Trial enrichment for AYA-aged sarcoma patients will produce more meaningful results that better represent the disease's biology, epidemiology, and treatment environment. To address the current deficit, this commentary outlines changes believed to be necessary to expediently achieve an increase in the enrollment of AYAs in sarcoma clinical trials. Cancer 2017;123:3434-40. © 2017 American Cancer Society.

Phase 2 study of dasatinib in patients with alveolar soft part sarcoma, chondrosarcoma, chordoma, epithelioid sarcoma, or solitary fibrous tumor.

BACKGROUND: Alveolar soft part sarcoma (ASPS), chondrosarcoma (CS), chordoma, epithelioid sarcoma, and solitary fibrous tumor (SFT) are malignant tumors that are relatively resistant to chemotherapy and for which more effective drug therapy is needed. METHODS: The 5 listed subtypes were enrolled into a single indolent sarcoma cohort in a phase 2 study of dasatinib using a Bayesian continuous monitoring rule for enrollment. The primary objective was to estimate the 6-month progression-free survival (PFS) rate according to the Choi criteria with a target of ≥50%. Cross-sectional imaging was performed before the start of treatment, every 2 months for 6 months, and then every 3 months during treatment. The 2- and 5-year survival rates were determined. RESULTS: One hundred sixteen patients were enrolled within 45 months, and 109 began treatment with dasatinib. The 6-month PFS rate and the median PFS were 48% and 5.8 months, respectively. The PFS rate at 6 months was highest with ASPS (62%) and lowest with SFT (30%). More than 10% of the patients with ASPS, CS, or chordoma had stable disease for more than 1 year. Collectively, for all 5 subtypes, the 2- and 5-year overall survival rates were 44% and 13%, respectively. An objective response was observed in 18% of the patients with CS or chordoma. CONCLUSIONS: Dasatinib failed to achieve control of sarcoma growth for at least 6 months in more than 50% of the patients in this trial according to the Choi tumor response criteria. An objective tumor response and prolonged stable disease was observed in >10% of patients with CS or chordoma. Cancer 2017;90-97. © 2016 American Cancer Society.

Eribulin versus dacarbazine in previously treated patients with advanced liposarcoma or leiomyosarcoma: a randomised, open-label, multicentre, phase 3 trial.

BACKGROUND: A non-randomised, phase 2 study showed activity and tolerability of eribulin in advanced or metastatic soft-tissue sarcoma. In this phase 3 study, we aimed to compare overall survival in patients with advanced or metastatic soft-tissue sarcoma who received eribulin with that in patients who received dacarbazine (an active control). METHODS: We did this randomised, open-label, phase 3 study across 110 study sites in 22 countries. We enrolled patients aged 18 years or older with intermediate-grade or high-grade advanced liposarcoma or leiomyosarcoma who had received at least two previous systemic regimens for advanced disease (including an anthracycline). Using an interactive voice and web response system, an independent statistician randomly assigned (1:1) patients to receive eribulin mesilate (1·4 mg/m(2) intravenously on days 1 and 8) or dacarbazine (850 mg/m(2), 1000 mg/m(2), or 1200 mg/m(2) [dose dependent on centre and clinician] intravenously on day 1) every 21 days until disease progression. Randomisation was stratified by disease type, geographical region, and number of previous regimens for advanced soft-tissue sarcoma and in blocks of six. Patients and investigators were not masked to treatment assignment. The primary endpoint was overall survival in the intention-to-treat population. The study is registered with ClinicalTrials.gov, number NCT01327885, and is closed to recruitment, but treatment and follow-up continue. FINDINGS: Between March 10, 2011 and May 22, 2013, we randomly assigned patients to eribulin (n=228) or dacarbazine (n=224). Overall survival was significantly improved in patients assigned to eribulin compared with those assigned to dacarbazine (median 13·5 months [95% CI 10·9-15·6] vs 11·5 months [9·6-13·0]; hazard ratio 0·77 [95% CI 0·62-0·95]; p=0·0169). Treatment-emergent adverse events occurred in 224 (99%) of 226 patients who received eribulin and 218 (97%) of 224 who received dacarbazine. Grade 3 or higher adverse events were more common in patients who received eribulin (152 [67%]) than in those who received dacarbazine (126 [56%]), as were deaths (10 [4%] vs 3 [1%]); one death (in the eribulin group) was considered treatment-related by the investigators. INTERPRETATION: Overall survival was improved in patients assigned to eribulin compared with those assigned to an active control, suggesting that eribulin could be a treatment option for advanced soft-tissue sarcoma. FUNDING: Eisai.

Vincristine, Ifosfamide, and Doxorubicin for Initial Treatment of Ewing Sarcoma in Adults.

