Final, 10-Year Outcomes with Nivolumab plus Ipilimumab in Advanced Melanoma.

BACKGROUND: Previous results from this trial showed longer overall survival after treatment with nivolumab plus ipilimumab or with nivolumab monotherapy than with ipilimumab monotherapy in patients with advanced melanoma. Given that patients with advanced melanoma are living longer than 7.5 years, longer-term data were needed to address new clinically relevant questions. METHODS: We randomly assigned patients with previously untreated advanced melanoma, in a 1:1:1 ratio, to one of the following regimens: nivolumab (1 mg per kilogram of body weight) plus ipilimumab (3 mg per kilogram) every 3 weeks for four doses, followed by nivolumab (3 mg per kilogram) every 2 weeks; nivolumab (3 mg per kilogram) every 2 weeks plus placebo; or ipilimumab (3 mg per kilogram) every 3 weeks for four doses plus placebo. Treatment was continued until the occurrence of disease progression, unacceptable toxic effects, or withdrawal of consent. Randomization was stratified according to BRAF mutation status, metastasis stage, and programmed death ligand 1 expression. Here, we report the final, 10-year results of this trial, including results for overall survival and melanoma-specific survival, as well as durability of response. RESULTS: With a minimum follow-up of 10 years, median overall survival was 71.9 months with nivolumab plus ipilimumab, 36.9 months with nivolumab, and 19.9 months with ipilimumab. The hazard ratio for death was 0.53 (95% confidence interval [CI], 0.44 to 0.65) for nivolumab plus ipilimumab as compared with ipilimumab and was 0.63 (95% CI, 0.52 to 0.76) for nivolumab as compared with ipilimumab. Median melanoma-specific survival was more than 120 months with nivolumab plus ipilimumab (not reached, with 37% of the patients alive at the end of the trial), 49.4 months with nivolumab, and 21.9 months with ipilimumab. Among patients who had been alive and progression-free at 3 years, 10-year melanoma-specific survival was 96% with nivolumab plus ipilimumab, 97% with nivolumab, and 88% with ipilimumab. CONCLUSIONS: The final trial results showed a continued, ongoing survival benefit with nivolumab plus ipilimumab and with nivolumab monotherapy, as compared with ipilimumab monotherapy, in patients with advanced melanoma. (Funded by Bristol Myers Squibb and others; CheckMate 067 ClinicalTrials.gov number, NCT01844505.).

Nirogacestat, a γ-Secretase Inhibitor for Desmoid Tumors.

BACKGROUND: Desmoid tumors are rare, locally aggressive, highly recurrent soft-tissue tumors without approved treatments. METHODS: We conducted a phase 3, international, double-blind, randomized, placebo-controlled trial of nirogacestat in adults with progressing desmoid tumors according to the Response Evaluation Criteria in Solid Tumors, version 1.1. Patients were assigned in a 1:1 ratio to receive the oral γ-secretase inhibitor nirogacestat (150 mg) or placebo twice daily. The primary end point was progression-free survival. RESULTS: From May 2019 through August 2020, a total of 70 patients were assigned to receive nirogacestat and 72 to receive placebo. Nirogacestat had a significant progression-free survival benefit over placebo (hazard ratio for disease progression or death, 0.29; 95% confidence interval, 0.15 to 0.55; P<0.001); the likelihood of being event-free at 2 years was 76% with nirogacestat and 44% with placebo. Between-group differences in progression-free survival were consistent across prespecified subgroups. The percentage of patients who had an objective response was significantly higher with nirogacestat than with placebo (41% vs. 8%; P<0.001), with a median time to response of 5.6 months and 11.1 months, respectively; the percentage of patients with a complete response was 7% and 0%, respectively. Significant between-group differences in secondary patient-reported outcomes, including pain, symptom burden, physical or role functioning, and health-related quality of life, were observed (P≤0.01). Frequent adverse events with nirogacestat included diarrhea (in 84% of the patients), nausea (in 54%), fatigue (in 51%), hypophosphatemia (in 42%), and maculopapular rash (in 32%); 95% of adverse events were of grade 1 or 2. Among women of childbearing potential receiving nirogacestat, 27 of 36 (75%) had adverse events consistent with ovarian dysfunction, which resolved in 20 women (74%). CONCLUSIONS: Nirogacestat was associated with significant benefits with respect to progression-free survival, objective response, pain, symptom burden, physical functioning, role functioning, and health-related quality of life in adults with progressing desmoid tumors. Adverse events with nirogacestat were frequent but mostly low grade. (Funded by SpringWorks Therapeutics; DeFi ClinicalTrials.gov number, NCT03785964.).

