The study of loading mode with in-vitro fatigue testing for mitral annuloplasty ring

To maintain the physiological dynamics of the mitral annulus, mitral annuloplasty rings (MAR) must be flexible. Enhanced flexibility implies decreased resistance to fatigue and potential for fatigue fracture. This study established new methods to test the flexible fatigue life of MAR in-vitro using numerical analysis; the purpose is that the fatigue test could reflect the real stress distribution in-vivo. Based on the conventional test methods (C1, D1), this paper presents a novel test method (C2, D2). Four testing methods for open-end annuloplasty rings (C1, C2) and closed-end annuloplasty rings (D1, D2) were modelled and their stress distribution calculated by finite element analysis. The mean absolute error (Χ) and the Pearson correlation coefficient (Φ) were used to quantify the difference in stress distribution between the loading modes in-vivo and in-vitro. For closed-end annuloplasty rings, the novel test method (D2) is not obvious better than conventional test methods(D1) in duplicating the stress distribution (ΦD1 = 0.88 vs ΦD2 = 0.92). However, the maximum values of stress in the novel test method are closer to the maximum value of stress under in-vivo loading (ΧD1 = 5.2Mpa vs ΧD2 = 4.4Mpa). For open-end annuloplasty rings, the novel test method(C2) is obviously superior to the conventional test method(C1) in duplicating both the stress distribution and the stress peak values of the in-vivo loading (ΦC1 = 0.22 vs ΦC2 = 0.98; ΧC1 = 59.1Mpa vs ΧC2 = 11.0Mpa). The in-vitro loading methods described in this article more closely approximated in-vivo conditions compared to traditional methods. They are simpler to operate, more efficient and can help manufacturers expedite new product development, assist regulatory agencies with product quality oversight.

Salidroside alleviates LPS-induced liver injury and inflammation through SIRT1- NF-κB pathway and NLRP3 inflammasome

Objectives

Salidroside (SAL), an active ingredient purified from the medicinal plant Rhodiola rosea, has anti-inflammatory, anti-oxidant, anticancer, and neuroprotective properties. The study aims to examine SAL's protective role in liver damage brought on by lipopolysaccharide (LPS).

Materials and Methods

Six to eight-week-old male C57BL/6 wild-type mice were intraperitoneally treated with 10 mg/kg LPS for 24 hr and 50 mg/kg SAL two hours before LPS administration. Mice were categorized into control, LPS, and LPS + SAL groups. To evaluate liver injury, biochemical and TUNNEL staining test studies were performed. The Elisa assay analyzed interleukin- 1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) pro-inflammatory cytokine expression levels. RT-qPCR and western blotting measured mRNA and protein expression of SIRT1, NF-кB, NLRP3, cleaved caspase-1, and GSDMD, respectively.

Results

Analysis of the serum alanine/aspartate aminotransferases (ALT/AST), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) revealed that SAL protected against hepatotoxicity induced by LPS. The pathological evaluation of the liver supported the protection provided by SAL. SAL treatment reversed IL-1β, TNF-α, and IL-6 pro-inflammatory cytokines after being induced by LPS (all, P<0.001). The western blotting examination results demonstrated that SAL increased the levels of Sirtuin 1 (SIRT1) expression but markedly reduced the phosphorylation of Nuclear Factor Kappa B (NF-B) and the expressions of NLRP3, cleaved caspase-1, and gasdermin D (GSDMD) induced by LPS (all, P<0.001).

Conclusion

Our results speculated that by inhibiting the SIRT1- NF-κB pathway and NLRP3 inflammasome, SAL defends against LPS-induced liver injury and inflammation.

A detailed multi-omics analysis of GNB2 gene in human cancers

Abstract The Guanine-nucleotide binding protein 2 (GNB2) encodes for β2 subunit (Gβ2) of the G-protein complex. Keeping in view the increased demand of reliable biomarkers in cancer, the current study was planned to extensively explored GNB2 expression variation and its roles in different cancers using online available databases and diverse methodology. In view of our results, the GNB2 was notably up-regulated relative to corresponding controls in twenty three cancer types. As well, the elevated expression of GNB2 was found to be associated with the reduced overall survival (OS) of the Liver Hepatocellular Carcinoma (LIHC) and Rectum Adenocarcinoma (READ) only out of all analyzed cancer types. This implies GNB2 plays vital role in the tumorigenesis of LIHC and READ. Several additional analysis also explored six critical pathways and few important correlations related to GNB2 expression and different other parameters such as promoter methylation, tumor purity, CD8+ T immune cells infiltration, and genetic alteration, and chemotherapeutic drugs. In conclusion, GNB2 gene has been identified in this study as a shared potential biomarker (diagnostic and prognostic) of LIHC and READ.

Cleaner outdoor air diminishes the overall risk of intracerebral hemorrhage but brings differential benefits to subpopulations: a time-stratified case-crossover study

BACKGROUND

Short-term air pollution exposure and intracerebral hemorrhage (ICH) risk are related. However, the impact of the pollutant levels decline on this relationship, which attributes to clean air policy implementation and the COVID-19 pandemic lockdown, is unclear. In the present research, we explored the influence of different pollutant levels on ICH risk during eight years in a southwestern China megacity.

METHODS

Our research used a time-stratified case-crossover design. We retrospectively analyzed ICH patients in a teaching hospital from January 1, 2014, to December 31, 2021, and divided 1571 eligible cases into two groups (1st group: 2014-2017; 2nd group: 2018-2021). We observed the trend of every pollutant in the entire study period and compared the pollution levels in each group, using air pollutants data (PM2.5, PM10, SO2, NO2, CO, and O3) documented by the local government. We further established a single pollutant model via conditional logistic regression to analyze the association between short-term air pollutants exposure and ICH risk. We also discussed the association of pollution levels and ICH risk in subpopulations according to individual factors and monthly mean temperature.

RESULTS

We found that five air pollutants (PM2.5, PM10, SO2, NO2, CO) exhibited a continuous downward trend for the whole duration, and the daily concentration of all six pollutants decreased significantly in 2018-2021 compared with 2014-2017. Overall, the elevation of daily PM2.5, SO2, and CO was associated with increased ICH risk in the first group and was not positively associated with risk escalation in the second group. For patients in subgroups, the changes in the influence of lower pollutant levels on ICH risk were diverse. In the second group, for instance, PM2.5 and PM10 were associated with lower ICH risk in non-hypertension, smoking, and alcohol-drinking participants; however, SO2 had associations with increased ICH risk for smokers, and O3 had associations with raised risk in men, non-drinking, warm month population.

CONCLUSIONS

Our study suggests that decreased pollution levels diminish the adverse effects of short-term air pollutants exposure and ICH risk in general. Nevertheless, the influence of lower air pollutants on ICH risk in subgroups is heterogeneous, indicating unequal benefits among subpopulations.

Effect of ureteral stent length and implantation position on migration after implantation

BACKGROUND

Ureteral obstruction is a urinary system disease that causes urinary retention, renal injury, renal colic, and infection. Ureteral stents are often used for conservative treatment in clinics, and their migration usually results in ureteral stent failure. The migrations include proximal migration to the kidney side and distal migration to the bladder side, but the biomechanism of stent migration is still unknown.

METHOD

Finite element models of stents with lengths from 6-30 cm were developed. The stents were implanted into the middle of the ureter to analyze the effect of stent length on its migration, and the effect of stent implantation position on 6-cm-long stent migration was also observed. The stents' maximum axial displacement was used to assess the ease of stent migration. A time-varying pressure was applied to the ureter outer wall to simulate peristalsis. The stent and ureter adopted friction contact conditions. The two ends of the ureter were fixed. The radial displacement of the ureter was used to evaluate the effect of the stent on peristalsis.

RESULTS AND DISCUSSION

The maximum migration occurs in the positive direction for a 6-cm-long stent implanted at the proximal ureter (CD and DE), but in the negative direction at the distal ureter (FG and GH). The 6-cm-long stent demonstrated almost no effect on ureteral peristalsis. The 12-cm-long stent diminished the radial displacement of the ureter from 3-5 s. The 18-cm stent diminished the radial displacement of the ureter from 0-8 s, and the radial displacement within 2-6 s was weaker than other time. The 24-cm stent diminished the radial displacement of the ureter from 0-8 s, and the radial displacement within 1-7 s was weaker than other time.

CONCLUSION

The biomechanism of stent migration and ureteral peristalsis weakening after stent implantation was explored. Shorter stents were more likely to migrate. The implantation position had less influence on ureteral peristalsis compared with the stent length, which provided a reference for stent design aimed at reducing stent migration. Stent length was the main factor affecting ureteral peristalsis. This study provides a reference for the study of ureteral peristalsis.

Abnormal flow pattern of low wall shear stress and high oscillatory shear index in spontaneous vertebral artery dissection with vertebral artery hypoplasia

Introduction

Spontaneous vertebral artery dissection (sVAD) might tend to develop in vertebral artery hypoplasia (VAH) with hemodynamic dysfunction and it is crucial to assess hemodynamics in sVAD with VAH to investigate this hypothesis. This retrospective study aimed to quantify hemodynamic parameters in patients with sVAD with VAH.

Methods

Patients who had suffered ischemic stroke due to an sVAD of VAH were enrolled in this retrospective study. The geometries of 14 patients (28 vessels) were reconstructed using Mimics and Geomagic Studio software from CT angiography (CTA). ANSYS ICEM and ANSYS FLUENT were utilized for mesh generation, set boundary conditions, solve governing equations, and perform numerical simulations. Slices were obtained at the upstream area, dissection or midstream area and downstream area of each VA. The blood flow patterns were visualized through instantaneous streamline and pressure at peak systole and late diastole. The hemodynamic parameters included pressure, velocity, time-averaged blood flow, time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell action potential (ECAP), relative residence time (RRT) and time-averaged nitric oxide production rate (TAR_NO).

