A multicenter phase II study of nivolumab +/- ipilimumab for patients with metastatic sarcoma (Alliance A091401): Results of expansion cohorts

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Background: In the open-label multicenter phase II study, A091401, nivolumab (N) and nivolumab+ipilimumab (N+I) demonstrated a confirmed response rate (RR) of 5% and 16%, respectively in patients (pts) with advanced sarcoma (D’Angelo SP et al Lancet Oncology 2018). Responses occurred in undifferentiated pleomorphic sarcoma (UPS), myxofibrosarcoma, leiomyosarcoma, sarcoma not otherwise specified and alveolar soft part sarcoma. Here, we report efficacy of N and N+I, in each of 3 expansion cohorts [gastrointestinal stromal tumor (GIST), UPS and dedifferentiated liposarcoma (DDLS)]. Methods: Pts refractory to ≥ 1 regimen(s) were randomized (non-comparative) to receive either N [N (3 mg/kg q2W)] or N+I [N (3 mg/kg Q3W x4, then Q2W) plus I (3 mg/kg q3W x4)]. The primary endpoint was 6 month confirmed RR (RECIST v1.1). For UPS and DDLS, 2 confirmed responses in the 1st 12 evaluable pts was needed (85% power, 1-sided alpha=0.15, 5 v 25% RR). For GIST, a confirmed response in the 1st 9 evaluable pts expanded enrollment to 24 (80% power, 1-sided alpha=0.10, 5 v 20% RR). Other endpoints: adverse events (AEs, TRAEs), progression-free and overall survival (PFS, OS), and correlatives. Results: See table. Clinical trial information: NCT02500797 . Conclusions: Neither N or N+I lead to confirmed responses in GIST. In DDLS and UPS, the primary response endpoint was met with N+I but not with N alone (RR 14% for N+I vs. 7% and 8% for N alone). For the GIST cohort TRAE was higher with N+I, holding enrollment as required per protocol. There remains a pressing need to determine genomic and clinical biomarkers of response, resistance and toxicity. Correlative analyses (whole exome sequencing, multiplex IHC and RNAseq) are in progress. Support: U10CA180821, U10CA180882; ClinicalTrials.gov Identifier: NCT02500797. [Table: see text]

Genomic Landscape of Uterine Sarcomas Defined Through Prospective Clinical Sequencing

PURPOSE

We examined whether prospective molecular characterization of advanced metastatic disease can reveal grade and/or histology-specific differences to inform diagnosis and facilitate enrollment onto clinical trials.

EXPERIMENTAL DESIGN

Patients with uterine sarcoma consented to a prospective study of next-generation sequencing (NGS). Clinical annotations were extracted from their medical record. Tumor and matched normal DNA were subjected to NGS, and the genomic landscape was explored for survival correlations and therapeutic targetability.

RESULTS

Tumors from 107 women were sequenced and included leiomyosarcoma (n = 80), high-grade non-leiomyosarcoma (n = 22), low-grade endometrial stromal sarcoma (LG-ESS, n = 4), and smooth muscle tumor of uncertain malignant potential (STUMP, n = 2). Genomic profiling influenced histologic diagnosis in three cases. Common uterine leiomyosarcoma alterations were loss-of-function mutations in TP53 (56%), RB1 (51%), and ATRX (31%). Homozygous deletions of BRCA2 were present in 5% of these patients. PTEN alteration frequency was higher in the metastases samples as compared with the primary samples. Genomes of low-grade tumors were largely silent, while 50.5% of high-grade tumors had whole-genome duplication. Two metastatic uterine leiomyosarcoma cases were hypermutated. Both had prolonged disease-free survival. Potentially actionable mutations were identified in 48 patients (45%), 8 (17%) of whom received matched therapy with 2 achieving clinical responses. Among patients with uterine leiomyosarcoma with somatic BRCA2 alterations, sustained partial responses were observed with PARP inhibitor-containing therapy.

DISCUSSION

Prospective genomic profiling can contribute to diagnostic precision and inform treatment selection in patients with uterine sarcomas. There was evidence of clinical benefit in patients with uterine leiomyosarcoma with somatic BRCA2 alterations treated with PARP inhibitors.

Effect of Doxorubicin Plus Olaratumab vs Doxorubicin Plus Placebo on Survival in Patients With Advanced Soft Tissue Sarcomas: The ANNOUNCE Randomized Clinical Trial

IMPORTANCE

Patients with advanced soft tissue sarcoma (STS) have a median overall survival of less than 2 years. In a phase 2 study, an overall survival benefit in this population was observed with the addition of olaratumab to doxorubicin over doxorubicin alone.

OBJECTIVE

To determine the efficacy of doxorubicin plus olaratumab in patients with advanced/metastatic STS.

DESIGN, SETTING, AND PARTICIPANTS

ANNOUNCE was a confirmatory, phase 3, double-blind, randomized trial conducted at 110 sites in 25 countries from September 2015 to December 2018; the final date of follow-up was December 5, 2018. Eligible patients were anthracycline-naive adults with unresectable locally advanced or metastatic STS, an Eastern Cooperative Oncology Group performance status of 0 to 1, and cardiac ejection fraction of 50% or greater.

INTERVENTIONS

Patients were randomized 1:1 to receive doxorubicin, 75 mg/m2 (day 1), combined with olaratumab (n = 258), 20 mg/kg in cycle 1 and 15 mg/kg in subsequent cycles, or placebo (n = 251) on days 1 and 8 for up to 8 21-day cycles, followed by olaratumab/placebo monotherapy.

MAIN OUTCOMES AND MEASURES

Dual primary end points were overall survival with doxorubicin plus olaratumab vs doxorubicin plus placebo in total STS and leiomyosarcoma (LMS) populations.

RESULTS

Among the 509 patients randomized (mean age, 56.9 years; 58.2% women; 46.0% with LMS), all were included in the primary analysis and had a median length of follow-up of 31 months. No statistically significant difference in overall survival was observed between the doxorubicin plus olaratumab group vs the doxorubicin plus placebo group in either population (total STS: hazard ratio, 1.05 [95% CI, 0.84-1.30], P = .69, median overall survival, 20.4 months vs 19.7 months; LMS: hazard ratio, 0.95 [95% CI, 0.69-1.31], P = .76, median overall survival, 21.6 months vs 21.9 months). Adverse events of grade 3 or greater reported in 15% or more of total patients with STS were neutropenia (46.3% vs 49.0%), leukopenia (23.3% vs 23.7%), and febrile neutropenia (17.5% vs 16.5%).

