Citations

11535 Background: Ripretinib is a novel switch-control tyrosine kinase inhibitor (TKI) that broadly inhibits KIT and PDGFRA kinase signaling through a dual mechanism of action. In INVICTUS (NCT03353753), a randomized, double-blind, placebo-controlled trial of ripretinib in ≥4th-line advanced GIST, ripretinib reduced the risk of disease progression or death by 85% vs placebo and had a favorable overall safety profile in patients previously treated with ≥3 prior TKIs. Methods: As part of the INVICTUS trial, patient reported outcome (PRO) measures were collected using EQ-5D-5L (EQ5D) and EORTC QLQ-C30 (C30). In prespecified and additional analyses, ANCOVA models were built to compare changes from baseline to cycle 2 day 1 (C2D1) for PRO measures within the ripretinib and placebo arms and determine the difference between treatment arms. PRO measures included the EQ5D visual analogue scale (VAS) and the C30 physical functioning (PF) and role functioning (RF) scales (all scores range from 0–100; higher scores are better). The C30 overall health and overall QoL questions were also assessed (scores range from 1–7; higher scores are better). Fixed effects included treatment arm, number of previous anticancer treatments (3 vs ≥4), and ECOG score at baseline (0 vs 1/2). Results: Overall, 129 patients were randomized and 128 received treatment (85 to ripretinib 150 mg QD; 43 to placebo). All PRO p-values are nominal, and no statistical significance is being claimed. VAS scores improved an average 3.7 points from baseline to C2D1 with ripretinib vs an average decline of 8.9 with placebo (P = 0.004; improvement or no change, 67% vs 41% of patients, respectively). Similarly, the average PF score improved 1.6 points with ripretinib and decreased 8.9 with placebo (P = 0.004; improvement or no change, 68% vs 44%). RF scores also improved an average of 3.5 points with ripretinib vs a decrease of 17.1 with placebo (P = 0.001; improvement or no change, 77% vs 50%). For the overall health and overall QoL questions, scores increased with ripretinib an average of 0.20 and 0.28, respectively, and decreased 0.78 and 0.76 with placebo (both P = 0.001; improvement or no change, 74% vs 47% and 79% vs 59%, respectively). Conclusions: Based on the 5 PRO measures assessed, when compared with placebo and best supportive care, ripretinib provided patient-benefit in advanced GIST with PRO measures of role and physical function, VAS, overall health, and overall QoL remaining stable. Clinical trial information: NCT03353753 .

e17535 Background: Androgen Deprivation Therapy (ADT) is commonly used to treat prostate cancer (PC), but has been associated with cardiac morbidity and mortality. The exact mechanisms of this association are unclear. We sought to use an artificial intelligence (AI) enabled algorithm to identify ECG changes in PC patients who received ADT compared to PC patients who did not receive ADT. Methods: From 1,000,000 ECGs performed on 210,414 patients between 1993 and 2017 at our institution, a convolutional neural network was developed to detect predictive signatures for cardiac pathologies. During this process, the ability to predict “estimated sex” of the patient was developed, with output values ranging from 0 (female) to 1 (male). We applied this algorithm to 8,619 ECGs performed on 1,057 men age 75 or younger treated with radiation for high-risk or recurrent PC at our institution, and compared estimated sex after receiving ADT (n = 1,065) to ADT-naive ECGs (n = 7,554). We correlated ECG-identified estimated sex with serum testosterone levels using Spearman rank correlation. Results: Patients who had received ADT had a mean (SD) estimated sex value of 0.81 (0.26) compared to 0.92 (0.17) for those who did not (p < 0.001). Difference between estimated sex in post-ADT ECGs and ADT-naive ECGs remained significant across age groups (Table). Decreased serum total testosterone correlated with decreased estimated sex values in men receiving ADT (R = .57, p < 0.001). Conclusions: ADT for prostate cancer is associated with changes in AI-identified ECG parameters, including lower estimated male sex after receiving ADT. Lower ECG male sex estimate was associated with decreased serum testosterone. In this study, we provide preliminary proof of concept for a potential non-invasive means of monitoring treatment effect and physiologic change using ECGs. [Table: see text]

