Prospective evaluation of quantitative response parameter in patients with Gastrointestinal Stroma Tumor undergoing tyrosine kinase inhibitor therapy-Impact on clinical outcome.

The purpose of this study was to determine if dual-energy CT (DECT) vital iodine tumor burden (ViTB), a direct assessment of tumor vascularity, allows reliable response assessment in patients with GIST compared to established CT criteria such as RECIST1.1 and modified Choi (mChoi). From 03/2014 to 12/2019, 138 patients (64 years [32-94 years]) with biopsy proven GIST were entered in this prospective, multi-center trial. All patients were treated with tyrosine kinase inhibitors (TKI) and underwent pre-treatment and follow-up DECT examinations for a minimum of 24 months. Response assessment was performed according to RECIST1.1, mChoi, vascular tumor burden (VTB) and DECT ViTB. A change in therapy management could be because of imaging (RECIST1.1 or mChoi) and/or clinical progression. The DECT ViTB criteria had the highest discrimination ability for progression-free survival (PFS) of all criteria in both first line and second line and thereafter treatment, and was significantly superior to RECIST1.1 and mChoi (p < .034). Both, the mChoi and DECT ViTB criteria demonstrated a significantly early median time-to-progression (both delta 2.5 months; both p < .036). Multivariable analysis revealed 6 variables associated with shorter overall survival: secondary mutation (HR = 4.62), polymetastatic disease (HR = 3.02), metastatic second line and thereafter treatment (HR = 2.33), shorter PFS determined by the DECT ViTB criteria (HR = 1.72), multiple organ metastases (HR = 1.51) and lower age (HR = 1.04). DECT ViTB is a reliable response criteria and provides additional value for assessing TKI treatment in GIST patients. A significant superior response discrimination ability for median PFS was observed, including non-responders at first follow-up and patients developing resistance while on therapy.

Onset and resolution of ovarian toxicity with nirogacestat treatment in females with desmoid tumors: Updated safety analyses from the DeFi phase 3 study.

INTRODUCTION: Nirogacestat is a targeted gamma secretase inhibitor approved in the United States for adults with progressing desmoid tumors. In the phase 3 DeFi study (NCT03785964) of nirogacestat, ovarian toxicity (OT) was identified as a safety signal among females of reproductive potential (FORP). This analysis further describes the incidence, presentation, and resolution of OT. METHODS: Patients were randomized to twice-daily oral nirogacestat (150 mg) or placebo, taken in continuous 28-day cycles. Investigator-identified OT in FORP was based on abnormal reproductive hormone values or perimenopausal symptoms (or both). Adverse event follow-up was conducted to assess OT resolution. Post hoc analyses included return of menstruation and return of follicle-stimulating hormone (FSH) to within normal limits (WNL) (≤20.4 mIU/mL). RESULTS: Of 92 randomized females, 73 in the safety population were FORP (n = 36 nirogacestat, n = 37 placebo). OT was identified in 75% (27 of 36) receiving nirogacestat and 0% (0 of 37) receiving placebo. As of October 24, 2022, investigators reported OT resolution in 78% (21 of 27) of patients, with median OT duration of 19.1 weeks. Off-treatment resolution was reported in all 11 patients (100%) who stopped nirogacestat treatment; of these, all nine with available menstruation information experienced return of menstruation and eight had FSH WNL at last reported assessment. Resolution was reported in 10 of 14 (71%) while on nirogacestat; of these, all 10 experienced return of menstruation and seven had FSH WNL. Two patients were lost to follow-up. CONCLUSION: Most FORP treated with nirogacestat experienced OT, with the majority resolving, including all who stopped treatment, suggesting that OT is transient.

Evolution of Initial Treatment for Desmoid Tumors.

INTRODUCTION: Desmoid tumors (DTs) are rare, fibroblastic cell proliferations that can exhibit locally aggressive behavior but lack metastatic potential. Initial management has traditionally involved upfront resection; however, contemporary guidelines and expert panels have increasingly advocated for prioritizing active surveillance strategies. METHODS: A single-institution, retrospective chart review identified all patients diagnosed with a primary DT at any site from 2007 to 2020. The primary outcome was the initial management strategy over time. Secondary outcomes included treatment-free survival (TFS) and time to treatment (TTT) for those undergoing active surveillance, as well as recurrence-free survival (RFS) and time to recurrence for those undergoing resection. RESULTS: Overall, 103 patients were included, with 68% female and a median follow-up of 44 months [24-74]. The most common tumor locations included the abdominal wall (27%), intra-abdominal/mesenteric (25%), chest wall (19%), and extremity (10%). Initial management included resection (60%), systemic therapy (20%), active surveillance (18%), and cryoablation (2%). Rates of surgical resection significantly decreased (p < 0.001) over time, from 69.6% prior to 2018 to 29.2% after 2018. For those treated with upfront resection, 5-year RFS was 41.2%, and for patients undergoing initial active surveillance, TFS was 66.7% at 2 years, with a median TTT of 4 months [4-10]. CONCLUSIONS: This single-institution cohort at a tertiary medical center spanning over a decade demonstrates the transition to active surveillance for initial management of DTs, and highlights salient metrics in the era of surveillance. This trend mirrors recommended treatment strategies by expert panels and consensus guidelines.

Case of a CIC::DUX4 fusion gene in a vascular neoplasm extends the spectrum of CIC-rearranged sarcomas.