PEC-PRO: A new prognostic score from a series of 87 patients with localized perivascular epithelioid cell neoplasms (PEComas) treated with curative intent.

BACKGROUND: Perivascular epithelioid cell neoplasms (PEComas) encompass a heterogeneous family of mesenchymal tumors. Previously described clinicopathologic features aimed at distinguishing benign from malignant variants but lacked prognostic value. METHODS: This retrospective analysis examined clinicopathologic data from patients who had localized PEComa across French Sarcoma Network centers. The authors analyzed 12 clinicopathologic features in a Cox proportional hazard framework to derive a multivariate prognostic risk model for event-free survival (EFS). They built the PEComa prognostic score (PEC-PRO), in which scores ranged from 0 to 5, based on the coefficients of the multivariate model. Three groups were identified: low risk (score = 0), intermediate risk (score = 1), and high risk (score ≥ 2). RESULTS: Analyzing 87 patients who had a median 46-month follow-up (interquartile range, 20-74 months), the median EFS was 96.5 months (95% confidence interval [CI], 47.1 months to not applicable), with 2-year and 5-year EFS rates of 64.7% and 58%, respectively. The median overall survival was unreached, with 2-year and 5-year overall survival rates of 82.3% and 69.3%, respectively. The simplified Folpe classification did not correlate with EFS. Multivariate analysis identified three factors affecting EFS: positive surgical margins (hazard ratio [HR], 5.17; 95% CI, 1.65-16.24; p = .008), necrosis (HR, 3.94; 95% CI, 1.16-13.43; p = .030), and male sex (HR, 3.13; 95% CI, 1.19-8.27; p = 0.023). Four variables were retained in the prognostic model. Patients with low-risk PEC-PRO scores had a 2-year EFS rate of 93.7% (95% CI, 83.8%-100.0%), those with intermediate-risk PEC-PRO scores had a 2-year EFS rate of 67.4% (95% CI, 53.9%-80.9%), and those with high-risk PEC-PRO scores had a 2-year EFS rate of 2.3% (95% CI, 0.0%-18.3%). CONCLUSIONS: The PEC-PRO score reliably predicts the risk of postoperative recurrence in patients with localized PEComa. It has the potential to improve follow-up strategies but requires validation in a prospective trial.

Extensive surgical resections for rare pleural neoplasms: a single-center experience with a yolk sac tumor and synovial sarcoma.

BACKGROUND: Pleural neoplasms are rare and can be subdivided into pleural metastasis and primary pleural neoplasms. Non-mesothelioma primary pleural neoplasms are a diverse group of extremely rare pathologies. CASE PRESENTATION: In this case series, we describe the presentation and management of two rare primary pleural neoplasms. A first case describes a primary pleural yolk sac tumor treated with neoadjuvant chemotherapy, extended pleurectomy decortication, and hyperthermic intrathoracic chemotherapy. In a second case we describe the management of a primary pleural synovial sarcoma by neoadjuvant chemotherapy and extrapleural pneumonectomy. A complete resection was obtained in both cases and the post-operative course was uncomplicated. No signs of tumor recurrence were noted during follow-up in the first patient. In the second patient a local recurrence was diagnosed 6 months after surgery. CONCLUSION: Neo-adjuvant chemotherapy followed by extensive thoracic surgery, including hyperthermic intrathoracic chemotherapy, is a feasible treatment strategy for non-mesothelioma primary pleural neoplasms, but careful follow-up is required.

Functional genomics of human clear cell sarcoma: genomic, transcriptomic and chemical biology landscape for clear cell sarcoma.

BACKGROUND: Systemic therapy for metastatic clear cell sarcoma (CCS) bearing EWSR1-CREB1/ATF1 fusions remains an unmet clinical need in children, adolescents, and young adults. METHODS: To identify key signaling pathway vulnerabilities in CCS, a multi-pronged approach was taken: (i) genomic and transcriptomic landscape analysis, (ii) integrated chemical biology interrogations, (iii) development of CREB1/ATF1 inhibitors, and (iv) antibody-drug conjugate testing (ADC). The first approach encompassed DNA exome and RNA deep sequencing of the largest human CCS cohort yet reported consisting of 47 patient tumor samples and 8 cell lines. RESULTS: Sequencing revealed recurrent mutations in cell cycle checkpoint, DNA double-strand break repair or DNA mismatch repair genes, with a correspondingly low to intermediate tumor mutational burden. DNA multi-copy gains with corresponding high RNA expression were observed in CCS tumor subsets. CCS cell lines responded to the HER3 ADC patritumab deruxtecan in a dose-dependent manner in vitro, with impaired long term cell viability. CONCLUSION: These studies of the genomic, transcriptomic and chemical biology landscape represent a resource 'atlas' for the field of CCS investigation and drug development. CHK inhibitors are identified as having potential relevance, CREB1 inhibitors non-dependence of CCS on CREB1 activity was established, and the potential utility of HER3 ADC being used in CCS is found.

