Understanding Combustion of H2/O2 Gases inside Nanobubbles Generated by Water Electrolysis Using Reactive Molecular Dynamic Simulations

This work explored the mechanism of spontaneous combustion of hydrogen-oxygen mixtures inside nanobubbles (which were generated by water electrolysis) using reactive molecular dynamic simulations based on the first-principles derived reactive force field ReaxFF. The effects of surface-assisted dissociation of H₂ and O₂ gases that produced H and O radicals were examined. Additionally, the ignition outcome and species evolution as a function of the initial system pressure (or bubble size) were studied. A significant amount of hydrogen peroxide (H₂O₂), 6-140 times water (H₂O), was observed in the combustion products. This was attributed to the low-temperature (∼300 K) and high-pressure (2-80 atm) conditions at which the chemical reactions were taking place. In addition, the rate of consumption of H₂ and O₂ molecules was found to increase with an increase in added H and O radical concentrations and initial system pressure. The rate at which heat was being lost from the combustion chamber (nanobubbles) was also compared to the rate at which heat was being released from the chemical reactions. Only a slight rise in the reaction temperature was observed (∼68 K), signifying that, at such small scales, heat losses dominate. The resulting chemistry was quite different from macroscopic combustion, which usually takes place at a much higher temperatures of above 1000 K.

New cytochalasin from Rosellinia sanctae-cruciana, an endophytic fungus of Albizia lebbeck

AIM

To explore the potential of Rosellinia sanctae-cruciana an endophytic fungus associated with Albizia lebbeck for pharmaceutically important cytotoxic compounds.

METHODS AND RESULTS

One novel cytochalasin, named jammosporin A (1) and four known analogues (2-5) were isolated from the culture of the endophytic fungus R. sanctae-cruciana, harboured from the leaves of the medicinal plant A. lebbeck. Their structures were elucidated by extensive spectroscopic analyses including one-dimensional and two-dimensional nuclear magnetic resonance data along with MS data and by comparison with literature reports. In preliminary screening the ethyl acetate extract of the fungal culture was tested for cytotoxic activity against a panel of four cancer cell lines (MOLT-4, A549, MIA PaCa-2 and MDA-MB-231), and found to be active against MOLT-4 with an IC₅₀ value of 10 μg ml^-1 . Owing to the remarkable cytotoxic activity of the extract the isolated compounds (1-5) were evaluated for their cytototoxicity against the MOLT-4 cell line by MTT assay. Interestingly, compounds 1-2, 4 and 5 showed considerable cytotoxic potential against the human leukaemia cancer cell line (MOLT-4) with IC₅₀ values of 20·0, 10·0, 8·0 and 6·0 μmol l^-1 , respectively, while compound 3 showed an IC₅₀ value of 25 μmol l^-1 . This is the first report of the existence of this class of secondary metabolites in R. sanctae-cruciana fungus.

CONCLUSION

This study discovered a novel compound, named jammosporin A, isolated for the first time from R. sanctae-cruciana, an endophytic fungus of A. lebbeck with anticancer activity against the MOLT-4 cell line.

SIGNIFICANCE AND IMPACT OF THE STUDY

Rosellinia sanctae-cruciana represents an interesting source of a new compound with bioactive potential as a therapeutic agent against a human leukaemia cancer cell line (MOLT-4).

Do law enforcement interactions reduce the initiation of injection drug use? An investigation in three North American settings

BACKGROUND

The prevention of drug injecting is often cited as a justification for the deployment of law enforcement and for the continuation of drug criminalization policies. We sought to characterize the impact of law enforcement interactions on the risk that people who inject drugs (PWID) report assisting others with injection initiation in three North American countries.

METHODS

Cross-sectional data from PWID participating in cohort studies in three cities (San Diego, USA; Tijuana, Mexico; Vancouver, Canada) were pooled (August 2014-December 2016). The dependent variable was defined as recently (i.e., past six months) providing injection initiation assistance; the primary independent variable was the frequency of recent law enforcement interactions, defined categorically (0 vs. 1 vs. 2-5 vs. ≥6). We employed multivariable logistic regression analyses to assess this relationship while controlling for potential confounders.

