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

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

Analysis of survival data with nonproportional hazards: A comparison of propensity-score-weighted methods.

One of the most common ways researchers compare cancer survival outcomes across treatments from observational data is using Cox regression. This model depends on its underlying assumption of proportional hazards, but in some real-world cases, such as when comparing different classes of cancer therapies, substantial violations may occur. In this situation, researchers have several alternative methods to choose from, including Cox models with time-varying hazard ratios; parametric accelerated failure time models; Kaplan-Meier curves; and pseudo-observations. It is unclear which of these models are likely to perform best in practice. To fill this gap in the literature, we perform a neutral comparison study of candidate approaches. We examine clinically meaningful outcome measures that can be computed and directly compared across each method, namely, survival probability at time T, median survival, and restricted mean survival. To adjust for differences between treatment groups, we use inverse probability of treatment weighting based on the propensity score. We conduct simulation studies under a range of scenarios, and determine the biases, coverages, and standard errors of the average treatment effects for each method. We then demonstrate the use of these approaches using two published observational studies of survival after cancer treatment. The first examines chemotherapy in sarcoma, which has a late treatment effect (i.e., similar survival initially, but after 2 years the chemotherapy group shows a benefit). The other study is a comparison of surgical techniques for kidney cancer, where survival differences are attenuated over time.

Sorafenib for Advanced and Refractory Desmoid Tumors.

BACKGROUND: Desmoid tumors (also referred to as aggressive fibromatosis) are connective tissue neoplasms that can arise in any anatomical location and infiltrate the mesentery, neurovascular structures, and visceral organs. There is no standard of care. METHODS: In this double-blind, phase 3 trial, we randomly assigned 87 patients with progressive, symptomatic, or recurrent desmoid tumors to receive either sorafenib (400-mg tablet once daily) or matching placebo. Crossover to the sorafenib group was permitted for patients in the placebo group who had disease progression. The primary end point was investigator-assessed progression-free survival; rates of objective response and adverse events were also evaluated. RESULTS: With a median follow-up of 27.2 months, the 2-year progression-free survival rate was 81% (95% confidence interval [CI], 69 to 96) in the sorafenib group and 36% (95% CI, 22 to 57) in the placebo group (hazard ratio for progression or death, 0.13; 95% CI, 0.05 to 0.31; P<0.001). Before crossover, the objective response rate was 33% (95% CI, 20 to 48) in the sorafenib group and 20% (95% CI, 8 to 38) in the placebo group. The median time to an objective response among patients who had a response was 9.6 months (interquartile range, 6.6 to 16.7) in the sorafenib group and 13.3 months (interquartile range, 11.2 to 31.1) in the placebo group. The objective responses are ongoing. Among patients who received sorafenib, the most frequently reported adverse events were grade 1 or 2 events of rash (73%), fatigue (67%), hypertension (55%), and diarrhea (51%). CONCLUSIONS: Among patients with progressive, refractory, or symptomatic desmoid tumors, sorafenib significantly prolonged progression-free survival and induced durable responses. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT02066181 .).

A Phase I Study of Binimetinib (MEK162) Combined with Pexidartinib (PLX3397) in Patients with Advanced Gastrointestinal Stromal Tumor.

LESSONS LEARNED: The combination of pexidartinib and binimetinib was safe and tolerable and demonstrated encouraging signs of efficacy in two patients with advanced gastrointestinal stromal tumor (GIST) refractory to tyrosine kinase inhibitors (TKIs).Molecular profiling of GISTs at diagnosis and upon progression may provide insight into the mechanisms of response or resistance to targeted therapies.Additional trials are needed to further explore combined KIT and MEK inhibition in treatment-naïve and TKI-refractory patients with advanced GIST. BACKGROUND: Nearly all patients with advanced gastrointestinal stromal tumor (GIST) develop resistance to imatinib, and subsequent treatments have limited efficacy. Dual inhibition of KIT and MAPK pathways has synergistic antitumor activity in preclinical GIST models. METHODS: This was an investigator-initiated, phase I, dose escalation study of the MEK inhibitor binimetinib combined with pexidartinib, a potent inhibitor of CSF1R, KIT, and FLT3, in patients with advanced or metastatic GIST who progressed on imatinib. The primary endpoint was phase II dose determination; secondary endpoints included safety, tolerability, and efficacy. An expansion cohort to further evaluate safety and efficacy was planned. RESULTS: Two patients were treated at dose level one (binimetinib 30 mg b.i.d. and pexidartinib 400 mg every morning and 200 mg every evening), after which the study was terminated by the manufacturer. No dose-limiting toxicities (DLTs) were reported, and treatment was well tolerated. The only grade ≥3 treatment-emergent adverse event (TEAE) was asymptomatic elevated creatine phosphokinase (CPK). Both patients had a best response of stable disease (SD) by RECIST. Progression-free survival (PFS) and overall survival (OS) were 6.1 and 14.6 months, respectively, in one patient with five prior lines of therapy. The second patient with NF1-mutant GIST had a 27% decrease in tumor burden by RECIST and remains on study after 19 months of treatment. CONCLUSION: Pexidartinib combined with binimetinib was tolerable, and meaningful clinical activity was observed in two imatinib-refractory patients.