BACKGROUND: There are no clinical trials specifically addressing chemotherapy for adults with Ewing sarcoma (ES). Five-year event-free survival (EFS) of adults on pediatric studies of ES (44%-47%) is worse than that of children treated with the same therapy (69%). The object of this study was to review the results of therapy with vincristine, ifosfamide, and doxorubicin (VID) in the multidisciplinary treatment of adults with ES at our institution. MATERIALS AND METHODS: Charts for adults treated for ES from 1995 to 2011 were retrospectively reviewed. Clinician-reported radiographic tumor response, type of local therapy, pathologic response, and survival data were collected. RESULTS: Seventy-one patients were identified who received VID as initial therapy. The median age was 25 (range: 16-64). Forty-two patients (59%) presented with a localized disease and 29 patients (41%) presented with a distant metastasis. Of all patients treated with VID, 83.6% showed a radiological response. Patients who presented with a localized disease had a 5-year overall survival (OS) of 68% (median not reached), compared with 10.3% (median: 1.9 years) in those who presented with distant metastases. Five-year EFS was 67%. The nine patients with a pelvic primary tumor had inferior 5-year OS (42%) to the 33 with primary tumors at other sites (75%). The 5-year OS of those who had greater than or equal to 95% necrosis after neoadjuvant VID (n = 20; 5-year OS: 84%) was superior to those who had less than 95% necrosis (n = 13; 5-year OS: 53%). CONCLUSION: In adults with primary ES, VID combined with an adjuvant strategy based on post-treatment percent necrosis has favorable outcomes compared with historical adult controls. IMPLICATIONS FOR PRACTICE: Ewing sarcoma (ES) is a rare tumor in adults, and there are no dedicated clinical trials in the adult population. Most therapy is modeled after the published pediatric studies, although the small numbers of adult patients included on those studies did significantly worse than the children. We modeled our treatment on other adult sarcomas and reviewed the charts of 71 adult patients with ES treated with vincristine, ifosfamide, and doxorubicin (VID). In adults with primary ES, VID combined with an adjuvant strategy based on post-treatment percent necrosis has favorable outcomes compared with historical adult controls.

Efficacy and safety of trabectedin or dacarbazine in patients with advanced uterine leiomyosarcoma after failure of anthracycline-based chemotherapy: Subgroup analysis of a phase 3, randomized clinical trial.

OBJECTIVE: Trabectedin demonstrated significantly improved disease control in leiomyosarcoma and liposarcoma patients in a global phase 3 trial (NCT01343277). A post hoc analysis was conducted to assess the efficacy and safety of trabectedin or dacarbazine in women with uterine leiomyosarcoma (uLMS), the largest subgroup of enrolled patients (40%). METHODS: Of 577 patients randomized 2:1 to receive trabectedin 1.5mg/m2 by 24-hour IV infusion or dacarbazine 1g/m2 by 20-120-minute IV infusion once every three weeks, 232 had uLMS (trabectedin: 144; dacarbazine: 88). The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival (PFS), objective response rate (ORR), clinical benefit rate (CBR: complete responses+partial responses+stable disease [SD] for at least 18weeks), duration of response (DOR), and safety. RESULTS: PFS for trabectedin was 4.0months compared with 1.5months for dacarbazine (hazard ratio [HR]=0.57; 95% CI 0.41-0.81; P=0.0012). OS was similar (trabectedin 13.4months vs. dacarbazine 12.9months, HR=0.89; 95% CI 0.65-1.24; P=0.51) between groups. ORR was 11% with trabectedin vs. 9% with dacarbazine (P=0.82). CBR for trabectedin was 31% vs. 18% with dacarbazine (P=0.05); median DOR was 6.5months for trabectedin vs. 4.1months for dacarbazine (P=0.32). Grade 3/4 treatment-emergent adverse events observed in ≥10% of patients in the trabectedin group included transient aminotransferase (aspartate/alanine) elevations, anemia, leukopenia, and thrombocytopenia. CONCLUSIONS: In this post hoc subset analysis of patients with uLMS who had received prior anthracycline therapy, trabectedin treatment resulted in significantly longer PFS versus dacarbazine, with an acceptable safety profile. There was no difference in OS.

The Role of Next-Generation Sequencing in Sarcomas: Evolution From Light Microscope to Molecular Microscope.

PURPOSE OF REVIEW: Sarcomas are rare, heterogeneous group of soft tissue and bone tumors. Precise diagnosis of specific subtypes is challenging using conventional methods. Herein, we review the role of next-generation sequencing (NGS) technology that is used for rapid sequencing of DNA and RNA. RECENT FINDINGS: Recent sarcoma specific studies recommend that molecular genetic testing should be added at diagnosis for appropriate clinical management in addition to diagnosis by expert pathologists. NGS has already been used to identify potentially actionable mutations, copy number alterations, and gene fusions. Rationally, choosing a drug based on an individual patient profile aka: "precision oncology" has been so far limited to few case reports in sarcomas. As we improve our ability to deliver personalized medicine using all modalities including conventional therapy, more patients may eventually benefit. As the cost and capacity of NGS outpace Moore's law, so does the probability of success.