CONCLUSIONS AND RELEVANCE

In this phase 3 clinical trial of patients with advanced STS, treatment with doxorubicin plus olaratumab vs doxorubicin plus placebo resulted in no significant difference in overall survival. The findings did not confirm the overall survival benefit observed in the phase 2 trial.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02451943.

Prognostic stratification of clinical and molecular epithelioid hemangioendothelioma subsets

Epithelioid hemangioendothelioma is a low-grade malignant vascular tumor with an intermediate clinical behavior between benign hemangiomas and high-grade angiosarcomas. Pathologic or molecular factors to predict this clinical heterogeneity are not well defined. A WWTR1-CAMTA1 fusion is present in most classic epithelioid hemangioendothelioma, regardless of their clinical behavior, suggesting that additional genetic abnormalities might be responsible in driving a more aggressive biology. A small subset of cases show distinct morphology and are characterized genetically by a YAP1-TFE3 fusion. Two histologic grades have been described in classic epithelioid hemangioendothelioma of the soft tissue. However, proposed criteria do not apply to other clinical presentations and have not been assessed in the YAP1-TFE3 positive tumors. Furthermore, no previous studies have compared the survival of these two molecular subsets. In this study we investigate the clinicopathologic and molecular findings of a large cohort of 93 translocation-positive epithelioid hemangioendothelioma managed at our institution. Patient characteristics, histologic features, treatment outcomes, and genetic abnormalities were investigated and these factors were correlated with overall survival. In 18 patients (15 with WWTR1-CAMTA1 and 3 with YAP1-TFE3) Memorial Sloan Kettering-IMPACT targeted DNA sequencing was performed to identify secondary genetic alterations showing more than half of tumors had a genetic alteration beyond the disease-defining gene fusion. Patients with conventional epithelioid hemangioendothelioma with WWTR1-CAMTA1 fusion had a less favorable outcome compared with the YAP1-TFE3 subset, the 5-year overall survival being 59% versus 86%, respectively. Soft tissue epithelioid hemangioendothelioma were frequently solitary, followed an uneventful clinical course being often managed with curative surgery. Multifocality, pleural involvement, lymph node or distant metastases had a significantly worse outcome. Patients with pleural disease or lymph node metastases had an aggressive clinical course akin to high-grade sarcomas, with 22% and 30%, respectively, alive at 5 years, compared with >70% survival rate in patients lacking these two adverse factors.

A novel image-based system for risk stratification in patients with desmoplastic small round cell tumor

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is an aggressive soft tissue sarcoma affecting children and young adults with 5-year overall survival (OS) of approximately 20%. Despite generally poor prognosis, long-term survival does occur. However, no evidence-based system exists to risk-stratify patients at diagnosis.

METHODS

We retrospectively reviewed all DSRCT cases diagnosed at our institution between January 2000 and September 2016. Demographics, diagnostic imaging, and clinical data were reviewed. Univariate and multivariate Cox proportional hazard modeling was used to evaluate associations between imaging characteristics and OS.

RESULTS

There were 130 patients (85% male; median age at presentation: 21.2 years) with confirmed DSRCT and sufficient imaging and clinical information for analysis. Median 5-year OS was 28% (95% CI: 19%-37%). In univariate analysis, shorter OS was associated with presence of liver lesions (hazard ratio [HR] 2.1, 95% CI: 1.28-3.45), chest lesions (HR 1.86, 95% CI: 1.11-3.1), and ascites (HR 1.69, 95% CI: 1.06-2.7). In multivariate analysis, liver involvement and ascites were predictive and were used to stratify risk (intermediate=no liver involvement or ascites; high=either liver involvement or ascites; very high=both liver involvement and ascites). Intermediate-risk patients had a 5-year survival of 61% (95% CI: 40%-76%) versus 16% (95% CI: 6%-29%) among high-risk patients and 8% (95% CI: 1%-29%) among very high risk patients.

CONCLUSION

Patients with DSRCT can be risk-stratified at diagnosis based on specific imaging characteristics.

TYPE OF STUDY

Retrospective study with no comparison group.

LEVEL OF EVIDENCE

Level IV.

Clinical Cancer Advances 2020: Annual Report on Progress Against Cancer From the American Society of Clinical Oncology

A MESSAGE FROM ASCO’S PRESIDENT

Shortly before I was elected President of ASCO, I attended the 65th birthday party of a current patient. She had been diagnosed 10 years earlier with metastatic breast cancer and hadn't been sure she wanted to move forward with further treatment. With encouragement, she elected to participate in a clinical trial of an investigational drug that is now widely used to treat breast cancer. Happily, here we were, celebrating with her now-married daughters, their husbands, and three beautiful grandchildren, ages 2, 4, and 8. Such is the importance of clinical trials and promising new therapies.Clinical research is about saving and improving the lives of individuals with cancer. It's a continuing story that builds on the efforts of untold numbers of researchers, clinicians, caregivers, and patients. ASCO's Clinical Cancer Advances report tells part of this story, sharing the most transformative research of the past year. The report also includes our latest thinking on the most urgent research priorities in oncology.ASCO's 2020 Advance of the Year-Refinement of Surgical Treatment of Cancer-highlights how progress drives more progress. Surgery has played a fundamental role in cancer treatment. It was the only treatment available for many cancers until the advent of radiation and chemotherapy. The explosion in systemic therapies since then has resulted in significant changes to when and how surgery is performed to treat cancer. In this report, we explore how treatment successes have led to less invasive approaches for advanced melanoma, reduced the need for surgery in renal cell carcinoma, and increased the number of patients with pancreatic cancer who can undergo surgery.Many research advances are made possible by federal funding. With the number of new US cancer cases set to rise by roughly a third over the next decade, continued investment in research at the national level is crucial to continuing critical progress in the prevention, screening, diagnosis, and treatment of cancer.While clinical research has translated to longer survival and better quality of life for many patients with cancer, we can't rest on our laurels. With ASCO's Research Priorities to Accelerate Progress Against Cancer, introduced last year and updated this year, we've identified the critical gaps in cancer prevention and care that we believe to be most pressing. These priorities are intended to guide the direction of research and speed progress.Of course, the effectiveness or number of new treatments is meaningless if patients don't have access to them. High-quality cancer care, including clinical trials, is out of reach for too many patients. Creating an infrastructure to support patients is a critical part of the equation, as is creating connections between clinical practices and research programs. We have much work to do before everyone with cancer has equal access to the best treatments and the opportunity to participate in research. I know that ASCO and the cancer community are up for this challenge.Sincerely,Howard A. "Skip" Burris III, MD, FACP, FASCOASCO President, 2019-2020.