EWSR1::POU2AF3(COLCA2) Sarcoma: An Aggressive, Polyphenotypic Sarcoma With a Head and Neck Predilection.

EWSR1::POU2AF3 (COLCA2) sarcomas are a recently identified group of undifferentiated round/spindle cell neoplasms with a predilection for the head and neck region. Herein, we report our experience with 8 cases, occurring in 5 men and 3 women (age range, 37-74 years; median, 60 years). Tumors involved the head/neck (4 cases), and one each the thigh, thoracic wall, fibula, and lung. Seven patients received multimodal therapy; 1 patient was treated only with surgery. Clinical follow-up (8 patients; range, 4-122 months; median, 32 months) showed 5 patients with metastases (often multifocal, with a latency ranging from 7 to 119 months), and 3 of them also with local recurrence. The median local recurrence-free and metastasis-free survival rates were 24 months and 29 months, respectively. Of the 8 patients, 1 died of an unknown cause, 4 were alive with metastatic disease, 1 was alive with unresectable local disease, and 2 were without disease. The tumors were composed of 2 morphologic subgroups: (1) relatively bland tumors consisting of spindled to stellate cells with varying cellularity and fibromyxoid stroma (2 cases) and (2) overtly malignant tumors composed of nests of "neuroendocrine-appearing" round cells surrounded by spindled cells (6 cases). Individual cases in the second group showed glandular, osteogenic, or rhabdomyoblastic differentiation. Immunohistochemical results included CD56 (4/4 cases), GFAP (5/8), SATB2 (4/6), keratin (AE1/AE3) (5/8), and S100 protein (4/7). RNA sequencing identified EWSR1::POU2AF3 gene fusion in all cases. EWSR1 gene rearrangement was confirmed by fluorescence in situ hybridization in 5 cases. Our findings confirm the head/neck predilection and aggressive clinical behavior of EWSR1::POU2AF3 sarcomas and widen the morphologic spectrum of these rare lesions to include relatively bland spindle cell tumors and tumors with divergent differentiation.

A multiplatform metabolomics approach for comprehensive analysis of GIST xenografts with various KIT mutations.

Metabolites in biological matrices belong to diverse chemical groups, ranging from non-polar long-chain fatty acids to small polar molecules. The goal of untargeted metabolomic analysis is to measure the highest number of metabolites in the sample. Nevertheless, from an analytical point of view, no single technique can measure such a broad spectrum of analytes. Therefore, we selected a method based on GC-MS and LC-MS with two types of stationary phases for the untargeted profiling of gastrointestinal stromal tumours. The procedure was applied to GIST xenograft samples (n = 71) representing four different mutation models, half of which were treated with imatinib. We aimed to verify the method coverage and advantages of applying each technique. RP-LC-MS measured most metabolites due to a significant fraction of lipid components of the tumour tissue. What is unique and worth noting is that all applied techniques were able to distinguish between different mutation models. However, for detecting imatinib-induced alterations in the GIST metabolome, RP-LC-MS and GC-MS proved to be more relevant than HILIC-LC-MS, resulting in a higher number of significantly changed metabolites in four treated models. Undoubtedly, the inclusion of all mentioned techniques makes the method more comprehensive. Nonetheless, for green chemistry and time and labour saving, we assume that RP-LC-MS and GC-MS analyses are sufficient to cover the global GIST metabolome.

Role of immune checkpoint inhibitors in metastatic uveal melanoma: a single-center retrospective cohort study.