RESULTS

Among 2122 participants, 87 (4.1%) reported recently providing injection initiation assistance, and 802 (37.8%) reported recent law enforcement interactions. Reporting either one or more than five recent interactions with law enforcement was not significantly associated with injection initiation assistance. Reporting 2-5 law enforcement interactions was associated with initiation assistance (Adjusted Odds Ratio=1.74, 95% Confidence Interval: 1.01-3.02).

CONCLUSIONS

Reporting interactions with law enforcement was not associated with a reduced likelihood that PWID reported initiating others into injection drug use. Instead, we identified a positive association between reporting law enforcement interactions and injection initiation assistance among PWID in multiple settings. These findings raise concerns regarding the effectiveness of drug law enforcement to deter injection drug use initiation.

UK Consensus on Normal Tissue Dose Constraints for Stereotactic Radiotherapy

Six UK studies investigating stereotactic ablative radiotherapy (SABR) are currently open. Many of these involve the treatment of oligometastatic disease at different locations in the body. Members of all the trial management groups collaborated to generate a consensus document on appropriate organ at risk dose constraints. Values from existing but older reviews were updated using data from current studies. It is hoped that this unified approach will facilitate standardised implementation of SABR across the UK and will allow meaningful toxicity comparisons between SABR studies and internationally.

Accuracy of New Ballard Score in Small-for-gestational Age Neonates

OBJECTIVE

The aim of this study was to evaluate the performance of New Ballard Score (NBS) in small-for-gestational age (SGA) neonates.

METHODOLOGY

Neonates born at 35-40 weeks of gestation were included if accurate obstetric gestation estimate was available and birth weight was <10th percentile for gestation. Gestation-matched appropriate-for-gestational-age neonates were enrolled as controls. Gestation derived from NBS was compared with gestation calculated from last menstrual period.

RESULTS

Gestational age estimated by NBS was significantly higher in SGA neonates (mean difference: 0.7 weeks). Neuromuscular component score was similar but physical component score was significantly higher in SGA neonates. Reanalysis after reducing score of 4 to 3 of SGA babies for skin and plantar crease physical parameters showed overestimation of gestational age decreased to 0.4 weeks.

CONCLUSIONS

The physical parameters of NBS overestimate gestation in SGA neonates. Changing scores of skin and plantar creases in SGA neonates better estimates gestation age.

A pilot study of cabergoline for the treatment of metastatic breast cancer

PURPOSE

The prolactin (PRL) receptor is over-expressed in breast cancer, and pre-clinical data indicate that it contributes to breast oncogenesis. Cabergoline is a potent dopamine receptor agonist of D2 receptors and has a direct inhibitory effect on pituitary PRL secretion.

METHODS

A phase II study of cabergoline in patients with metastatic breast cancer was conducted. The primary end point of the study was to determine the clinical benefit rate (CBR) at 2 months. Eligible patients had tumors of any receptor status with no limit of prior lines of therapy. Measurable and unmeasurable diseases were allowed. Cabergoline 1 mg orally, twice weekly (1 cycle = 4 weeks) was given until disease progression or unacceptable toxicity. PRL receptor immunohistochemical staining was performed on available baseline tumor tissue; serial serum PRL levels were assessed.

RESULTS

Twenty women were enrolled; 18 were evaluable for CBR. Tumor receptor status was distributed as follows: HR-any/HER2+ 2(10%), HR+/HER2- 18 (90%). The CBR was 33% (6/18), median progression free survival was 1.8 months, and median overall survival was 10.4 months. Two patients experienced disease control for over 12 months. Most common treatment-related adverse events were nausea (30%), fatigue (25%), and elevation in alkaline phosphatase (15%). Nine patients had baseline tissue for analysis; there was no association between baseline tumor PRL receptor expression and clinical benefit (p = 0.24). Change in serum PRL level and response were not correlated after 2 months of treatment (p = 0.64).

