Incidence, clinicopathological features, and clinical outcomes of low HER2 expressed, inoperable, advanced, or recurrent gastric/gastroesophageal junction adenocarcinoma

BACKGROUND

According to the DESTINY-Breast04 trial, treating patients with breast cancer and low human epidermal growth factor receptor 2 expressions (HER2-low) varies from that of those with no HER2 expression. However, it is interesting to know if HER2-low indicates for anti-HER2 therapy in the gastric or gastroesophageal junction (G/GEJ) adenocarcinoma. Hence we conducted this study to assess the incidence, clinicopathological features, and treatment outcomes of patients with HER2-low G/GEJ adenocarcinoma.

PATIENTS AND METHODS

This was a single-center, retrospective observational study. Patients with previously untreated G/GEJ adenocarcinoma were classified based on their HER2 status using immunohistochemistry (IHC) with or without in situ hybridization (ISH) as follows: HER2 negative (IHC 0), HER2-low (IHC 1+ or 2+/ISH-), and HER2-positive (IHC2+/ISH+ or 3+).

RESULTS

In total, 734 patients with G/GEJ adenocarcinoma were divided into three groups (HER2-negative, n = 410; HER2-low, n = 154, and HER2-positive, n = 170). The intestinal-type histology, peritoneal metastasis, and higher serum carcinoembryonic antigen (CEA) levels differed significantly among patients with negative, low, and positive HER2 statuses: intestinal-type histology (21.0%, 44.2%, and 59.8%, respectively), peritoneal metastasis (56.3%, 44.8%, and 21.8%, respectively), and higher serum CEA level (32.2%, 41.6%, and 56.5%, respectively). Improved survival was observed in the HER2-positive group than in the HER2-negative G/GEJ adenocarcinoma group [hazard ratio (HR) = 0.73, 95% confidence interval (CI) 0.59-0.89; P = 0.002]. However, the prognoses of the HER2-low and HER2-negative groups were similar (HR = 1.01, 95% CI 0.82-1.23; P = 0.843).

CONCLUSIONS

Patients with HER2-low G/GEJ adenocarcinoma exhibited intermediate and distinct characteristics than those in the HER2-negative group. Similarly, the HER2-low group's prognosis was worse than that of the HER2-positive group. Therefore developing novel therapeutic strategies targeting HER2-low G/GEJ adenocarcinoma is required.

Correlation between magnesium pre-loading and cisplatin-induced nephrotoxicity in 5-fluorouracil/cisplatin combination therapy for esophageal cancer

The use of cisplatin may cause nephrotoxicity in patients. Hydration solutions supplemented with magnesium could reduce cisplatin-induced nephrotoxicity. In this study, we evaluated the preventive effect of magnesium pre-loading on cisplatin-induced nephrotoxicity in patients with esophageal cancer. We retrospectively evaluated the prevalence of, and risk factors for, nephrotoxicity in 160 patients with esophageal cancer treated with the 5-fluorouracil/cisplatin regimen from 2014 to 2016 with and without magnesium supplementation. Significant differences were observed between the magnesium and non-magnesium groups in terms of frequency of estimated creatinine clearance of grade 2 or higher that was at 4% (n = 3) and 13% (n = 10) (p = 0.027), respectively. The logistic regression analysis revealed that eCcr of grade 2 or higher was significantly associated with the non-magnesium regimen (odds ratio (OR), 4.175; 95% confidence interval (CI) = 1.061-16.430; p = 0.041) and age ≥ 65 years (OR, 13.951; 95% CI = 1.723-112.974; p = 0.014). This study suggests that 20 mEq magnesium pre-loading significantly reduces the prevalence of cisplatin-induced nephrotoxicity. Furthermore, when cisplatin is administered to individuals older than 64 years, a close observation for the onset of cisplatin-induced nephrotoxicity is crucial.

460 Remote Orthopaedic Clinics during COVID-19: Lessons for a Sustainable Future

Aim

The COVID-19 pandemic has led to a focus on non-face to face (NF2F) orthopaedic clinics. Our aim was to establish whether NF2F clinics were sustainable according to the ‘Triple Bottom Line’ framework by taking account of the impact on patients, the planet and financial cost.

