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Purpose: Most patients with gastrointestinal stromal tumor (GIST) have activating mutations in KIT/PDGFRA and are initially responsive to tyrosine kinase inhibitors (TKI). The acquisition of secondary mutations leads to refractory/relapsed disease. This study reports the results of an analysis from the phase III INVICTUS study (NCT03353753) characterizing the genomic heterogeneity of tumors from patients with advanced GIST and evaluating ripretinib efficacy across KIT/PDGFRA mutation subgroups. Patients and Methods: Tumor tissue and liquid biopsy samples that captured circulating tumor DNA were collected prior to study enrollment and sequenced using next-generation sequencing. Subgroups were determined by KIT/PDGFRA mutations and correlation of clinical outcomes and KIT/PDGFRA mutational status was assessed. Results: Overall, 129 patients enrolled (ripretinib 150 mg once daily, n = 85; placebo, n = 44). The most common primary mutation subgroup detected by combined tissue and liquid biopsies were in KIT exon 11 (ripretinib, 61.2%; placebo, 77.3%) and KIT exon 9 (ripretinib, 18.8%; placebo, 15.9%). Patients receiving ripretinib demonstrated progression-free survival (PFS) benefit versus placebo regardless of mutation status (HR 0.16) and in all assessed subgroups in Kaplan–Meier PFS analysis (exon 11, P < 0.0001; exon 9, P = 0.0023; exon 13, P < 0.0001; exon 17, P < 0.0001). Among patients with wild-type KIT/PDGFRA by tumor tissue, PFS ranged from 2 to 23 months for ripretinib versus 0.9 to 10.1 months for placebo. Conclusions: Ripretinib provided clinically meaningful activity across mutation subgroups in patients with advanced GIST, demonstrating that ripretinib inhibits a broad range of KIT/PDGFRA mutations in patients with advanced GIST who were previously treated with three or more TKIs.

Purpose: Ripretinib is a switch-control tyrosine kinase inhibitor that broadly inhibits KIT and platelet-derived growth factor receptor a kinase signalling. Ripretinib showed preliminary efficacy in patients with advanced gastrointestinal stromal tumour (GIST) in a phase I study across a range of doses. Results were confirmed in the phase III INVICTUS study, and ripretinib 150 mg once daily (QD) was subsequently approved as a >fourth-line therapy. Here, we report the phase I study results of intrapatient dose escalation (IPDE) in patients with GIST treated across second, third and later lines of therapy. Methods: Patients with advanced GIST who experienced disease progression (PD) at ripretinib 150 mg QD could dose escalate to 150 mg twice daily (BID). Progression-free survival (PFS) 1 was calculated from the date of the first dose of ripretinib 150 mg QD to PD (as per Response Evaluation Criteria in Solid Tumours 1.1); PFS2 was from the date of IPDE (150 mg BID) to PD or death. Treatment-emergent adverse events (TEAEs) were summarised by dosing periods and compared descriptively. Results: Of 142 patients with GIST receiving ripretinib 150 mg QD, 67 underwent IPDE. IPDE provided benefit across all lines of therapy; the median PFS2 was 5.6, 3.3 and 4.6 months for patients on second-, third-and >fourth-line therapy, respectively. A partial metabolic response after IPDE was demonstrated in 13 of 37 patients with available positron emission tomography scans. TEAEs reported at both doses were similar. Conclusion: Ripretinib IPDE after PD provided continued clinical benefit in advanced GIST across second, third and later lines of therapy with a similar safety profile to that observed with the QD regimen. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

The NCCN Guidelines for Uterine Neoplasms provide recommendations for diagnostic workup, clinical staging, and treatment options for patients with endometrial cancer or uterine sarcoma. These NCCN Guidelines Insights focus on the recent addition of molecular profiling information to aid in accurate diagnosis, classification, and treatment of uterine sarcomas.

Globally, there has been little change in mortality rates from cardiovascular (CV) diseases or cancers over the past two decades (1997–2018). This is especially true for heart failure (HF) where 5-year mortality rates remain as high as 45–55%. In the same timeframe, the proportion of drug revenue, and regulatory drug approvals for cancer drugs, far out paces those for CV drugs. In 2018, while cancer drugs made 27% of Food and Drug Administration drug approvals, only 1% of drug approvals was for a CV drug, and over this entire 20 year span, only four drugs were approved for HF in the USA. Cardiovascular trialists need to reassess the design, execution, and purpose of CV clinical trials. In the area of oncology research, trials are much smaller, follow-up is shorter, and targeted therapies are common. Cardiovascular diseases and cancer are the two most common causes of death globally, and although they differ substantially, this review evaluates whether some elements of oncology research may be applicable in the CV arena. As one of the most underserved CV diseases, the review focuses on aspects of cancer research that may be applicable to HF research with the aim of streamlining the clinical trial process and decreasing the time and cost required to bring safe, effective, treatments to patients who need them. The paper is based on discussions among clinical trialists, industry representatives, regulatory authorities, and patients, which took place at the Cardiovascular Clinical Trialists Workshop in Washington, DC, on 8 December 2019 (https://www.globalcvctforum.com/2019 (14 September 2020)).

The purpose of this study was to determine the Magnetic Resonance (MR) imaging features that best differentiate leiomyosarcoma (LMS) from leiomyoma, and to explore a scoring system to preoperatively identify those at highest risk of having LMS. Our Institutional Review Board approved this retrospective HIPAA-compliant study with a waiver for written informed consent. Institutional Research Patient Data Registry identified patients with histopathologically-proven LMS (n = 19) or leiomyoma (n = 25) and a pelvic MRI within six months prior to surgery. Qualitative differentiating MRI features were selected based on prior publications and clinical experience. Patient and MRI characteristics for leiomyomas versus LMS were compared using Wilcoxon rank-sum tests or Fisher’s exact tests and using a basic classification tree. Hypothesis testing was two-tailed, with a p value

Currently, the only approved treatments for gastrointestinal stromal tumor (GIST) are tyrosine kinase inhibitors (TKI), which eventually lead to the development of secondary resistance mutations in KIT or PDGFRA and disease progression. Herein, we identified G protein–coupled receptor 20 (GPR20) as a novel non–tyrosine kinase target in GIST, developed new GPR20 IHC, and assessed GPR20 expression in cell lines, patient-derived xenografts, and clinical samples from two institutes (United States and Japan). We studied GPR20 expression stratified by treatment line, KIT expression, GIST molecular subtype, and primary tumor location. We produced DS-6157a, an anti-GPR20 antibody–drug conjugate with a novel tetrapeptide-based linker and DNA topoisomerase I inhibitor exatecan derivative (DXd). DS-6157a exhibited GPR20 expression–dependent antitumor activity in GIST xenograft models including a GIST model resistant to imatinib, sunitinib, and regorafenib. Preclinical pharmacokinetics and safety profile of DS-6157a support its clinical development as a potential novel GIST therapy in patients who are refractory or have resistance or intolerance to approved TKIs. Significance: GPR20 is selectively expressed in GIST across all treatment lines, regardless of KIT/PDGFRA genotypes. We generated DS-6157a, a DXd-based antibody–drug conjugate that exhibited antitumor activity in GIST models by a different mode of action than currently approved TKIs, showing favorable pharmacokinetics and safety profiles. This article is highlighted in the In This Issue feature, p. 1307

Purpose: Restrictive clinical trial eligibility criteria (EC) limit the number of patients who can enroll and potentially benefit from protocol-driven, investigational treatment plans and reduce the generalizability of trial results to the broader population. Following publication of expert stakeholder recommendations for broadening EC in 2017, the American Society of Clinical Oncology (ASCO) and Friends of Cancer Research (Friends) convened working groups to produce additional recommendations and analyze the potential impact on clinical trials using real-world data. Experimental Design: Multistakeholder working groups were appointed by an ASCO-Friends leadership group to propose recommendations for more inclusive EC related to: washout periods, concomitant medications, prior therapies, laboratory reference ranges and test intervals, and performance status. Results: The four working groups, ASCO Board of Directors, and Friends leadership support the recommendations included in this statement to modernize EC related to washout periods, concomitant medications, prior therapies, laboratory references ranges and test intervals, and performance status to make trial populations more inclusive and representative of cancer patient populations. Conclusions: Implementation of the recommendations is intended to result in greater ease of determining patient eligibility. Increased opportunities for patient participation in research will help address longstanding underrepresentation of certain groups in clinical trials and produce evidence that is more informative for a broader patient population. More patients eligible will also likely speed clinical trial accrual. See related commentary by Giantonio, p. 2369

Gastrointestinal stromal tumor (GIST) provides a paradigm to evaluate new molecularly targeted therapies and to identify structural and functional mechanisms for drug response and resistance. Drug development in GIST has successfully exploited the high reliance on KIT/PDGFRA oncogenic signaling as a therapeutic vulnerability. The recent arrival of avapritinib and ripretinib to the GIST arena has aimed to further improve on precision kinase inhibition and address tumor heterogeneity in imatinib-resistant GIST. The two main clinical challenges for the forthcoming years entail tumor eradication in patients with early-stage GIST, and maximization of tumor response in late-stage disease. To succeed, we will need to better understand the mechanisms behind adaptation to KIT inhibition and apoptosis evasion, tumor evolution after successive lines of treatment, and to explore clinically novel creative therapeutic strategies, with the overarching goal to tackle the intrinsic oncogenic complexity while minimizing adverse events.