CONCLUSION

Cabergoline was well tolerated, and while the ORR was low, a small subset of patients experienced extended disease control.

Macronutrients in Breastmilk of Mothers of Preterm Infants

OBJECTIVE

To evaluate the variability in macronutrient and energy content of breastmilk of Indian women delivering at ≤34 weeks of gestation.

METHODS

In this cross-sectional study, samples of breastmilk expressed manually for feeding of preterm neonates were collected from 106 mothers at 3±1 (n=26), 7±2 (n=34), 14±2 (n=24), 21±3 (n=12) and 28±3 (n=10) days after birth. Protein, fat and carbohydrate content were estimated and total energy content was calculated.

RESULTS

Protein content in the human milk declined from 4.1±2.1 g/dL on the 3rd postpartum day to 2.2±0.6 g/dL by the 28th day postpartum. Lactose (from 2.2±0.7 g/dL to 3.0±0.9 g/dL), fat (1.9±1.8 g/dL to 3.4±2.1 g/dL) and energy (42.3±18.8 Kcal/dL to 51.9±21.5 Kcal/dL) contents increased from day 3 to day 28.

CONCLUSION

Preterm human milk has high temporal and inter-individual variation in the macronutrient composition and without fortification is unlikely to meet the nutritional requirement of preterm neonates.

Vortex dynamics and frequency splitting in vertically coupled nanomagnets

We explored the dynamic response of a vortex core in a circular nanomagnet by manipulating its dipole-dipole interaction with another vortex core confined locally on top of the nanomagnet. A clear frequency splitting is observed corresponding to the gyrofrequencies of the two vortex cores. The peak positions of the two resonance frequencies can be engineered by controlling the magnitude and direction of the external magnetic field. Both experimental and micromagnetic simulations show that the frequency spectra for the combined system is significantly dependent on the chirality of the circular nanomagnet and is asymmetric with respect to the external bias field. We attribute this result to the strong dynamic dipole-dipole interaction between the two vortex cores, which varies with the distance between them. The possibility of having multiple states in a single nanomagnet with vertical coupling could be of interest for magnetoresistive memories.

Role of nebivolol in the control and management of central aortic blood pressure in hypertensive patients

Measurement of blood pressure (BP) using a brachial cuff sphygmomanometer is universally accepted for the diagnosis of hypertension and prediction of cardiovascular diseases. However, brachial systolic BP does not represent actual systolic BP in the central arteries which encounter cardiac load directly. Due to wave amplification from central to peripheral arteries, a significant difference exists between the two. Central BP measurements also account for arterial stiffness, vessel branching and vascular mechanics, unlike brachial BP. Emerging data suggests that hypertension can be diagnosed more accurately by central pressure indices as compared to brachial BP. Various non-invasive techniques are now available to measure central BP indices owing to recent technological advances. Recently, it has been reported that different classes of anti-hypertensive drugs display differential effects on brachial and central BPs. Nebivolol is a cardio-selective beta-blocker which targets central systolic BP and reduces it significantly along with brachial BP. In this article, we will review the current literature to evaluate the role of central BP to diagnose hypertension in detail. We will also assess the clinical evidence to evaluate the role of nebivolol in the management of elevated central systolic BP. Central BP indices offer better estimation of BP in central arteries and should be considered in routine clinical practice. Nebivolol has shown significant reduction in aortic pressure and wave reflection and improvements in endothelial dysfunction and arterial stiffness in hypertensive patients.

Pharmacogenetic Association Between Glutamatergic Genes and Sri Treatment Response in Obsessive Compulsive Disorder

Introduction

Pharmacogenetic studies in obsessive-compulsive disorder (OCD) primarily focussing on serotonergic and dopaminergic polymorphisms, provided inconsistent findings. There is recent evidence for glutamatergic abnormalities in OCD.