Method

This retrospective cohort study was carried out at a large DGH with 261 patients identified as having undergone F2F or NF2F orthopaedic consultations (April 2020). These patients were contacted by telephone to establish their experience, mode of transport and preference for future consultations. Data was also collected relating to environmental and financial costs to the patient and trust.

Results

Final analysis included 180 patients (69%): 42% had a F2F consultation and 58% a NF2F consultation. There was no significant difference between each group in terms of convenience, ease of communication, subjective patient safety, or overall satisfaction rating (p>0.05). 80% of NF2F patients would be happy with virtual consultations in future. Mean journey distance was 18.6 miles leading to a reduction in total carbon emissions of 563.9kg CO2e (66%), equating to 2106 miles in a medium sized car. The hospital visit carbon cost (heating, lighting, and waste generation) was reduced by 3,967kg CO2e (58%). The financial cost (petrol and parking) was also reduced by an average of £8.96 per person.

Conclusions

NF2F consultations are aligned to the NHS ‘Long Term Plan’. They (i) deliver high patient satisfaction with equivalent outcomes to F2F consultations; (ii) have reduced carbon emissions from transportation and hospital running; and (iii) are cheaper.

130 Improving Documentation of Bowel Movement on Geriatric Wards

Introduction

Constipation is a widely prevalent issue in older adults that may result in complications such as urinary retention, delirium and bowel obstruction. Previous studies have indicated that while stool charts are well completed by nursing staff, they are infrequently monitored by doctors. This project aimed to improve the documentation of bowel movement by doctors on ward rounds to 85%, by the end of a 3-month period.

Methods

Formulation of the project was achieved using group work and a fishbone diagram which focussed on how doctors can improve on documenting bowel movements. Baseline data were collected from inpatient notes on weekdays over a three-week period on a geriatric ward in Northern General Hospital, Sheffield. Interventions of posters and stickers of the poo emoji were placed on walls and in inpatient notes respectively as a reminder. Post-intervention data were collected on weekdays over two weeks, and then repeated a month later to assess for a sustained change.

Results

The data on bowel activity documentation were collected from 28 patients. The baseline data showed that bowel activity was monitored daily on the ward 56.25% of the time. There was a significant increase in documentation of 85.75% following the interventions. The sustainability study showed that bowel activity was documented on the ward 59.09% of the time.

Conclusions

This study shows how a strong effect on behavioural change can be accomplished through simple interventions such as stickers and posters. As most wards currently still use paper notes, this is a generalisable model that other wards can trial. However, this study also shows the difficulty in maintaining behavioural change over extended periods of time. Further PDSA cycles should examine the reasons behind the difficulty sustaining the change and implement new changes that aim to overcome them.

Application of a Medicare claims-based model predicting left ventricular ejection fraction subtype to investigate the epidemiology of heart failure in the US Medicare program

Introduction

Administrative claims do not contain ejection fraction (EF) information for heart failure (HF) patients. To address this limitation, we recently developed a claims-based model to classify HF patients into reduced EF (rEF) or preserved EF (pEF) using 35 predictors.

Purpose

To report distribution of key patient characteristics and rates of HF decompensation and mortality in model-identified rEF and pEF patients from nationwide Medicare claims (2012–2016) and compare with estimates from the literature.

Methods

We identified HF patients ≥65 years from US Medicare claims using recorded diagnosis after ≥6 months of continuous enrollment. The date of HF diagnosis was the cohort entry date. The 6-month baseline period prior to the cohort entry date was used to identify predictors and apply the claims-based model to distinguish rEF and pEF. Patients were followed for the composite outcome of time to first HF decompensation (HF hospitalization or outpatient IV diuretic treatment) or all-cause mortality. Descriptive statistics were used to summarize baseline patient characteristics. Cumulative incidence estimates along with 95% confidence intervals (CI) were calculated for the composite endpoint as well as all-cause and cause-specific mortality (derived from National Death Index linkage) using the Kaplan-Meier method.