BACKGROUND: Uveal melanoma is an orphan malignancy with very limited data on treatment options in metastatic setting. METHODS: In this single-center retrospective study, we describe real-world epidemiological and survival data on 121 metastatic uveal melanoma (MUM) patients registered in our institution. As a large tertiary referral center, almost 30% of all diagnoses in the Flemish region of Belgium were covered. Primarily, we determined whether introduction of immune checkpoint inhibitors (ICI) led to improved overall survival (OS) in MUM patients. Secondarily, response rates to ICI were assessed and we evaluated whether first-line ICI could be a valid alternative to liver-directed therapy (LDT) in liver-only disease. RESULTS: The initially perceived 10.8 months survival benefit from treatment with ICI disappeared after correction for immortality bias. By analyzing treatment type as time-varying covariate on OS, no significant benefit of ICI over other systemic therapies (HR = 0.771) or best supportive care (BSC) (HR = 0.780) was found. Also comparison of the pre-ICI versus ICI era showed no OS improvement after introduction of ICI in our center (p = 0.7994). Only liver-directed and local oligometastatic approaches were associated with a lower chance of mortality when compared to ICI (p = 0.0025), other systemic therapies (p = 0.0001) and BSC (p = 0.0003), yet without correction for selection bias. We reported overall response rates on ICI ranging from 8-15% and we found some support for neoadjuvant strategies with ICI resulting in remission or downsizing, allowing oligometastatic approaches later on. In first-line liver-only disease, median real-world progression-free survival and OS did not significantly differ between patients treated with LDT or ICI upfront (p = 0.2930 and p = 0.5461 respectively). CONCLUSION: Although we documented responses to ICI, our analyses do not demonstrate an OS benefit of ICI over alternative treatment strategies for MUM. However, local treatment options, whether liver-directed or for oligometastatic disease, may be beneficial and should be considered.

Brightline-1: phase II/III trial of the MDM2-p53 antagonist BI 907828 versus doxorubicin in patients with advanced DDLPS.

Dedifferentiated liposarcoma (DDLPS) is a rare, aggressive liposarcoma associated with poor prognosis. First-line treatment for advanced/metastatic DDLPS is systemic chemotherapy, but efficacy is poor and toxicities substantial. Most DDLPS tumors have amplification of the MDM2 gene, which encodes a negative regulator of the p53 suppressor protein. BI 907828 is a highly potent, oral MDM2-p53 antagonist that inhibits the interaction between p53 and MDM2, thereby restoring p53 activity. BI 907828 has shown promising activity in preclinical studies and in a phase Ia/Ib study in patients with solid tumors, particularly those with DDLPS. This manuscript describes the rationale and design of an ongoing multicenter, randomized, phase II/III trial (Brightline-1; NCT05218499) evaluating BI 907828 versus doxorubicin as first-line treatment for advanced DDLPS.

Dedifferentiated liposarcoma (DDLPS) is a rare, fast-growing cancer that begins in fat cells. Patients with DDLPS that cannot be removed surgically or has spread to other areas of the body are usually treated with chemotherapy at first, but this typically stops working only 2­4 months after the start of treatment and has a lot of side effects. The drug BI 907828 works differently to chemotherapy by specifically targeting a gene called MDM2. This gene is abnormally increased in most DDLPS tumors and causes cancer by shutting down one of the pathways that the body uses to kill cancerous cells. BI 907828 restores this pathway, leading to the targeted destruction of tumor cells. Results from initial studies show that BI 907828 is able to slow the growth of DDLPS, and is now being investigated further, in a study called Brightline-1. Brightline-1, which is currently underway, is comparing BI 907828 with the chemotherapy drug doxorubicin for the initial treatment of DDLPS that is inoperable or has spread to other areas of the body. Clinical Trial Registration: NCT05218499 (ClinicalTrials.gov).

Validation of a novel risk score to predict early and late recurrence in solitary fibrous tumour.

BACKGROUND: Current risk models in solitary fibrous tumour (SFT) were developed using cohorts with short follow-up and cannot reliably identify low-risk patients. We recently developed a novel risk model (G-score) to account for both early and late recurrences. Here, we aimed to validate the G-score in a large international cohort with long-term follow-up. METHODS: Data were collected from nine sarcoma referral centres worldwide. Recurrence-free interval (RFi) was the primary endpoint. RESULTS: The cohort comprised 318 patients with localised extrameningeal SFTs. Disease recurrence occurred in 96 patients (33%). The estimated 5-year RFi rate was 72%, and the 10-year RFi rate was 52%. G-score precisely predicted recurrence risk with estimated 10-year RFi rate of 84% in low risk, 54% in intermediate risk and 36% in high risk (p < 0.001; C-index 0.691). The mDemicco (p < 0.001; C-index 0.749) and SalasOS (p < 0.001; C-index 0.674) models also predicted RFi but identified low-risk patients less accurate with 10-year RFi rates of 72% and 70%, respectively. CONCLUSIONS: G-score is a highly significant predictor of early and late recurrence in SFT and is superior to other models to predict patients at low risk of relapse. A less intensive follow-up schedule could be considered for patients at low recurrence risk according to G-score.

Five-Year Survival with Combined Nivolumab and Ipilimumab in Advanced Melanoma.