Results

Significant focal increased velocity was present in the dissection area of steno-occlusive sVAD with VAH compared to other nondissected areas (0.910 m/s vs. 0.449 vs. 0.566, p < 0.001), while focal slow flow velocity was observed in the dissection area of aneurysmal dilatative sVAD with VAH according to velocity streamlines. Steno-occlusive sVAD with VAH arteries had a lower time-averaged blood flow (0.499 cm³/s vs. 2.268, p < 0.001), lower TAWSS (1.115 Pa vs. 2.437, p = 0.001), higher OSI (0.248 vs. 0.173, p = 0.006), higher ECAP (0.328 Pa^-1 vs. 0.094, p = 0.002), higher RRT (3.519 Pa^-1 vs. 1.044, p = 0.001) and deceased TAR_NO (104.014 nM/s vs. 158.195, p < 0.001) than the contralateral VAs.

Conclusion

Steno-occlusive sVAD with VAH patients had abnormal blood flow patterns of focal increased velocity, low time-averaged blood flow, low TAWSS, high OSI, high ECAP, high RRT and decreased TAR_NO. These results provide a good basis for further investigation of sVAD hemodynamics and support the applicability of the CFD method in testing the hemodynamic hypothesis of sVAD. More detailed hemodynamic conditions with different stages of sVAD are warranted in the future.

Clinical outcomes of intra-arterial chemotherapy combined with iodine-125 seed brachytherapy in the treatment of malignant superior vena cava syndrome caused by small cell lung cancer

PURPOSE

Currently there is a lack of effective treatment strategies for malignant superior vena cava syndrome (SVCS). We aim to investigate the therapeutic effect of intra-arterial chemotherapy (IAC) combined with the Single Needle Cone Puncture method for the ¹²⁵I brachytherapy (SNCP-¹²⁵I) in treating SVCS caused by stage III/IV Small Cell Lung Cancer (SCLC).

MATERIALS AND METHODS

Sixty-two patients with SCLC who developed SVCS from January 2014 to October 2020 were investigated in this study. Out of these 62 patients, 32 underwent IAC combined with SNCP-¹²⁵I (Group A) and 30 patients received IAC treatment only (Group B). Clinical symptom remission, response rate, disease control rate, and overall survival of these two groups of patients were analyzed and compared.

RESULTS

The remission rate of symptoms including dyspnea, edema, dysphagia, pectoralgia, and cough of malignant SVCS in Group A was significantly higher than that in Group B (70.5 and 50.53%, P=0.0004, respectively). The disease control rates (DCR, PR+CR+SD) of Group A and B were 87.5 and 66.7%, respectively (P=0.049). Response rates (RR, PR+CR) of Group A and Group B were 71.9 and 40% (P=0.011). The median overall survival (OS) of Group A was significantly longer than that in Group B which was 18 months compared to 11.75 months (P=0.0360).

CONCLUSIONS

IAC treatment effectively treated malignant SVCS in advanced SCLC patients. IAC combined with SNCP-¹²⁵I in the treatment of malignant SVCS caused by SCLC showed improved clinical outcomes including symptom remission and local tumor control rates than IAC treatment only in treating SCLC-induced malignant SVCS.

Impact of redox-related genes on tumor microenvironment immune characteristics and prognosis of high-grade gliomas

Introduction

High-grade glioma (HGG) defines a group of brain gliomas characterized by contrast enhancement, high tumor heterogeneity, and poor clinical outcome. Disturbed reduction-oxidation (redox) balance has been frequently associated with the development of tumor cells and their microenvironment (TME).

Methods

To study the influence of redox balance on HGGs and their microenvironment, we collected mRNA-sequencing and clinical data of HGG patients from TCGA and CGGA databases and our own cohort. Redox-related genes (ROGs) were defined as genes in the MSigDB pathways with keyword "redox" that were differentially expressed between HGGs and normal brain samples. Unsupervised clustering analysis was used to discover ROG expression clusters. Over-representation analysis (ORA), gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) were also employed to understand the biological implication of differentially expressed genes between HGG clusters. CIBERSORTx and ESTIMATE were used to profile the immune TME landscapes of tumors, and TIDE was used to evaluated the potential response to immune checkpoint inhibitors. Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression was used to construct HGG-ROG expression risk signature (GRORS).

Results

Seventy-five ROGs were found and consensus clustering using the expression profile of ROGs divided the both IDH-mutant (IDHmut) and IDH-wildtype (IDHwt) HGGs into subclusters with different prognosis. Functional enrichment analysis revealed that the differential aggressiveness between redox subclusters in IDHmut HGGs were significantly associated with cell cycle regulation pathways, while IDHwt HGG redox subclusters showed differentially activated immune-related pathways. In silico TME analysis on immune landscapes in the TME showed that the more aggressive redox subclusters in both IDHmut and IDHwt HGGs may harbor a more diverse composition of tumor-infiltrating immune cells, expressed a higher level of immune checkpoints and were more likely to respond to immune checkpoint blockade. Next, we established a GRORS which showed AUCs of 0.787, 0.884, and 0.917 in predicting 1-3-year survival of HGG patients in the held-out validation datasets, and the C-index of a nomogram combining the GRORS and other prognostic information reached 0.835.

Conclusion

Briefly, our results suggest that the expression pattern of ROGs was closely associated with the prognosis as well as the TME immune profile of HGGs, and may serve as a potential indicator for their response to immunotherapies.

Tucatinib plus trastuzumab for chemotherapy-refractory, HER2-positive, RAS wild-type unresectable or metastatic colorectal cancer (MOUNTAINEER): a multicentre, open-label, phase 2 study

BACKGROUND

HER2 is an actionable target in metastatic colorectal cancer. We assessed the activity of tucatinib plus trastuzumab in patients with chemotherapy-refractory, HER2-positive, RAS wild-type unresectable or metastatic colorectal cancer.

METHODS

MOUNTAINEER is a global, open-label, phase 2 study that enrolled patients aged 18 years and older with chemotherapy-refractory, HER2-positive, RAS wild-type unresectable or metastatic colorectal cancer at 34 sites (clinics and hospitals) in five countries (Belgium, France, Italy, Spain, and the USA). Initially, the study was designed as a single-cohort study, which was expanded following an interim analysis to include more patients. Initially, patients were given tucatinib (300 mg orally twice daily) plus intravenous trastuzumab (8 mg/kg as an initial loading dose, then 6 mg/kg every 21 days; cohort A) for the duration of treatment (until progression), and after expansion, patients were randomly assigned (4:3), using an interactive web response system and stratified by primary tumour location, to either tucatinib plus trastuzumab (cohort B) or tucatinib monotherapy (cohort C). The primary endpoint was confirmed objective response rate per blinded independent central review (BICR) for cohorts A and B combined and was assessed in patients in the full analysis set (ie, patients with HER2-positive disease who received at least one dose of study treatment). Safety was assessed in all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT03043313, and is ongoing.

FINDINGS

Between Aug 8, 2017, and Sept 22, 2021, 117 patients were enrolled (45 in cohort A, 41 in cohort B, and 31 in cohort C), of whom 114 patients had locally assessed HER2-positive disease and received treatment (45 in cohort A, 39 in cohort B, and 30 in cohort C; full analysis set), and 116 patients received at least one dose of study treatment (45 in cohort A, 41 in cohort B, and 30 in cohort C; safety population). In the full analysis set, median age was 56·0 years (IQR 47-64), 66 (58%) were male, 48 (42%) were female, 88 (77%) were White, and six (5%) were Black or African American. As of data cutoff (March 28, 2022), in 84 patients from cohorts A and B in the full analysis set, the confirmed objective response rate per BICR was 38·1% (95% CI 27·7-49·3; three patients had a complete response and 29 had a partial response). In cohorts A and B, the most common adverse event was diarrhoea (55 [64%] of 86), the most common grade 3 or worse adverse event was hypertension (six [7%] of 86), and three (3%) patients had tucatinib-related serious adverse events (acute kidney injury, colitis, and fatigue). In cohort C, the most common adverse event was diarrhoea (ten [33%] of 30), the most common grade 3 or worse adverse events were increased alanine aminotransferase and aspartate aminotransferase (both two [7%]), and one (3%) patient had a tucatinib-related serious adverse event (overdose). No deaths were attributed to adverse events. All deaths in treated patients were due to disease progression.

INTERPRETATION

Tucatinib plus trastuzumab had clinically meaningful anti-tumour activity and favourable tolerability. This treatment is the first US Food and Drug Administration-approved anti-HER2 regimen for metastatic colorectal cancer and is an important new treatment option for chemotherapy-refractory HER2-positive metastatic colorectal cancer.

FUNDING

Seagen and Merck & Co.