Clinical activity of avapritinib in ≥ fourth-line (4L+) and PDGFRA Exon 18 gastrointestinal stromal tumors (GIST)

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Background: Targeting oncogenic KIT and PDGFRA mutations revolutionized treatment of patients (pts) with advanced GIST; however, nearly all pts succumb to resistant disease. Avapritinib is a potent and selective kinase inhibitor with broad activity against oncogenic KIT/PDGFRA mutants, including PDGFRA D842V and other primary or secondary resistance mutations. Results from the phase 1 NAVIGATOR (NCT02508532) study of avapritinib in pts with advanced GIST are presented. Methods: Adult pts with unresectable PDGFRA D842V or other mutant GIST who progressed on imatinib and ≥1 other tyrosine kinase inhibitor (TKI) were treated with oral, daily, continuous avapritinib. Adverse events (AE) and response by mRECIST 1.1 per central radiology were assessed. Overall population safety (30-600 mg starting doses) and efficacy in the response-evaluable 4L+ and PDGFRA Exon 18 (Ex 18) populations treated at the MTD (400 mg)/RP2D (300 mg) were analyzed. Results: As of 16 Nov 2018, 237 pts [172 KIT, 62 PDGFRA Ex 18 [56 D842V, 6 non-D842V), 2 PDGFRA N659K, 1 missing] were enrolled including 111 in the 4L+ population (primarily KIT, median 4 prior TKI) and 43 in the Ex 18 population (median 1 prior TKI). The 4L+ ORR was 22% [1 CR, 23 PR (1 pending)], and 52 SD with mDOR of 10.2 months (95% CI: 7.2–NE). The Ex 18 ORR was 86% [3 CR, 34 PR (1 pending)] and 5 SD; mDOR was not reached (95% CI: 11.3–NE). Most AEs were grade 1–2, most commonly nausea (63%), fatigue (58%), anemia (49%), periorbital edema (42%), diarrhea (40%), vomiting (40%), decreased appetite (38%), increased lacrimation (33%), peripheral edema (33%) and memory impairment (most common cognitive AE, 29%). 10% of pts discontinued due to a related AE. Grade 3–4 related AE ≥ 2% were anemia, fatigue, hypophosphatemia, hyperbilirubinemia, neutropenia, and diarrhea. Conclusions: Avapritinib has important clinical activity in pts with advanced GIST who have no effective therapies. The ORR and DOR of avapritinib in 4L+ exceeds that of approved 2nd and 3rd line therapies and shows impressive activity in D842V and other Ex 18 mutant PDGFRA GIST. Results suggest avapritinib has the potential to change the treatment paradigm of pts with advanced GIST. Clinical trial information: NCT02508532.

Soft Tissue Sarcoma, Version 2.2018, NCCN Clinical Practice Guidelines in Oncology

Soft tissue sarcomas (STS) are rare solid tumors of mesenchymal cell origin that display a heterogenous mix of clinical and pathologic characteristics. STS can develop from fat, muscle, nerves, blood vessels, and other connective tissues. The evaluation and treatment of patients with STS requires a multidisciplinary team with demonstrated expertise in the management of these tumors. The complete NCCN Guidelines for STS provide recommendations for the diagnosis, evaluation, and treatment of extremity/superficial trunk/head and neck STS, as well as intra-abdominal/retroperitoneal STS, gastrointestinal stromal tumors, desmoid tumors, and rhabdomyosarcoma. This portion of the NCCN Guidelines discusses general principles for the diagnosis, staging, and treatment of STS of the extremities, superficial trunk, or head and neck; outlines treatment recommendations by disease stage; and reviews the evidence to support the guidelines recommendations.

Genomic Profiling Identifies Association of IDH1/IDH2 Mutation with Longer Relapse-Free and Metastasis-Free Survival in High-Grade Chondrosarcoma

PURPOSE

Chondrosarcomas are the second most common primary malignant bone tumors. Although histologic grade is the most important factor predicting the clinical outcome of chondrosarcoma, it is subject to interobserver variability. Isocitrate dehydrogenase 1 (IDH1) and IDH2 hotspot mutations were recently found to be frequently mutated in central chondrosarcomas. However, a few published articles have been controversial regarding the association between IDH1/IDH2 mutation status and clinical outcomes in chondrosarcomas.

EXPERIMENTAL DESIGN

We performed hotspot sequencing of IDH1 and IDH2 genes in 89 central chondrosarcomas and targeted next-generation sequencing in 54 of them, and then correlated the IDH1/IDH2 mutation status with the patient's clinical outcome.

RESULTS

Although no association was discovered between IDH mutation status and the patient's overall survival, IDH1/IDH2 mutation was found to be associated with longer relapse-free and metastasis-free survival in high-grade chondrosarcomas. Genomic profiling reveals TERT gene amplification and ATRX mutation, for the first time, in addition to TERT promoter mutation in a subset (6/30, 20%) of high-grade and dedifferentiated chondrosarcomas. These abnormalities in telomere genes are concurrent with IDH1/IDH2 mutation and with CDKN2A/2B deletion or TP53 mutation, suggesting a possible association and synergy among these genes in chondrosarcoma progression. We found 21% of patients with chondrosarcoma also had histories of second malignancies unrelated to cartilaginous tumors, suggesting possible unknown genetic susceptibility to chondrosarcoma.

CONCLUSIONS

IDH1/IDH2 mutations are associated with longer relapse-free and metastasis-free survival in high-grade chondrosarcomas, and they tend to co-occur with TERT mutations and with CDKN2A/2B and TP53 alterations in a subset of high-grade chondrosarcomas.

Pexidartinib versus placebo for advanced tenosynovial giant cell tumour (ENLIVEN): a randomised phase 3 trial

BACKGROUND

Tenosynovial giant cell tumour (TGCT), a rare, locally aggressive neoplasm, overexpresses colony-stimulating factor 1 (CSF1). Surgery is standard with no approved systemic therapy. We aimed to evaluate pexidartinib, a CSF1 receptor inhibitor, in patients with TGCT to provide them with a viable systemic treatment option, especially in cases that are not amenable to surgical resection.