Summary Background Targeting of KIT and PDGFRA with imatinib revolutionised treatment in gastrointestinal stromal tumour; however, PDGFRA Asp842Val (D842V)-mutated gastrointestinal stromal tumour is highly resistant to tyrosine kinase inhibitors. We aimed to assess the safety, tolerability, and antitumour activity of avapritinib, a novel KIT and PDGFRA inhibitor that potently inhibits PDGFRA D842V, in patients with advanced gastrointestinal stromal tumours, including patients with KIT and PDGFRA D842V-mutant gastrointestinal stromal tumours (NAVIGATOR). Methods NAVIGATOR is a two-part, open-label, dose-escalation and dose-expansion, phase 1 study done at 17 sites across nine countries (Belgium, France, Germany, Poland, Netherlands, South Korea, Spain, the UK, and the USA). Patients aged 18 years or older, with an Eastern Cooperative Oncology Group performance status of 2 or less, and with adequate end-organ function were eligible to participate. The dose-escalation part of the study included patients with unresectable gastrointestinal stromal tumours. The dose-expansion part of the study included patients with an unresectable PDGFRA D842V-mutant gastrointestinal stromal tumour regardless of previous therapy or gastrointestinal stromal tumour with other mutations that either progressed on imatinib and one or more tyrosine kinase inhibitor, or only received imatinib previously. On the basis of enrolment trends, ongoing review of study data, and evolving knowledge regarding the gastrointestinal stromal tumour treatment paradigm, it was decided by the sponsor's medical director together with the investigators that patients with PDGFRA D842V mutations would be analysed separately; the results from this group of patients is reported in this Article. Oral avapritinib was administered once daily in the dose-escalation part (starting dose of 30 mg, with increasing dose levels once daily in continuous 28-day cycles until the maximum tolerated dose or recommended phase 2 dose was determined; in the dose-expansion part, the starting dose was the maximum tolerated dose from the dose-escalation part). Primary endpoints were maximum tolerated dose, recommended phase 2 dose, and safety in the dose-escalation part, and overall response and safety in the dose-expansion part. Safety was assessed in all patients from the dose-escalation part and all patients with PDGFRA D842V-mutant gastrointestinal stromal tumour in the dose-expansion part, and activity was assessed in all patients with PDGFRA D842V-mutant gastrointestinal stromal tumour who received avapritinib and who had at least one target lesion and at least one post-baseline disease assessment by central radiology. This study is registered with ClinicalTrials.gov , NCT02508532 . Findings Between Oct 26, 2015, and Nov 16, 2018 (data cutoff), 46 patients were enrolled in the dose-escalation part, including 20 patients with a PDGFRA D842V-mutant gastrointestinal stromal tumour, and 36 patients with a PDGFRA D842V-mutant gastrointestinal stromal tumour were enrolled in the dose-expansion part. At data cutoff (Nov 16, 2018), 38 (46%) of 82 patients in the safety population (median follow-up of 19·1 months [IQR 9·2–25·5]) and 37 (66%) of the 56 patients in the PDGFRA D842V population (median follow-up of 15·9 months [IQR 9·2–24·9]) remained on treatment. The maximum tolerated dose was 400 mg, and the recommended phase 2 dose was 300 mg. In the safety population (patients with PDGFRA D842V-mutant gastrointestinal stromal tumour from the dose-escalation and dose-expansion parts, all doses), treatment-related grade 3–4 events occurred in 47 (57%) of 82 patients, the most common being anaemia (14 [17%]); there were no treatment-related deaths. In the PDGFRA D842V-mutant population, 49 (88%; 95% CI 76–95) of 56 patients had an overall response, with five (9%) complete responses and 44 (79%) partial responses. No dose-limiting toxicities were observed at doses of 30–400 mg per day. At 600 mg, two patients had dose-limiting toxicities (grade 2 hypertension, dermatitis acneiform, and memory impairment in patient 1, and grade 2 hyperbilirubinaemia in patient 2). Interpretation Avapritinib has a manageable safety profile and has preliminary antitumour activity in patients with advanced PDGFRA D842V-mutant gastrointestinal stromal tumours. Funding Blueprint Medicines.

Due to the efficacy of immune checkpoint inhibitor therapy in tumors with deficient mismatch repair, there has been a surge in demand for mismatch repair deficiency testing in various tumor types. Mismatch repair deficiency is not known to play a significant role in the pathogenesis of sarcomas, and the utility of testing these tumor types is not established. This study aimed to determine the frequency, pattern, and clinicopathologic correlates of mismatch repair deficiency in sarcomas. Three hundred and four sarcomas were profiled using a genomic platform that employs massively parallel sequencing to interrogate 447 cancer-associated genes. Mismatch repair status was evaluated by determining the number of small insertion/deletion events occurring in homopolymer regions per megabase of exonic sequence data across all genes. Molecular characteristics of mismatch repair-deficient sarcomas were compared to mismatch repair-deficient carcinomas (n = 70) also identified using the sequencing panel. Seven sarcomas (2.3%) were classified as mismatch repair-deficient: four unclassified sarcomas, and one each of pleomorphic rhabdomyosarcoma, epithelioid leiomyosarcoma and malignant PEComa. One patient had an established diagnosis of Lynch syndrome. In the remaining patients, the mismatch repair gene mutation was confirmed or suspected to be somatic. Mismatch repair immunohistochemistry confirmed the mismatch repair-deficiency status of all cases with alterations in the tested proteins. As expected, mismatch repair-deficient sarcomas showed a significantly elevated tumor mutation burden relative to mismatch repair-proficient sarcomas (median 16 versus 4.6, p

Management of leiomyosarcoma is based on the specifics of each individual case. Specifically, the location of the disease and whether the disease is metastatic or localized and if localized disease, whether the tumor is resectable or unresectable. In patients with recurrent or metastatic disease, factors such as disease-free interval and pattern of spread should be considered within the context of treatment planning. In general, patients with metastatic disease are typically treated with systemic chemotherapy with either an anthracycline-based regimen or gemcitabine-based regimen as first-line therapy. Additional systemic options include trabectedin, pazopanib, eribulin, and DTIC. Uterine LMS has been the most studied site-specific LMS with respect to systemic therapy. The increasing use of tumor genomics may ultimately define subsets which may benefit from tailored systemic therapies.

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

BackgroundAvapritinib, a potent inhibitor of KIT and platelet-derived growth factor receptor A (PDGFRA) tyrosine kinases, has demonstrated unprecedented clinical activity in PDGFRA D842V-mutant gastrointestinal stromal tumors (GIST).MethodsThis retrospective analysis compared efficacy of avapritinib in patients enrolled in the NAVIGATOR phase 1 trial (NCT02508532) with the efficacy of other tyrosine kinase inhibitors (TKIs) in patients with unresectable/metastatic PDGFRA D842V-mutant GIST enrolled in a retrospective natural history study (Study 1002). The primary endpoint was overall survival (OS) from the start of reference treatment (avapritinib for NAVIGATOR patients or first-line TKI for treatment of unresectable/metastatic GIST for Study 1002 patients); the secondary endpoint was progression-free survival (PFS). Adjusted Kaplan–Meier survival curves were compared by Cox regression.ResultsFifty-six (NAVIGATOR) and 19 (Study 1002) patients with PDGFRA D842V-mutant GIST were evaluated; of the 56 patients from NAVIGATOR, a subgroup of patients treated with either 300 mg (recommended phase 2 dose) or 400 mg (maximum tolerated dose) avapritinib starting dose (n = 38) were analyzed separately. Patient characteristics were adjusted for imbalances by propensity score between the study groups. Inverse probability of treatment weighting-adjusted Kaplan–Meier analysis of OS showed median OS was not reached for NAVIGATOR patients treated with any of the avapritinib doses tested and was 12.6 months for Study 1002 patients; OS rate at 6/48 months was 100%/63% in NAVIGATOR and 56%/17% in Study 1002 (P = 0.0001). In the 300/400 mg subgroup, adjusted OS rates at 6/36 months were 100%/73 and 68%/20% in Study 1002 (P = 0.0016). Adjusted median PFS was 29.5 months in NAVIGATOR and 3.4 months in Study 1002.ConclusionsIn this indirect, retrospective analysis, avapritinib demonstrated more durable survival outcomes compared with other TKIs in patients with unresectable/metastatic PDGFRA D842V-mutant GIST.Trial registrationThe NAVIGATOR trial was registered at ClinicalTrials.gov as per July 2015, Identifier:NCT02508532.