AbstractBackgroundOutcomes data regarding advanced synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) are limited, consisting primarily of retrospective series and post hoc analyses of clinical trials.MethodsIn this multi‐center retrospective study, data were abstracted from the medical records of 350 patients from nine sarcoma centers throughout the United States and combined into a registry. Patients with advanced/unresectable or metastatic SS (n = 249) or MRCL (n = 101) who received first‐line systemic anticancer therapy and had records of tumor imaging were included. Overall survival (OS), time to next treatment, time to distant metastasis, and progression‐free survival (PFS) were evaluated using the Kaplan‐Meier method and Cox regression.ResultsAt start of first‐line systemic anticancer therapy, 92.4% of patients with SS and 91.1% of patients with MRCL had metastatic lesions. However, 74.7% of patients with SS and 72.3% of patients with MRCL had ≥2 lines of systemic therapy. Median OS and median PFS from first‐line therapy for SS was 24.7 months (95% CI, 20.9‐29.4) and 7.5 months, respectively (95% CI, 6.4‐8.4). Median OS and median PFS from start of first‐line therapy for MRCL was 29.9 months (95% CI, 27‐44.6) and 8.9 months (95% CI 4.5‐12.0).ConclusionsTo the best of our knowledge, this is the largest retrospective study of patients with SS and MRCL. It provides an analysis of real‐world clinical outcomes among patients treated at major sarcoma cancer centers and could inform treatment decisions and design of clinical trials. In general, the survival outcomes for this selected population appear more favorable than in published literature.

Abstract Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm. It usually originates from the parietal pleura. SFT originating from the esophagus is exceedingly rare and even more so as a malignancy. We report a 57-year-old patient with a malignant 18 cm SFT of the esophagus that was treated with esophagectomy through a left thoracoabdominal incision. We discuss his surgical and oncologic management.

Objective: To report and discuss the effectiveness of stereotactic radiosurgery (SRS) or fractionated radiotherapy (FRT) for tumor control following surgical resection of endolymphatic sac tumors (ELST). Study Design: Retrospective case series. Setting: Multi-institutional academic referral centers. Patients: Patients undergoing surgical resection for ELST followed by SRS or FRT. Intervention(s): Surgical resection followed by radiotherapy. Main Outcome Measures: Local tumor control. Results: Two of the five patients experienced tumor recurrence after gross total microsurgical at 78 and 11 months, respectively. The former patient received salvage 3D conformal radiotherapy (3D-CRT) and while the latter patient underwent three courses of salvage SRS for recurrence, two of which were in-field and was disease-free at last follow up. Two additional patients underwent subtotal tumor resection (STR) followed by intensity-modulated radiation therapy (IMRT) and are currently without disease. One patient underwent STR followed by proton-beam therapy (PBT) and was free of disease at most recent follow-up. Conclusion: SRS/FRT remains a useful adjuvant for treatment of residual or recurrent ELSTs, where the risk of revision microsurgical resection is high.

TPS11077 Background: The response rates of advanced soft tissue sarcomas (STS) to single-agent, first-line anthracycline are typically less than 25%. P-glycoprotein 1 (P-gp), a cell membrane drug efflux pump, is believed to be a resistance mechanism in STS. CBT-1 is a small molecule, orally administered, P-gp antagonist currently under clinical development. This is a multi-institutional open label phase I study of CBT-1 in combination with doxorubicin in patients with anthracycline-refractory sarcoma. The study is designed to determine a maximum tolerable dose (MTD), recommended phase II dose (RP2D), and the safety/tolerability of the combination of CBT-1 and doxorubicin. The study will evaluate anti-cancer activity as a secondary objective as measured by Disease Control Rate (DCR; complete response [CR] + partial response [PR] + stable disease [SD]) at 12 weeks. Objective Response Rate (ORR; CR+PR) and Progression Free Survival (PFS) will be monitored. Correlative studies include assessment of pharmacokinetic and pharmacodynamicendpoints. Methods: Patients 18 years or older with locally advanced metastatic, unresectable STS, prior progression on ≤ 150 mg/m2 of doxorubicin (or another anthracycline equivalent), ECOG PS ≤ 1 and normal organ function, are eligible for this study. Dosing includes fixed doxorubicin (37.5 mg/m2 IV day 5 and day 6) and escalation of oral CBT-1 on days 1-7 of a 21 day cycle. This study follows a standard 3+3 phase I design where dose escalation will occur if < 0/3 or 1/6 patients experience a dose-limiting toxicity (DLT). Tumor assessments are conducted at Week 6 and Week 12. For patients with response or stable disease, treatment is allowed to continue for 4-5 cycles to a maximum of 450 mg/m2 lifetime doxorubicin exposure. Once RP2D is defined, an additional 10 patients will be enrolled into the dose expansion phase. To date, Cohorts 1 (50 mg CBT-1) and 2 (100 mg CBT-1) have been completed with one DLT of grade 4 neutropenia lasting longer than 7 days in Cohort 1. Enrollment to Cohort 3 began December 2018. (References: Oldham, R. K., Reid, W. K., Preisler, H. D., and Barnett, D. (1998) Cancer Biother. Radiopharm. 13, 71-80; Kelly, R. J., Robey, R. W., Chen, C. C., Draper, D., Luchenko, V., Barnett, D., Oldham, R. K., Caluag, Z., Frye, R. A., Steinberg, S. M., Fojo, T., Bates, S. E. (2012) The Oncologist 17 (4) 512-e523; Robey, R. W., Shukla, S., Finely, E. M., Oldham, R. K., Barnett, D., Ambudkar, S. V., Fojo, T., Bates, S. E., (2008) Biochemical Pharmacology 75, 6, 1302-1312). Clinical trial information: NCT03002805.