METHODS

This phase 3 randomised trial had two parts. Part one was a double-blind study in which patients with symptomatic, advanced TGCT for whom surgery was not recommended were randomly assigned via an integrated web response system (1:1) to the pexidartinib or placebo group. Individuals in the pexidartinib group received a loading dose of 1000 mg pexidartinib per day orally (400 mg morning; 600 mg evening) for the first 2 weeks, followed by 800 mg per day (400 mg twice a day) for 22 weeks. Part two was an open-label study of pexidartinib for all patients. The primary endpoint, assessed in all intention-to-treat patients, was overall response at week 25, and was centrally reviewed by RECIST, version 1.1. Safety was analysed in all patients who received at least one dose of the study drug. This study is registered with ClinicalTrials.gov, number NCT02371369.

FINDINGS

Between May 11, 2015, and Sept 30, 2016, of 174 patients assessed for eligibility, 120 patients were randomly assigned to, and received, pexidartinib (n=61) or placebo (n=59). There were 11 dropouts in the placebo group and nine in the pexidartinib group. Emergence of mixed or cholestatic hepatotoxicity caused the data monitoring committee to stop enrolment six patients short of target. The proportion of patients who achieved overall response was higher for pexidartinib than placebo at week 25 by RECIST (24 [39%] of 61 vs none of 59; absolute difference 39% [95% CI 27-53]; p<0·0001). Serious adverse events occurred in eight (13%) of 61 patients in the pexidartinib group and one (2%) of 59 patients in the placebo group. Hair colour changes (67%), fatigue (54%), aspartate aminotransferase increase (39%), nausea (38%), alanine aminotransferase increase (28%), and dysgeusia (25%) were the most frequent pexidartinib-associated adverse events. Three patients given pexidartinib had aminotransferase elevations three or more times the upper limit of normal with total bilirubin and alkaline phosphatase two or more times the upper limit of normal indicative of mixed or cholestatic hepatotoxicity, one lasting 7 months and confirmed by biopsy.

INTERPRETATION

Pexidartinib is the first systemic therapy to show a robust tumour response in TGCT with improved patient symptoms and functional outcomes; mixed or cholestatic hepatotoxicity is an identified risk. Pexidartinib could be considered as a potential treatment for TGCT associated with severe morbidity or functional limitations in cases not amenable to improvement with surgery.

FUNDING

Daiichi Sankyo.

NTRK Fusions Define a Novel Uterine Sarcoma Subtype With Features of Fibrosarcoma

Tropomyosin receptor kinase (Trk) inhibitors have shown high response rates in patients with tumors harboring NTRK fusions. We identified 4 NTRK fusion-positive uterine sarcomas that should be distinguished from leiomyosarcoma and undifferentiated uterine sarcoma. NTRK rearrangements were detected by fluorescence in situ hybridization (FISH) and/or targeted RNA or DNA sequencing in 4 undifferentiated uterine sarcomas with spindle cell morphology. Because of histologic overlap with leiomyosarcoma, TrkA and pan-Trk immunohistochemistry was performed in 97 uterine leiomyosarcomas. NTRK1 and NTRK3 FISH was performed on tumors with TrkA or pan-Trk staining. We also performed whole transcriptome RNA sequencing of a leiomyosarcoma with TrkA expression and targeted RNA sequencing of 2 additional undifferentiated uterine sarcomas. FISH and/or targeted RNA or DNA sequencing in the study group showed TPM3-NTRK1, LMNA-NTRK1, RBPMS-NTRK3, and TPR-NTRK1 fusions. All tumors were composed of fascicles of spindle cells. Mitotic index was 7 to 30 mitotic figures per 10 high power fields; tumor necrosis was seen in 2 tumors. Desmin, estrogen receptor, and progesterone receptor were negative in all tumors, while pan-Trk was expressed in all tumors with concurrent TrkA staining in 3 of them. TrkA and/or pan-Trk staining was also seen in 6 leiomyosarcomas, but these tumors lacked NTRK fusions or alternative isoforms by FISH or whole transcriptome sequencing. No fusions were detected in 2 undifferentiated uterine sarcomas. NTRK fusion-positive uterine spindle cell sarcomas constitute a novel tumor type with features of fibrosarcoma; patients with these tumors may benefit from Trk inhibition. TrkA and pan-Trk expression in leiomyosarcomas is rare and does not correlate with NTRK rearrangement.

Incidence and Management of Olaratumab Infusion-Related Reactions

PURPOSE:

Olaratumab is a human monoclonal immunoglobulin G1 antibody against platelet-derived growth factor receptor-α. We report the nature and frequency of infusion-related reactions (IRRs) with olaratumab in clinical trials and postmarketing reports.

METHODS:

Data from patients exposed to olaratumab across nine clinical trials were reviewed for IRRs. Blood samples were also analyzed for pre-existing immunoglobulin E anti–galactose-α-1,3-galactose (anti–α-Gal) antibodies.

RESULTS:

In the clinical trials, IRRs were identified in 70 of 485 patients (14.4%). The most frequent symptoms included flushing, fever or chills, and dyspnea. For 68 of 70 patients (97.1%), the first IRR occurred during the first two cycles of treatment. Grade 3 or worse IRRs were reported in 11 patients (2.3%), all during the first infusion and usually within 15 minutes of the start of the infusion. One IRR-related fatality (0.2%) occurred in a nonpremedicated patient with grade 3 or worse cardiac comorbidities. There was an association between grade 3 or worse IRRs and pre-existing anti–α-Gal antibodies, with a trend toward higher IRR rates in US geographies known to have a higher prevalence of anti–α-Gal antibodies. IRRs in postmarketing reports were consistent in nature and severity with those in the clinical trials.

CONCLUSION:

Premedication with corticosteroids and antihistamines should occur in all patients before olaratumab infusion, as indicated in labels in the United States and the European Union. Patients receiving olaratumab should be monitored for IRRs in a setting where resuscitation equipment is available for the treatment of IRRs.