Avapritinib; Tumors de l'estroma gastrointestinal; PDGFRA Avapritinib; Tumores del estroma gastrointestinal; PDGFRA Avapritinib; Gastrointestinal stromal tumours; PDGFRA Background PDGFRA D842V mutations occur in 5–10% of gastrointestinal stromal tumours (GISTs), and previously approved tyrosine kinase inhibitors (TKIs) are inactive against this mutation. Consequently, patients have a poor prognosis. We present an updated analysis of avapritinib efficacy and long-term safety in this patient population. Methods NAVIGATOR (NCT02508532), a two-part, open-label, dose-escalation/dose-expansion phase I study, enrolled adult patients with unresectable GISTs. Patients with PDGFRA D842V-mutant GIST were a prespecified subgroup within the overall safety population, which included patients who received ≥1 avapritinib dose. Primary end-points were overall response rate (ORR) and avapritinib safety profile. Secondary end-points were clinical benefit rate (CBR), duration of response (DOR) and progression-free survival (PFS). Overall survival (OS) was an exploratory end-point. Results Between 7 October 2015 and 9 March 2020, 250 patients enrolled in the safety population; 56 patients were included in the PDGFRA D842V population, 11 were TKI-naïve. At data cut-off, median follow-up was 27.5 months. Safety profile was comparable between the overall safety and PDGFRA D842V populations. In the PDGFRA D842V population, the most frequent adverse events were nausea (38 [68%] patients) and diarrhoea (37 [66%]), and cognitive effects occurred in 32 (57%) patients. The ORR was 91% (51/56 patients). The CBR was 98% (55/56 patients). The median DOR was 27.6 months (95% confidence interval [CI]: 17.6–not reached [NR]); median PFS was 34.0 months (95% CI: 22.9–NR). Median OS was not reached. Conclusion Targeting PDGFRA D842V-mutant GIST with avapritinib resulted in an unprecedented, durable clinical benefit, with a manageable safety profile. Avapritinib should be considered as first-line therapy for these patients. The NAVIGATOR study (NCT02508532) was supported by Blueprint Medicines Corporation, Cambridge, Massachusetts, USA.

Background Most gastrointestinal stromal tumors (GIST) driven by KIT or platelet‐derived growth factor receptor A (PDGFRA) mutations develop resistance to available tyrosine kinase inhibitor (TKI) treatments. NAVIGATOR is a two‐part, single‐arm, dose escalation and expansion study designed to evaluate safety and antineoplastic activity of avapritinib, a selective, potent inhibitor of KIT and PDGFRA, in patients with unresectable or metastatic GIST. Materials and Methods Eligible patients were 18 years or older with histologically or cytologically confirmed unresectable GIST and Eastern Cooperative Oncology Group performance status ≤2 and initiated avapritinib at 300 mg or 400 mg once daily. Primary endpoints were safety in patients who initiated avapritinib at 300 mg or 400 mg once daily and overall response rate (ORR) in patients in the safety population with three or more previous lines of TKI therapy. Results As of November 16, 2018, in the safety population (n = 204), the most common adverse events (AEs) were nausea (131 [64%]), fatigue (113 [55%]), anemia (102 [50%]), cognitive effects (84 [41%]), and periorbital edema (83 [41%]); 17 (8%) patients discontinued due to treatment‐related AEs, most frequently confusion, encephalopathy, and fatigue. ORR in response‐evaluable patients with GIST harboring KIT or non‐D842V PDGFRA mutations and with at least three prior therapies (n = 103) was 17% (95% confidence interval [CI], 10–25). Median duration of response was 10.2 months (95% CI, 7.2–10.2), and median progression‐free survival was 3.7 months (95% CI, 2.8–4.6). Conclusion Avapritinib has manageable toxicity with meaningful clinical activity as fourth‐line or later treatment in some patients with GIST with KIT or PDGFRA mutations. Implications for Practice In the NAVIGATOR trial, avapritinib, an inhibitor of KIT and platelet‐derived growth factor receptor A tyrosine kinases, provided durable responses in a proportion of patients with advanced gastrointestinal stromal tumors (GIST) who had received three or more prior therapies. Avapritinib had a tolerable safety profile, with cognitive adverse events manageable with dose interruptions and modification in most cases. These findings indicate that avapritinib can elicit durable treatment responses in some patients with heavily pretreated GIST, for whom limited treatment options exist., This article presents safety and efficacy findings of the phase I NAVIGATOR trial of avapritinib in patients with metastatic or unresectable KIT‐ or PDGFRA‐ mutant gastrointestinal stromal tumors with the efficacy analysis focused on patients who had previously received a minimum of three prior lines of therapy.

Background Globally, methamphetamine use has increased in prevalence in recent years. In Australia, there has been a dramatic increase in numbers of people seeking treatment, including residential rehabilitation, for methamphetamine use disorder (MUD). While residential rehabilitation is more effective for MUD than withdrawal treatment (i.e. “detoxification”) alone, relapse rates remain high, with approximately half of rehabilitation clients using methamphetamine within 3 months of rehabilitation. “Approach bias modification” (ABM) is a computerised cognitive training approach that aims to dampen automatically triggered impulses to approach drugs and drug-related stimuli. ABM has been demonstrated to reduce alcohol relapse rates, but no randomised controlled trials of ABM for MUD have yet been conducted. We aim to test whether a novel “personalised” form of ABM, delivered during rehabilitation, reduces post-treatment methamphetamine use, relative to a sham-training control condition. Secondary outcomes will include dependence symptoms, cravings, and approach bias. Methods We aim to recruit 100 participants attending residential rehabilitation for MUD at 3 sites in the Melbourne metropolitan area. Participants will complete baseline measures of methamphetamine use, craving, dependence severity, and approach bias before being randomised to receiving 6 sessions of ABM or “sham” training. In the active condition, ABM will be personalised for each participant, using those methamphetamine images that they rate as most relevant to their recent methods of methamphetamine use as “avoidance” images and using positive images representing their goals or healthy sources of pleasure as “approach” images. Approach bias and craving will be re-assessed following completion of training, and methamphetamine use, dependence, and craving will be assessed 4 weeks and 3 months following discharge from residential treatment. Discussion This study is the first randomised controlled trial of ABM for MUD and also the first ABM study to test using a personalised set of both approach and avoid images for ABM training. If effective, the low cost and easy implementation of ABM means it could be widely implemented as a standard part of MUD treatment. Trial registration Australian New Zealand Clinical Trials Registry ACTRN12620000072910. Registered on 30 January 2020 (prospectively registered): https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378804&isReview=true

PURPOSE Primary or secondary mutations in KIT or platelet-derived growth factor receptor alpha ( PDGFRA) underlie tyrosine kinase inhibitor resistance in most GI stromal tumors (GISTs). Avapritinib selectively and potently inhibits KIT- and PDGFRA-mutant kinases. In the phase I NAVIGATOR study ( NCT02508532 ), avapritinib showed clinical activity against PDGFRA D842V–mutant and later-line KIT-mutant GIST. VOYAGER ( NCT03465722 ), a phase III study, evaluated efficacy and safety of avapritinib versus regorafenib as third-line or later treatment in patients with unresectable or metastatic GIST. PATIENTS AND METHODS VOYAGER randomly assigned patients 1:1 to avapritinib 300 mg once daily (4 weeks continuously) or regorafenib 160 mg once daily (3 weeks on and 1 week off). Primary end point was progression-free survival (PFS) by central radiology per RECIST version 1.1 modified for GIST. Secondary end points included objective response rate, overall survival, safety, disease control rate, and duration of response. Regorafenib to avapritinib crossover was permitted upon centrally confirmed disease progression. RESULTS Four hundred seventy-six patients were randomly assigned (avapritinib, n = 240; regorafenib, n = 236). Median PFS was not statistically different between avapritinib and regorafenib (hazard ratio, 1.25; 95% CI, 0.99 to 1.57; 4.2 v 5.6 months; P = .055). Overall survival data were immature at cutoff. Objective response rates were 17.1% and 7.2%, with durations of responses of 7.6 and 9.4 months for avapritinib and regorafenib; disease control rates were 41.7% (95% CI, 35.4 to 48.2) and 46.2% (95% CI, 39.7 to 52.8). Treatment-related adverse events (any grade, grade ≥ 3) were similar for avapritinib (92.5% and 55.2%) and regorafenib (96.2% and 57.7%). CONCLUSION Primary end point was not met. There was no significant difference in median PFS between avapritinib and regorafenib in patients with molecularly unselected, late-line GIST.