A novel score system based on arginine metabolism-related genes to predict prognosis, characterize immune microenvironment, and forecast response to immunotherapy in IDH-wildtype glioblastoma

Introduction: Glioblastoma is one of the most lethal cancers and leads to more than 200,000 deaths annually. However, despite lots of researchers devoted to exploring novel treatment regime, most of these attempts eventually failed to improve the overall survival of glioblastoma patients in near 20 years. Immunotherapy is an emerging therapy for cancers and have succeeded in many cancers. But most of its application in glioblastoma have been proved with no improvement in overall survival, which may result from the unique immune microenvironment of glioblastoma. Arginine is amino acid and is involved in many physiological processes. Many studies have suggested that arginine and its metabolism can regulate malignancy of multiple cancers and influence the formation of tumor immune microenvironment. However, there is hardly study focusing on the role of arginine metabolism in glioblastoma. Methods: In this research, based on mRNA sequencing data of 560 IDH-wildtype glioblastoma patients from three public cohorts and one our own cohort, we aimed to construct an arginine metabolism-related genes signature (ArMRS) based on four essential arginine metabolism-related genes (ArMGs) that we filtered from all genes with potential relation with arginine metabolism. Subsequently, the glioblastoma patients were classified into ArMRS high-risk and low-risk groups according to calculated optimal cut-off values of ArMRS in these four cohorts. Results: Further validation demonstrated that the ArMRS was an independent prognostic factor and displayed fine efficacy in prediction of glioblastoma patients' prognosis. Moreover, analyses of tumor immune microenvironment revealed that higher ArMRS was correlated with more immune infiltration and relatively "hot" immunological phenotype. We also demonstrated that ArMRS was positively correlated with the expression of multiple immunotherapy targets, including PD1 and B7-H3. Additionally, the glioblastomas in the ArMRS high-risk group would present with more cytotoxic T cells (CTLs) infiltration and better predicted response to immune checkpoint inhibitors (ICIs). Discussion: In conclusion, our study constructed a novel score system based on arginine metabolism, ArMRS, which presented with good efficacy in prognosis prediction and strong potential to predict unique immunological features, resistance to immunotherapy, and guide the application of immunotherapy in IDH-wild type glioblastoma.

Astragaloside IV attenuates lipopolysaccharide induced liver injury by modulating Nrf2-mediated oxidative stress and NLRP3-mediated inflammation

Aims and objectives

Sepsis-associated liver injury is a common public health problem in intensive care units. Astragaloside IV (AS-IV) is an active component extracted from the Chinese herb Astragalus membranaceus, and has been shown to have anti-oxidation, anti-inflammation, and anti-apoptosis properties. The research aimed to investigate the protective effect of AS-IV in lipopolysaccharide (LPS)-induced liver injury.

Methods

Male C57BL/6 wild-type mice (6-8 week-old) were intraperitoneally injected with 10 mg/kg LPS for 24 h and AS-IV (80 mg/kg) 2 h before the LPS injection. Biochemical and histopathological analyses were carried out to assess liver injury. The RT-qPCR analyzed the mRNA expression of IL-1β, TNF-α, and IL-6. The mRNA and protein expression of SIRT1, nuclear Nrf2, Nrf2, and HO-1 were measured by Western blotting.

Results

Serum alanine/aspartate aminotransferases (ALT/AST) analysis, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) were showed that AS-IV protected against LPS-induced hepatotoxicity. The protection afforded by AS-IV was confirmed by pathological examination of the liver. Pro-inflammatory cytokines, including interleukin- 1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6), were observed to be reversed by AS-IV after exposure to LPS. Western blot analysis demonstrated that AS-IV enhanced the expression levels of Sirtuin 1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1).

Conclusions

AS-IV protects against LPS-induced Liver Injury and Inflammation by modulating Nrf2-mediated oxidative stress and NLRP3-mediated inflammation.

HER2 testing in colorectal cancer: Concordance analysis between breast and gastric scoring algorithms from the MOUNTAINEER trial

198

Background: HER2 overexpression/amplification (HER2+) occurs in 3%-5% of patients (pts) w/ metastatic colorectal cancer (mCRC). Rates of HER2+ can increase to ~10% in pts w/ RAS/BRAF wild-type mCRC tumors. The MOUNTAINEER trial (NCT03043313) evaluated the efficacy and safety of the investigational combination of tucatinib with trastuzumab in pts with HER2+ and RAS wild-type mCRC. Established regional guidelines for mCRC recommend HER2 testing and HER2-directed treatment options; however, there is currently no established best practice for HER2 testing and interpretation in mCRC. Here, we present data from a concordance analysis comparing breast and gastric HER2 testing algorithms in the mCRC setting. Methods: The MOUNTAINEER trial enrolled pts w/ HER2+ mCRC identified using ≥1 method: tissue-based local immunohistochemistry (IHC), in situ hybridization (ISH), and/or next-generation sequencing (NGS) testing. Archival or fresh tumor tissue was submitted to a sponsor-designated central laboratory for confirmatory HER2 testing w/ IHC/FISH per the package insert of the FDA approved assay and scored by both the breast and gastric algorithms for HER2 IHC. A positive result per the breast scoring criteria for IHC requires circumferential membrane staining for HER2, while the gastric criteria allows for circumferential, basolateral, or lateral staining patterns. Results: A total of 114 pts were enrolled with HER2+ tumors per ≥1 local testing methods; 69 pts were HER2+ by NGS, 46 by IHC 3+, and 36 by ISH. Of 105 pts who had tissue available for central HER2 testing w/IHC/FISH, 98 had valid HER2 results; 82/98 (83.7%) of pts had tumors centrally confirmed as HER2+ using both the breast and gastric algorithms. Tissue samples from pts in the MOUNTAINEER trial had 100% concordance between breast and gastric algorithms in HER2 status and 99% concordance in HER2 IHC score. Conclusions: Central pathology testing using both the breast and gastric criteria showed high concordance between these two commonly used algorithms. A high central confirmation rate of local HER2+ results was also observed. These data support the use of either the breast or gastric algorithms to identify HER2+ mCRC tumors until an FDA-approved HER2 assay is available for mCRC. Clinical trial information: NCT03043313 . [Table: see text]

Tucatinib vs Placebo, Both in Combination With Trastuzumab and Capecitabine, for Previously Treated ERBB2 (HER2)-Positive Metastatic Breast Cancer in Patients With Brain Metastases: Updated Exploratory Analysis of the HER2CLIMB Randomized Clinical Trial

Importance

It is estimated that up to 50% of patients with ERBB2 (HER2)-positive metastatic breast cancer (MBC) will develop brain metastases (BMs), which is associated with poor prognosis. Previous reports of the HER2CLIMB trial have demonstrated that tucatinib in combination with trastuzumab and capecitabine provides survival and intracranial benefits for patients with ERBB2-positive MBC and BMs.

Objective

To describe overall survival (OS) and intracranial outcomes from tucatinib in combination with trastuzumab and capecitabine in patients with ERBB2-positive MBC and BMs with an additional 15.6 months of follow-up.

Design, Setting, and Participants

HER2CLIMB is an international, multicenter, randomized, double-blind, placebo-controlled clinical trial evaluating tucatinib in combination with trastuzumab and capecitabine. The 612 patients, including those with active or stable BMs, had ERBB2-positive MBC previously treated with trastuzumab, pertuzumab, and trastuzumab emtansine. The study was conducted from February 23, 2016, to May 3, 2019. Data from February 23, 2016, to February 8, 2021, were analyzed.

Interventions

Patients were randomized 2:1 to receive tucatinib (300 mg orally twice daily) or placebo (orally twice daily), both in combination with trastuzumab (6 mg/kg intravenously or subcutaneously every 3 weeks with an initial loading dose of 8 mg/kg) and capecitabine (1000 mg/m2 orally twice daily on days 1-14 of each 3-week cycle).

Main Outcomes and Measures

Evaluations in this exploratory subgroup analysis included OS and intracranial progression-free survival (CNS-PFS) in patients with BMs, confirmed intracranial objective response rate (ORR-IC) and duration of intracranial response (DOR-IC) in patients with measurable intracranial disease at baseline, and new brain lesion-free survival in all patients. Only OS was prespecified before the primary database lock.

Results

At baseline, 291 of 612 patients (47.5%) had BMs. Median age was 52 years (range, 22-75 years), and 289 (99.3%) were women. At median follow-up of 29.6 months (range, 0.1-52.9 months), median OS was 9.1 months longer in the tucatinib-combination group (21.6 months; 95% CI, 18.1-28.5) vs the placebo-combination group (12.5 months; 95% CI, 11.2-16.9). The tucatinib-combination group showed greater clinical benefit in CNS-PFS and ORR-IC compared with the placebo-combination group. The DOR-IC was 8.6 months (95% CI, 5.5-10.3 months) in the tucatinib-combination group and 3.0 months (95% CI, 3.0-10.3 months) in the placebo-combination group. Risk of developing new brain lesions as the site of first progression or death was reduced by 45.1% in the tucatinib-combination group vs the placebo-combination group (hazard ratio, 0.55 [95% CI, 0.36-0.85]).

Conclusions and Relevance

This subgroup analysis found that tucatinib in combination with trastuzumab and capecitabine improved OS while reducing the risk of developing new brain lesions, further supporting the importance of this treatment option for patients with ERBB2-positive MBC, including those with BMs.

Trial Registration

ClinicalTrials.gov Identifier: NCT02614794.

Serine and glycine metabolism-related gene expression signature stratifies immune profiles of brain gliomas, and predicts prognosis and responses to immunotherapy

Glioma is one of the most lethal cancers and causes more than 200,000 deaths every year. Immunotherapy was an inspiring therapy for multiple cancers but failed in glioma treatment. The importance of serine and glycine and their metabolism has been well-recognized in the physiology of immune cells and microenvironment in multiple cancers. However, their correlation with prognosis, immune cells, and immune microenvironment of glioma remains unclear. In this study, we investigated the relationships between the expression pattern of serine and glycine metabolism-related genes (SGMGs) and clinicopathological features, prognosis, and tumor microenvironment in glioma based on comprehensive analyses of multiple public datasets and our cohort. According to the expression of SGMGs, we conducted the consensus clustering analysis to stratify all patients into four clusters with remarkably distinctive clinicopathological features, prognosis, immune cell infiltration, and immune microenvironment. Subsequently, a serine and glycine metabolism-related genes signature (SGMRS) was constructed based on five critical SGMGs in glioma to stratify patients into SGMRS high- and low-risk groups and tested for its prognostic value. Higher SGMRS expressed genes associated with the synthesis of serine and glycine at higher levels and manifested poorer prognosis. Besides, we confirmed that SGMRS was an independent prognostic factor and constructed nomograms with satisfactory prognosis prediction performance based on SGMRS and other factors. Analyzing the relationship between SGMRS and immune landscape, we found that higher SGMRS correlated with 'hotter' immunological phenotype and more immune cell infiltration. Furthermore, the expression levels of multiple immunotherapy-related targets, including PD-1, PD-L1, and B7-H3, were positively correlated with SGMRS, which was validated by the better predicted response to immune checkpoint inhibitors. In conclusion, our study explored the relationships between the expression pattern of SGMGs and tumor features and created novel models to predict the prognosis of glioma patients. The correlation of SGMRS with immune cells and microenvironment in gliomas suggested an essential role of serine and glycine metabolism in reforming immune cells and microenvironment. Finally, the results of our study endorsed the potential application of SGMRS to guide the selection of immunotherapy for gliomas.