Aims

Examine the association glutamatergic genes with serotonin reuptake inhibitor (SRI) response in OCD.

Objectives

To study pharmacogenetic association between SLC1A1 and GRIN2B polymorphisms with SRI response in OCD.

Methods

DSM-IV OCD patients were recruited from a specialty OCD clinic and evaluated using the Yale-Brown obsessive compulsive scale (YBOCS), Mini International Neuropsychiatric Interview (MINI) plus, Clinical Global Impression scale (CGI). They were subsequently reassessed with YBOCS and CGI. To study extreme phenotypes, we included only full responders (> 35% YBOCS improvement and CGI-I score of 1 or 2) to any SRI (n = 191) and non-responders (< 25% YBOCS improvement and CGI-I score ≥ 4) to adequate trial of at least two SRIs (n = 84). Partial responders were excluded. Genotyping was performed using an ABI9700 PCR machine.

Results

Genotype frequencies did not deviate significantly from the values predicted by the Hardy-Weinberg equation. Case-control association analyses revealed no significant association between genotype/allele frequencies with SRI response.

Conclusion

Our data does not show any association between polymorphisms in glutamatergic genes and SRI response in OCD though such associations have been found in other studies. More SNP's in the same gene could be responsible for the pharmacogenetic associations. More homogenous sample considering symptom dimensions and other phenotypic variables may be needed. It may be critical to go beyond “usual suspect” candidate gene research. In this regard, a novel approach to identify SRI response biomarkers is the use of cellular models.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Identification and Characterization of microRNAs Associated With Human β-Cell Loss in a Mouse Model

Currently there is no effective approach for monitoring early β-cell loss during islet graft rejection following human islet transplantation (HIT). Due to ethical and technical constraints, it is difficult to directly study biomarkers of islet destruction in humans. Here, we established a humanized mouse model with induced human β-cell death using adoptive lymphocyte transfer (ALT). Human islet grafts of ALT-treated mice had perigraft lymphocyte infiltration, fewer insulin⁺ β cells, and increased β-cell apoptosis. Islet-specific miR-375 was used to validate our model, and expression of miR-375 was significantly decreased in the grafts and increased in the circulation of ALT-treated mice before hyperglycemia. A NanoString expression assay was further used to profile 800 human miRNAs in the human islet grafts, and the results were validated using quantitative real-time polymerase chain reaction. We found that miR-4454 and miR-199a-5p were decreased in the human islet grafts following ALT and increased in the circulation prior to hyperglycemia. These data demonstrate that our in vivo model of induced human β-cell destruction is a robust method for identifying and characterizing circulating biomarkers, and suggest that miR-4454 and miR-199a-5p can serve as novel biomarkers associated with early human β-cell loss following HIT.

Protective effects of nebivolol from oxidative stress to prevent hypertension-related target organ damage

Hypertension is one of the leading risk factors for morbidity and mortality in patients with cardiovascular and cerebrovascular diseases and renal impairment. It also leads to target organ damage (TOD), which worsens organ function and the patient's clinical status. Reactive oxygen species (ROS)-mediated oxidative stress may contribute significantly to TOD in patients with hypertension. NO (nitric oxide) is a paracrine factor derived from endothelial cells that has been shown to alleviate ROS-mediated oxidative damage. Nebivolol is a third-generation β-blocker with vasodilator activity, both actions contributing to decreased blood pressure in hypertensive patients. Its vasodilatory function is mediated by the endothelial l-arginine NO pathway. Nebivolol increases the bioavailability of NO in the vasculature. Its efficacy and safety profile is comparable to other commonly used antihypertensive agents. In this article, we review the current literature to understand TOD secondary to oxidative stress in patients with hypertension and the role of nebivolol in its prevention. A better understanding of the underlying mechanisms by which nebivolol reduces ROS-mediated TOD will not only help in the development of targeted therapies but may also improve health outcomes in hypertensive patients.