e22520 Background: Outcomes of patients (pts) with advanced synovial sarcoma (SS) and myxoid/round cell sarcoma (MRCL) is lacking. Current data is limited to single institution studies or post hoc analyses of clinical trials. To understand the natural history of these subtypes of soft tissue sarcoma we performed a systematic analysis of SS and MRCL patients from large medical institutions. Methods: Data was abstracted at 7 U.S. centers for pts treated from 2005 to 2015. Advanced SS or MRCL were eligible if they had received chemotherapy and were 18 years or older. The primary endpoint was overall survival, and secondary endpoints were progression free survival, time to next treatment, time to new distant metastasis. Results: 350 pts with locally advanced (LA), unresectable and/or or metastatic (Met) SS (n = 249) and MRCL (n = 101) were analyzed. The median age at diagnosis was 40 years for SS pts (58.2% male). The median age of MRCL pts was 50 years (67.3% male). 249 SS pts all had ≥ 1line of therapy, 74.7% had ≥2 lines of treatment. All MRCL pts received ≥1 line of treatment, 72.3% had ≥2 lines. The clinical outcomes (median overall survival (OS), progression free survival (PFS), time to next treatment (TTNT) and time to distant metastasis (TTDM)) from start of first-line chemotherapy are: The OS and PFS from second line chemotherapy decreased for all evaluable pts (n = 259) was 17.9 months (mos) [95% confidence interval (CI) (15.0, 22.3)]; 3.9 mos (3.4, 4.8), respectively. A similar trend toward shortened OS and PFS were seen with each subsequent line of chemotherapy. Conclusions: This registry analyzing real-world clinical outcomes among advanced SS and MRCL pts is the most comprehensive performed to date. It provides data on clinical outcomes depending on line of therapy and can provide the backbone for better patient management and design of future clinical trials.[Table: see text]

11011 Background: CMB305 (C) is an immunotherapy designed to generate an anti-NY-ESO-1 immune response (IR). C consists of a dendritic cell-targeting lentiviral vector encoding NY-ESO-1 gene (LV305), and a TLR-4 agonist NY-ESO-1 recombinant protein plus GLA-SE (G305). A Phase 1 study demonstrated C is safe, generates IR and conveys a median overall survival (mOS) of 23.7 months (15.5, not reached [NR]) for soft tissue sarcomas & 29.2 months (12.2, NR) for synovial sarcoma (SS) (ESMO 2018). We evaluated efficacy and safety of C and atezolizumab (A) vs A alone in NY-ESO-1+ SS and myxoid round cell liposarcoma (MRCL). Methods: A prospective randomized open label phase 2 study of C (LV305 Intradermal Days 0, 14, 42, 70 + G305 Intramuscular Days 28, 56, 84 then q 6wk up to one year (yr)) + A (1200mg IV q3wk) vs A alone in advanced NY-ESO-1+ SS/MRCL. Primary endpoints of OS and progression-free survival (PFS); secondary endpoints of safety, IR, and response rate and post hoc analysis by line of therapy. Results: 88 patients (pts) were enrolled and dosed. Arm C+A: median age 48 yrs, 73% SS, 98% relapsed metastatic, 73% ≥2 prior lines chemotherapy; Arm A: 47 yrs, 67% SS, 84% relapsed metastatic, 53% ≥2 prior lines chemotherapy. Most treatment-related adverse events (TRAE) Grade 1/2, no treatment related deaths. Summary of clinical outcomes. Conclusions: Despite no major differences in PFS and OS between the treatment arms (Arm C+A had more advanced disease and more prior lines of chemotherapy), Arm A +C achieved PRs, a higher level of anti-NY-ESO-1 IR, and pts with IR had numerically superior outcomes. Moreover, the clinical benefit of C+A in earlier lines of therapy warrant further study. Clinical trial information: NCT02609984. [Table: see text]