Results

A total of 3,134,414 HF patients with an average age of 79 years were identified, of which 200,950 (6.4%) were classified as rEF. Among those classified as rEF, men comprised a larger proportion (68% vs 41%), the average age was lower (76 vs 79 years), and history of myocardial infarction was more frequent (32% vs 13%) compared to pEF. One-year cumulative incidence (95% CI) of the composite endpoint was 42.6% (42.4–42.8%) for rEF and 36.9% (36.7–37.0%) for pEF. One-year all-cause mortality incidence was similar between the groups (27.4% [27.2–27.6%] for rEF and 26.4% [26.3–26.4%] for pEF), however, cardiovascular mortality was higher for rEF (16.7% [16.5–16.8%] vs 12.3% [12.2–12.3%]), whereas non-cardiovascular mortality was higher for pEF (12.9% [12.7–13.1%] vs 16.0% (16.0–16.1%) (Figure 1). These results were in line with estimates from other well-established cardiovascular cohorts including the Get With The Guidelines-HF cohort and the Olmstead County HF epidemiology cohort.

Conclusion

We replicated well-documented differences in key patient characteristics and endpoints between rEF and pEF in these populations identified based on application of a claims-based model. Our results support use of this model for identifying cohorts of rEF and pEF to conduct subtype specific investigations of treatment outcomes. However, a notably lower proportion of patients were identified as having rEF compared to previous reports indicating low sensitivity of this approach for rEF and suggesting that model-based classification may not be useful in tracking subtype specific incidence or prevalence of HF using Medicare claims.

Cumulative incidence of outcomes in HF

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Novartis Inc.

Treatment with macitentan for pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD): real-world experience from the combined OPUS and OrPHeUS data sets

Introduction

Restrictive inclusion criteria can exclude some CHD-PAH patients from clinical trials. The OPsumit® USers (OPUS) Registry and the OPsumit® Historical USers (OrPHeUS) data sets provide real-world data in PAH patients newly started on macitentan, including patients with CHD-PAH regardless of defect type.

Purpose

To describe the characteristics, safety and clinical outcomes of CHD-PAH patients newly treated with macitentan.

Methods

OPUS is a prospective, US, multicentre, observational drug registry ongoing since April 2014. OrPHeUS was a retrospective, US, multicentre chart review; observation period Oct 2013–Mar 2017. This analysis reports information on CHD-PAH patients in the combined OPUS/OrPHeUS data set, descriptively compared with idiopathic/heritable PAH (I/HPAH) patients.

Results

As of Sept 2019, there were 4268 PAH patients with follow-up data, of whom 264 (6%) had CHD-PAH and 2396 (56%) had I/HPAH. For CHD-PAH and I/HPAH patients respectively at macitentan initiation: median age (Q1, Q3) was 48 (36, 62) and 65 (53, 73) years; 199 (75%) and 1748 (73%) were female; 67/114 (59%) and 802/1301 (62%) were WHO functional class III/IV; median (Q1, Q3) 6-minute walk distances were 350 (274, 420) and 289 (195, 375) m for the 82 and 840 patients with measurements; median (Q1, Q3) time from PAH diagnosis to macitentan initiation was 37.3 (4.5, 113.1) and 7.4 (1.4, 38.3) months; and 99 (38%) and 1056 (44%) initiated macitentan as monotherapy. The number of patients with ≥1 hepatic adverse event (HAE) was similar for CHD-PAH and I/HPAH (22 [8%] and 184 [8%]), as were the adverse event (AE) profiles (collected from OPUS only). Exposure, discontinuations, outcomes and most common AEs are shown in the table.

Conclusions

In general, compared with I/HPAH patients, CHD-PAH patients were younger and a greater proportion had prevalent disease than I/HPAH patients. Safety and outcomes were similar between the groups.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Actelion Pharmaceuticals Ltd

Long-term outcomes in newly diagnosed pulmonary arterial hypertension (PAH) patients receiving initial triple oral combination therapy: insights from the randomised controlled TRITON study

Introduction

Long-term outcomes are important in PAH.