The Regulatory Effect of Braided Silk Fiber Skeletons with Differential Porosities on In Vivo Vascular Tissue Regeneration and Long-Term Patency

The development of small-diameter vascular grafts that can meet the long-term patency required for implementation in clinical practice presents a key challenge to the research field. Although techniques such as the braiding of scaffolds can offer a tunable platform for fabricating vascular grafts, the effects of braided silk fiber skeletons on the porosity, remodeling, and patency in vivo have not been thoroughly investigated. Here, we used finite element analysis of simulated deformation and compliance to design vascular grafts comprised of braided silk fiber skeletons with three different degrees of porosity. Following the synthesis of low-, medium-, and high-porosity silk fiber skeletons, we coated them with hemocompatible sulfated silk fibroin sponges and then evaluated the mechanical and biological functions of the resultant silk tubes with different porosities. Our data showed that high-porosity grafts exhibited higher elastic moduli and compliance but lower suture retention strength, which contrasted with low-porosity grafts. Medium-porosity grafts offered a favorable balance of mechanical properties. Short-term in vivo implantation in rats indicated that porosity served as an effective means to regulate blood leakage, cell infiltration, and neointima formation. High-porosity grafts were susceptible to blood leakage, while low-porosity grafts hindered graft cellularization and tended to induce intimal hyperplasia. Medium-porosity grafts closely mimicked the biomechanical behaviors of native blood vessels and facilitated vascular smooth muscle layer regeneration and polarization of infiltrated macrophages to the M2 phenotype. Due to their superior performance and lack of occlusion, the medium-porosity vascular grafts were evaluated in long-term (24-months) in vivo implantation. The medium-porosity grafts regenerated the vascular smooth muscle cell layers and collagen extracellular matrix, which were circumferentially aligned and resembled the native artery. Furthermore, the formed neoarteries pulsed synchronously with the adjacent native artery and demonstrated contractile function. Overall, our study underscores the importance of braided silk fiber skeleton porosity on long-term vascular graft performance and will help to guide the design of next-generation vascular grafts.

Purine metabolism-related gene expression signature predicts survival outcome and indicates immune microenvironment profile of gliomas

Glioma is the most common malignant tumor in the central nervous system. The impact of metabolism on cancer development and the immune microenvironment landscape has recently gained broad attention. Purines are involved in multiple metabolic pathways. It has been proved that purine metabolism could regulate malignant biological behaviors and response to immune checkpoint inhibitors in multiple cancers. However, the relationship of purine metabolism with clinicopathological features and the immune landscape of glioma remains unclear. In this study, we explored the relationships between the expression of purine metabolism-related genes (PuMGs) and tumor features, including prognosis and microenvironment of glioma, based on analyses of 1,523 tumors from 4 public databases and our cohort. Consensus clustering based on 136 PuMGs classified the glioma patients into two clusters with significantly distinguished prognosis and immune microenvironment landscapes. Increased immune infiltration was associated with more aggressive gliomas. The prognostic Purine Metabolism-Related Genes Risk Signature (PuMRS), based on 11 critical PuMGs, stratified the patients into PuMRS low- and high-risk groups in the training set and was validated by validation sets from multiple cohorts. The high-risk group presented with significantly shorter overall survival, and further survival analysis demonstrated that the PuMRS was an independent prognostic factor in glioma. The nomogram combining PuMRS and other clinicopathological factors showed satisfactory accuracy in predicting glioma patients’ prognosis. Furthermore, analyses of the tumor immune microenvironment suggested that higher PuMRS was correlated with increased immune cell infiltration and gene expression signatures of “hotˮ tumors. Gliomas in the PuMRS high-risk group presented a higher expression level of multiple immune checkpoints, including PD-1 and PD-L1, and a better-predicted therapy response to immune checkpoint inhibitors. In conclusion, our study elucidated the relationship between the expression level of PuMGs and the aggressiveness of gliomas. Our study also endorsed the application of PuMRS to construct a new robust model for the prognosis evaluation of glioma patients. The correlations between the profiles of PuMGs expression and tumor immune microenvironment potentially provided guidance for immunotherapy in glioma.

Prognosis prediction and tumor immune microenvironment characterization based on tryptophan metabolism-related genes signature in brain glioma

Glioma is the most common malignant tumor in the central nervous system with no significant therapeutic breakthrough in recent years. Most attempts to apply immunotherapy in glioma have failed. Tryptophan and its metabolism can regulate malignant features of cancers and reshape immune microenvironment of tumors. However, the role of tryptophan metabolism in glioma remains unclear. In current study, we explored the relationships between the expression pattern of tryptophan metabolism-related genes (TrMGs) and tumor characteristics, including prognosis and tumor microenvironment of gliomas through analyzing 1,523 patients' samples from multiple public databases and our own cohort. Based on expression of TrMGs, K-means clustering analysis stratified all glioma patients into two clusters with significantly different TrMG expression patterns, clinicopathological features and immune microenvironment. Furthermore, we constructed a tryptophan metabolism-related genes signature (TrMRS) based on seven essential TrMGs to classify the patients into TrMRS low- and high-risk groups and validated the prognostic value of the TrMRS in multiple cohorts. Higher TrMRS represented for potentially more active tryptophan catabolism, which could subsequently lead to less tryptophan in tumor. The TrMRS high-risk group presented with shorter overall survival, and further analysis confirmed TrMRS as an independent prognostic factor in gliomas. The nomograms uniting TrMRS with other prognostic factors manifested with satisfactory efficacy in predicting the prognosis of glioma patients. Additionally, analyses of tumor immune landscapes demonstrated that higher TrMRS was correlated with more immune cell infiltration and "hot" immunological phenotype. TrMRS was also demonstrated to be positively correlated with the expression of multiple immunotherapy targets, including PD1 and PD-L1. Finally, the TrMRS high-risk group manifested better predicted response to immune checkpoint inhibitors. In conclusion, our study illustrated the relationships between expression pattern of TrMGs and characteristics of gliomas, and presented a novel model based on TrMRS for prognosis prediction in glioma patients. The association between TrMRS and tumor immune microenvironment of gliomas indicated an important role of tryptophan and its metabolism in reshaping immune landscape and the potential ability to guide the application of immunotherapy for gliomas.

Prognostic value of cuproptosis-related genes signature and its impact on the reshaped immune microenvironment of glioma

Glioma is the most prevalent malignancy in the central nervous system. The impact of ion-induced cell death on malignant tumors’ development and immune microenvironment has attracted broad attention in recent years. Cuproptosis is a novel copper-dependent mechanism that could potentially regulate tumor cell death by targeting mitochondria respiration. However, the role of cuproptosis in gliomas remains unclear. In the present study, we investigated the relationships between the expression of cuproptosis-related genes (CRGs) and tumor characteristics, including prognosis and microenvironment of glioma, by analyzing multiple public databases and our cohort. Consensus clustering based on the expression of twelve CRGs stratified the glioma patients into three subgroups with significantly different prognosis and immune microenvironment landscapes. Reduced immune infiltration was associated with the less aggressive CRG cluster. A prognostic CRGs risk signature (CRGRS), based on eight critical CRGs, classified the patients into low- and high-risk groups in the training set and was endorsed by validation sets from multiple cohorts. The high-risk group manifested a shorter overall survival, and further survival analysis demonstrated that the CRGRS was an independent prognostic factor. The nomogram combining CRGRS and other clinicopathological factors exhibited good accuracy in predicting the prognosis of glioma patients. Moreover, analyses of tumor immune microenvironment indicated that higher CRGRS was correlated with increased immune cell infiltration but diminished immune function. Gliomas in the high-risk group exhibited higher expression of multiple immune checkpoints, including PD-1 and PD-L1, and a better predicted therapy response to immune checkpoint inhibitors. In conclusion, our study elucidated the connections between CRGs expression and the aggressiveness of gliomas, and the application of CRGRS derived a new robust model for prognosis evaluation of glioma patients. The correlations between the profiles of CRGs expression and immune tumor microenvironment illuminated prospects and potential indications of immunotherapy for glioma.

Radiomic study on preoperative multi-modal magnetic resonance images identifies IDH-mutant TERT promoter-mutant gliomas

OBJECTIVES

Gliomas with comutations of isocitrate dehydrogenase (IDH) genes and telomerase reverse transcriptase (TERT) gene promoter (IDHmut pTERTmut) show distinct biological features and respond to first-line treatment differently in comparison with other gliomas. This study aimed to characterize the IDHmut pTERTmut gliomas in multimodal MRI using the radiomic method and establish a precise diagnostic model identifying this group of gliomas.