Kidney Exchange to Overcome Financial Barriers to Kidney Transplantation

Organ shortage is the major limitation to kidney transplantation in the developed world. Conversely, millions of patients in the developing world with end-stage renal disease die because they cannot afford renal replacement therapy-even when willing living kidney donors exist. This juxtaposition between countries with funds but no available kidneys and those with available kidneys but no funds prompts us to propose an exchange program using each nation's unique assets. Our proposal leverages the cost savings achieved through earlier transplantation over dialysis to fund the cost of kidney exchange between developed-world patient-donor pairs with immunological barriers and developing-world patient-donor pairs with financial barriers. By making developed-world health care available to impoverished patients in the developing world, we replace unethical transplant tourism with global kidney exchange-a modality equally benefitting rich and poor. We report the 1-year experience of an initial Filipino pair, whose recipient was transplanted in the United states with an American donor's kidney at no cost to him. The Filipino donor donated to an American in the United States through a kidney exchange chain. Follow-up care and medications in the Philippines were supported by funds from the United States. We show that the logistical obstacles in this approach, although considerable, are surmountable.

Abstract PD1-02: Circulating tumor DNA (ctDNA): A real-time application of precision medicine to the management of metastatic breast cancer (MBC)

Background: Molecular diagnostic, in particular next-generation sequencing (NGS) technologies, improved the detection of actionable mutations (muts) in MBC at baseline and recurrence. We evaluated the ability of ctDNA to detect molecular abnormalities, monitor disease progression and predict outcome.

Methods: We conducted a retrospective study of 91 patients (pts) with locally advanced and MBC, who had longitudinal assessment of their disease by ctDNA analysis. The plasma-based assay was performed utilizing Guardant360 (Guardant Health, CA), a digital NGS technology to sequence a panel of &gt; 50 cancer genes. After tabulating number of muts and quantification of overall ctDNA detected for every patient at baseline, a receiver operating characteristic (ROC) analysis was performed to identify the best cut-offs that separated the pts who had a disease progression from those who hadn't, and the patients who died from those still alive. The overall survival (OS) analysis has been performed using Kaplan-Meier curves.

Results: 84 pts (92%) had stage IV cancer. 63% cases were ER+, 27% HER2+, 29% TNBC. 277 blood samples were collected and 84% had muts. 65% of the pts had serial samples. The average number of alterations detected in each sample was 3 (0-27) and the average ctDNA fraction detected was 4.5% (0-88.2%). The most common alterations were: TP53 (52%), PIK3CA (40%), ERBB2 (20%), NOTCH1 (15.5%), APC (14%), MET (13%). 16 pts (19%) were initiated on a targeted therapy based on ctDNA test results. At the time of analysis 36 pts (39.6%) were dead, 55 (60.4%) were currently alive. PFS was 5.2 months (ms) and OS was 21.5 ms. A statistically significant difference in PFS and OS by log rank test was found between % ctDNA at baseline &lt; 0.5 versus ≥ 0.5 (p = 0.003 and p = 0.012, respectively) and number of muts at baseline &lt; 2 versus ≥ 2 (p = 0.059 borderline and p = 0.0015). Moreover, a statistically significant association by Fisher's exact test was found between the number of alterations and the % ctDNA detected in the baseline sample (% of pts with muts ≥ 2 was 19% when % ctDNA &lt; 0.5%, versus 85% when % ctDNA ≥ 0.5%; p &lt; 0.0001).