© 2020 The Author(s)., Sarcomas are a heterogeneous group of malignancies with mesenchymal lineage differentiation. The discovery of neurotrophic tyrosine receptor kinase (NTRK) gene fusions as tissue-agnostic oncogenic drivers has led to new personalized therapies for a subset of patients with sarcoma in the form of tropomyosin receptor kinase (TRK) inhibitors. NTRK gene rearrangements and fusion transcripts can be detected with different molecular pathology techniques, while TRK protein expression can be demonstrated with immunohistochemistry. The rarity and diagnostic complexity of NTRK gene fusions raise a number of questions and challenges for clinicians. To address these challenges, the World Sarcoma Network convened two meetings of expert adult oncologists and pathologists and subsequently developed this article to provide practical guidance on the management of patients with sarcoma harboring NTRK gene fusions. We propose a diagnostic strategy that considers disease stage and histologic and molecular subtypes to facilitate routine testing for TRK expression and subsequent testing for NTRK gene fusions., GDD was supported in part by the Ludwig Center at Harvard; the Dr Miriam and Sheldon G. Adelson Medical Research Foundation; and the Pan Mass Challenge (no grant numbers). IMS is supported by the National Institutes of Health/National Cancer Institute (grant number K08 CA241085). JYB was supported by NetSARC (INCA & DGOS) and RREPS (INCA & DGOS), RESOS (INCA & DGOS), EURACAN (EC 739521), LYRICAN (INCA-DGOS-INSERM 12563), LabEx DEvweCAN (ANR-10-LABX-0061), Institut Convergence PLASCAN (17-CONV-0002), RHU4 DEPGYN (ANR-18-RHUS-0009).

PURPOSE In advanced gastrointestinal stromal tumor (GIST), there is an unmet need for therapies that target both primary and secondary mutations of pathogenic KIT/PDGFRA oncoproteins. Ripretinib is a novel switch-control kinase inhibitor designed to inhibit a wide range of KIT and PDGFRA mutations. PATIENTS AND METHODS This first-in-human, to our knowledge, phase I study of ripretinib (ClinicalTrials.gov identifier: NCT02571036) included a dose-escalation phase and subsequent expansion phase at the recommended phase II dose (RP2D). Eligible patients included those with advanced GIST, intolerant to or experienced progression on ≥ 1 line of systemic therapy, and other advanced malignancies. Safety, dose-limiting toxicities (DLTs), maximum-tolerated dose (MTD), and preliminary antitumor activity were evaluated. RESULTS At data cutoff (August 31, 2019), 258 patients (n = 184 GIST) were enrolled, with 68 patients in the dose-escalation phase. Three DLTs were reported: grade 3 lipase increase (n = 2; 100 mg and 200 mg twice a day) and grade 4 increased creatine phosphokinase (n = 1; 150 mg once daily). MTD was not reached (maximum dose evaluated, 200 mg twice a day); 150 mg once daily was established as the RP2D. The most frequent (> 30%) treatment-emergent adverse events in patients with GIST receiving ripretinib 150 mg once daily (n = 142) were alopecia (n = 88 [62.0%]), fatigue (n = 78 [54.9%]), myalgia (n = 69 [48.6%]), nausea (n = 65 [45.8%]), palmar-plantar erythrodysesthesia (n = 62 [43.7%]), constipation (n = 56 [39.4%]), decreased appetite (n = 48 [33.8%]), and diarrhea (n = 47 [33.1%]). Objective response rate (confirmed) of 11.3% (n = 16/142) ranging from 7.2% (n = 6/83; fourth line or greater) to 19.4% (n = 6/31; second line) and median progression-free survival ranging from 5.5 months (fourth line or greater) to 10.7 months (second line), on the basis of investigator assessment, were observed. CONCLUSION Ripretinib is a well-tolerated, novel inhibitor of KIT and PDGFRA mutant kinases with promising activity in patients with refractory advanced GIST.

Highlights • A woman with a history of Stage IA low-risk uterine adenosarcoma presented with shortness of breath and rib pain. • She was found to have recurrent metastatic disease with resultant fatal SVC Syndrome. • Better methods to determine which patients with uterine adenosarcoma are at risk of recurrence and death are needed.

Predictive markers; Sarcoma; Gastrointestinal stromal tumours Marcadores predictivos; Sarcoma; Tumores del estroma gastrointestinal Marcadors predictius; Sarcoma; Tumors estromals gastrointestinals Background Most patients with KIT-mutant gastrointestinal stromal tumours (GISTs) benefit from imatinib, but treatment resistance results from outgrowth of heterogeneous subclones with KIT secondary mutations. Once resistance emerges, targeting KIT with tyrosine kinase inhibitors (TKIs) sunitinib and regorafenib provides clinical benefit, albeit of limited duration. Methods We systematically explored GIST resistance mechanisms to KIT-inhibitor TKIs that are either approved or under investigation in clinical trials: the studies draw upon GIST models and clinical trial correlative science. We subsequently modelled in vitro a rapid TKI alternation approach against subclonal heterogeneity. Results Each of the KIT-inhibitor TKIs targets effectively only a subset of KIT secondary mutations in GIST. Regorafenib and sunitinib have complementary activity in that regorafenib primarily inhibits imatinib-resistance mutations in the activation loop, whereas sunitinib inhibits imatinib-resistance mutations in the ATP-binding pocket. We find that rapid alternation of sunitinib and regorafenib suppresses growth of polyclonal imatinib-resistant GIST more effectively than either agent as monotherapy. Conclusions Our data highlight that heterogeneity of KIT secondary mutations is the main mechanism of tumour progression to KIT inhibitors in imatinib-resistant GIST patients. Therapeutic combinations of TKIs with complementary activity against resistant mutations may be useful to suppress growth of polyclonal imatinib-resistance in GIST. This work was supported in part by an ASCO Young Investigator Award (CS), a Spanish Society of Medical Oncology Translational Award (CS), Río Hortega-ISCIII CM14/00241 (CS) FERO Foundation (CS), US National Institutes of Health grants 1P50CA127003 (GDD, ES, JAF), 1P50CA168512 (JAF, AME), GIST Cancer Research Fund (JAF, MCH), Life Raft Group (JAF, MCH, SB), V Foundation Translational Grant (MCH), VA Merit Review Award (2I01BX000338–05) (MCH) and the Deutsche Krebshilfe (SB). CS acknowledges to the Cellex Foundation for providing facilities and equipment.

Leiomyosarcoma (LMS) is one of the most common subtypes of soft tissue sarcoma in adults and can occur in almost any part of the body. Uterine leiomyosarcoma is the most common subtype of uterine sarcoma. Increased awareness of this unique histology has allowed for the development of drugs that are specific to LMS and has begun to shed light on the similarities and possible unique aspects of soft tissue and uterine LMS. In this review, we summarize the current understanding of the epidemiology, diagnosis, genomics, and treatment options for LMS.

Background Immunotherapy has changed the therapeutic landscape in oncology. Advanced uterine leiomyosarcoma (ULMS) remains an incurable disease in most cases, and despite new drug approvals, improvements in overall survival have been modest at best. The goal of this study was to evaluate programmed-death 1 (PD-1) inhibition with nivolumab in this patient population. Methods This single-center phase 2 trial completed enrollment between May and October 2015. Patients received 3 mg/kg of intravenous nivolumab on day 1 of each 2-week cycle until disease progression or unacceptable toxicity. The primary endpoint was objective response rate. We assessed PD-1, PD-ligand 1 (PD-L1), and PD-L2 expression in archival tumor samples and variations in immune-phenotyping of circulating immune cells during treatment. Results Twelve patients were enrolled in the first stage of the 2-stage design. A median of 5 (range, 2-6) 2-week cycles of nivolumab were administered. Of the 12 patients, none responded to treatment. The overall median progression-free survival was 1.8 months (95% confidence interval, 0.8-unknown). The study did not open the second stage due to lack of benefit as defined by the statistical plan. Archival samples were available for 83% of patients. PD-1 (>3% of cells), PD-L1, and PD-L2 (>5% and >10% of tumor cells, respectively) expression were observed in 20%, 20%, and 90% of samples, respectively. No significant differences were observed between pre- and posttreatment cell phenotypes. Conclusion Single-agent nivolumab did not demonstrate a benefit in this cohort of previously treated advanced ULMS patients. Further biomarker-driven approaches and studies evaluating combined immune checkpoint-modulators should be considered. Cancer 2017;123:3285-90. © 2017 American Cancer Society.

Background The majority of patients with advanced gastrointestinal stromal tumours (GISTs) develop resistance to imatinib and sunitinib, the standard of care for these patients. This study evaluated the combination of buparlisib, an oral phosphoinositide 3-kinase (PI3K) inhibitor, with imatinib in patients with advanced GIST, who have failed prior therapy with imatinib and sunitinib. Methods This Phase 1b, multicentre, open-label study aimed to determine the maximum tolerated dose (MTD) and/or a recommended Phase 2 dose of buparlisib in combination with 400 mg of imatinib through a dose-escalation part and a dose-expansion part, and also evaluated the clinical profile of the combination. Results Sixty patients were enrolled, including 25 in the dose-escalation part and 35 in the dose-expansion part. In the combination, MTD of buparlisib was established as 80 mg. No partial or complete responses were observed. The estimated median progression-free survival was 3.5 months in the expansion phase. Overall, 98.3% of patients had treatment-related adverse events (AEs), including 45% with grade 3 or 4 AEs. Conclusions Buparlisib in combination with imatinib provided no additional benefit compared with currently available therapies. Due to the lack of objective responses, further development of this combination was not pursued for third-line/fourth-line advanced/metastatic GIST. Trial registration number NCT01468688.