Trabectedin and Eribulin: Where Do They Fit in the Management of Soft Tissue Sarcoma?

OPINION STATEMENT: Trabectedin and eribulin are two agents that have been recently approved for the treatment of specific soft tissue sarcoma subtypes. They have proved to be a much-needed line of additional treatment for patients with these rare tumors, but their activity remains admittedly modest in most cases. Further exploitation of these novel agents is likely to require a more granular understanding of the salient mechanisms of action. For example, if as some studies suggest, eribulin derives its benefit from restructuring of tumor vasculature to improve efficacy of subsequent lines of therapy, then patients may benefit from its use earlier in the treatment pathway. The sequencing of trabectedin with other agents is also worth examining. In a disease like myxoid liposarcoma, consideration should be given to using trabectedin before other salvage regimens like gemcitabine and docetaxel, given its tolerability and excellent efficacy against this sarcoma subtype. Also, to be further investigated is the use of trabectedin in sarcoma subtypes which were excluded from the phase III study, but in which activity has been documented in earlier trials and subsequent reports. Combinations of trabectedin with other agents, particularly doxorubicin, have been explored, but the data to date do not support the routine use of these regimens.

Chemotherapy for soft tissue sarcoma.

Soft tissue sarcoma is a term used to describe a heterogeneous group of many rare tumors. Since the initial description of activity of doxorubicin, several additional agents have been brought to bear in the treatment of these diseases. Despite 2 recent drug approvals, doxorubicin and ifosfamide remain the most effective chemotherapy drugs available for the treatment of majority of these tumors. Optimal dosing and administration influence outcomes because of the steep dose-response curves associated with these agents. The debate endures regarding whether patients who have advanced disease should routinely receive single agents sequentially or in combination. Adjuvant therapy remains similarly controversial, although meta-analyses do support its use. Contemporary treatment of soft tissue sarcoma routinely incorporates additional lines of treatment that have become available over the last 15 years. Fixed-dose-rate gemcitabine with or without docetaxel is a standard second-line treatment. In keeping with the paradigm shift favoring subset-specific therapy, several recent approvals are linked with specific sarcoma subtypes. Eribulin has recently been approved on the basis of improved overall survival for patients with adipocytic sarcomas, and trabectedin is now approved in the United States for patients with leiomyosarcoma and liposarcoma. Within the spectrum of targeted therapies, pazopanib is approved for all nonadipocytic sarcomas, and imatinib is approved for dermatofibrosarcoma protuberans. Each of these drugs represents incremental rather than radical progress, although they constitute important and much needed treatment options for patients with these diseases. Cancer 2016;122:2952-2960. © 2016 American Cancer Society.

SARC009: Phase 2 study of dasatinib in patients with previously treated, high-grade, advanced sarcoma.

BACKGROUND: Dasatinib exhibited activity in preclinical models of sarcoma. The Sarcoma Alliance for Research through Collaboration (SARC) conducted a multicenter, phase 2 trial of dasatinib in patients with advanced sarcoma. METHODS: Patients received dasatinib twice daily. The primary objective was to estimate the clinical benefit rate (CBR) (complete response or partial response within 6 months or stable disease duration of ≥6 months) with a target of ≥25%. Patients were enrolled into 1 of 7 different cohorts and assessed by imaging every 8 weeks using Choi criteria tumor response and a Bayesian hierarchical design. For each subtype, enrollment was stopped after a minimum of 9 patients were treated if there was a <1% chance the CBR was ≥25%. RESULTS: A total of 200 patients were enrolled. Accrual was stopped early in 5 cohorts because of low CBR. The leiomyosarcoma (LMS) and undifferentiated pleomorphic sarcoma (UPS) cohorts fully accrued and 6 of 47 and 8 of 42 evaluable patients, respectively, exhibited clinical benefit. The probability that the CBR was ≥25% in the LMS and UPS cohorts was 0.008 and 0.10, respectively. The median progression-free survival ranged from 0.9 months in patients with rhabdomyosarcoma to 2.2 months in patients with LMS. The median overall survival was 8.6 months. The most frequent adverse events were constitutional, gastrointestinal, and respiratory, and 36% of patients required dose reduction for toxicity. Serious adverse events attributed to therapy occurred in 11% of patients. CONCLUSIONS: Dasatinib may have activity in patients with UPS but is inactive as a single agent in the other sarcoma subtypes included herein. The Bayesian design allowed for the early termination of accrual in 5 subtypes because of lack of drug activity.