Purpose

To evaluate the long-term efficacy and safety of initial triple oral therapy with selexipag, macitentan and tadalafil vs initial double oral therapy with macitentan and tadalafil in PAH.

Methods

TRITON, a multicentre, double-blind, placebo-controlled, phase 3b study, randomised 1:1 newly diagnosed, treatment-naïve PAH patients to initial triple vs double therapy. Macitentan and tadalafil were initiated at randomisation and selexipag/placebo at day 15 (uptitrated to wk 12). Efficacy and safety were assessed in a blinded manner until the last patient randomised completed wk 26 (end of observation period). Pulmonary vascular resistance (PVR; primary endpoint) and 6-minute walk distance (6MWD) were assessed at wk 26. Other secondary endpoints included time to first disease progression event (centrally adjudicated) to end of observation period +7 days. Time to all-cause mortality up to end of observation period was analysed post-hoc.

Results

247 patients were randomised to initial triple (n=123) or initial double therapy (n=124); baseline characteristics were balanced between groups. Median follow-up was 77.6 (initial triple) and 75.8 wks (initial double). Initial triple and initial double therapy improved PVR (by 54% and 52%) and 6MWD (by 55 and 56 m), with no difference between groups. A 41% reduction in the risk of first disease progression event driven by PAH-related hospitalisation and all-cause death was observed with initial triple vs initial double therapy (hazard ratio 0.59, 95% CI 0.32–1.09, p=0.087; Figure). Two patients died in the initial triple vs 9 in the initial double therapy group (hazard ratio 0.23, 95% CI 0.05–1.04). Adverse events were consistent with the known safety profiles of the study drugs.

Conclusions

In TRITON, assessments at wk 26 showed marked improvements in both treatment arms, with no difference between groups. Exploratory analysis indicated a signal for improved long-term outcome with initial triple versus initial double therapy.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Actelion Pharmaceuticals Ltd.

Combination therapy with macitentan and phosphodiesterase type-5 inhibitor (PDE5i) in pulmonary arterial hypertension (PAH): real-world data from OPUS and OrPHeUS

Introduction

Guidelines for the management of PAH recommend combination therapy for most patients, yet real-world data on treatment patterns in PAH are limited.

Purpose

To describe the characteristics, safety and clinical outcomes of PAH patients newly treated with double combination therapy with macitentan and PDE5i in the OPsumit® USers (OPUS) Registry and the OPsumit® Historical USers cohort study (OrPHeUS) combined dataset.

Methods

OPUS is a prospective, US, multicentre, observational drug registry (NCT02126943) ongoing since April 2014. OrPHeUS was a retrospective, US, multicentre chart review (NCT03197688); Oct 2013–Mar 2017. This cohort included patients initiating combination therapy with macitentan and a PDE5i (in any order) ≤60 days apart. Baseline was defined as the start date of the second therapy (i.e., start of combination therapy). Patient characteristics at baseline, changes in 6-minute walk distance (6MWD) and WHO functional class (FC) from baseline to follow-up, safety and outcomes are described.

Results

Of the 4428 OPUS/OrPHeUS PAH patients initiating macitentan, 2490 received this in combination with a PDE5i; of these patients, 740 (29.7%) initiated macitentan and a PDE5i concurrently (≤60 days apart). Data on disease duration was recorded in 729 patients at baseline; of these, 588 (80.7%) patients were incident (≤6 months since diagnosis) and 141 (19.3%) were prevalent (>6 months since diagnosis); median time from diagnosis to start of combination therapy of was 1.4 (Q1=0.6, Q3=3.6) months. At baseline, median age was 60 (Q1=49, Q3=70) years and 73.6% of patients were female. Mean baseline 6MWD was 264.5 (SD=119.8) m, recorded in 240 (32.4%) patients. WHO FC was recorded at baseline for 347 (46.9%) patients; 263 (75.8%) were in FC III/IV. Median combination therapy exposure was 10.2 (Q1=3.4, Q3=21.8) months, with 58.8% of patients ongoing at data cut. Changes from baseline to follow up in FC and 6MWD are shown in the figure. There was ≥1 adverse event (AE) reported in 455 (61.5%) patients and ≥1 hepatic AE (HAE) in 76 (10.3%) patients. In total, 232 (31.4%) patients discontinued macitentan; 122 (16.5%) due to AEs, 4 (0.5%) due to HAEs, 98 (13.2%) not due to an AE/HAE, and 8 (1.1%) for unknown reasons. Of the 305 patients who discontinued combination therapy, 137 (18.5%) discontinued macitentan only, 73 (9.9%) discontinued PDE5i only, and 95 (12.8%) discontinued both drugs at the same time. Kaplan-Meier estimates (95% CI) showed that 60.7% (56.4, 64.8) of patients were free from hospitalisation and 88.7% (85.7, 91.1) were alive at 12 months.