ANNOUNCE: A randomized, placebo (PBO)-controlled, double-blind, phase (Ph) III trial of doxorubicin (dox) + olaratumab versus dox + PBO in patients (pts) with advanced soft tissue sarcomas (STS)

LBA3

Background: Dox is standard therapy in STS. In a Ph 2 trial, olaratumab (a human IgG1 antibody targeting PDGFRα) + dox improved overall survival (OS) and progression-free survival (PFS) vs dox. ANNOUNCE aimed to confirm the OS benefit in advanced STS. Methods: Adult pts with unresectable locally advanced or metastatic STS, anthracycline-naïve, and ECOG PS 0-1 were eligible. Pts were randomized 1:1 to olaratumab (20mg/kg Cycle 1, 15mg/kg subsequent cycles) or PBO on Days 1 and 8 of each 21-day cycle combined with dox (75mg/m2) on Day 1 for up to 8 cycles. After 8 cycles, pts with disease control continued olaratumab or PBO until progression or toxicity. Randomization was stratified by histology, prior systemic therapy, ECOG PS, and geographic region. Dexrazoxane use was allowed to mitigate dox-related cardiotoxicity. Primary endpoints were OS in the intent-to-treat (ITT) population and/or leiomyosarcoma (LMS) subset of the ITT population; the study was designed to be positive if either primary endpoint was met. Secondary endpoints included PFS, response/disease control rates, safety, and pharmacokinetics. Results: 509 pts were randomized: 258 in the investigational and 251 in the control arm. Baseline pt characteristics were well balanced. Dexrazoxane was received by 63.0% vs 65.1% of pts (investigational vs control arm, respectively, for all data). In the ITT population, median OS was 20.4 vs 19.8 months (m) (HR=1.05, 95% CI: 0.84-1.30; p = 0.69) and was 21.6 vs 21.9 m in LMS pts (HR=0.95, 95% CI: 0.69-1.31; p = 0.76). Median PFS was lower in the investigational arm in the ITT population (5.4 vs 6.8 m; HR=1.23, 95% CI: 1.01-1.50; p = 0.04) and in LMS pts (4.3 vs 6.9 m, HR=1.22, 95% CI: 0.92-1.63; p = 0.17). Median dox exposure was 6 vs 7 cycles. Safety was similar between arms. Olaratumab serum concentrations reached levels expected from prior trials. Additional subgroup/biomarker results will be presented. Conclusions: ANNOUNCE did not confirm that olaratumab + dox, followed by olaratumab monotherapy, improves OS over dox in pts with advanced STS. Further analyses are warranted to explore the inconsistent outcomes between the Ph 3 and Ph 2 studies. Clinical trial information: NCT02451943.

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.

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

BACKGROUND

Sorafenib and dacarbazine have low single-agent response rates in metastatic sarcomas. As angiogenesis inhibitors can enhance the efficacy of chemotherapy, we investigated the combination of sorafenib and dacarbazine in select sarcoma subtypes.

MATERIALS AND METHODS

Patients with leiomyosarcoma (LMS), synovial sarcoma (SS), or malignant peripheral nerve sheath tumors (MPNST) with up to two previous lines of therapy and adequate hepatic, renal, and marrow function received 3-week cycles of sorafenib at 400 mg oral twice daily and dacarbazine 1,000 mg/m2 intravenously (later reduced to 850 mg/m2). Patients were evaluated for response every 6 weeks. The primary objective was to determine the disease control rate (DCR) of sorafenib plus dacarbazine in the selected sarcoma subtypes.

RESULTS

The study included 37 patients (19 female); median age was 55 years (range 26-87); and histologies included LMS (22), SS (11), and MPNST (4). The DCR was 46% (17/37). Median progression-free survival was 13.4 weeks. The RECIST response rate was 14% (5/37). The Choi response rate was 51% (19/37). Median overall survival was 13.2 months. Of the first 25 patients, 15 (60%) required dacarbazine dose reductions for hematologic toxicity, with one episode of grade 5 neutropenic fever. After reducing the starting dose of dacarbazine to 850 mg/m2, only 3 of the final 12 (25%) patients required dose reduction.

CONCLUSION

This phase II study met its primary endpoint with an 18-week DCR of 46%. The clinical activity of dacarbazine plus sorafenib in patients with these diagnoses is modest.

IMPLICATIONS FOR PRACTICE

Metastatic soft tissue sarcomas are a heterogeneous group of relatively rare malignancies. Most patients are treated with cytotoxic chemotherapy or targeted therapy in the form of tyrosine kinase inhibitors. Response rates are relatively low, and there is a need for better therapies. This clinical trial demonstrates that combining a cytotoxic therapy (dacarbazine) with an antiangiogenic small molecule (sorafenib) is feasible and associated with favorable disease-control rates; however, it also increases the potential for significant toxicity.

Pilot study of NKTR214 and nivolumab in patients with sarcomas

11010

Background: Monotherapy checkpoint inhibitors have minimal efficacy in most patients with metastatic sarcoma. NKTR-214 is a CD122-preferential IL-2 pathway agonist that activates and expands natural killer and CD8+ T cells. Phase I/II data demonstrated the safety and efficacy of nivolumab plus NKTR-214 in multiple tumor types. A trial of NKTR-214 plus nivolumab was initiated in patients with selected sarcomas. Methods: This is a multi-center pilot study enrolling patients (pts) failing prior regimens within 9 cohorts: leiomyosarcoma (LMS), undifferentiated pleomorphic sarcoma (UPS), dedifferentiated liposarcoma (DDLPS), chondrosarcoma (CS), osteosarcoma (OS), angiosarcoma (AS), alveolar soft part sarcoma (ASPS), synovial sarcoma/small blue round cell and other. Pts received NKTR 0.006mg/kg with nivolumab 360 mg every 3 weeks. Primary endpoint was objective response rate (ORR), secondary endpoints were adverse events (AEs), progression-free, overall survival (PFS,OS) and clinical benefit rate (CBR.) Pre/on treatment biopsies performed on patients for correlative studies including PD-L1 expression and TIL characterization by immunohistochemistry, whole exome sequencing and RNAseq. Results: Enrollment completed with 10 patients in cohorts below. 50 pts enrolled (median age 58, range 14-80), 54% female. Median follow-up time is 13m. 50% of patients were refractory ≥3 lines of therapy. Grade 3/4 treatment related adverse events occurred in 26% of patients. 2% of patients stopped due to AEs. Median time to response was 3.6m. Responses seen in LMS, UPS, dedifferentiated CS; on-going in UPS/CS. Prolonged disease stability in DDLPS. 6 patients remain on treatment. Conclusions: Nivolumab plus NKTR-214 was safe and tolerable in heavily pre-treated and refractory sarcoma patients. Responses were protracted overtime; on-going in UPS and dedifferentiated CS. Prolonged disease stability seen in DDLPS in patients. All correlative analyses are in progress and will be presented. Enrollment continues with plans to add a treatment naïve cohort. Clinical trial information: NCT03282344. [Table: see text]