Loss of the DNA Repair Gene RNase H2 Identifies a Unique Subset of DDR-Deficient Leiomyosarcomas.

Targeting the DNA damage response (DDR) pathway is an emerging therapeutic approach for leiomyosarcoma (LMS), and loss of RNase H2, a DDR pathway member, is a potentially actionable alteration for DDR-targeted treatments. Therefore, we designed a protein- and genomic-based RNase H2 screening assay to determine its prevalence and prognostic significance. Using a selective RNase H2 antibody on a pan-tumor microarray (TMA), RNase H2 loss was more common in LMS (11.5%, 9/78) than across all tumors (3.8%, 32/843). In a separate LMS cohort, RNase H2 deficiency was confirmed in uterine LMS (U-LMS, 21%, 23/108) and soft-tissue LMS (ST-LMS; 30%, 39/102). In the TCGA database, RNASEH2B homozygous deletions (HomDels) were found in 6% (5/80) of LMS cases, with a higher proportion in U-LMS (15%; 4/27) compared with ST-LMS (2%; 1/53). Using the SNiPDx targeted-NGS sequencing assay to detect biallelic loss of function in select DDR-related genes, we found RNASEH2B HomDels in 54% (19/35) of U-LMS cases with RNase H2 loss by IHC, and 7% (3/43) HomDels in RNase H2 intact cases. No RNASEH2B HomDels were detected in ST-LMS. In U-LMS patient cohort (n = 109), no significant overall survival difference was seen in patients with RNase H2 loss versus intact, or RNASEH2B HomDel (n = 12) versus Non-HomDel (n = 37). The overall diagnostic accuracy, sensitivity, and specificity of RNase H2 IHC for detecting RNA-SEH2B HomDels in U-LMS was 76%, 93%, and 71%, respectively, and it is being developed for future predictive biomarker driven clinical trials targeting DDR in U-LMS.

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.

Impact of Biomarker-Matched Therapies on Outcomes in Patients with Sarcoma Enrolled in Early-Phase Clinical Trials (SAMBA 101).

PURPOSE: Developing new therapeutics for any of the more than 100 sarcoma subtypes presents a challenge. After progression from standard therapies, patients with sarcoma may be referred for enrollment in early-phase trials. This study aimed to investigate whether enrollment in biomarker-matched early-phase clinical trials leads to better outcomes for patients with advanced sarcoma. EXPERIMENTAL DESIGN: In this retrospective analysis, investigational treatment characteristics and longitudinal survival outcomes were analyzed in patients with biopsy-confirmed sarcoma enrolled in early-phase trials at MD Anderson Cancer Center from May 2006 to July 2021. RESULTS: Five hundred eighty-seven patients were included [405 soft tissue, 122 bone, 60 gastrointestinal stromal tumor (GIST); median of three prior lines of therapy]. Most common subtypes were leiomyosarcoma (17.2%), liposarcoma (14.0%), and GIST (10.2%). Molecular testing was available for 511 patients (87.1%); 221 patients (37.6%) were treated in matched trials. Overall response rate was 13.1% matched compared with 4.9% in unmatched (P < 0.001); the clinical benefit rate at 6 months was 43.9% vs. 19.9% (P < 0.001). Progression-free survival was longer for patients in matched trials (median, 5.5 vs. 2.4 months; P < 0.001), and overall survival was also superior for patients in matched trials (median, 21.5 vs. 12.3 months; P < 0.001). The benefit of enrollment in matched trials was maintained when patients with GIST were excluded from the analysis. CONCLUSIONS: Enrollment in biomarker-matched early-phase trials is associated with improved outcomes in heavily pretreated patients with metastatic sarcoma. Molecular testing of tumors from patients with advanced sarcoma and enrollment in matched trials is a reasonable therapeutic strategy.

Best clinical management of tenosynovial giant cell tumour (TGCT): A consensus paper from the community of experts.

Tenosynovial giant cell tumour (TGCT) is a rare, locally aggressive, mesenchymal tumor arising from the joints, bursa and tendon sheaths. TGCT comprises a nodular- and a diffuse-type, with the former exhibiting mostly indolent course and the latter a locally aggressive behavior. Although usually not life-threatening, TGCT may cause chronic pain and adversely impact function and quality of life (QoL). CSFR1 inhibitors are effective with benefit on symptoms and QoL but are not available in most countries. The degree of uncertainty in selecting the most appropriate therapy and the lack of guidelines on the clinical management of TGCT make the adoption of new treatments inconsistent across the world, with suboptimal outcomes for patients. A global consensus meeting was organized in June 2022, involving experts from several disciplines and patient representatives from SPAGN to define the best evidence-based practice for the optimal approach to TGCT and generate the recommendations presented herein.