BACKGROUND: Nivolumab plus ipilimumab or nivolumab alone resulted in longer progression-free and overall survival than ipilimumab alone in a trial involving patients with advanced melanoma. We now report 5-year outcomes in the trial. METHODS: We randomly assigned patients with previously untreated advanced melanoma to receive one of the following regimens: nivolumab (at a dose of 1 mg per kilogram of body weight) plus ipilimumab (3 mg per kilogram) every 3 weeks for four doses, followed by nivolumab (3 mg per kilogram every 2 weeks); nivolumab (3 mg per kilogram every 2 weeks) plus ipilimumab-matched placebo; or ipilimumab (3 mg per kilogram every 3 weeks for four doses) plus nivolumab-matched placebo. The two primary end points were progression-free survival and overall survival in the nivolumab-plus-ipilimumab group and in the nivolumab group, as compared with the ipilimumab group. RESULTS: At a minimum follow-up of 60 months, the median overall survival was more than 60.0 months (median not reached) in the nivolumab-plus-ipilimumab group and 36.9 months in the nivolumab group, as compared with 19.9 months in the ipilimumab group (hazard ratio for death with nivolumab plus ipilimumab vs. ipilimumab, 0.52; hazard ratio for death with nivolumab vs. ipilimumab, 0.63). Overall survival at 5 years was 52% in the nivolumab-plus-ipilimumab group and 44% in the nivolumab group, as compared with 26% in the ipilimumab group. No sustained deterioration of health-related quality of life was observed during or after treatment with nivolumab plus ipilimumab or with nivolumab alone. No new late toxic effects were noted. CONCLUSIONS: Among patients with advanced melanoma, sustained long-term overall survival at 5 years was observed in a greater percentage of patients who received nivolumab plus ipilimumab or nivolumab alone than in those who received ipilimumab alone, with no apparent loss of quality of life in the patients who received regimens containing nivolumab. (Funded by Bristol-Myers Squibb and others; CheckMate 067 ClinicalTrials.gov number, NCT01844505.).

Machine learning for rhabdomyosarcoma histopathology.

Correctly diagnosing a rare childhood cancer such as sarcoma can be critical to assigning the correct treatment regimen. With a finite number of pathologists worldwide specializing in pediatric/young adult sarcoma histopathology, access to expert differential diagnosis early in case assessment is limited for many global regions. The lack of highly-trained sarcoma pathologists is especially pronounced in low to middle-income countries, where pathology expertise may be limited despite a similar rate of sarcoma incidence. To address this issue in part, we developed a deep learning convolutional neural network (CNN)-based differential diagnosis system to act as a pre-pathologist screening tool that quantifies diagnosis likelihood amongst trained soft-tissue sarcoma subtypes based on whole histopathology tissue slides. The CNN model is trained on a cohort of 424 centrally-reviewed histopathology tissue slides of alveolar rhabdomyosarcoma, embryonal rhabdomyosarcoma and clear-cell sarcoma tumors, all initially diagnosed at the originating institution and subsequently validated by central review. This CNN model was able to accurately classify the withheld testing cohort with resulting receiver operating characteristic (ROC) area under curve (AUC) values above 0.889 for all tested sarcoma subtypes. We subsequently used the CNN model to classify an externally-sourced cohort of human alveolar and embryonal rhabdomyosarcoma samples and a cohort of 318 histopathology tissue sections from genetically engineered mouse models of rhabdomyosarcoma. Finally, we investigated the overall robustness of the trained CNN model with respect to histopathological variations such as anaplasia, and classification outcomes on histopathology slides from untrained disease models. Overall positive results from our validation studies coupled with the limited worldwide availability of sarcoma pathology expertise suggests the potential of machine learning to assist local pathologists in quickly narrowing the differential diagnosis of sarcoma subtype in children, adolescents, and young adults.

A multicenter, dose-finding, phase 1b study of imatinib in combination with alpelisib as third-line treatment in patients with advanced gastrointestinal stromal tumor.

BACKGROUND: Acquired resistance to approved tyrosine kinase inhibitors limits their clinical use in patients with gastrointestinal stromal tumor (GIST). This study investigated the safety, tolerability and efficacy of alpelisib, a phosphatidylinositol 3-kinase inhibitor, used in combination with imatinib in patients with advanced GIST who had failed prior therapy with both imatinib and sunitinib. METHODS: This phase 1b, multicenter, open-label study consisted of 2 phases: dose escalation and dose expansion. Dose escalation involved 200 mg once daily (QD) alpelisib, initially, followed by 250 and 350 mg. These were combined with 400 mg QD imatinib until maximum tolerated dose (MTD) and/or a recommended phase 2 dose (RP2D) of alpelisib in combination with imatinib was determined. This MTD/RP2D dose was tested to evaluate the clinical activity of this combination in dose expansion. RESULTS: Fifty-six patients were enrolled, 21 and 35 in the dose escalation and expansion phases, respectively. The MTD of alpelisib given with imatinib was determined as 350 mg QD. Combination treatment showed partial response in 1 (2.9%) and stable disease in 15 (42.9%) patients. Median progression-free survival was 2 months (95% CI 1.8-4.6). Overall, 92.9% patients had adverse events (AEs) while 46.4% had grade 3/4 AEs, hyperglycemia being the most common (23.2%). CONCLUSIONS: The MTD of alpelisib was estimated as 350 mg QD when used in combination with imatinib 400 mg QD after oral administration in patients with advanced GIST. The safety and tolerability profile of this combination was acceptable; however, the combination did not demonstrate sufficient clinical activity to justify additional clinical testing. TRIAL REGISTRATION: ClinicalTrials.gov NCT01735968 (date of initial registration 28/11/2012).