[Background] Gastrointestinal stromal tumor (GIST) initiation and evolution is commonly framed by KIT/PDGFRA oncogenic activation, and in later stages by the polyclonal expansion of resistant subpopulations harboring KIT secondary mutations after the onset of imatinib resistance. Thus, circulating tumor (ct)DNA determination is expected to be an informative non-invasive dynamic biomarker in GIST patients., [Methods] We performed amplicon-based next-generation sequencing (NGS) across 60 clinically relevant genes in 37 plasma samples from 18 GIST patients collected prospectively. ctDNA alterations were compared with NGS of matched tumor tissue samples (obtained either simultaneously or at the time of diagnosis) and cross-validated with droplet digital PCR (ddPCR)., [Results] We were able to identify cfDNA mutations in five out of 18 patients had detectable in at least one timepoint. Overall, NGS sensitivity for detection of cell-free (cf)DNA mutations in plasma was 28.6%, showing high concordance with ddPCR confirmation. We found that GIST had relatively low ctDNA shedding, and mutations were at low allele frequencies. ctDNA was detected only in GIST patients with advanced disease after imatinib failure, predicting tumor dynamics in serial monitoring. KIT secondary mutations were the only mechanism of resistance found across 10 imatinib-resistant GIST patients progressing to sunitinib or regorafenib., [Conclusions] ctDNA evaluation with amplicon-based NGS detects KIT primary and secondary mutations in metastatic GIST patients, particularly after imatinib progression. GIST exhibits low ctDNA shedding, but ctDNA monitoring, when positive, reflects tumor dynamics., This research is supported by a Fero Fellowship Award (C.S.), Asociación Española Contra el Cáncer (J.P. Barcelona) (C.S.), and ISCIII PI16/01371 (C.S.). C.S. and A.V. acknowledge to the Cellex Foundation for providing facilities and equipment.

Ripretinib (DCC-2618) is a novel, type II tyrosine switch control inhibitor designed to broadly inhibit activating and drug-resistant mutations in KIT and PDGFRA. Ripretinib has emerged as a promising investigational agent for the treatment of gastrointestinal stromal tumor owing to targeted inhibition of secondary resistance mutations that may develop following treatment with prior line(s) of tyrosine kinase inhibitors. Here we describe the rationale and design of intrigue (NCT03673501), a global, randomized (1:1), open-label, Phase III study comparing the safety and efficacy of ripretinib versus sunitinib in patients with advanced gastrointestinal stromal tumor following imatinib. The primary end point is progression-free survival and key secondary objectives include objective response rate and overall survival. Clinical Trial Registration: NCT03673501. ispartof: FUTURE ONCOLOGY vol:16 issue:1 pages:4251-4264 ispartof: location:England status: published

11539 Background: Ripretinib is a novel switch-control TKI that broadly inhibits KIT and PDGFRA kinase signaling. In INVICTUS (NCT03353753), a randomized, double-blind, placebo (PBO)-controlled trial of ripretinib in ≥4th-line advanced GIST, ripretinib reduced the risk of disease progression or death by 85% vs PBO with a favorable overall safety profile. Common ( > 20%) adverse events (AEs) included, but were not limited to, alopecia and PPES. Exploratory analyses evaluated the impact of alopecia and PPES on quality of life (QoL). Methods: Patients (pts) with advanced GIST previously treated with at least imatinib, sunitinib, and regorafenib were randomized (2:1) to ripretinib 150 mg QD or PBO. AEs were graded using CTCAE v4 and PROs collected using EQ-5D-5L (EQ5D) and EORTC QLQ-C30 (C30). Repeated measures (RM) models assessed the impact of alopecia and PPES on 5 PROs (EQ5D visual analogue scale; and C30 physical functioning, role functioning, and the overall health and overall QoL questions) within the ripretinib arm. Fixed effects were sex, alopecia/PPES, and ECOG scores at baseline. Results: 128/129 randomized pts received treatment (85 ripretinib 150 mg QD; 43 PBO). Alopecia, regardless of causality, occurred in 44 (51.8%) on ripretinib (34 [40.0%] grade 1; 10 [11.8%] grade 2) and 2 (4.7%) on PBO (both grade 1). PPES occurred in 18 (21.2%) on ripretinib (11 [12.9%] grade 1; 7 [8.2%] grade 2); none on PBO. The median times in days to first occurrence and worst severity grade with ripretinib were 57.0 and 62.5 for alopecia; 56.5 and 57.0 for PPES. The RM models showed a slight trend towards improvement in PRO score over time for pts with alopecia; the only association reaching a P-value of < 0.05 was between alopecia and increased overall QoL. None of the associations between PPES and PRO scores reach P < 0.05. All PRO p-values are nominal, and no statistical significance is being claimed. Conclusions: Ripretinib had a favorable overall safety and tolerability profile. When stratified by alopecia and PPES, patient-reported assessments of function, overall health, and overall QoL were maintained over time. For both alopecia and PPES, onset and maximum severity occurred almost simultaneously, indicating that these events generally did not progressively worsen. These results suggest that alopecia and PPES are manageable and do not have a negative effect on function, overall health, and QoL. Clinical trial information: NCT03353753 .

Background Resistance to approved inhibitors of KIT proto-oncogene, receptor tyrosine kinase (KIT), and platelet-derived growth factor receptor alpha (PDGFRA) is a clinical challenge for patients with advanced gastrointestinal stromal tumours. We compared the efficacy and safety of ripretinib, a switch-control tyrosine kinase inhibitor active against a broad spectrum of KIT and PDGFRA mutations, with placebo in patients with previously treated, advanced gastrointestinal stromal tumours.Methods In this double-blind, randomised, placebo-controlled, phase 3 study, we enrolled adult patients in 29 specialised hospitals in 12 countries. We included patients aged 18 years or older who had advanced gastrointestinal stromal tumours with progression on at least imatinib, sunitinib, and regorafenib or documented intolerance to any of these treatments despite dose modifications, and who had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. Eligible patients were randomly assigned (2:1) to receive either oral ripretinib 150 mg once daily (ripretenib group) or placebo once daily (placebo group). Randomisation was done via an interactive response system using randomly permuted block sizes of six and stratified according to number of previous therapies and ECOG performance status. Patients, investigators, research staff, and the sponsor study team were masked to a patient's treatment allocation until the blinded independent central review (BICR) showed progressive disease for the patient. The primary endpoint was progression-free survival, assessed by BICR. The primary analysis was done in the intention-to-treat population and safety was assessed in patients who received at least one dose of study drug. Patients randomly assigned to placebo were permitted to cross over to ripretinib 150 mg at the time of disease progression. The INVICTUS study is registered with ClinicalTrials.gov , number NCT03353753, and with WHO International Clinical Trials Registry Platform, number EUCTR2017-002446-76-ES; follow-up is ongoing.Findings Between Feb 27, 2018, and Nov 16, 2018, 129 of 154 assessed patients were randomly assigned to receive either ripretinib (n=85) or placebo (n=44). At data cutoff (May 31, 2019), at a median follow-up of 6.3 months (IQR 3. 2-8. 2) in the ripretinib group and 1.6 months (1.1-2.7) in the placebo group, 51 patients in the ripretinib group and 37 in the placebo group had had progression-free survival events. In the double-blind period, median progression-free survival was 6.3 months (95% CI 4.6-6.9) with ripretinib compared with 1.0 months (0.9-1.7) with placebo (hazard ratio 0.15, 95% CI 0.09-0.25; p2%) grade 3 or 4 treatment-related treatment-emergent adverse events in the ripretinib group (n=85) included lipase increase (four [5%]), hypertension (three [4%]), fatigue (two [2%]), and hypophosphataemia (two [2%]); in the placebo group (n=43), the most common (>2%) grade 3 or 4 treatment-related treatment-emergent adverse events were anaemia (three [7%]), fatigue (one [2%]), diarrhoea (one [2%]), decreased appetite (one [2%]), dehydration (one [2%]), hyperkalaemia (one [2%]), acute kidney injury (one [2%]), and pulmonary oedema (one [2%]). Treatment-related serious adverse events were reported in eight (9%) of 85 patients who received ripretinib and three (7%) of 43 patients who received placebo. Treatment-related deaths occurred in one patient in the placebo group (septic shock and pulmonary oedema) and one patient in the ripretinib group (cause of death unknown; the patient died during sleep).Interpretation Ripretinib significantly improved median progression-free survival compared with placebo and had an acceptable safety profile in patients with advanced gastrointestinal stromal tumours who were resistant to approved treatments. Copyright (C) 2020 Elsevier Ltd. All rights reserved.