10521 Background: Sarcomas are rare cancers, with > 50 subtypes, and require multi-disciplinary care. Their management benefits from multi-institutional input due to the paucity of concentrated experience with each subtype. However, sarcoma tumor boards, wherein a patient-specific, consensus treatment approach is determined, are predominantly conducted in isolation at individual centers. Methods: Since March 2010, we have conducted a weekly multi-institutional, multi-disciplinary sarcoma tumor board to combine knowledge and experience in the management of our most challenging patients. The Mayo Clinic bridge links sites by interactive videofeed. Each site may contribute cases. De-identified history, radiology and pathology are reviewed. A didactic series reviews a rotation of seminal papers, newly published research, or our own data. An “Expert Guest" series allows outside experts to connect to one conference. A yearly participant survey assesses quality. Conference is free to sites and is CME accredited. Results: Currently, 8 sarcoma programs connect Mondays from 8-9am ET. Median attendance is 20 (range: 8-27). In 2012, 342 cases were reviewed over 43 conferences (median: 8 cases/conference; range: 4-12 cases/conference). The 2012 survey revealed 96% (25/26) agreed HIPAA rules are followed; 93% (25/27) agreed conference is educational; 93% (25/27) agreed recommendations are evidenced-based or reasonable; 100% (27/27) agreed participants are respectful; and 86% (18/21) agreed input from other sites has changed their management. Staff attendance (quantity) rated as meets/exceeds needs was 100% (25/25) for medical oncology; 96% (26/27) for pathology; 93% (25/27) for orthopedic oncology; 92% (23/25) for radiation oncology, surgical oncology and radiology; and 61% (17/23) for thoracic oncology. Conclusions: To our knowledge, this is the only weekly multi-institutional sarcoma tumor board in existence. It permits consistent oncology care across a wide geographic area, and is a model for providing consensus recommendations regardless of the remoteness of the patient and care team. Future plans for this group include prospective collection of outcomes data.

11015 Background: Immune checkpoint inhibitors have demonstrated activity in multiple tumor types but their activity in soft tissue sarcomas remains limited. In the multicenter phase II study, SARC028, the anti-PD-1 antibody, P demonstrated objective responses that were largely restricted to UPS and LPS subtypes. We now report outcomes from 2 expansion cohorts of SARC 028 in advanced UPS and LPS. Methods: To further confirm the clinical activity of P in UPS and LPS, we enrolled an additional 30 pts in each of 2 expansion cohorts for a total of 40 UPS and 40 LPS pts. Primary endpoint was investigator-assessed response by RECIST v1.1. Secondary endpoints were safety, progression-free survival (PFS), 12-week PFS rate, and overall survival (OS). An ORR of 25% was considered clinically meaningful and < 10% was considered to show lack of efficacy. P was to be considered a success if 8 or more of 40 enrolled patients had a PR or better (1-sided α = 0.042, 82% power). Pts age ≥18 with advanced, refractory UPS or LPS received 200 mg of P IV every 3 weeks until progression or unacceptable toxicity. Results: Preliminary results from the first 10 pts in each of the UPS and LPS cohorts have been reported. We now present summary data after enrolling an additional 30 pts in each cohort. The ORR in the UPS cohort was 23% (9/40), with an additional 5/30 PRs observed in the expansion cohort (total 2 CRs, 7 PRs). In the LPS cohort, the ORR was 10% (4/39 evaluable pts), with an additional 2/30 PRs observed (total 4 PRs). Median PFS for the UPS group was 3 months [95% CI: 2, 5] and 2 months [95% CI: 2, 4] for the LPS group. 12-week PFS rate was 50% in UPS [95% CI: 35, 65] and 44% in LPS [95% CI: 28, 60]. The UPS group had a median OS of 12 months [95% CI: 7, 34] and 13 months [95% CI: 8, NR] for the LPS group. P was well tolerated with no unexpected toxicities. Conclusions: The UPS cohort achieved its primary endpoint, however the activity of P in UPS deserves further evaluation in a randomized study. The activity of P was not confirmed in the LPS cohort. Ongoing biomarker analyses may direct better patient selection and guide future combination strategies. Clinical trial information: NCT02301039.