Conclusions

In this real-world setting, less than one third of patients treated with macitentan received initial oral combination therapy, despite current expert consensus favouring such therapeutic approaches. Patients initiating macitentan+PDE5i ≤60 days apart had improved 6MWD and WHO FC from baseline to follow-up.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Actelion Pharmaceuticals Ltd

P3674Patient characteristics and treatment patterns in the multicentre, retrospective chart review of first-time Opsumit (macitentan) users in the United States (OrPHeUS)

Introduction

The OPsumit® Historical USers cohort (OrPHeUS) is a multicentre, US, retrospective medical chart review conducted to supplement the OPsumit® USers (OPUS) Registry to fulfil the FDA request to characterise the safety of macitentan in clinical practice.

Purpose

To describe patient characteristics, treatment patterns, hepatic safety and survival in patients with pulmonary hypertension (PH) newly treated with macitentan.

Methods

OrPHeUS (NCT03197688) aimed to include 2200 new users of macitentan, between October 2013 and March 2017, who were not enrolled in OPUS. Here we present patients with follow-up data, including characteristics and treatment patterns at macitentan initiation, hepatic adverse events (HAEs) identified using preferred terms in chart entries and pharmacovigilance reporting, hospitalisations and survival.

Results

OrPHeUS included 2982 patients newly treated with macitentan and with follow-up data; the reason for macitentan prescription was pulmonary arterial hypertension (PAH) in 2362 (79.3%) patients, other PH aetiologies in 612 (20.6%) patients and 8 patients with other/unknown reasons. At macitentan initiation, the median (Q1, Q3) age of the patients was 62 (51, 72) years and 73.9% were female. WHO functional class (FC) was documented in 654 (21.9%) patients, 35.6% of patients were in FC I/II and 64.4% in FC III/IV; median (Q1, Q3) 6-minute walk distance, documented in 411 (13.8%) patients, was 293 (200, 383) metres. At macitentan initiation, 41.5% (n=1239) of patients were not receiving PAH therapy, 46.3% (n=1382) were already receiving one PAH therapy and 11.9% (n=356) were already receiving two PAH therapies. The median (Q1, Q3) exposure to macitentan was 14.9 (5.6, 27.1) months; 57% and 43% of patients had exposures of >12 and >18 months. During the exposure period, 933 (31.3%) patients discontinued treatment, including 474 (15.9%) patients who discontinued due to an adverse event (AE), 6 (0.2%) due to a HAE, 449 (15.1%) for reasons other than an AE/HAE, and 4 (0.1%) for unknown reasons. There were 275 (9.2%) patients who experienced ≥1 HAE (incidence rate [IR]: 0.07 [95% CI, 0.06, 0.08] per 1 person-year); alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥3x upper limit of normal (ULN) were experienced by 113 (3.8%) patients (IR: 0.028 [95% CI, 0.023, 0.033] per 1 person-year); ALT/AST ≥x3 ULN and bilirubin ≥2x ULN was experienced by 33 (1.1%) patients (IR: 0.008 [95% CI, 0.006, 0.011] per 1 person-year). There were 1148 (38.5%) patients who experienced at least one hospitalisation (IR: 0.36 [95% CI, 0.34, 0.39] per 1 person-year). The 12-month Kaplan-Meier survival estimate was 92% (95% CI, 91, 93).