METHODS

A total of 140 patients with untreated primary gliomas were admitted between 2016 and 2020 to West China Hospital as a discovery cohort, including 22 IDHmut pTERTmut patients. Thirty-four additional cases from a different hospital were included in the study as an independent validation cohort. A total of 3654 radiomic features were extracted from the preoperative multimodal MRI images (T1c, FLAIR, and ADC maps) and filtered in a data-driven approach. The discovery cohort was split into training and test sets by a 4:1 ratio. A diagnostic model (multilayer perceptron classifier) for detecting the IDHmut pTERTmut gliomas was trained using an automatic machine-learning algorithm named tree-based pipeline optimization tool (TPOT). The most critical radiomic features in the model were identified and visualized.

RESULTS

The model achieved an area under the receiver-operating curve (AUROC) of 0.971 (95% CI, 0.902-1.000), the sensitivity of 0.833 (95% CI, 0.333-1.000), and the specificity of 0.966 (95% CI, 0.931-1.000) in the test set. The area under the precision-recall curve (AUCPR) was 0.754 (95% CI, 0.572-0.833) and the F1 score was 0.833 (95% CI, 0.500-1.000). In the independent validation set, the model reached 0.952 AUROC, 0.714 sensitivity, 0.963 specificity, 0.841 AUCPR, and 0.769 F1 score. MR radiomic features of the IDHmut pTERTmut gliomas represented homogenous low-complexity texture in three modalities.

CONCLUSIONS

An accurate diagnostic model was constructed for detecting IDHmut pTERTmut gliomas using multimodal radiomic features. The most important features were associated with the homogenous simple texture of IDHmut pTERTmut gliomas in MRI images transformed using Laplacian of Gaussian and wavelet filters.

Prognostic value of lactate metabolism-related gene expression signature in adult primary gliomas and its impact on the tumor immune microenvironment

Glioma is one of the most malignant intracerebral tumors, whose treatment means was limited, and prognosis was unsatisfactory. Lactate metabolism patterns have been shown to be highly heterogenous among different tumors and produce diverse impact on the tumor microenvironment. To understand the characteristics and implications of lactate metabolism gene expression, we developed a lactate metabolism-related gene expression signature of gliomas based on RNA-sequencing data of a total of 965 patient samples from TCGA, CGGA, and our own glioma cohort. Sixty-three lactate metabolism-related genes (LMGs) were differentially expressed between glioma and normal brain tissue, and consensus clustering analysis identified two clusters distinct LMG expression patterns. The consensus clusters differed in prognosis, molecular characteristics and estimated immune microenvironment landscape involving immune checkpoint proteins, T cell dysfunction and exclusion, as well as tumor purity. Univariate Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO) Cox hazard regression was applied in determining of prognosis-related lactate metabolism genes (PRLMGs), on which prognostic lactate metabolism risk score (PLMRS) was constructed. The high PLMRS group was associated with significantly poorer patient outcome. A nomogram containing PLMRS and other independent prognostic variables was established with remarkable predictive performance on patient survival. Exploration on the somatic mutations and copy number variations of the high- and low-PLMRS groups demonstrated their distinct genetic background. Together, our results indicated that the expression signature of LMG was associated with the prognosis of glioma patients and influenced the activity of immune cells in the tumor microenvironment, which may serve as a potential biomarker for predicting response of gliomas to immunotherapy.

Microdermabrasion facilitates direct current stimulation by lowering skin resistance

Background

Transcranial direct current stimulation (tDCS) is reported to induce irritating skin sensations and occasional skin injuries, which limits the applied tDCS dose. Additionally, tDCS hardware safety profile prevents high current delivery when skin resistance is high.

Objective

To test if decreasing skin resistance can enable high-dose tDCS delivery without increasing tDCS-related skin sensations or device hardware limits.

Methods

We compared the effect of microdermabrasion and sonication on 2 mA direct current stimulation (DCS) through forearm skin for 2-3 min on 20 subjects. We also surveyed the subjects using a questionnaire throughout the procedure. We used a linear mixed-effects model for repeated-measures and multiple logistic regression, with adjustments for age, race, gender and visit.

Results

Microdermabrasion, with/out sonication, led to significant decrease in skin resistance (1.6 ± 0.1 kΩ or ∼32% decrease, p < 0.0001). The decrease with sonication alone (0.4 ± 0.1 kΩ or ∼7% decrease, p = 0.0016) was comparable to that of sham (0.3 ± 0.1 kΩ or ∼5% decrease, p = 0.0414). There was no increase in the skin-electrode interface temperature. The perceived DCS-related sensations did not differ across skin preparation procedures (p > 0.16), but microdermabrasion (when not combined with sonication) led to increased perceived sensation (p < 0.01).

Conclusions

Microdermabrasion (with/out sonication) resulted in reduced skin resistance without increase in perceived skin sensations with DCS. Higher current can be delivered with microdermabrasion-pre-treated skin without changing the device hardware while reducing, otherwise higher voltage required to deliver the same amount of current.

Bovine pericardium leaflet damage during transcatheter aortic valve crimping: a study of the mechanisms

Leaflet damage has been documented to occur while deploying a transcatheter aortic valve (TAV) due to mechanical loads during the crimping procedures. In this study, the impact of compressive stress on folded leaflets was measured to investigate the mechanism of traumatic leaflet tissue damage. Numerical simulation of TAV crimping procedure was adapted to calculate stress magnitude and distribution of leaflets. A 20 mm balloon expanding short stent TAV with 0.25 mm thickness leaflets was used in the simulation. Then the calculated stresses were applied on leaflet material (bovine pericardium) samples by loading experiments. Mechanical properties evaluation combined with histological and microscopy observation were used to investigate the tissue damage. The elastic modulus and the tensile strength of the tissue began to decrease significantly at 2 MPa stress and 2.5 MPa stress, respectively. No significant differences were observed at 0-1.5 MPa stress. When the TAV was crimped to 14 Fr and 12 Fr, the 2 MPa greater areas on leaflets increased from 18.17% to 76.96%. 2 MPa compressive stress might be the threshold value for leaflet damage. The TAV crimping size should be paid attention to avoid the compressive stress higher than 2 MPa.

[Analysis of clinical features and poor prognostic factors of acute hematogenous osteomyelitis in children]

Objective: To analyze the clinical characteristics, pathogenic bacteria, complications and risk factors of prognosis of acute hematogenous osteomyelitis in children. Methods: The clinical manifestations, laboratorg tests, etiological charateristics and clinical data of 107 patients with acute hematogenous osteomyelitis admitted to Beijing Children's Hospital from January 2017 to December 2020 were retrospectively analyzed. According to the drug sensitivity results of Staphylococcus aureus, the group was divided into methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) group; according to the presence or absence of complications, the group was divided into the group with and without complications; according to the prognosis of the follow-up children, the group was divided into good prognosis and poor prognosis. The χ² test or Mann-Whitney U test used for comparison between groups, and Logistic regression was used to analyze the risk factors for complications and prognosis. Results: Of the 107 patients, 62 were males and 45 were females. The age of presentation was 5.6 (1.7, 10.0) years, including 5 patients (4.7%) age from >28 days to 3 months, 46 patients (43.0%) age from >3 months to 5 years, 43 patients (40.2%)>5-12 years of age, and 13 patients (12.1%)>12-18 years of age. The first symptoms were acute fever in 35 patients (32.7%), limb pain in 24 patients (22.4%), and fever with limb pain in 23 patients (21.5%). Pathogen culture was positive in 75 patients (70.1%), Streptococcus pyogenes, Salmonella enterica and Escherichia coli in 1 case (1.4%) each, and Staphylococcus aureus in 72 cases (96.0%), among them, 47 cases were MSSA, 22 cases were MRSA, and 3 cases had positive reports of Staphylococcus aureus from other hospitals without drug-sensitive tests. The proportion of infected children living in rural areas and receiving surgical treatment was higher in the MRSA group than in the MSSA group (14 cases (63.6%) vs. 18 cases (38.3%) and 21 cases (95.5%) vs. 33 cases (70.2%), χ²=3.87, 4.23, both P<0.05). Sixty-five children had no complications while 42 children (39.3%) suffered from complications. Common complications consisted of 19 cases (17.8%) of sepsis, 17 cases (15.9%) of septic arthritis, and 12 cases (11.2%) of venous thrombosis. The group with complications showed higher mental changes, decreased appetite and (or) weakness, positive pathogenic cultures, and time from admission to surgery than the group without complications (18 cases (42.9%) vs. 9 cases (13.8%), 20 cases (47.6%) vs. 12 cases (18.5%), 34 cases (81.0%) vs. 41 cases (63.1%), 3.5 (2.0, 6.0) vs. 2.0 (1.0, 4.0) d,χ²=11.38, 10.35, 3.89, Z=2.21, all P<0.05). The poor prognosis group had more comorbidities, combined local complications, and positive aureus than the good prognosis group (10/15 vs. 34.9% (30/86), 7/15 vs. 17.4% (15/86), 14/15 vs. 61.6% (53/86), χ²=5.39, 6.40, 4.42, all P<0.05). Multifactorial Logistic regression analysis showed that acute phase C-reactive protein (CRP) was both an independent risk factor for complications (OR=1.01, 95%CI 1.01-1.02) and an independent risk factor for poor prognosis (OR=1.01, 95%CI 1.00-1.02). Conclusions: The first symptoms of acute hematogenous osteomyelitis are acute fever, limb pain, and fever with limb pain are most common. Staphylococcus aureus is the most common pathogenic organism. Those with loss of appetite and (or) weakness, mental changes, positive pathogenic cultures, and longer time between admission and surgery are prone to complications. Those with complications, combined local complications, and positive for Staphylococcus aureus had a poor prognosis. Elevated CRP is an independent risk factor not only for complications but for poor prognosis as well.