PFS (ms) p = 0.059 (log rank test)Muts &lt; 2 (n = 32)Muts ≥ 2 (n = 58)658%40%1230%13%1821%6%24--PFS(ms) p = 0.003 (log rank test)% ctDNA &lt; 0.5(n = 27)% ctDNA ≥ 0.5(n = 60)665%39%1241%10%1823%6%24--

OS(ms) p = 0.002 (log rank test)Muts &lt; 2(n = 32)Muts ≥ 2(n = 57)697%66%1288%51%1888%42%24-29%OS(ms) p = 0.012 (log rank test)% ctDNA &lt; 0.5(n = 27)% ctDNA ≥ 0.5(n = 59)696%69%1290%55%1885%48%24-35%

Conclusions: ctDNA liquid biopsy provides a real-time, quantitative NGS-based assessment of MBC which is useful for treatment planning, disease monitoring and prognostic evaluation. Future prospective studies should consider the use of ctDNA for molecular and prognostic stratification.

Citation Format: Rossi G, Austin LK, Nagy RJ, Rademaker AW, Gradishar WJ, Santa-Maria CA, Curry-Edwards RL, Jain S, Flaum LE, Lima Barros Costa R, Zagonel V, Platanias LC, Giles FJ, Talasaz A, Cristofanilli M. Circulating tumor DNA (ctDNA): A real-time application of precision medicine to the management of metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD1-02.

Abstract P1-05-06: Estrogen receptor 1 (ESR1) mutations in circulating tumor DNA (ctDNA): A guide to the management of advanced breast cancer (ABC)

Background: Estrogen receptor (ER)-α is expressed in about 70% of breast cancers and drugs that target the receptor function, selective estrogen receptor modulators (SERM) and aromatase inhibitors (AIs) represent the standard of care for patients (pts) with ER+ breast cancer. Nevertheless, prolonged exposure to endocrine therapy may result in acquired resistance and subsequent progression of disease. Recent evidence showed that activating mutations (muts) in the ligand-binding domain of ER-α occur in approximately 20% of pts exposed to endocrine therapies and those genomic abnormalities may represent the driver of endocrine resistance. In this context, ctDNA provides a non-invasive source for real-time next generation sequencing (NGS) studies, in order to understand the biology of ABC and guide and monitor treatment.

Methods: We conducted a retrospective review of 91 pts with ABC, including 57 pts with ER+ tumor, who had longitudinal assessment of their disease by ctDNA analysis. At the time of baseline sampling, 50/57 pts had stage IV cancer. The total number of blood samples collected was 184. 38 (67%) pts had serial samples. The average number of samples for each pt was 3 (range 1-7). The plasma-based assay was performed utilizing Guardant360 (Guardant Health, CA), a digital NGS technology to sequence a panel of &gt; 50 cancer genes.

Results: Among the ER+ subgroup (57 pts), we identified 11 pts (19%) harboring ESR1 muts in ctDNA. All 11 pts had metastatic disease: 2 (18%) had bone metastases, 2 (18%) had visceral metastases, 7 (64%) had both sites of disease. The median age was 55 years (range 33-73). 5 pts had inflammatory breast cancer. The most common ESR1 muts were: Y537S (6/11, 55%), D538G (4/11, 36%) and Y537N (3/11, 27%). 7 pts carried polyclonal muts. At the time of testing, 10 pts had already failed at least 1 line of endocrine therapy (average 2, range 1-5), including 6 pts that had received a fulvestrant-containing regimen, 8 pts ≥ 1 line of AIs. After the mut detection, 5 pt were on endocrine therapy and 4 pts were started on/continued chemotherapy. ESR1 muts disappeared in 2 pts (fulvestrant-palbociclib and chemotherapy respectively) who achieved stable disease as best response. Three pts continued to harbour muts and then progressed (one died). 2 pts had tissue NGS and ESR1 mut was not identified. Progression free survival and overall survival were 8 months (ms) and 21.5 ms in ESR1+ subpopulation versus 6.2 ms and 22.2 ms in the ESR1- pts (p = 0.78 and p = 0.97, respectively). At the time of analysis 5 pts were dead, 6 were currently alive.