DNA damage response pathway alterations and clinical outcome in leiomyosarcoma

11048

Background: Leiomyosarcoma (LMS) is a complex karyotype sarcoma with frequent alterations in the homologous recombination (HR) pathway. Genomically unstable tumors with DNA damage repair (DDR) deficiencies may have improved responses to DNA damaging therapies, such as cytotoxic chemotherapy or PARP inhibitors. Methods: We retrospectively reviewed LMS patients treated at MSKCC who had targeted somatic DNA sequencing (MSK-IMPACT) performed on tumor tissue. 33 DDR genes, including 16 HR genes, were analyzed for oncogenic alterations. A composite HR deficiency (HRD) score measured tumor genomic scarring for each patient. To determine if DDR alteration status is prognostic of outcome, we analyzed the recurrence-free survival (RFS) of patients who underwent complete resection, and the overall survival (OS) of the whole cohort. Results: 211 patients had IMPACT testing between March 2014 and October 2018; 48% of samples were primary tumors and 52% recurrent/metastatic sites. Among soft tissue LMS (stLMS), there were 35 men and 55 women. 20% of patients had an oncogenic DDR gene alteration, 72% of which were in the HR pathway (table below). Uterine LMS (uLMS) had more DDR alterations than stLMS, though not statistically significant (p = 0.084). BRCA2 (n = 14 cases), RAD51B (8), and ERCC5 (4) were most frequently altered. HRD score significantly correlated with HRD alteration status (p = 0.004). DDR or HRD altered status and HRD score were associated with shorter RFS in patients with resectable disease, independent of age (p < 0.05). Median OS for the cohort was 75 months (95% CI: 64 – 84). Men with stLMS had shorter OS compared to women (p = 0.025). OS did not significantly differ based on DDR or HRD status (p > 0.05). Conclusions: One-fifth of LMS patients have one or more oncogenic somatic alterations in the DDR pathway, predominantly in effectors of HR. DDR status may be prognostic of recurrence risk. Further analyses to determine the association between DDR status and response to cytotoxic chemotherapy are ongoing. [Table: see text]

Clinical activity of avapritinib in ≥ fourth-line (4L+) and PDGFRA Exon 18 gastrointestinal stromal tumors (GIST)

11022

Background: Targeting oncogenic KIT and PDGFRA mutations revolutionized treatment of patients (pts) with advanced GIST; however, nearly all pts succumb to resistant disease. Avapritinib is a potent and selective kinase inhibitor with broad activity against oncogenic KIT/PDGFRA mutants, including PDGFRA D842V and other primary or secondary resistance mutations. Updated results from the phase 1 NAVIGATOR (NCT02508532) study of avapritinib in pts with advanced GIST are presented. Methods: Adult pts with unresectable PDGFRA D842V or other mutant GIST who progressed on imatinib and ≥ 1 other tyrosine kinase inhibitor (TKI) were treated with oral, daily, continuous avapritinib. Adverse events (AE) and response by mRECIST 1.1 per central radiology were assessed. Safety from the overall population (30-600 mg doses) and efficacy in the response evaluable 4L+ and PDGFRA Exon 18 (Ex 18) populations treated at the MTD (400 mg)/RP2D (300 mg) were analyzed. Results: As of 16 Nov 2018, 237 pts [172 KIT, 62 PDGFRA Ex 18 (56 D842V, 6 non-D842V), 2 PDGFRA N659K, 1 missing] were enrolled including 111 in the 4L+ population (primarily KIT, median 4 prior TKI) and 43 in the Ex 18 population (median 1 prior TKI). The 4L+ ORR was 22% [1 CR, 23 PR (1 pending)], and 52 SD with median duration of response (mDOR) of 10.2 months (95% CI: 7.2-NE). The Ex 18 ORR was 86% [3 CR, 34 PR (1 pending)] and 5 SD; mDOR was not reached (95% CI: 11.3-NE). Most AE were grade 1-2, most commonly nausea (63%), fatigue (58%), anemia (49%), periorbital edema (42%), diarrhea (40%), vomiting (40%), decreased appetite (38%), increased lacrimation (33%), peripheral edema (33%) and memory impairment (most common cognitive AE, 29%). 10% of pts discontinued due to a related AE. Grade 3-4 related AE ≥ 2% were anemia, fatigue, hypophosphatemia, hyperbilirubinemia, neutropenia, and diarrhea. Conclusions: Avapritinib has important clinical activity in pts with advanced GIST who have no effective therapies. The ORR and DOR of avapritinib in 4L+ exceeds that of approved 2nd and 3rd line therapies and shows unprecedented activity in D842V and other Ex 18 mutant PDGFRA GIST. Results suggest avapritinib has the potential to change the treatment paradigm of pts with advanced GIST. Clinical trial information: NCT02508532.

Somatic mutational profile of Merkel cell carcinoma treated with immune checkpoint blockade: Preliminary results from a planned multiplatform analysis

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Background: Merkel cell carcinoma (MCC) is an immunogenic neuroendocrine malignancy with promising responses to immune checkpoint blockade (ICB). Although ICB is standard of care in advanced MCC patients, approximately 50% of patients are resistant to ICB. Thus, it is crucial to identify biomarkers predictive of response. Methods: To understand the genomic landscape of MCC, we performed exome capture sequencing on 27 tumor and matched normal samples from 25 patients with MCC treated at Memorial Sloan Kettering. Herein, we report the analysis of 16 paired samples from 14 patients. Nonsynonymous, high-confidence somatic mutations were identified and tumor reads aligned to the Merkel cell polyoma virus (MCPyV) were quantified. Results: Tumor and matched normal samples were sequenced to a median target coverage depth of 53x and 79x reads, respectively. One sample was not analyzed due to inadequate coverage. The MCPyV genome was detected in 12 of 13 patients (92%). The median somatic mutation burden among analyzed samples was 19 nonsynonymous variants per exome (range: 8 - 120). No recurrent driver mutations were identified in any sample. Four samples lacked potential driver mutations and, among the remaining 11 samples, 36 putatively oncogenic mutations were detected in 33 genes (variant allele frequency: 0.08 – 1), including genes involved in the cell cycle checkpoint ( TP53, RB1), DNA damage repair ( ERCC4, FANCA, FANCD2), PI3K-AKT-mTOR ( PIK3CA, PIK3CG), and Notch ( NOTCH1, NOTCH2) pathways. One sample with undetected MCPyV DNA demonstrated loss of heterozygosity of both TP53 and RB1. Four samples contained strand coordinated clusters of mutations in more than 20 distinct gene regions, suggesting an APOBEC-high mutagenesis signature. Conclusions: The MCPyV genome was detected in most tumors analyzed and tumor mutation burden was low in such tumors, consistent with published literature. Analysis of an additional 11 sample pairs is ongoing, along with personalized neoantigen binding predictions on all samples. Immunohistochemistry (IHC) for PDL1 and CD8 expression is in progress. Associations between the aforementioned and response to ICB will be reported.