Patient-reported outcomes in individuals with advanced gastrointestinal stromal tumor treated with ripretinib in the fourth-line setting: analysis from the phase 3 INVICTUS trial.

BACKGROUND: Ripretinib is a novel switch-control kinase inhibitor that inhibits KIT and PDGFRA signaling. In the INVICTUS phase 3 trial, ripretinib increased median progression-free survival and prolonged overall survival vs. placebo in ≥ fourth-line advanced GIST. Here, we report prespecified analysis of quality of life (QoL) as assessed by patient-reported outcome (PRO) measures and an exploratory analysis evaluating the impact of alopecia on QoL. METHODS: In the INVICTUS trial (NCT03353753), QoL was assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30; physical function, role function, overall health, and overall QoL) and the EuroQoL 5-Dimension 5-Level (EQ-5D-5 L; visual analogue scale). Analysis of covariance (ANCOVA) models compared changes in scores from baseline to treatment cycle 2, day 1 within and between ripretinib and placebo. Within the ripretinib arm, repeated measures models assessed the impact of alopecia on QoL. RESULTS: Patients receiving ripretinib maintained QoL (as assessed by the EORTC QLQ-C30 and EQ-5D-5 L PRO measures) from baseline to cycle 2, day 1 whereas QoL declined with placebo, resulting in clinically significant differences between treatments (nominal P < 0.01). The most common treatment-emergent adverse event with ripretinib was alopecia; however, QoL was similarly maintained out to treatment cycle 10, day 1 in patients receiving ripretinib who developed alopecia and those who did not. CONCLUSION: PRO assessments in the INVICTUS trial suggest that patients on ripretinib maintain their QoL out to C2D1, unlike patients receiving placebo. Longitudinal QoL was maintained for patients receiving ripretinib out to cycle 10, day 1 (approximately 8 months; past the point of median progression-free survival with ripretinib [6.3 months]), even if the patients developed alopecia. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03353753 ; first posted: November 27, 2017.

Exploratory analysis of tumor imaging in a Phase 2 trial with cabozantinib in gastrointestinal stromal tumor: lessons learned from study EORTC STBSG 1317 'CaboGIST'.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are malignant mesenchymal tumors arising in the gastrointestinal tract. Their systemic treatment is based on the use of tyrosine kinase inhibitors (TKIs) with imatinib, sunitinib, and regorafenib being the preferred agents. Assessment of tumor response to TKI treatment in GISTs is traditionally done according the Response Evaluation Criteria in Solid Tumors (RECIST), while Choi criteria have also been proposed as alternative tool assessing both volumetric and density changes on computer tomography (CT) scans. EORTC STBSG 1317 'CaboGIST' was a single-arm prospective Phase 2 trial which met its primary endpoint, as 60% of patients previously treated with imatinib and sunitinib were progression-free at 12 weeks (95% CI 45-74%) based on local RECIST assessment. MATERIALS AND METHODS: We report here an exploratory analysis of local versus central RECIST version 1.1 assessment and a comparison of RECIST version 1.1 versus Choi criteria. RESULTS: Comparisons between local and central RECIST version 1.1 at week 12 revealed discrepancies in 17/43 evaluable cases (39.5%). When comparing Choi with local and central RECIST version 1.1, discrepancies were observed in 27/43 (62.8%) and 21/43 (48.8%) cases, respectively. A total of 68% of evaluable patients were progression-free and alive at week 12 based on local RECIST, 84% according to central RECIST analysis and 81% when applying Choi criteria. Central assessment upgraded the treatment response both with RECIST version 1.1 and Choi. CONCLUSIONS: The results of this exploratory analysis support the conclusion that cabozantinib is active in patients with metastatic or recurrent GIST after treatment with imatinib and sunitinib and confirm once again the limitations of RECIST to capture response to TKI in GIST, and the importance to include density changes in the response evaluation in this setting. Clinical trial number: EORTC 1317, NCT02216578.