Purpose: Polyclonal emergence of KIT secondary mutations is a main mechanism of imatinib progression in gastrointestinal stromal tumor (GIST). Approved KIT inhibitors sunitinib and regorafenib have complementary activity against KIT resistance mutations. Preclinical evidence suggests that rapid alternation of sunitinib and regorafenib broadens the spectrum of imatinib-resistant subclones targeted. Patients and Methods: Phase Ib study investigating continuous treatment with cycles of sunitinib (3 days) followed by regorafenib (4 days) in patients with tyrosine kinase inhibitor (TKI)-refractory GIST. A 3+3 dosing schema was utilized to determine the recommended phase II dose (RP2D). Plasma samples were analyzed for pharmacokinetics and circulating tumor DNA (ctDNA) studies using targeted error correction sequencing (TEC-seq) and droplet digital PCR (ddPCR). Results: Of the 14 patients enrolled, 2 experienced dose-limiting toxicities at dose level 2 (asymptomatic grade 3 hypophosphatemia). Sunitinib 37.5 mg/day and regorafenib 120 mg/day was the RP2D. Treatment was well-tolerated and no unexpected toxicities resulted from the combination. Stable disease was the best response in 4 patients, and median progression-free survival was 1.9 months. Combined assessment of ctDNA with TEC-seq and ddPCR detected plasma mutations in 11 of 12 patients (92%). ctDNA studies showed that KIT secondary mutations remain the main mechanism of resistance in TKI-refractory GIST, revealing effective suppression of KIT-mutant subpopulations in patients benefiting from the combination. Conclusions: Sunitinib and regorafenib combination is feasible and tolerable. Rapid alternation of TKIs with complementary activity might be effective when combining drugs with favorable pharmacokinetics, potentially allowing active doses while minimizing adverse events. Serial monitoring with ctDNA may guide treatment in patients with GIST.

Purpose: Most gastrointestinal stromal tumors (GIST) have activating mutations of KIT, PDGFRA, or uncommonly BRAF. Fifteen percent of adult and 85% of pediatric GISTs are wild type (WT), commonly having high expression of IGF-1R and loss of succinate dehydrogenase (SDH) complex function. We tested the efficacy of linsitinib, an oral TKI IGF-1R inhibitor, in patients with WT GIST. Patients and Methods: A multicenter phase II trial of linsitinib was conducted. The primary endpoint was objective response rate. Secondary endpoints were clinical benefit rate: complete response, partial response, and stable disease (SD) ≥ 9 months, and quantitative 2[18F]fluoro-2-deoxy-D-glucose (FDG) metabolic response (MR) at week 8. Serum levels for glucose, insulin, IGF-1R ligand IGF1, and binding proteins were obtained to explore correlations to patient outcomes and FDG-PET results. Results: Twenty patients were accrued in a 6-month period. Grade 3–4 toxicities possibly related to linsitinib were uncommon (8.5%). No objective responses were seen. Clinical benefit rate (CBR) at 9 months was 40%. Intense FDG uptake was observed at baseline, with partial MR of 12% and stable metabolic disease of 65% at week 8; these patients had RECIST 1.1 SD as their best response. Progression-free survival (PFS) and overall survival Kaplan–Meier estimates at 9 months were 52% and 80%, respectively. SDHA/B loss determined by IHC was seen in 35% and 88% of cases, respectively. Conclusions: Linsitinib is well tolerated in patients with WT GIST. Although the 9-month CBR was 40%, and PFS at 9 months was 52%, no objective responses were observed. Rapid accrual to this study demonstrates that clinical trials of experimental agents in selected subtypes of GIST are feasible.

Chemotherapy objective response rates (ORRs) in metastatic soft tissue sarcoma (STS) are typically 20–40% with median progression-free survival (PFS) less than 6 months. Lurbinectedin is a new anticancer agent under investigation. The primary objective of this three-arm, phase II study was to determine the disease control rate (DCR = ORR + stable disease [SD]) at 24 weeks of lurbinectedin alone or with chemotherapy in STS. Eligible patients included adults with ≤2 prior cytotoxic therapies. Study cohorts were: stratum A (StrA; anthracycline-naive), lurbinectedin/doxorubicin; stratum B (StrB; prior anthracycline), lurbinectedin/gemcitabine; stratum C (StrC; prior anthracycline/gemcitabine) lurbinectedin monotherapy. Each stratum was analysed separately by Simon two-stage design. Forty-two patients were accrued (StrA = 20, StrB = 10, StrC = 12) including leiomyosarcoma [LMS] (n = 20), synovial sarcoma [SS](n = 4), malignant peripheral nerve sheath tumour (n = 3) and other STS histologies (n = 15). For StrA there were seven partial responses (PR) plus one stable disease (SD) at 24 weeks. For StrB, two patients met the 24-week DCR including one PR (leiomyosarcoma) and one SD (desmoplastic small round cell tumour [DSRCT]). StrB did not continue to the second stage. In StrC, no patients met the primary end-point. Median progression-free survival (PFS) was: StrA = 4.2 months (90% CI 1.4–7.8), StrB = 1.7 months (90% confidence interval (CI) 1.0–7.4), and StrC = 1.3 months (90% CI 1.1–3.0). Lurbinectedin as a single agent or with chemotherapy was well tolerated with haematologic adverse events (AE's) as the most common toxicity. There were no treatment-related deaths. The combination of lurbinectedin/doxorubicin reached the DCR end-point with seven PR and one patient with SD (ORR 35.0%, 24-week DCR 40.0%). Evidence of drug benefit was seen in leiomyosarcoma, dedifferentiated liposarcoma (DDLS), myxoid liposarcoma (MLS), synovial sarcoma (SS), and desmoplastic small round cell tumour (DSRCT). Trial registration clinicaltrials.gov; NCT02448537

Ripretinib is a tyrosine kinase inhibitor (TKI) indicated for the treatment of adult patients with advanced gastrointestinal stromal tumor (GIST) who have received prior treatment with 3 or more kinase inhibitors, including imatinib. In a phase 1 study (NCT02571036), the maximum tolerated dose was not reached at doses up to 200 mg twice daily (BID). Ripretinib 150 mg BID intrapatient dose escalation regimen was offered to patients in the phase 1 and 3 trials (INVICTUS, NCT03353753) after radiologic progression at 150 mg once daily (QD). The BID dose was well tolerated with a similar safety profile to the 150 mg QD (approved dose regimen). In this analysis, the population pharmacokinetics (popPK) of ripretinib and DP-5439, a metabolite TKI with in vitro activity and exposure similar to ripretinib, were characterized and potential covariates influencing exposure were evaluated. The popPK models were developed for ripretinib and DP-5439 using 5284 and 5160 quantifiable concentrations, respectively, from 350 patients pooled from the phase 1 and INVICTUS phase 3 studies. Models were estimated using first-order conditional estimation with interaction method in NONMEM® (version 7.3; ICON, Hanover, MD, USA) and evaluated based on standard goodness-of-fit metrics. A covariate analysis was conducted to assess the sources of variability in ripretinib pharmacokinetics (PK) using a full model approach with backward elimination (significance level = 0.005). Tested covariates included age, body weight, sex, race, tumor type, prior gastrectomy, and mild hepatic impairment and mild to moderate renal impairment. Ripretinib oral PK was well described by a 2-compartment model with zero-order drug release at the absorption site followed by first-order absorption with a modest, linear dose-dependent decrease in relative bioavailability and linear elimination. A high-fat meal was predicted to increase the ripretinib AUC by 36% at 150 mg QD relative to the fasted state. The only covariate effect retained in the final popPK model for ripretinib was 29% lower apparent clearance in females compared with males, resulting in a 40% higher AUC in females. No other covariates were identified for ripretinib. The resulting effect on DP-5439 was similar. PK exposure in patients with mild hepatic impairment or mild to moderate renal impairment was similar to that in patients with normal organ function. There were no clinically meaningful differences in the PK of ripretinib based on age, race, body weight, or tumor type. Based on the safety profile of ripretinib observed in patients with advanced GIST and PK variability, the effects of sex, fasted state, and prior gastrectomy on ripretinib PK were not considered clinically significant. Therefore, ripretinib can be taken with or without food by all patients and no dose adjustment is recommended for patients with mild hepatic impairment or patients with mild to moderate renal impairment. Citation Format: Suzanne George, Filip Janku, Ping Chi, Margaret von Mehren, Neeta Somaiah, Hans Gelderblom, Robin L. Jones, Martine Allard, Adekemi Taylor, Xiaoyan Li, Julie Meade, Vienna Reichert, Rodrigo Ruiz-Soto, Jing Wang, Michael C. Heinrich. Population pharmacokinetics of ripretinib in patients with advanced malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT123.