  ESR1+ (n. pts) ESR1- (n. pts) Pts (total n.)1146 Previous chemotherapies11 (100%)31 (67%) Previous fulvestrant-containing regimens6 (54%)20 (43%) Previous AIs ± targeted therapy8 (73%)27 (59%)

Conclusions: We observed that ESR1 muts, a known driver of endocrine resistance, occurs at a high frequency in heavily pre-treated estrogen receptor positive ABC. Blood-based diagnostics can be used to identify ESR1 muts sometimes not detected by tissue-based sequencing of the metastatic lesions indicating tumor heterogeneity and allowing dynamic monitoring of ABC.

Citation Format: Rossi G, Lima Barros Costa R, Nagy RJ, Rademaker AW, Gradishar WJ, Santa-Maria CA, Curry-Edwards RL, Jain S, Flaum LE, Zagonel V, Platanias LC, Giles FJ, Talasaz A, Cristofanilli M. Estrogen receptor 1 (ESR1) mutations in circulating tumor DNA (ctDNA): A guide to the management of advanced breast cancer (ABC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-05-06.

Abstract OT2-01-19: A randomized phase II trial of fulvestrant with or without ribociclib after progression on aromatase inhibition plus cyclin-dependent kinase 4/6 inhibition in patients with unresectable or metastatic hormone receptor positive, HER2 negative breast cancer

Background

Cyclin dependent kinase 4 and 6 inhibitors (CDK4/6i), including palbociclib and ribociclib (R), have demonstrated remarkable benefit in progression free survival (PFS) in patients (pts) with hormone receptor positive (HR+), HER2- metastatic breast cancer (MBC) when combined with anti-estrogen therapy. Switching between anti-estrogen therapies at disease progression is standard of care in the treatment of HR+ MBC. We evaluate the strategy of switching anti-estrogen therapy to fulvestrant (F) and maintaining CDK4/6 inhibition with R in pts with HR+, HER2- MBC who have progressed on an aromatase inhibitor (AI) + CDK4/6i.

Trial Design

Phase II, multi-center, randomized, double-blind, placebo-controlled trial to evaluate F +/- R in pts with HR+, HER2- MBC who have previously progressed on any AI + CDK4/6i. Pts can be screened and registered at two different time points:

Scenario 1: Before receiving any CDK4/6i

Scenario 2: At the time of progression of disease (POD) while being treated with an AI + CDK4/6i

In scenario 1, the study will provide pts with letrozole + R, but pts will not be randomized until they demonstrate POD. At randomization, pts will be assigned 1:1 to either a) F + R or b) F + placebo, with treatment given in 4-week cycles. F will be given as a 500 mg dose intramuscularly every 2 weeks for 3 times and then every 4 weeks, as per standard of care. R or placebo will be given orally at 600 mg daily, 3 weeks on/1 week off. CT scans and bone scan are to be performed prior to every third cycle. Serum and whole blood samples and optional tissue biopsies for biomarker assessment will be performed prior to study treatment (scenario 1), prior to randomization to R +/- F, and when the patient goes off study.

Main Eligibility Criteria:

1. Age ≥ 18 years with unresectable or metastatic BC

2. Estrogen and/or progesterone receptor positive, HER2 negative, as per ASCO-CAP

3. Postmenopausal status or receiving ovarian suppression

4. Measurable or unmeasurable disease; stable CNS disease allowed

5. No clinically significant cardiac disease

6. No concomitant CYP3A4/5 inducer or inhibitor

Specific Aims

Primary: Progression free survival (PFS), defined as the time from randomization to POD or death.

Secondary: Objective response rate (ORR), clinical benefit rate (CBR = ORR + stable disease rate), overall survival (OS), and duration of response. Pts in scenario 1 will also be assessed for PFS, OS, CBR, and safety while receiving AI + R (pre-randomization).

Biomarker assessment will include amplification of cyclin D1 and cyclin E, phosphoRb and TK1 expression, Rb1 and p16 loss, and ctDNA for ESR1 and PIK3CA mutations.

Target Accrual

132 pts accrued from 11 academic medical centers in the U.S, with a goal of completing accrual in two years (∼60 to 72 pts in each scenario).