Abstract PD4-04: Updated results of tucatinib vs placebo added to trastuzumab and capecitabine for patients with previously treated HER2-positive metastatic breast cancer with brain metastases (HER2CLIMB)

Background: Tucatinib is an oral tyrosine kinase inhibitor highly specific for HER2 that is approved for use in combination with trastuzumab and capecitabine in adults with advanced or metastatic HER2+ breast cancer, including patients with brain metastases, who have received one or more prior anti-HER2-based regimens in the metastatic setting. In the HER2CLIMB trial, the tucatinib regimen significantly prolonged progression-free survival (PFS) and overall survival (OS) in patients with HER2+ metastatic breast cancer (Murthy, NEJM 2020), including in patients with untreated, treated stable, and treated progressing brain metastases (Lin, J Clin Oncol, 2020). With an additional 15.6 months of follow-up, addition of tucatinib continued to show clinically meaningful prolongation of PFS and OS in the total study population (Curigliano, ASCO Meeting, 2021). We report updated results of exploratory efficacy analyses in patients with brain metastases. Methods: All patients in HER2CLIMB had a baseline brain MRI. Patients with brain metastases were eligible and classified as untreated, treated stable, or treated progressing. Patients were randomized 2:1 to receive tucatinib 300 mg twice daily or placebo, in combination with trastuzumab and capecitabine. Following the primary analysis, the protocol was amended to unblind sites to treatment assignment and allowed crossover from the placebo regimen to the tucatinib regimen. Efficacy analyses in patients with brain metastases at baseline were performed at approximately 2 years from the last patient randomized by applying RECIST 1.1 to the brain based on investigator evaluation. OS and CNS-PFS (progression in the brain or death) were evaluated in all patients with brain metastases. Patients without CNS-PFS events were censored at the last brain MRI. Confirmed intracranial (IC) objective response rate (ORR-IC) was evaluated in patients with measurable IC disease. Results: At a median follow-up of 29.6 months, median OS was 21.6 months vs 12.5 months in all patients with brain metastases (HR: 0.60; 95% CI: 0.44, 0.81), 21.4 months vs 11.8 months in patients with untreated/treated progressing brain metastases (HR: 0.52; 95% CI: 0.36, 0.77), and 21.6 months vs 16.4 months in patients with treated stable brain metastases (HR: 0.70; 95% CI: 0.42, 1.16). Median CNS-PFS was 9.9 months vs 4.2 months in all patients with brain metastases (HR: 0.39; 95% CI: 0.27, 0.56), 9.6 months vs 4.0 months in patients with untreated/treated progressing brain metastases (HR: 0.34; 95% CI: 0.22, 0.54), and 13.9 months vs 5.6 months in patients with treated stable brain metastases (HR: 0.41; 95% CI: 0.19, 0.85). ORR-IC was higher in the tucatinib arm (47.3%; 95% CI: 33.7, 61.2) vs the placebo arm (20.0%; 95% CI: 5.7, 43.7) for patients with brain metastases, and median duration of response (DOR) was 8.6 months (95% CI: 5.5, 10.3) vs 3.0 months (95% CI: 3.0, 10.3). Conclusions: With 15.6 months of additional follow-up, the tucatinib-trastuzumab-capecitabine regimen resulted in a robust and durable prolongation of OS for all patients with HER2+ metastatic breast cancer and brain metastases. Additionally, this benefit was maintained in patients with untreated/treated progressing and treated stable brain metastases. Treatment with tucatinib continued to show clinically meaningful benefit in CNS-PFS consistent with the primary analysis.

Citation Format: Nancy U Lin, Rashmi K Murthy, Vandana Abramson, Carey Anders, Thomas Bachelot, Philippe Bedard, Virginia Borges, David Cameron, David Cameron, Lisa Carey, A Jo Chien, Giuseppe Curigliano, Michael DiGiovanna, Karen Gelmon, Gabriel Hortobagyi, Sara Hurvitz, Ian Krop, Sherene Loi, Sibylle Loibl, Volkmar Mueller, Mafalda Oliveira, Elisavet Paplomata, Mark Pegram, Dennis Slamon, Amelia Zelnak, Jorge Ramos, Wentao Feng, Eric Winer. Updated results of tucatinib vs placebo added to trastuzumab and capecitabine for patients with previously treated HER2-positive metastatic breast cancer with brain metastases (HER2CLIMB) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD4-04.

Exosomes derived from the blood of patients with sepsis regulate apoptosis and aerobic glycolysis in human myocardial cells via the hsa‑miR‑1262/SLC2A1 signaling pathway

Myocardial injury occurs in the majority of patients with sepsis and is associated with early mortality. MicroRNAs (miRs) transported by exosomes have been implicated in numerous diseases, such as tumors, acute myocardial infarction and cardiovascular disease. Human serum albumin (hsa)‑miR‑1262 has been shown to serve a role in sepsis; however, its role in exosomes isolated from patients with sepsis and septic myocardial injury remains unclear. In the present study, serum exosomes were isolated via ultracentrifugation. Solute carrier family 2 member 1 (SLC2A1), an essential mediator in energy metabolism, was silenced and overexpressed in the human myocardial AC16 cell line using lentiviral plasmids containing either SLC2A1‑targeting short interfering RNAs or SLC2A1 cDNA, respectively. Cell apoptosis was analyzed using flow cytometry, and the extracellular acidification rate and oxygen consumption rate of AC16 cells were determined using an XFe24 Extracellular Flux Analyzer. Furthermore, the dual‑luciferase reporter assay was used to evaluate the interaction between hsa‑miR‑1262 and SLC2A1. Finally, reverse transcription‑quantitative PCR and western blotting were used to evaluate gene and protein expression levels, respectively. Exosomes isolated from the blood of patients with sepsis (Sepsis‑exo) markedly reduced aerobic glycolysis activity, but significantly promoted the apoptosis of human AC16 cells in a time‑dependent manner. Moreover, Sepsis‑exo significantly increased hsa‑miR‑1262 expression levels, but significantly decreased SLC2A1 mRNA expression levels in a time‑dependent manner. Bioinformatics analysis indicated that hsa‑miR‑1262 bound to the 3' untranslated region of SLC2A1 to negatively regulate its expression. The silencing of SLC2A1 promoted apoptosis and suppressed glycolysis in AC16 cells, whereas SLC2A1 overexpression resulted in the opposite effects. Therefore, the present study demonstrated that exosomes derived from patients with sepsis may inhibit glycolysis and promote the apoptosis of human myocardial cells through exosomal hsa‑miR‑1262 via its target SLC2A1. These findings highlighted the importance of the hsa‑miR‑1262/SLC2A1 signaling pathway in septic myocardial injury and provided novel insights into therapeutic strategies for septic myocardial depression.

Variations of human cerebral and ocular blood flow during exposure to multi-axial accelerations : A mathematical modeling study

Human hemodynamic responses during exposure to multi-axial acceleration was a relatively new topic in the fields of acceleration physiology. This study aimed to focus on these responses, especially variations of blood perfusion to brain and eyes, through mathematical modeling. A mathematical model was established using lumped parameter methods, containing compartments of four heart chambers, systemic arteries and veins, circulation of typical systemic organs, and some compartments for pulmonary circulation, together with autonomic regulation considered. This model was firstly validated by using experimental data from experiment of posture change and centrifuge tests of +Gz accelerations, and then applied to analyze human hemodynamic responses to typical multi-axial accelerations. Validation results demonstrated the mathematical model could generate reasonable responses of human cardiovascular system during posture change and exposure to +Gz accelerations. Simulation results of hemodynamic responses to multi-axial accelerations depicted Gy induced significant differences of blood flow to the left and right eyes. And some contour maps were generated based on these results, which provided a quick way to estimate blood flow variations in brain and eyes during exposure to different accelerations. Graphical Abstract This study aimed to focus on variations of blood perfusion to brain and eyes during exposure to typical multi-axial accelerations through mathematical modeling. This model was firstly validated by using experimental data from experiment of posture change and centrifuge tests of +Gz accelerations, and then applied to analyze human hemodynamic responses to typical multi-axial accelerations. Simulation results of hemodynamic responses to multi-axial accelerations depicted Gy induced significant differences of blood flow to the left and right eyes. And contour maps that generated based on these results provided a quick way to estimate blood flow variations in brain and eyes during exposure to different accelerations.

Exploring optimal heart team protocol to improve decision-making stability for complex coronary artery disease: a sequential explanatory mixed method study

Background

Although heart team was recommended by guideline for decision-making in patients with complex coronary artery disease (CAD), the decision-making stability was lack of evaluation and optimal protocol remained unknown.

Purpose

We aimed to assess inter-team agreement for revascularization decision-making and related influencing factors, so as to provide recommendations for optimal protocol.

Methods

A sequential, explanatory mixed method study was conducted, including (1) a cross-sectional study retrospectively enrolling patients with complex CAD and four heart teams to assess the inter-team decision-making agreement and (2) a qualitative study that semi-structurally interviewed all heart team members to analyze the potential factors associated with decision-making discrepancy. Primary outcome was kappa value of inter-team decision-making agreement. Inductive thematic analysis was used to generate themes and subthemes attributing to decision-making discrepancy. Integrating qualitative and quantitative data, we explained how each subtheme affected decision-making agreement and provided corresponding recommendations based on these explanations. Finally, we provided a detailed heart team protocol by integrating our recommendations, published experience and guideline. Patient sample size was precalculated and interviewee sample size was identified by theoretical saturation.