11515 Background: Dedifferentiated liposarcoma (DDL) is characterized by ring chromosomes of chromosone12, which includes amplification of MDM2 and CDK4. Exposure to CDK4 inhibitors in Rb+ leiomyosarcoma (LMS) cell lines leads to decreased cell proliferation, and increased senescence, and G0/G1-phase arrest. When combined, ribociclib a CDK4 inhibitor and everolimus, an mTOR inhibitor show synergistic growth inhibition in multiple tumor models. We hypothesized that this combination could lead to increased disease control in patients with DDL. Methods: This study enrolled patients (pts) into one of two cohorts: DDL or Rb+ LMS. LMS pts were required to have 1 prior line of therapy; DDL pts required no prior therapy. There were no limits to prior therapies in either group. Measurable disease by RECIST 1.1 was also required. Ribociclib was given at 300 mg daily for 21/28 days and everolimus was given continuously at 2.5 mg daily in 28 day cycles. The primary endpoint was progression free rate at 16 weeks. A Simon two-stage design was utilized and if at least 8 out of 24 pts were progression free at 16 weeks, the treatment was declared promising for the cohort. Here in we present data on the DDL cohort. Results: To date, 21 DDS pts, median age of 63 (range 40-79), of which 43% (n = 9) female were treated. Median prior lines of therapy was 1 (range 0-6). Of 19 pts with complete data, 8 (42%) met the primary endpoint of non-progression at 16 weeks. Confirmed partial response was seen in 2 pts (10%). Median PFS was 16 weeks, and stable disease occurring as best response in 11 (55%) pts. Grade 3-4 toxicities were uncommon except for lymphopenia (24%) and neutropenia (33%); no episode of neutropenic fever were observed. There was one death on study secondary to myocardial infarction, considered possibly related to therapy. Results of optional tissue biopsies pre and on therapy obtained to assess pharmacodynamic changes in PTEN, pAKT, CDK4, Rb and pS6 will be presented. Conclusions: The combination of ribociclib and everolimus demonstrates activity in DDL with prolonged stable disease (>16 weeks) meeting the primary protocol endpoint. Notably partial responses were also observed. The combination was well tolerated with acceptable side effects. Updated outcomes will be presented. Clinical trial information: NCT03114527.

11536 Background: Ripretinib is a switch-control tyrosine kinase inhibitor that broadly inhibits KIT and PDGFRA kinase signaling. In the INVICTUS study (NCT03353753), patients with advanced GIST (≥4th-line) receiving ripretinib had a median progression-free survival (mPFS) of 6.3 months vs 1.0 month for patients receiving placebo (HR = 0.15, p

11519 Background: ASPS constitutes < 1% of soft tissue sarcomas and frequently presents in adolescents and young adults. There are no approved therapies for ASPS. We are currently evaluating the clinical activity of atezolizumab (atezo), an anti-PD-L1 antibody, in patients (pts) with advanced ASPS. Methods: This is a multicenter, open-label, single-arm phase II study where atezo is administered at a fixed dose of 1200 mg in adults or 15 mg/kg (1200 mg max) in pediatric pts age ≥2 once Q21 days. The primary objective is to determine the objective response rate (ORR) of atezo using RECIST 1.1. Secondary objectives include duration of response and correlating response with the immune effects of atezo in blood and paired tumor biopsies (pre- and post-treatment). Tumor specimens were analyzed with multiplex immunofluorescence immuno-oncology panels to quantify CD8+, PD-1+, and PD-L1+ cells/mm2 in the tumor microenvironment. CD8+ density was calculated as the total number of CD8+ cells divided by the entire area (mm2) of the tumor and invasive margins of the biopsy. Results: As of February 4, 2021, 44 pts have been enrolled. The median age in the study was 31 years (range, 12–70) with equal male: female distribution. 54.5% of pts were Caucasian. Baseline ECOG ≤1 was present in 97.7%. The median time on study was 11.5 months (range, 0.8–40.3 months). At data cutoff, response evaluation was available for 43 pts with an ORR of 37.2% (16/43). One pt experienced a complete response and 15 pts experienced a partial response (PR), of which 14 were confirmed. The median time to confirmed response was 3.5 months (range, 2.1–14.9 months). The median duration of confirmed response was 16.5 months (range, 4.9–38.1 months). Stable disease (SD) was present in 58.1% (25/43). One or more grade 3 adverse events potentially related to atezo were identified in 16.3% (7/43) pts. These include diarrhea, hypothyroidism, transaminitis, anemia, vertigo, extremity pain, myalgia, pneumonitis, rash, and stroke (n = 1 each). No grade 4 or 5 events have been reported. Among 8 cases with evaluable biopsy pairs, both baseline and C3D1 specimens in all cases demonstrated CD8+ T cell infiltration and PD-L1 expression. PD-1 expression was detected at baseline in 5 cases and at C3D1 in 7 cases. In 6 cases (3 SDs and 3 PRs), treatment did not change CD8+ cell density. In the other 2 cases (both PRs), CD8+ density increased > 3x above baseline by C3D1. Analysis of T cell activation using pharmacodynamic response biomarkers, along with whole exome and RNA-seq to evaluate the genomic and transcriptomic landscape of ASPS, are ongoing. Conclusions: Atezo is well tolerated and demonstrates promising single agent activity with durable responses in advanced ASPS. Preliminary tumor biomarker analysis confirms the presence of multiple PD-1/PD-L1 immune checkpoint (IC) components, indicating that advanced ASPS is an ideal candidate for therapeutic IC inhibition. Funded by NCI Contract No HHSN261200800001E. Clinical trial information: NCT03141684.

Purpose Wild-type gastrointestinal stromal tumors (WT-GISTs) that lack KIT or PDGFRA mutations represent a unique subtype of GIST that predominantly affects children. We sought to determine the effect on event-free survival (EFS) of staging variables, extent of resection, and repeat resection of tumors. Methods In 2008, a WT-GIST clinic was established at the National Cancer Institute, allowing the development of a large clinical database. We included participants who underwent resection of WT-GIST. Associations with EFS (ie, freedom from disease progression or recurrence) were evaluated using the Kaplan-Meier method and Cox proportional hazards modeling. Results Among 76 participants with WT-GISTs, the median follow-up was 4.1 years. Overall EFS (± SE) was 72.6 ± 5.4% at 1 year, 57.6 ± 6.2% at 2 years, 23.7 ± 6.0% at 5 years, and 16.3 ± 5.5% at 10 years postoperatively. Hazard of disease progression or recurrence was significantly increased for patients with metastatic disease (adjusted hazard ratio [AHR], 2.3; 95% CI, 1.0 to 5.1; P = .04) and > 5 mitoses per 50 high-power fields (AHR, 2.5; 95% CI, 1.1 to 6.0; P = .03), whereas there was no significant effect of negative microscopic resection margins (AHR, 0.9; 95% CI, 0.4 to 2.2; P = 0.86). There was no association between type of gastric resection (ie, anatomic v partial/wedge) and EFS ( P = .67). Repeated resection after the initial resection was significantly associated with decreasing postoperative EFS ( P < .01). Five patients (6%) died after initial enrollment in 2008. Conclusion WT-GIST is an indolent disease, and most patients survive with disease progression. We found no improvement in EFS with more extensive or serial resections. Disease progression or recurrence may be more closely related to tumor biology than surgical management. These data suggest that resections for WT-GISTs be restricted to the initial procedure and that subsequent resections be performed only to address symptoms such as obstruction or bleeding.

To study whether the CT features of treatment-naïve gastric GIST may be used to assess metastatic risk.In this IRB approved retrospective study, with informed consent waived, contrast enhanced CT images of 143 patients with pathologically confirmed treatment-naïve gastric GIST (74 men, 69 women; mean age 61 years, SD ± 14) were reviewed in consensus by two oncoradiologists blinded to clinicopathologic features and clinical outcome and morphologic features were recorded. The metastatic spread was recorded using available imaging studies and electronic medical records (median follow up 40 months, interquartile range, IQR, 21-61). The association of maximum size in any plane (≤10 cm or10 cm), outline (smooth or irregular/lobulated), cystic areas (≤50% or50%), exophytic component (≤50% or50%), and enhancing solid component (present or absent) with metastatic disease were analyzed using univariate (Fisher's exact test) and multivariate (logistic regression) analysis.Metastatic disease developed in 42 (29%) patients (28 at presentation, 14 during follow-up); 23 (16%) patients died. On multivariate analysis, tumor size10 cm (p = 0.0001, OR 9.9), irregular/lobulated outline (p = 0.001, OR 5.6) and presence of a enhancing solid component (p 0.0001, OR 9.1) were independent predictors of metastatic disease. On subgroup analysis, an irregular/lobulated outline and an enhancing solid component were more frequently associated with metastases in tumors ≤5 cm and5-≤10 cm (p 0.05).CT morphologic features can be used to assess the metastatic risk of treatment-naïve gastric GIST. Risk assessment based on pretreatment CT is especially useful for patients receiving neoadjuvant tyrosine kinase inhibitors and those with tumors5 cm in size.