Conclusion

OrPHeUS provides additional real-world evidence in patients newly treated with macitentan, confirming the hepatic safety profile of macitentan.

Acknowledgement/Funding

Actelion Pharmaceuticals Ltd

P4673Macitentan in chronic thromboembolic pulmonary hypertension (CTEPH): combined data from OPUS and OrPHeUS real-world data sets

Introduction

The OPsumit® USers Registry (OPUS) provides real-world data in patients (pts) with pulmonary hypertension newly started on macitentan. The OPsumit® Historical USers cohort (OrPHeUS) study was conducted to supplement OPUS to fulfil the FDA request to characterise the safety of macitentan in clinical practice. Both studies included pts with CTEPH.

Purpose

To describe the characteristics and safety outcomes of CTEPH pts newly treated with macitentan.

Methods

OPUS is a prospective, US, multicentre, long-term, observational drug registry (NCT02126943) ongoing since Apr 2014. OrPHeUS was a retrospective, US, multicentre medical chart review (NCT03197688); data collected Oct 2013-Mar 2017. This subgroup analysis describes CTEPH patient characteristics at macitentan initiation, hospitalisations, survival and liver function tests (LFTs) in the combined OPUS/OrPHeUS data set. LFTs are also provided for the OPUS/OrPHeUS pulmonary arterial hypertension (PAH) population.

Results

As of Oct 2018, OPUS/OrPHeUS included 144 CTEPH pts with follow-up data. At macitentan initiation, median (Q1, Q3) age was 66 (56, 73) years; of the 53 pts with a WHO functional class (FC) assessment, 35.8%, 49.1% and 15.1% were in FC II, III and IV, respectively. Median (Q1, Q3) time from CTEPH diagnosis was 18.6 (7.4, 56.4) months (n=141). At macitentan initiation, 32.6% of pts had no PAH therapy, 63.9% were receiving one and 3.5% were receiving two PAH therapies. Median (Q1, Q3) exposure to macitentan was 15.9 (4.3, 30.4) months. There were 43 (29.9%) CTEPH pts who discontinued treatment; 23 due to an adverse event (AE), 0 due to a hepatic AE (HAE) and 20 not due to an AE/HAE. There were 58 (40.3%) CTEPH pts who experienced ≥1 hospitalisation and 9 (6.3%) pts died. LFTs are presented in the table.

LFTs CTEPH follow-up pts PAH follow-up pts (N=144) (N=4072) ALT or AST ≥3x ULN   Pts with ≥1 event, n (%) 1 (0.7) 132 (3.2)   Incidence rate per 1 person-year (95% CI) 0.005 (0.001, 0.035) 0.024 (0.020, 0.029) ALT or AST ≥3x ULN and total bilirubin ≥2x ULN   Pts with ≥1 event, n (%) 1 (0.7) 27 (0.7)   Incidence rate per 1 person-year (95% CI) 0.005 (0.001, 0.035) 0.005 (0.003, 0.007) ALT: alanine aminotransferase; AST: aspartate aminotransferase; CI: confidence interval; ULN: upper limit of normal.

Conclusions

Analysis of OPUS/OrPHeUS data provides further insight into real-world use of macitentan in CTEPH pts. The observed hepatic safety profile in CTEPH pts is in line with that of PAH pts.

Acknowledgement/Funding

Actelion Pharmaceuticals Ltd

4973Efficacy and safety of selexipag in pulmonary arterial hypertension (PAH) patients with and without significant cardiovascular (CV) comorbidities

Introduction

Many PAH patients today have a number of CV comorbidities, yet data on the efficacy and safety of therapies in such patients remain scarce. Most recent PAH clinical trials also include patients with comorbidities.

Purpose

To assess the long-term efficacy and safety of the oral, selective IP prostacyclin receptor agonist, selexipag, in PAH patients with and without significant CV comorbidities using post hoc analysis of GRIPHON data.