Results

A total of 101 patients with complex CAD were randomly enrolled from a consecutive angiography registry. Sixteen specialists were invited and randomly established four heart teams to make decisions for enrolled patients. Inter-team decision-making agreement was moderate (kappa 0.582) (Table 1). Decision-making may be influenced at three themes (specialist quality; team composition; meeting process) and ten subthemes (decision thought; understanding of disease and evidence; understanding of other discipline; personality; learning curve; personnel quality; number of team members; discipline selection; ratio of different disciplines and meeting form). Recommendations at five levels were provided, including (1) specialist selection, (2) specialist training, (3) team composition, (4) team training and (5) meeting process. A detailed implementation protocol to establish and deploy a qualified heart team was generated.

Conclusions

Agreement between heart teams for revascularization decision-making in patients with complex CAD was moderate. Five recommendations to improve heart team modality were provided based on factors associated with decision-making discrepancy. A detailed heart team implementation protocol came into being. Randomized controlled trial was warranted to further confirm the protocol.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): the national key research and development program;Beijing municipal commission of science and technology project Table 1. Inter-team agreement of decision making

Improved robot-assisted laparoscopic telesurgery: feasibility of network converged communication

The converged transmission-assisted network communication architecture used in this study could meet the requirements of telesurgery, and effectively guarantee the security and immediacy of communication. With the security, flexibility, and universality of the network converged transmission, the clinical practical application of telesurgery and telemedicine would step up to a higher level.

Prognostic Significance of Preoperative Albumin to Alkaline Phosphatase Ratio in Patients with Glioblastoma

Objective: To explore the prognostic value of preoperative albumin to alkaline phosphatase ratio (AAPR) in patients with newly-diagnosed glioblastoma (GBM) and its association with clinical characteristics. Patients and methods: A retrospective analysis was carried out on patients with newly diagnosed GBM who had undergone operation at the Department of Neurosurgery at West China Hospital between June 1st 2016 to December 31st 2018. X-tile software was applied to determine the optimal cut-off values for AAPR, neutrophil to lymphocyte ratio (NLR), and albumin. Cox regression analyses were applied to evaluate the prognostic value of AAPR in GBM. PSM analysis was conducted to verify the results. Results: A total of 197 and 154 GBM patients were included in original cohort and PSM cohort respectively. The optimal cut-off value for AAPR, NLR, and albumin were 0.56, 4.55 and 42.2 g/L respectively. High AAPR was only significantly related to longer overall survival (OS) (p=0.010) in original cohort. In PSM cohort, no clinical variable was evidently related to the level of AAPR. AAPR was determined to be an independent prognostic indicator in both original cohort (HR=0.599, 95%CI 0.437-0.822, p=0.001) and PSM cohort (HR=0.649, 95%CI 0.459-0.918, p=0.015). Prognostic models including AAPR had better prognostic accuracy than that including albumin. Conclusion: Preoperative AAPR was determined to be an independent risk factor of prognosis in newly-diagnosed GBM patients, and its prognostic ability was stronger than albumin. And PSM analysis also validated the results.

Preservation of quality of life in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer treated with tucatinib or placebo when added to trastuzumab and capecitabine (HER2CLIMB trial)

AIMS

In HER2CLIMB, tucatinib significantly improved progression-free and overall survival in patients with human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer. We evaluated the impact of tucatinib on health-related quality of life (HR-QoL) in HER2CLIMB.

METHODS

Patients were randomised 2:1 to tucatinib or placebo combined with trastuzumab and capecitabine. Starting with protocol version 7, the EuroQol 5 Dimensions 5 Levels (EQ-5D-5L) questionnaire and EQ visual analogue scale (VAS) were administered at day 1 of cycle 1, every two cycles during cycles 3-9, every three cycles during cycle 12 and thereafter and at each patient's 30-day follow-up visit.

RESULTS

Among 364 patients eligible for HR-QoL assessment, 331 (91%) completed ≥1 assessment. EQ-VAS scores were similar for both arms at baseline and maintained throughout treatment. EQ-5D-5L scores were similar between the treatment arms, stable throughout therapy and worsened after discontinuing treatment. Risk of meaningful deterioration (≥7 points) on EQ-VAS was reduced 19% in the tucatinib vs. placebo arm (hazard ratio [HR]: 0.81; 95% confidence interval [CI]: 0.55, 1.18); the median (95% CI) time to deterioration was not reached in the tucatinib arm and was 5.8 months (4.3, -) in the placebo arm. Among patients with brain metastases (n = 164), risk of meaningful deterioration on EQ-VAS was reduced 49% in the tucatinib arm (HR: 0.51; 95% CI: 0.28, 0.93); the median (95% CI) time to deterioration was not reached in the tucatinib arm and was 5.5 months (4.2, -) in the placebo arm.

CONCLUSIONS

HR-QoL was preserved for patients with HER2+ metastatic breast cancer who were treated with tucatinib added to trastuzumab and capecitabine and maintained longer with tucatinib therapy than without it among those with brain metastases.

CLINICAL TRIAL REGISTRATION

NCT02614794.

Investigation of failure modes of explanted porcine valves in the mitral position

Background

Porcine valves are used for mitral valve replacement, but the limited long-term durability has restricted the application in younger patients. Degenerated porcine mitral valves were explanted to analyze the failure modes and damage characteristics.

Methods

Twelve porcine valves were explanted via secondary mitral valve replacement surgery. Microcomputed tomography scanning, morphological and pathological examinations were performed to classify the cusp tears, calcification, and pannus formation. The causes of valve deterioration were subsequently analyzed.

Results

The mean age at first implantation was 45.42±19.58 years (range, 11–64 years). The mean duration of implantation was 9.39±4.14 years (range, 4.25–18.75 years). The indications for first surgery were rheumatic heart disease in 8 patients (66.67%), infective endocarditis in 2 patients (16.67%), degenerative valvular disease in one patient (8.33%), and congenital heart disease in one patient (8.33%). Type I cusp tears and commissural dehiscence that occurred near the stent post position were found in 6 (50%) and 5 (41.67%) valves, respectively. Calcification was detected in 6 (50%) cases, and pannus was found in most valves (91.67%).

Conclusions

Leaflet damage occurred near the stent posts area was the main failure mode of porcine mitral valves in this study. Patients who undergo the first surgery at younger age, the higher prevalence rate of rheumatic heart disease, the structure of bioprosthetic porcine valve, and left ventricular stresses could be considered as the main factors causing valve deterioration.

Clinical Significance of Preoperative Fibrinogen to Albumin Ratio in Patients with Glioblastoma: A Singe Center Experience

Objective

To explore the prognostic value of preoperative fibrinogen to albumin ratio (FAR) in patients with glioblastoma (GBM) and its association with clinical characteristics.

Patients and Methods

A retrospective analysis was carried out on patients with newly diagnosed GBM who had undergone operation at the Department of Neurosurgery at West China Hospital between June 1st 2015 to June 31st 2018. Receiver operating characteristic (ROC) curves were performed to determine the optimal cut-off values for fibrinogen, albumin, neutrophil to lymphocyte ratio (NLR), and FAR by calculating the maximum Youden index. Kaplan–Meier curves and Cox regression analyses were applied to evaluate the prognostic value of FAR in GBM. Harrell concordance index (C-index) and Akaike information criterion (AIC) were calculated to compare different prognostic models.

Results

A total of 206 GBM patients were included in this research. The optimal cut-off value for fibrinogen, albumin, NLR, and FAR were 2.57, 42.4, 2.28, and 0.068 respectively. High FAR was significantly related to older age, KPS≤80, IDH-1 wildtype, presence of preoperative seizures, higher NLR, and tumor location. In Cox regression analyses, high FAR was significantly associated with poor prognosis. Prognostic models including FAR had the largest C-index and lowest AIC.

Conclusion

FAR was determined to be an independent risk factor of prognosis in patients with newly-diagnosed GBM. And the prognostic predictive ability of FAR is stronger than fibrinogen and albumin.

[Comparison on short-term safety outcomes between off-pump and on-pump coronary artery bypass grafting by experienced surgeons: a single center study with 31 075 cases]

Objective: To compare the short-term outcomes between off-pump and on-pump coronary artery bypass graft (CABG) by experienced surgeons with similar surgical team in a single large-volume cardiac surgery center. Methods: A total of 31 075 patients with multivessel coronary disease who underwent isolated off-pump or on-pump CABG between January 1, 2009 and December 31, 2019 by experienced surgeons in Fuwai hospital were enrolled in this retrospective study. Patients was divided into on-pump CABG group and on-pump CABG group on an intention-to treat basis. Short term safety endpoints, including 30 days mortality, composite endpoint of major morbidity or mortality, prolonged postoperative length of stay (PLOS), and prolonged ICU length of stay (PICULOS), and distal anastomosis were compared between the two groups. Mortality was evaluated on 30 days post operation, other endpoints were collected before discharge. After 1∶1 propensity-score matching of baseline characteristics for on-pump and off-pump CABG, postoperative endpoints were compared with use of McNemar's test and further adjusted with the use of a logistic regression model. Results: After propensity-score matching, 10 243 matched pairs of patients were included in the final analysis, there were 4 605(22.5%) females and mean age was (60.7±8.6) years. The standardized differences were less than 5% for all baseline variables in matched cohort. Univariate analysis indicated lower risk of 30 days mortality (0.2% vs. 0.7%, P<0.001), major morbidity or mortality (5.7% vs. 8.8%, P<0.001), PLOS (3.2% vs. 4.9%, P<0.001), PICULOS (9.4% vs. 12.2, P<0.001), and lower number of distal anastomosis ((3.3±0.8) vs. (3.6±0.8), P<0.001) in off-pump CABG group than in on-pump CABG group. After adjustment of cofounders, multivariate analysis showed that off-pump CABG was still associated with a lower risk of 30 days mortality (OR=0.29, 95%CI: 0.09-0.87, P=0.027), composite endpoint of major morbidity or mortality (OR=0.60, 95%CI: 0.53-0.68, P<0.001), PLOS (OR=0.64, 95%CI 0.54-0.75, P<0.001), PICULOS (OR=0.76, 95%CI: 0.69-0.84, P<0.001). Conclusions: Off-pump CABG is related with superior short-term safety outcomes than on-pump CABG by experienced surgeons in our center.