Phase 2 study of the CDK4 inhibitor abemaciclib in dedifferentiated liposarcoma

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Background: The oncogene cyclin-dependent kinase 4 (CDK4) is amplified in > 90% of de-differentiated liposarcomas (DDLS). We previously demonstrated that treatment with the CDK4 inhibitor palbociclib results in favorable progression-free survival (PFS) in DDLS. Abemaciclib is a newer and more potent CDK4 inhibitor. This single-arm phase 2 study was designed to test the activity of abemaciclib in DDLS. Methods: Participants were adults with advanced DDLS, measurable disease by RECIST 1.1, any (or no) priory therapy, and progression by RECIST in the 6 months prior to study entry. The primary endpoint was PFS at 12 weeks. Based on historical data, promising drugs have 12-week PFS of ≥ 40% and not promising ≤ 20%. This study would be positive if 12-week PFS was ≥ 60%. The study was approved by the Institutional Review Board of Memorial Sloan-Kettering Cancer Center and all patients provided written informed consent. The study was registered at Clinicaltrials.gov (NCT02846987) and study drug was provided by Eli-Lilly. Results: Treatment was abemaciclib 200 mg by mouth twice daily continuously. 30 patients were treated and 29 were evaluable for the primary endpoint. Patient characteristics: Median age 62 (range 39-88), 60% male. Lines of prior therapy: 0 (50%); 1 (33%); ≥ 2 (17%). The observed PFS at 12 weeks was 76% (95% CI 57-90%). Median PFS was 30.4 weeks (95% CI 28.9-NE). There was one partial response. A further 3 patients had > 10% decrease in tumor size by RECIST but did not meet the criterion for partial response. Grade 3-4 toxicity included anemia (37%), neutropenia (20%), thrombocytopenia (17%) and diarrhea (7%). Conclusions: This study met its primary endpoint. In patients with advanced progressive DDLS, abemaciclib treatment results in favorable PFS and objective tumor response with manageable toxicity. Updated response data and results of paired tumor biopsies will be presented. Clinical trial information: NCT02846987.

Responder analysis of patient-reported outcomes measurement information system (PROMIS) physical function (PF) and worst stiffness among patients with tenosynovial giant cell tumors (TGCT) in the ENLIVEN study

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Background: The double-blind, randomized, placebo-controlled phase 3 ENLIVEN study in TGCT demonstrated a significant tumor response at week 25 by RECIST for pexidartinib (39% vs. 0% for placebo) and improvement in joint function and symptoms. The aim of this analysis was to identify a threshold score for responder definitions for PROMIS-PF scale and Worst Stiffness Numerical Rating Scale (WS-NRS) and compared responder rates for pexidartinib versus placebo. Methods: Anchor- and distribution-based estimates were calculated, and cumulative distribution function (CDF) plots were generated to derive responder definition threshold estimates. Anchor- and distribution-based results and CDFs were evaluated through triangulation, following FDA PRO Guidance, to determine a single responder definition threshold (i.e., meaningful change) for each instrument. The proportion of responders at Week 25 between treatments was compared with Fisher’s Exact Test (2-sided). Results: 120 patients were randomized to pexidartinib (n = 61) and placebo (n = 59) and assessed through 25 weeks of treatment. Anchor-based analysis showed one-level improvement on the patient global rating of PF item was associated with a mean change of 4.0 on PROMIS-PF. Distribution-based estimates (0.5 SD and 1 SEM) for PROMIS-PF were 2.8 and 2.5, respectively. For WS-NRS, a response of “A little improved” by patients on the perception of stiffness item was associated with a mean change of 1.1. The distribution-based estimates for the WS-NRS item were 0.9 and 0.5, respectively. This resulted in the following responder definition thresholds: ≥3 points for PROMIS-PF and ≥1 for WS-NRS improvement. A greater proportion of pexidartinib as compared to placebo patients were responders by PROMIS-PF (30% vs. 5%, p < 0.001) and WS-NRS (39% vs. 19%, p = 0.02) at week 25, respectively. Conclusions: Triangulation yielded responder definitions of ≥3 points for PROMIS-PF and ≥1 for WS-NRS. With these definitions, a greater proportion of patients treated with pexidartinib compared to placebo had meaningful improvement in physical function and stiffness.

Pexidartinib for advanced tenosynovial giant cell tumor (TGCT): Long-term efficacy and safety from the phase 3 ENLIVEN and phase 1 PLX108-01 (TGCT cohort) studies

11042

Background: TGCT is a rare, locally aggressive neoplasm of the joint/tendon sheath linked to colony-stimulating factor 1 (CSF1) overexpression. Pexidartinib (pex), a selective inhibitor of CSF1 receptor, KIT, and FLT3-ITD, had a compelling tumor response rate in the TGCT cohort of a phase 1 study (NCT01004861) and significant tumor response vs placebo by RECIST v1.1 (39% vs 0%, P< 0.0001) and tumor volume score (TVS) (56% vs 0%, P< 0.0001) in the randomized, 2-part, crossover phase 3 ENLIVEN study (NCT02371369). Updated efficacy and safety with longer treatment are reported. Methods: Patients (pts) were ≥18 y with TGCT that was inoperable or for which surgery would likely be associated with worsening functional limitation or severe morbidity. Best overall response (complete or partial [CR/PR]) and duration of response (DOR) by RECIST and TVS were assessed by independent central review. Data cutoff was Jan 31, 2018, 16-67 mo after pts’ first dose. Results: In both studies 130 pts received pex, 61 ongoing at data cutoff. Median treatment duration was 17 mo (1, 60+). CR/PR rates were high and consistent and, together with DOR, improved with prolongation of treatment (Table). Most frequent adverse events were hair color change (75%), fatigue (60%), nausea (45%), arthralgia (38%), AST increase (30%), and diarrhea (30%). In ENLIVEN part 1, 3 of 61 (5%) pts had reversible ALT and AST ≥3 × ULN with TBil and ALP ≥2 × ULN; all started in the first 8 weeks of treatment, and no new cases emerged with continuation of treatment. Conclusions: Tumor response rate increased with continuation of pex treatment. The safety profile remained similar, with no new mixed or cholestatic hepatotoxicity. Clinical trial information: NCT01004861 and NCT02371369. [Table: see text]