Overall survival improvement in patients with metastatic clear-cell renal cell carcinoma between 2000 and 2020: a retrospective cohort study.

BACKGROUND: Only a few recent phase III trials with targeted therapies or immune checkpoint inhibitors (ICIs) in metastatic clear-cell renal cell carcinoma (m-ccRCC) demonstrated an overall survival (OS) benefit compared to standard of care. We aimed to study the evolution of OS since the start of systemic therapy from 2000 to 2020. PATIENTS AND METHODS: Retrospective study on all consecutively treated m-ccRCC patients in three Belgian hospitals starting with systemic therapy. The study outcome was OS since the start of systemic therapy. We used a univariable Cox model for OS with year of the start of therapy as a predictor, and a multivariable analysis including known prognostic factors. Linear and non-linear trends of time were tested. RESULTS: Five hundred patients were included. In a linear model, the HR for OS depending on the year of the start of therapy was 0.95 (95%CI 0.93-0.97; p < 0.0001), estimated for an increase with 1 year in time. In a non-linear model, OS started to improve from 2006 on, when vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) replaced interferon alfa (IFNa) as a standard of care and continued to increase steadily during the following years. On multivariable analysis, the year of the start of therapy remained an independent prognostic factor for OS. Two-year OS after the start of systemic therapy was 23%, 34%, 50% and 59% for patients who started treatment in 2000-2005, 2006-2011, 2012-2017, and 2018-2020, respectively. The five-year OS of the first three groups was 7%, 14% and 24%. The mean number of administered lines of therapy increased over time, with an incidence rate ratio of 1.07 (95%CI 1.05-1.08; p < 0.0001) per year increase for the period 2000-2016. CONCLUSION: OS of m-ccRCC patients has been improving significantly over the last 15 years since the introduction of VEGFR-TKIs and ICIs.

Plocabulin, a Novel Tubulin Inhibitor, Has Potent Antitumour Activity in Patient-Derived Xenograft Models of Soft Tissue Sarcoma.

A clinically relevant subset of patients with soft tissue sarcoma presents with either locally advanced or upfront metastatic disease, or will develop distant metastases over time, despite successful treatment of their primary tumour. The currently available systemic agents to treat such advanced cases only provide modest disease control and are not active in all histological subtypes. Thus, there is an unmet need for novel and more efficacious agents to improve the outcome of this rare disease. In the current preclinical in vivo study, we evaluated plocabulin, a novel tubulin inhibitor, in five distinct histological subtypes of soft tissue sarcoma: dedifferentiated liposarcoma, leiomyosarcoma, undifferentiated sarcoma, intimal sarcoma and CIC-rearranged sarcoma. The efficacy was tested in seven patient-derived xenograft models, which were generated by the engraftment of tumour fragments from patients directly into nude mice. The treatment lasted 22 days, and the efficacy of the drug was assessed and compared to the doxorubicin and vehicle groups by volumetric analysis, histopathology and immunohistochemistry. We observed tumour volume control in all the tested histological subtypes. Additionally, in three sarcoma subtypes, extensive central necrosis, associated with significant tumour regression, was seen. This histological response is explained by the drug's vascular-disruptive properties, reflected by a decreased total vascular area in the xenografts. Our results demonstrate the in vivo efficacy of plocabulin in the preclinical models of soft tissue sarcoma and corroborate the findings of our previous study, which demonstrated similar vascular-disruptive effects in gastrointestinal stromal tumours-another subtype of soft tissue sarcoma. Our data provide a convincing rationale for further clinical exploration of plocabulin in soft tissue sarcomas.

Enapotamab Vedotin, an AXL-Specific Antibody-Drug Conjugate, Demonstrates Antitumor Efficacy in Patient-Derived Xenograft Models of Soft Tissue Sarcoma.

Doxorubicin (doxo) remains the standard of care for patients with advanced soft tissue sarcoma (STS), even though response rates to doxo are only around 14% to 18%. We evaluated enapotamab vedotin (EnaV), an AXL-specific antibody-drug conjugate (ADC), in a panel of STS patient-derived xenografts (PDX). Eight models representing multiple STS subtypes were selected from our STS PDX platform (n = 45) by AXL immunostaining on archived passages. Models were expanded by unilateral transplantation of tumor tissue into the left flank of 20 NMRI nu/nu mice. Once tumors were established, mice were randomized into an EnaV treatment group, or a group treated with isotype control ADC. Treatment efficacy was assessed by tumor volume evaluation, survival analysis, and histological evaluation of tumors, and associated with AXL expression. EnaV demonstrated significant tumor growth delay, regression, and/or prolonged survival compared to isotype control ADC in 5/8 STS PDX models investigated. Experimental passages of responding models were all found positive for AXL at varying levels, but no linear relationship could be identified between the level of expression and level of response to EnaV. One model was found negative for AXL on experimental passage and did not respond to EnaV. This study provides a preclinical rationale for the evaluation of AXL-targeting ADCs in the treatment of AXL-expressing sarcomas.