Retroperitoneal Sarcomas: Does Laterality Matter?

BACKGROUND: Sarcomas are malignant tumors of connective tissue that can vary widely in etiology. Parameters such as grade, extent of resection, and tumor integrity have been shown to affect prognosis. Our principal aim was to examine associations between the laterality of retroperitoneal sarcomas and tumor characteristics, treatment, and patient outcomes. MATERIALS AND METHODS: We performed a retrospective study of patients treated at our tertiary referral center with a diagnosis of primary retroperitoneal sarcoma who underwent tumor resection. Categorical variables were compared using the chi-square test, whereas continuous variables were compared using one-way analysis of variance. Cox regression was used to estimate the risk of death. RESULTS: Data from 106 patients were analyzed. A greater proportion of bilateral or midline tumors were leiomyosarcomas (P = 0.02), whereas right-sided tumors were more likely to be liposarcoma (P = 0.02). There was no significant relationship between laterality and tumor grade or stage. Two-thirds of patients had at least one contiguous organ resected (n = 68, 65.4%). Patients with nephrectomy during sarcoma resection were more likely to have right-sided disease (P = 0.02). Splenectomy and pancreatectomy were associated with left-sided disease (P < 0.01; P < 0.01), and pancreaticoduodenectomies with bilateral or midline disease (P < 0.001). Adjusting for age, sex, race, grade, stage, histology, and treatment, there was no increased risk of death or recurrence based on laterality. CONCLUSIONS: Although laterality did not seem to have a measurable relationship with patient outcomes or survival, there was a significant association between laterality, tumor histology, and resection of contiguous organs. These preliminary findings warrant further investigation.

Role of Molecular Profiling in Soft Tissue Sarcoma.

Diagnosis and treatment of soft tissue sarcoma (STS) is a particularly daunting task, largely due to the profound heterogeneity that characterizes these malignancies. Molecular profiling has emerged as a useful tool to confirm histologic diagnoses and more accurately classify these malignancies. Recent large-scale, multiplatform analyses have begun the work of establishing a more complete understanding of molecular profiling in STS subtypes and to identify new molecular alterations that may guide the development of novel targeted therapies. This review provides a brief and general overview of the role that molecular profiling has in STS, highlighting select sarcoma subtypes that are notable for recent developments. The role of molecular profiling as it relates to diagnostic strategies is discussed, along with ways that molecular profiling may provide guidance for potential therapeutic interventions.

Granular cell tumor experience at a comprehensive cancer center.

BACKGROUND: Granular cell tumors (GCTs) are rare lesions occurring almost anywhere in the body. Multiple case reports have been published. However, there are very few large-scale studies regarding GCT. The aim of this study was to define characteristics, treatment patterns and outcomes of patients with GCT. METHODS: An institutional review board-approved retrospective chart review was performed. Descriptive statistics, chi-square analyses, and Kaplan-Meier survival estimates were produced. RESULTS: Fifty patients were treated for GCT at our institution between 1992 and 2015. The median age was 47 y; 62% of patients were female and 64% were whites. Median tumor size was 0.8 cm. Four percent of patients had malignant tumors, 10.0% had atypical tumors, and 86.0% had benign tumors. The most frequent location of tumors was the gastrointestinal tract (n = 30; 60%), followed by skin/subcutaneous tissues (n = 19; 38%), then respiratory tract (n = 1; 2%). Most patients underwent surgical excision or endoscopic removal of their tumors without prior biopsy. Three patients (6%) had multifocal tumors; they were more likely to experience recurrence than patients with unifocal tumors (33.3% versus 10.6%, respectively; P = 0.05). Six patients (12.0%) experienced recurrence, with a median time to recurrence of 13.5 mo. Overall cancer-specific 5-y survival was 98.0%. Overall recurrence-free 5-y survival was 86.4%. Patients with atypical tumors had a lower recurrence-free 5-y survival rate than those with benign tumors (75.0% versus 89.7%, respectively; P = 0.04). CONCLUSIONS: Patients with GCT fair well, particularly when tumors are benign. Patients with multifocal tumors are more likely to experience recurrence and should be closely monitored.

Pembrolizumab in advanced soft-tissue sarcoma and bone sarcoma (SARC028): a multicentre, two-cohort, single-arm, open-label, phase 2 trial.