Sequenced circulating tumor (ct) DNA to detect the molecular landscape in advanced GIST

11036

Background: Molecular (mol) characteristics-guided precision therapy has well-established utility in GIST management. The GIST mol landscape is poorly represented by selective tumor biopsy (bx) material, especially in metastatic and treatment-refractory GIST. ctDNA can overcome some of the limitations of selective tissue bx specimens and provide comparable or greater mol information. ctDNA represents an emerging mol biomarker in advanced (adv) GIST. Methods: Next generation sequencing analyses (MSK-IMPACT or custom-capture GIST specific panel) were performed on ctDNA prospectively collected from patients (pts) with adv GIST. MSK-IMPACT was performed on tumor material (archival tissue or paired tissue bx specimens taken in parallel with ctDNA collection from clinical trial participants). The primary objective was to determine the concordance between the mol landscape of GIST identified by sequenced tumor tissue versus ctDNA. Secondary objective was to correlate characteristics of sequenced ctDNA with standard measurements of response assessment. Results: 47 ctDNA samples collected from 25 pts with adv GIST were sequenced using MSK-IMPACT ( > 400 genes). MSK-IMPACT was performed on archival tumor material. Sequenced ctDNA detected the mutational spectrum of tumor tissue in 48% of cases. In 50% of these cases, ctDNA identified novel treatment-resistance mutations not previously identified in the archival tissues. To optimize sensitivity of detection, a custom-designed GIST specific ctDNA sequencing panel was developed incorporating 19 of the most commonly altered genes observed from MSK-IMPACT analysis performed on > 75 imatinib-refractory adv GIST tumor samples. 52 ctDNA samples collected from 30 pts with paired tumor bx samples have been sequenced using the custom-capture GIST panel. The tumor bx samples have been sequenced using MSK-IMPACT. Results are pending and will be presented. A separate cohort of ctDNA samples serially collected in the setting of a prospective clinical trial are being sequenced. The mol results with correlated treatment response by RECIST will also be presented. Conclusions: ctDNA could detect a broad spectrum of mol heterogeneity and potentially be used as a biomarker to guide precision therapy in adv GIST. Further research is necessary to determine the optimal ctDNA sequencing assay and the appropriate clinical setting to utilize in GIST.

A phase II study of epacadostat and pembrolizumab in patients with advanced sarcoma

11049

Background: Tumors express IDO1, an intracellular enzyme involved in the degradation of tryptophan to kynurenine, in order to evade immunosurveillance. Epacadostat inhibits IDO1 and shifts the tumor microenvironment from an immunosuppressive state to an immune-stimulated state. Pembrolizumab previously demonstrated activity in select sarcoma subtypes. We performed an open-label, single-center, phase II study of epacadostat and pembrolizumab in patients with advanced sarcoma. Methods: Patients received the recommended phase II dose of oral epacadostat (100mg) twice per day and intravenous pembrolizumab (200mg/dose) every 3 weeks. The primary endpoint was best objective response rate (ORR) (complete response and partial response [PR]) at 24 weeks by RECIST 1.1. Secondary endpoints included adverse events (AEs), ORR by irRECIST, progression free survival (PFS) and overall survival (OS). Correlative studies performed on pre/on-treatment biopsy specimens included PD-L1, IDO1, and kynurenine expression and characterization of tumor infiltrating lymphocytes by IHC, whole exome and RNA sequencing. Results: Twenty-nine patients were enrolled [median age 53 years (range, 24-78), 57% male, ECOG PS 0 83%]. Histological subtypes included leiomyosarcoma (17%), UPS (17%), myxofibrosarcoma (7%), liposarcoma (10.5%), EHE (10.5%), angiosarcoma (3%), “other” sarcoma subtype (35%). Patients were refractory to 0 (21%), 1 (38%), 2 (24%) and ≥ 3 (17%) prior lines of therapy. The most common ( > 20% of pts) grade (G)1 or 2 treatment related AEs (TRAEs) observed included fatigue (31%), rash (31%) and ALT elevation (24%). G3 TRAEs included AST elevation (10%), ALT elevation, anemia, hypophosphatemia and increased lipase each occurred in 3% of pts. Three patients discontinued therapy due to G3 immune mediated hepatitis. Among the 29 evaluable patients 1 (3%) confirmed PR (leiomyosarcoma), 13 stable diseases (45%) and 15 progressions (52%) were observed by RECIST 1.1. The median PFS was 8.0 weeks (two-sided 95% CI: 6.9 ~ 26.7) and the PFS rate at 24 weeks was 27.9% (two-sided 95% CI: 15.0% ~ 52.2%). The median OS was not estimable (two-sided 95% CI: 40.9 weeks ~ NE). The OS at 24 weeks was 85.2% (95% CI: 72.8%, 99.7%). Conclusions: Epacadostat in combination with pembrolizumab was generally well tolerated. Limited anti-tumor activity was observed among advanced sarcoma patients. Correlative analyses including determination of adequacy of IDO1 inhibition will be reported. Clinical trial information: NCT03414229.

Establishing a Mutually Respectful Environment in the Workplace: A Toolbox for Performance Excellence

Most health care professionals spend a substantial amount of their time at the workplace. Our interactions with team members can define our daily experiences, impact our work performance, and influence our overall job satisfaction. Over the last years, how we interact with colleagues and patients has changed with the introduction of social media, a tenser political climate, and an evolving health care system. In oncology, a team can be composed of medical students, clinicians, and support and administrative staff within a heavy emotional environment where some of our patients are facing the risk of early mortality and most are dealing with the unmeasurable burden of cancer. Many of these factors can increase the risk for professionalism lapses. We discuss common challenges faced in the practice of cancer care, including the generational gap between medical trainees and senior members, gender disparities, and microaggressions. Microaggressions represent verbal, behavioral, and environmental indignities that communicate hostile, derogatory, and negative slights that insult a target person or group. Microaggressions should not be accepted as the norm in the workplace. It is essential to recognize these negative behaviors and manage them effectively to reduce or even prevent the long-term toxicities that these behaviors can bring to the workplace environment. Ultimately, we must acknowledge that these issues exist and remember that education and collaboration are the pillars of an inclusive workplace. We owe such efforts to our patients who deserve good care, to our partners in the care of patients so that they feel supported and included, and to ourselves.