Abstract PD3-08: Tucatinib vs placebo in combination with trastuzumab and capecitabine for patients with locally advanced unresectable or HER2-positive metastatic breast cancer (HER2CLIMB): Outcomes by hormone receptor status

Background Tucatinib (TUC) is a highly selective oral tyrosine kinase inhibitor of HER2 with minimal inhibition of EGFR. It was recently approved by the FDA for patients (pts) with HER2+ metastatic breast cancer (MBC), including pts with brain metastases (BM) whose cancers have progressed on at least 1 prior anti-HER2 regimen in the metastatic setting. In the HER2CLIMB (NCT02614794) pivotal trial, pts with HER2+ MBC previously treated with trastuzumab (T), pertuzumab, and trastuzumab emtansine (T-DM1) were randomized to receive TUC or placebo in combination with T and capecitabine (C). The addition of TUC resulted in clinically meaningful and statistically significant improvements in overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) in HER2+ MBC pts. Primary methods and outcomes have been reported previously (Murthy, NEJM 2019). Here we present an exploratory analysis describing the outcomes in the HER2CLIMB trial based on hormone receptor (HR) status.

Methods Pts were randomized 2:1 to receive TUC or placebo in combination with T and C. All pts had a baseline brain MRI and randomization was stratified by presence of BM, ECOG status, and geographic region. All pts with HER2+ MBC who were positive for either or both estrogen receptor and progesterone receptor (&gt; 1%) were assigned to the HR “positive” subgroup. Pts not meeting the above criteria were assigned to the HR “negative” subgroup. For the exploratory HR+/HR- efficacy analysis presented here, PFS per RECIST 1.1 by blinded independent central review was evaluated in the first 480 pts enrolled. OS, PFS in pts with baseline BM, and confirmed ORR in pts with measurable disease were evaluated in the total study population. P values presented for PFS are nominal.

Results Overall, 612 pts were enrolled to HER2CLIMB; 370 pts (60%) had HR+ and 242 (40%) had HR- tumors. Baseline demographics and disease characteristics in HR+/HR- subgroups were generally balanced between treatment arms. In the HR+ group, there was a 42% reduction in the risk of progression or death in the TUC arm (hazard ratio: 0.58; 95% CI: 0.42, 0.80; P=0.0008); median (95% CI) PFS was 7.6 mo (7.4, 9.5) in the TUC arm vs 5.6 mo (4.3, 7.4) in the control arm. In the HR- group, there was a 46% reduction in the risk of progression or death in the TUC arm (hazard ratio: 0.54; 95% CI: 0.34, 0.86; P=0.008); median (95% CI) PFS was 8.1 mo (7.0, 11.6) in the TUC arm vs 4.2 mo (3.1, 8.6) in the control arm. In the total population, median OS was 21.7 mo vs 18.2 mo in HR+ in the TUC arm vs control arm, respectively; median OS in HR- was 31.1 mo in the TUC arm vs 14.1 mo in the control arm. In pts with BM in the HR+ group (n=166 [45%]), there was a 52% reduction in the risk of progression or death (hazard ratio: 0.48; 95% CI: 0.31, 0.75; P=0.0008); median (95% CI) PFS was 7.5 mo (5.6, 9.5) in the TUC arm vs 5.1 mo (4.1, 5.7) in the control arm, and median OS was 18.1 mo vs 12.8 mo, respectively. In pts with BM in the HR- group (n=125 [52%]), there was a 50% reduction in the risk of progression or death (hazard ratio: 0.50; 95% CI: 0.27, 0.95; P=0.03); median (95% CI) PFS was 7.8 mo (6.1, 11.6) in the TUC arm vs 5.4 mo (2.9, 8.6) in the control arm, and median OS was 18.5 mo vs 11.5 mo, respectively. In the total population, ORR was numerically higher in the TUC arm vs the control arm regardless of HR status (HR+: 37.4% [95% CI: 30.8, 44.5] vs 27.1% [95% CI: 19.0, 36.6], respectively and HR-: 45.3% [95% CI: 36.7, 54.0] vs 15.6% [95% CI: 7.8, 26.9], respectively).

Conclusions Among pts with HER2+ MBC previously treated with T, pertuzumab, and T-DM1, the addition of TUC to T and C showed clinically meaningful improvements of PFS, OS, and ORR independent of HR status. Furthermore, pts with HR+ and HR- MBC with BM derived similar benefit from the addition of TUC to T and C.

Citation Format: Erika Hamilton, Mattea Reinisch, Sherene Loi, Alicia Okines, Paula R. Pohlmann, Eva Harder Brix, Hugues Bourgeois, Belinda Yeo, Cheryl Aylesworth, Melody Cobleigh, Anthony Goncalves, Rebecca Moroose, Katherine H.R. Tkaczuk, Michaela Tsai, Christine Simmons, Michael Andersson, Hatem Soliman, Michelina Cairo, Lisa A. Carey, David Cameron, Jorge Ramos, Wentao Feng, Mafalda Oliveira. Tucatinib vs placebo in combination with trastuzumab and capecitabine for patients with locally advanced unresectable or HER2-positive metastatic breast cancer (HER2CLIMB): Outcomes by hormone receptor status [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD3-08.

[Design and mechanical properties of biodegradable polymeric stent]

Biodegradable stents (BDSs) are the milestone in percutaneous coronary intervention(PCI). Biodegradable polymeric stents have received widespread attention due to their good biocompatibility, moderate degradation rate and degradation products without toxicity or side effects. However, due to the defects in mechanical properties of polymer materials, the clinical application of polymeric BDS has been affected. In this paper, the BDS geometric configuration design was analyzed to improve the radial strength, flexibility and reduce the shrinkage rate of biodegradable polymeric stents. And from the aspects of numerical simulation, in vitro experiment and animal experiment, the configuration design and mechanical properties of biodegradable polymeric stents were introduced in detail in order to provide further references for the development of biodegradable polymeric stents.

MOUNTAINEER-02: Phase II/III study of tucatinib, trastuzumab, ramucirumab, and paclitaxel in previously treated HER2+ gastric or gastroesophageal junction adenocarcinoma—Trial in Progress

TPS252

Background: Tucatinib (TUC), a highly selective HER2-directed TKI recently approved for HER2+ metastatic breast cancer (MBC), is being developed as a novel therapy for patients (pts) with metastatic colorectal cancer (mCRC) and other GI tumors. While trastuzumab (Tras) with chemotherapy is standard in the 1st-line setting for metastatic HER2+ gastric or gastroesophageal junction adenocarcinoma (GEC), no anti-HER2 therapy has demonstrated an OS benefit over chemotherapy in 2nd-line, possibly due to loss of HER2 expression following Tras-based therapy. In GEC xenograft models, dual targeting of HER2 with TUC and Tras showed superior activity to either agent alone. Interim results from the MOUNTAINEER study have shown promising activity for TUC and Tras in HER2+ mCRC. The MOUNTAINEER-02 study is evaluating the efficacy and safety of TUC in combination with Tras, ramucirumab (Ram), and paclitaxel (Pac) in pts with HER2+ GEC. Methods: MOUNTAINEER-02 (NCT04499924) is a phase 2/3 study evaluating TUC and Tras with the 2nd-line standard of care, Ram and Pac. Pts receive TUC 300 mg or placebo PO BID, Tras (6 then 4 mg/kg) or placebo (IV on Days 1 and 15 of each 28-day cycle), Pac (IV on Days 1, 8, 15), and Ram (IV on Days 1 and 15). Eligible pts have locally-advanced unresectable or metastatic HER2+ GEC, have received a HER2-directed antibody, and 1 prior line of therapy for advanced disease. Pts must be ≥18 years of age, with an ECOG ≤1, and have had no prior exposure to Ram, anti-HER2 or anti-EGFR TKI, HER2-directed antibody-drug conjugates, or taxanes ≤12 months before enrollment. Due to the potential impact of TUC on Pac metabolism, the study will include an initial Pac dose finding stage. The open-label phase 2 part will determine the recommended dose of Pac (60 or 80 mg/m²) combined with TUC, Tras, and Ram in 6-12 patients, and evaluate the safety and activity of the regimen in Cohorts 2A and 2B (30 patients each). The randomized, double-blind, phase 3 part will compare the efficacy and safety of TUC and Tras (Arm 3A; ~235 patients) vs. placebo (Arm 3B; ~235 patients), both in combination with Ram and Pac, and also evaluate activity of TUC with Ram and Pac (Arm 3C; ~30 patients). The dual primary phase 3 endpoints are OS and PFS per investigator, with confirmed ORR as a key secondary endpoint. HER2 status is determined at baseline using a blood-based NGS assay, and IHC/ISH of fresh or archival tumor biopsies, if available. Pts must be HER2+ by blood-based NGS in Cohort 2A and phase 3; in Cohort 2B, pts must be HER2+ in a biopsy taken post-progression during/after 1st-line therapy, but HER2-negative by blood-based NGS. Disease assessments per RECISTv1.1 will occur q6 weeks for 36 weeks, then q9 weeks. The pharmacokinetics of TUC, Pac, and their metabolites will be evaluated in a subset of pts, including a cohort with gastrectomies. Enrollment is ongoing in the U.S. Clinical trial information: NCT04499924.