Correlation of Immunological and Molecular Profiles with Response to Crizotinib in Alveolar Soft Part Sarcoma: An Exploratory Study Related to the EORTC 90101 "CREATE" Trial.

Alveolar soft part sarcoma (ASPS) is a rare subtype of soft tissue sarcoma characterized by an unbalanced translocation, resulting in ASPSCR1-TFE3 fusion that transcriptionally upregulates MET expression. The European Organization for Research and Treatment of Cancer (EORTC) 90101 "CREATE" phase II trial evaluated the MET inhibitor crizotinib in ASPS patients, achieving only limited antitumor activity. We performed a comprehensive molecular analysis of ASPS tissue samples collected in this trial to identify potential biomarkers correlating with treatment outcome. A tissue microarray containing 47 ASPS cases was used for the characterization of the tumor microenvironment using multiplex immunofluorescence. DNA isolated from 34 available tumor samples was analyzed to detect recurrent gene copy number alterations (CNAs) and mutations by low-coverage whole-genome sequencing and whole-exome sequencing. Pathway enrichment analysis was used to identify diseased-associated pathways in ASPS sarcomagenesis. Kaplan-Meier estimates, Cox regression, and the Fisher's exact test were used to correlate histopathological and molecular findings with clinical data related to crizotinib treatment, aiming to identify potential factors associated with patient outcome. Tumor microenvironment characterization showed the presence of PD-L1 and CTLA-4 in 10 and 2 tumors, respectively, and the absence of PD-1 in all specimens. Apart from CD68, other immunological markers were rarely expressed, suggesting a low level of tumor-infiltrating lymphocytes in ASPS. By CNA analysis, we detected a number of broad and focal alterations. The most common alteration was the loss of chromosomal region 1p36.32 in 44% of cases. The loss of chromosomal regions 1p36.32, 1p33, 1p22.2, and 8p was associated with shorter progression-free survival. Using whole-exome sequencing, 13 cancer-associated genes were found to be mutated in at least three cases. Pathway enrichment analysis identified genetic alterations in NOTCH signaling, chromatin organization, and SUMOylation pathways. NOTCH4 intracellular domain dysregulation was associated with poor outcome, while inactivation of the beta-catenin/TCF complex correlated with improved outcome in patients receiving crizotinib. ASPS is characterized by molecular heterogeneity. We identify genetic aberrations potentially predictive of treatment outcome during crizotinib therapy and provide additional insights into the biology of ASPS, paving the way to improve treatment approaches for this extremely rare malignancy.

Comprehensive targeted next-generation sequencing approach in the molecular diagnosis of gastrointestinal stromal tumor.

Mutational analysis guides therapeutic decision making in patients with advanced-stage gastrointestinal stromal tumors (GISTs). We evaluated three targeted next-generation sequencing (NGS) assays, consecutively used over 4 years in our laboratory for mutational analysis of 162 primary GISTs: Agilent GIST MASTR, Illumina TruSight 26 and an in-house developed 96 gene panels. In addition, we investigated the feasibility of a more comprehensive approach by adding targeted RNA sequencing (Archer FusionPlex, 11 genes) in an attempt to reduce the number of Wild Type GISTs. We found KIT or PDGFRA mutations in 149 out of 162 GISTs (92.0%). Challenging KIT exon 11 alterations were initially missed by different assays in seven GISTs and typically represented deletions at the KIT intron 10-exon 11 boundary or large insertions/deletions (>24 base pairs). Comprehensive analysis led to the additional identification of driver alterations in 8/162 GISTs (4.9%): apart from BRAF and SDHA mutations (one case each), we found five GISTs harboring somatic neurofibromatosis type 1 (NF1) alterations (3.1%) and one case with an in-frame TRIM4-BRAF fusion not reported in GIST before. Eventually, no driver alteration was found in two out of 162 GISTs (1.2%) and three samples (1.9%) failed analysis. Our study shows that a comprehensive targeted NGS approach is feasible for routine mutational analysis of GIST, thereby substantially reducing the number of Wild Type GISTs, and highlights the need to optimize assays for challenging KIT exon 11 alterations.