Desmoid-type fibromatosis (DF) is a locally aggressive fibroblastic neoplasm that has variable clinical and biologic behaviors ranging from indolent tumors that can undergo spontaneous regression to aggressive tumors with a tendency toward local invasion and recurrence. The management of DF has evolved considerably in the last decade from aggressive first-line surgery and radiation therapy to systemic treatment (chemotherapy, hormonal therapy, and targeted therapy) and symptomatic local control (surgery and radiation therapy). Imaging plays an important role in each of these treatment settings. In surgical candidates, computed tomography (CT) and magnetic resonance (MR) imaging are the modalities of choice for assessing resectability and surgical planning. For evaluating recurrence, MR imaging is the modality of choice for extra-abdominal recurrence, whereas CT is the preferred modality for intra-abdominal recurrence. Signal intensity changes at MR imaging can be used to monitor the biologic behavior of certain DFs chosen for expectant management. Response to systemic treatment with anti-inflammatory agents, hormonal therapy (eg, tamoxifen), cytotoxic chemotherapy (eg, doxorubicin, vinblastine, methotrexate), and targeted therapy (eg, sorafenib), as well as to radiation therapy, can be assessed at CT by monitoring size and attenuation changes or at MR imaging by monitoring size, T2 signal intensity, and degree of enhancement. Several patterns of response can be seen at imaging. Imaging also helps in detecting complications associated with systemic therapy and radiation therapy. (©)RSNA, 2016.

More than 85% of GISTs are driven by activating mutations in KIT proto-oncogene receptor tyrosine kinase (KIT) or platelet-derived growth factor receptor alpha (PDGFRA). Currently, the only approved treatments for GIST are KIT directed tyrosine kinase inhibitors (TKIs). However, treatment with approved TKIs eventually results in disease progression most often due to the development of secondary resistance mutations in KIT. In addition, these agents have limited activity in PDGFRA mutant GIST and KIT/PDGFRA wild type (WT) GIST as primary therapy. Therefore, it is essential to develop novel therapeutic strategies with different modes of action in advanced GIST. G protein-coupled receptor 20 (GPR20) is an orphan GPCR selectively and abundantly expressed in GIST. GPR20 expression is regulated by FOXF1 and ETV1, transcription factors that play critical roles in KIT-driven GIST initiation, proliferation, and survival. We hypothesize that GPR20 is a potential therapeutic target for ADC development for the treatment of GIST. In this study, 1) GPR20 and KIT protein expression was assessed by IHC staining on GIST samples from DFCI (n=144) and NCCHE (n=100) as well as on normal and malignant tissue microarrays obtained commercially, and 2) an anti-GPR20 ADC (DS-6157a) was generated to evaluate antitumor activity in GIST models and to assess safety. GPR20 was expressed in more than 88% of the GIST samples analyzed, with higher expression levels in samples that: (I) received multiple treatment lines compared to naïve/early treated samples, (II) expressed higher KIT levels, (III) were small intestinal GIST, and/or (IV) had no KIT mutation, including succinate dehydrogenase (SDH) deficient GIST and neurofibromatosis type 1 (NF1)-associated GIST. The interstitial cells of Cajal were the only normal cells positive for GPR20. Normal mast cells expressed KIT but not GPR20. DS-6157a is an ADC composed of a humanized anti-GPR20 antibody, a Gly-Gly-Phe-Gly tetra-peptide-based linker, and a DNA topoisomerase I (TOP1) inhibitor Dxd. DS-6157a exhibited GPR20 expression-dependent cell growth-inhibitory activity and induced tumor regression with dosing at 3 to 10 mg/kg in multiple GIST xenograft models. In addition, DS-6157a showed antitumor activity in a GIST patient-derived xenograft model that was resistant to imatinib, sunitinib, and regorafenib. In vitro, DS-6157a induced TOP1 inhibitor-associated markers of DNA damage (phosphorylation of Chk1) and apoptosis (cleaved PARP) in GPR20 expressing cells. In preclinical toxicology studies using rats and cynomolgus monkeys, the pharmacokinetics and safety profile of DS-6157a were favorable at up to 200 mg/kg and 30 mg/kg, respectively. These data support the clinical development of DS-6157a as a potential novel GIST therapy with activity in patients that are resistant, refractory, or intolerant to approved TKIs. Citation Format: Kenji Iida, Amr H. Abdelhamid, Akiko Kawano Nagatsuma, Tomoko Shibutani, Satoru Yasuda, Michiko Kitamura, Chiharu Hattori, Manabu Abe, Jun Hasegawa, Takuma Iguchi, Tsuyoshi Karibe, Takashi Nakada, Koichiro Inaki, Reiko Kamei, Yuki Abe, Jessica L. Andersen, Sandro Santagata, Matthew L. Hemming, Suzanne George, Toshihiko Doi, Atsushi Ochiai, George D. Demetri, Toshinori Agatsuma. Therapeutic targeting of GPR20, selectively expressed in gastrointestinal stromal tumor (GIST), with DS-6157a, an antibody-drug conjugate (ADC) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5181.

Purpose Leiomyosarcoma (LMS) is a soft-tissue sarcoma characterized by multiple copy number alterations (CNAs) and without common recurrent single-nucleotide variants. We evaluated the feasibility of detecting circulating tumor DNA (ctDNA) with next-generation sequencing in a cohort of patients with LMS whose tumor burden ranged from no evidence of disease to metastatic progressive disease. Patients and Methods We evaluated cell-free DNA in plasma samples and paired genomic DNA from resected tumors from patients with LMS by ultra-low passage whole-genome sequencing. Sequencing reads were aligned to the human genome and CNAs that were identified in cell-free DNA and tumor DNA by ichorCNA software to determine the presence of ctDNA. Clinical data were reviewed to assess disease burden and clinicopathologic features. Results We identified LMS ctDNA in 11 (69%) of 16 patients with disease progression and total tumor burden greater than 5 cm. Sixteen patients with stable disease or low disease burden at the time of blood draw were found to have no detectable ctDNA. Higher ctDNA fraction of total cell-free DNA was associated with increasing tumor size and disease progression. Conserved CNAs were found between primary tumors and ctDNA in each case, and recurrent CNAs were found across LMS samples. ctDNA levels declined after resection of progressive disease in one case and became detectable upon disease relapse in another individual patient. Conclusion These results suggest that ctDNA, assayed by a widely available sequencing approach, may be useful as a biomarker for a subset of patients with uterine and extrauterine LMS. Higher levels of ctDNA correlate with tumor size and disease progression. Liquid biopsies may assist in guiding treatment decisions, monitoring response to systemic therapy, surveying for disease recurrence, and differentiating benign and malignant smooth muscle tumors.

11511 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]

11506 Background: Uterine leiomyosarcoma (uLMS) is an aggressive sarcoma subtype with frequent metastatic relapse. After failure of front-line chemotherapy, remaining options provide limited benefit (trabectedin: ORR 11%, mPFS 4.0 mos; pazopanib: ORR 11%, median PFS 2.9 mos; dacarbazine: ORR 9%, mPFS 1.5 mos). Recent molecular studies suggest uLMS harbors characteristic defects in the homologous recombination (HR) DNA repair pathway, including somatic biallelic BRCA2 deletion in 10%, implicating potential sensitivity to PARP-inhibitor based treatment approaches. In preclinical uLMS models in which temozolomide (T, an oral equivalent to dacarbazine) or the PARP inhibitor olaparib (O) showed limited single agent activity, the combination of T + O was highly effective in inhibiting uLMS tumor growth and promoting apoptosis. Methods: NCI protocol #10250 is a single-arm, open-label, multi-center phase II study evaluating T + O in advanced uLMS. Pts had progression on ≥ 1 prior line and ECOG PS ≤ 2. Pts received T 75 mg/m2 PO daily + O 200 mg PO BID days 1-7 in 21-day cycles. Primary endpoint was ORR. A one-stage binomial design was used. If ≥ 5/22 responded, the treatment was considered promising (95% power; α = 0.06). All pts underwent paired tumor biopsies. Correlative assays to evaluate for HR deficiency (whole exome sequencing/RNAseq, RAD51 foci formation) and for intrinsic PARP inhibitor resistance (SLFN11 expression) will be correlated with response. Results: 22 patients were evaluable (median age 55, median prior treatment lines 3). Median follow-up was 10.8 mos. Primary endpoint, ORR within 6 mos of initiating treatment, was 23% (5/22). Overall ORR was 27% (6/22). Median PFS was 6.9 mos (95% CI: 5.4 mos – not estimable (NE)). Median duration of response (DOR) was 12.0 mos (95% CI: 9.5 mos – NE). Hematologic toxicity was common (grade 3/4 neutropenia, 77%; thrombocytopenia 32%) but manageable with dose modification. Correlative assays are ongoing with plans to present at the meeting. An immunohistochemical assay for RAD51 foci has been adapted for uLMS samples and clearly distinguishes BRCA2- deleted and wild-type tumors. Conclusions: NCI 10250 met the prespecified primary efficacy endpoint of ORR in a population of patients with heavily pre-treated uLMS. Responses are durable (median DOR 12 mos). Correlative assays are being completed to evaluate whether uLMS tumors with HR deficiency or with preserved SLFN11 expression are most sensitive to T + O and may underlie durable responses. A randomized study of the combination is planned. Clinical trial information: NCT03880019.

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 .