CIC-rearranged sarcomas comprise a group of exceptionally aggressive round-cell sarcomas. These tumors most commonly demonstrate CIC::DUX4 fusion and show similar histopathology to Ewing sarcomas, though lesions mimicking vascular neoplasms have recently been described. Here, we describe a case of a patient with CIC::DUX4 fusion sarcoma identified using RNA-based molecular testing who was initially diagnosed with an endothelial neoplasm. The tumor showed extensive vasoformative growth, complete WT1 negativity, and global positive staining for ERG, CD31, and DUX4 by immunohistochemistry. Methylation testing of the tumor clustered more closely with angiosarcomas than with CIC-rearranged sarcomas. Our findings suggest that CIC::DUX4 fused neoplasms may demonstrate a more diverse phenotypic range than previously appreciated and offer evidence that both molecular and immunohistochemical studies are needed for accurate diagnosis.

Open-Label, Multicenter, Phase I/II, First-in-Human Trial of TK216: A First-Generation EWS::FLI1 Fusion Protein Antagonist in Ewing Sarcoma.

PURPOSE: Ewing Sarcoma (ES), a rare cancer with a pathognomonic translocation resulting in the Ewing sarcoma gene (EWS)::FLI1 oncoprotein, has a poor prognosis in the relapsed/refractory (R/R) setting. Tokalas (TK)216 was designed to bind EWS::FLI1 proteins directly, disrupt protein-protein interactions, and inhibit transcription factor function. TK216 plus vincristine showed synergistic activity in preclinical tumor models. To our knowledge, we report the results of a first-in-class, first-in-human phase I/II trial of TK216 in R/R ES. PATIENTS AND METHODS: TK216 was administered intravenously as a continuous infusion to patients with R/R ES in 11 cohorts. The dosing duration of 7 days was later extended to 10, 14, and 28 days. Vincristine could be added on day 1 after cycle 2, per investigators' choice. The trial used a 3 + 3 design with an expansion cohort at the recommended phase II dose (RP2D). RESULTS: A total of 85 patients with a median age of 27 years (range, 11-77) were enrolled. The maximum tolerated dose for the 14-day infusion of TK216, 200 mg/m2 once daily, was determined in cohort 9 and selected as the RP2D. The median previous number of systemic therapies regimens was three (range, 1-10). The most frequent-related adverse events in patients treated at the RP2D included neutropenia (44.7%), anemia (29.4%), leukopenia (29.4%), febrile neutropenia (15.3%), thrombocytopenia (11.8%), and infections (17.6%). In cohorts 9 and 10, two patients had a complete response, one had a partial response, and 14 had stable disease; the 6-month progression-free survival was 11.9%. There were no responses among the eight patients in cohort 11. CONCLUSION: TK216 administered as 14-day continuous infusion with or without vincristine was well tolerated and showed limited activity at the RP2D in R/R ES.

Phase II Trial of nab-Sirolimus in Patients With Advanced Malignant Perivascular Epithelioid Cell Tumors (AMPECT): Long-Term Efficacy and Safety Update.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.nab-Sirolimus is approved in the United States for the treatment of metastatic or locally advanced malignant perivascular epithelioid cell tumor (PEComa) on the basis of the primary analysis results of the phase II Advanced Malignant Perivascular Epithelioid Cell Tumors (AMPECT) trial (ClinicalTrials.gov identifier: NCT02494570). Results from the primary analysis were previously published; however, the median duration of response (mDOR) had not been reached at that time. Here, 3 years after the primary analysis, we report final efficacy and safety data (data cutoff: April 29, 2022). At study completion, the confirmed overall response rate (by independent radiologist review using RECIST v1.1) was 38.7% (95% CI, 21.8 to 57.8), with an additional converted confirmed complete response (n = 2). Median progression-free survival remained the same at 10.6 months (95% CI, 5.5 to 41.2). The mDOR was reached at 39.7 months (95% CI, 6.5 to not reached [NR]), and the median overall survival at completion was 53.1 months (95% CI, 22.2 to NR). The most common treatment-related adverse events (TRAEs) were stomatitis (82.4%) and fatigue and rash (each 61.8%). No new or unexpected adverse events occurred, and no grade ≥4 TRAEs were reported. These results highlight the long-term clinical benefit of nab-sirolimus in patients with advanced malignant PEComa, with a DOR of >3 years.

A Single Arm Phase 2 Trial of Trametinib in Patients With Locally Advanced or Metastatic Epithelioid Hemangioendothelioma.

PURPOSE: Epithelioid hemangioendothelioma (EHE) is a rare vascular cancer with pathogenic TAZ-CAMTA1 operating as an oncogenic driver through activation of MAPK pathway. Trametinib is an inhibitor of MEK, a critical kinase in the MAPK pathway. We sought to evaluate the effect of trametinib in patients with EHE. PATIENTS AND METHODS: A phase 2 trial of trametinib was conducted in patients with locally advanced or metastatic EHE. Eligibility requirements included evidence of tumor progression or presence of EHE-related pain requiring opiates for management prior to enrollment. The primary endpoint was objective response rate (ORR) per RECIST1.1 in cases with TAZ-CAMTA1 confirmed by fusion-FISH. Secondary objectives were to estimate ORR for all patients, median PFS, 2-year OS rate, patient safety, and change in patient-reported global health and pain scores per PROMIS questionnaires. RESULTS: 44 patients enrolled and 42 started trametinib. TAZ-CAMTA1 was detected in 27 tumor samples. The ORR was 3.7% (95% CI: 0.094, 19.0), median PFS was 10.4 months (95% CI: 7.1, NA), and 2-year OS rate was 33.3% (95% CI: 19.1, 58.2) in the target population. Median pain intensity and interference scores improved significantly after 4 weeks of trametinib in patients using opiates. Common AEs related to trametinib were rash, fatigue, nausea/vomiting, diarrhea/constipation, alopecia and edema; one Grade 5 ARDS/pneumonitis was related to trametinib. CONCLUSIONS: Trametinib was associated with reduction in EHE-related pain and median PFS of more than 6 months providing palliative benefit in patients with advanced EHE, but the trial did not meet the ORR goal.