BACKGROUND: Patients with advanced sarcomas have a poor prognosis and few treatment options that improve overall survival. Chemotherapy and targeted therapies offer short-lived disease control. We assessed pembrolizumab, an anti-PD-1 antibody, for safety and activity in patients with advanced soft-tissue sarcoma or bone sarcoma. METHODS: In this two-cohort, single-arm, open-label, phase 2 study, we enrolled patients with soft-tissue sarcoma or bone sarcoma from 12 academic centres in the USA that were members of the Sarcoma Alliance for Research through Collaboration (SARC). Patients with soft-tissue sarcoma had to be aged 18 years or older to enrol; patients with bone sarcoma could enrol if they were aged 12 years or older. Patients had histological evidence of metastatic or surgically unresectable locally advanced sarcoma, had received up to three previous lines of systemic anticancer therapy, had at least one measurable lesion according to the Response Evaluation Criteria In Solid Tumors version 1.1, and had at least one lesion accessible for biopsy. All patients were treated with 200 mg intravenous pembrolizumab every 3 weeks. The primary endpoint was investigator-assessed objective response. Patients who received at least one dose of pembrolizumab were included in the safety analysis and patients who progressed or reached at least one scan assessment were included in the activity analysis. Accrual is ongoing in some disease cohorts. This trial is registered with ClinicalTrials.gov, number NCT02301039. FINDINGS: Between March 13, 2015, and Feb 18, 2016, we enrolled 86 patients, 84 of whom received pembrolizumab (42 in each disease cohort) and 80 of whom were evaluable for response (40 in each disease cohort). Median follow-up was 17·8 months (IQR 12·3-19·3). Seven (18%) of 40 patients with soft-tissue sarcoma had an objective response, including four (40%) of ten patients with undifferentiated pleomorphic sarcoma, two (20%) of ten patients with liposarcoma, and one (10%) of ten patients with synovial sarcoma. No patients with leiomyosarcoma (n=10) had an objective response. Two (5%) of 40 patients with bone sarcoma had an objective response, including one (5%) of 22 patients with osteosarcoma and one (20%) of five patients with chondrosarcoma. None of the 13 patients with Ewing's sarcoma had an objective response. The most frequent grade 3 or worse adverse events were anaemia (six [14%]), decreased lymphocyte count (five [12%]), prolonged activated partial thromboplastin time (four [10%]), and decreased platelet count (three [7%]) in the bone sarcoma group, and anaemia, decreased lymphocyte count, and prolonged activated partial thromboplastin time in the soft-tissue sarcoma group (three [7%] each). Nine (11%) patients (five [12%] in the bone sarcoma group and four [10%] in the soft-tissue sarcoma group) had treatment-emergent serious adverse events (SAEs), five of whom had immune-related SAEs, including two with adrenal insufficiency, two with pneumonitis, and one with nephritis. INTERPRETATION: The primary endpoint of overall response was not met for either cohort. However, pembrolizumab showed encouraging activity in patients with undifferentiated pleomorphic sarcoma or dedifferentiated liposarcoma. Enrolment to expanded cohorts of those subtypes is ongoing to confirm and characterise the activity of pembrolizumab. FUNDING: Merck, SARC, Sarcoma Foundation of America, QuadW Foundation, Pittsburgh Cure Sarcoma, and Ewan McGregor.

NCCN Guidelines Insights: Bone Cancer, Version 2.2017.

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

FGFR1 and NTRK3 actionable alterations in "Wild-Type" gastrointestinal stromal tumors.

BACKGROUND: About 10-15% of adult, and most pediatric, gastrointestinal stromal tumors (GIST) lack mutations in KIT, PDGFRA, SDHx, or RAS pathway components (KRAS, BRAF, NF1). The identification of additional mutated genes in this rare subset of tumors can have important clinical benefit to identify altered biological pathways and select targeted therapies. METHODS: We performed comprehensive genomic profiling (CGP) for coding regions in more than 300 cancer-related genes of 186 GISTs to assess for their somatic alterations. RESULTS: We identified 24 GIST lacking alterations in the canonical KIT/PDGFRA/RAS pathways, including 12 without SDHx alterations. These 24 patients were mostly adults (96%). The tumors had a 46% rate of nodal metastases. These 24 GIST were more commonly mutated at 7 genes: ARID1B, ATR, FGFR1, LTK, SUFU, PARK2 and ZNF217. Two tumors harbored FGFR1 gene fusions (FGFR1-HOOK3, FGFR1-TACC1) and one harbored an ETV6-NTRK3 fusion that responded to TRK inhibition. In an independent sample set, we identified 5 GIST cases lacking alterations in the KIT/PDGFRA/SDHx/RAS pathways, including two additional cases with FGFR1-TACC1 and ETV6-NTRK3 fusions. CONCLUSIONS: Using patient demographics, tumor characteristics, and CGP, we show that GIST lacking alterations in canonical genes occur in younger patients, frequently metastasize to lymph nodes, and most contain deleterious genomic alterations, including gene fusions involving FGFR1 and NTRK3. If confirmed in larger series, routine testing for these translocations may be indicated for this subset of GIST. Moreover, these findings can be used to guide personalized treatments for patients with GIST. Trial registration NCT 02576431. Registered October 12, 2015.