Statistical Methods

Assuming a median PFS of 3.8 months with F alone, we predict that F + R will lead to a median PFS of at least 6.5 months. A one-sided log-rank test with a sample size of N=120 and alpha=0.025, achieves 80% power to detect a difference in PFS of 2.7 months. N=132 pts allows for a 10% drop-out rate.

Citation Format: Mundi PS, Codruta C, Accordino MK, Sparano J, Andreopoulou E, Vadhat LT, Tiersten A, Esteva F, O'Regan R, Jain S, Mayer I, Forero A, Crew KD, Hershman DL, Kalinsky KM. A randomized phase II trial of fulvestrant with or without ribociclib after progression on aromatase inhibition plus cyclin-dependent kinase 4/6 inhibition in patients with unresectable or metastatic hormone receptor positive, HER2 negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-19.

Abstract OT3-01-01: A phase II study of PD-L1 and CTLA-4 inhibition and immunopharmcogenomics in metastatic breast cancer

Background

A hallmark of cancer is its ability to evade the immune system, however, it can be harnessed to detect and destroy cancer cells through inhibition of immune checkpoints such as CTLA-4 and PD-L1. This strategy has complementary and non-redundant mechanisms resulting in immune activation and antitumor synergy; progression free survival benefit has already been demonstrated in melanoma. A critical barrier in developing immunotherapies, however, is the identification of predictive biomarkers of response to therapy. Immunopharmacogenomic biomarkers, such as mutational burden, neoantigen profiles, and T cell receptor sequencing will elucidate the molecular interface between cancer and immune system, and may predict those most likely to benefit.

Methods

A single arm Phase II study was designed to determine the efficacy of PD-L1 and CTLA-4 inhibition and effects on immunopharmacogenomic dynamics in patients with metastatic breast cancer. The primary endpoint of this proposal is to investigate the response rate of the PD-L1 inhibitor, durvalumab, and the CTLA-4 inhibitor, tremelimumab, in metastatic breast cancer; secondary endpoints will examine the T cell receptor repertoire clonality, tumor mutational burden and neoantigen profiles. A total of 30 patients will be enrolled and treated with durvalumab 1500mg IV and tremelimumab 75mg IV monthly for 4 doses, then durvalumab 750mg every 2 weeks for 18 doses to complete 1 year of therapy with the option to renew therapy for an additional year; biopsies and blood at baseline and 2 months will be collected to assess immunopharmacogenomic biomarkers. Patients are eligible if they have triple negative or ER-positive breast cancer and have progressed on at least one line of chemotherapy and standard endocrine therapy if applicable. This is the first study to investigate immunopharmacogenomic biomarkers of response to dual checkpoint blockade in patients with metastatic breast cancer.

Citation Format: Santa-Maria CA, Jain S, Flaum L, Park J-H, Kato T, Gross L, Uthe R, Tellez C, Stein R, Rademaker A, Gradishar WJ, Nakamura Y, Giles FJ, Cristofanilli M. A phase II study of PD-L1 and CTLA-4 inhibition and immunopharmcogenomics in metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT3-01-01.

Aortic and pulmonary artery calcification: An unusual manifestation of twin-to-twin transfusion syndrome

Twin-to-twin transfusion syndrome (TTTS) at times complicates monochorionic twin gestations, resulting in conditions ranging from discordant sizes to fetal demise of one baby. Various types of cardiac defects have been described in the recipient twin of this syndrome. Isolated great artery calcification, i.e. aortic and pulmonary artery calcification is one such uncommon condition associated with TTTS. Calcification of the walls of great vessels may be due to chronic vascular injury sustained as a result of circulatory volume overload in the recipient twin. It may also cause severe systemic hypertension and cardiomyopathy. An accurate diagnosis is important for an optimal follow-up and appropriate genetic counseling. We report a case of aortic and pulmonary artery calcification in association with TTTS.