Methods

GRIPHON enrolled 1156 PAH patients randomised 1:1 to placebo:selexipag. The present analysis includes patients with right heart catheterisation within 1 year of randomisation who were categorised as with or without CV comorbidities. Patients with CV comorbidities were defined as having ≥3 of the following: body mass index (BMI) >30 kg/m2, history of essential hypertension, diabetes mellitus, or historical evidence of significant coronary artery disease; if PAWP/LVEDP was >12 but <15 mmHg, pulmonary vascular resistance (PVR) had to be >500 dyn.sec/cm5; if PAWP/LVEDP was <12, then PVR had to be >300 dyn.sec/cm5. Selexipag effect on time to first morbidity/mortality (M/M) event up to end of treatment was assessed for both subgroups. Baseline (BL) adjusted treatment hazard ratios with 95% CIs were calculated using Cox models. Model building involved stepwise backward elimination of BL covariates.

Results

752 PAH patients could be categorised based on these criteria (99 with CV comorbidities, 653 without). At BL, patients with CV comorbidities were older (median [range] 60 [28–80] vs 46 [18–78] yrs), had higher BMI (mean [SD] 33.3 [7.23] vs 26.0 [5.64] kg/m2) and lower 6-minute walk distance (mean [SD] 319 [95.7] vs 354 [79.3] m) vs those without. A greater proportion were from Western Europe/Australia/North America (60.6% vs 38.9%) and in WHO functional class III (69.7% vs 49.9%). At BL, 82.8% of patients with CV comorbidities were receiving PAH therapies vs 75.7% of those without. As expected, at BL a higher proportion of patients with CV comorbidities (vs without) had previous/concomitant cardiac disease (62.6% vs 43.0%), metabolism/nutrition disorders (75.8% vs 31.2%), respiratory/thoracic/mediastinal disorders (59.6% vs 37.5%) and vascular disorders (76.8% vs 37.4%). Selexipag reduced the risk of M/M events vs placebo in both subgroups (Figure), with no evidence of an inconsistent treatment effect (interaction p-value=0.1544). Adverse events leading to treatment discontinuation were reported in 35.4% (25.9% selexipag, 46.7% placebo) of patients with CV comorbidities and 35.0% (32.0% selexipag, 38.0% placebo) of those without. Common prostacyclin associated side effects observed with selexipag (headache, diarrhoea, nausea) were reported at a similar incidence in both subgroups.

Conclusions

Selexipag had a beneficial effect on long-term outcome in PAH patients both with and without CV comorbidities. Safety in both groups was consistent with the known profile of selexipag.

Acknowledgement/Funding

Actelion Pharmaceuticals Ltd

Abstract P2-08-03: An essential role of GRB7 in promoting the growth of therapy resistant HER-2 positive human breast cancer cells in culture and animal models

Background- GRB7 gene encodes a multi-domain signal transduction molecule and is part of the core of the HER-2 amplicon. GRB7 is commonly co-amplified and over-expressed with HER-2 in human breast cancer. Earlier studies found a functional role of GRB7 in breast cancer. The role of GRB7 in HER-2 positive human breast cancer resistant to HER-2 targeted therapy remains unexplored however.

Materials and Methods- HCC-1954, 21MT1 and JimT1 are human HER-2 positive breast cancer cell lines that are resistant to trastuzumab and lapatinib treatment. Transient knock down of GRB7 protein expression was achieved with siRNA transfection and stable knock down with lentiviral vector mediated shRNA over-expression. Cell lines transfected with non-targeting siRNA or shRNA serve as negative controls. Knock down of GRB7 protein expression is verified by Western blotting. The growth of human breast cancer cell lines after GRB7 knock down in vitro is measured with the CellTiter Glo assay as well as the Incucyte live cell imaging. Activation status of specific signaling pathways was examined with phospho-specific antibody by immune-blotting and immune-precipitation. To assess the growth promoting function of GRB7 in human breast cancer cell lines in vivo, polyclonal HCC-1954, 21MT1 and JimT1 cells, with GRB7 knock down or their corresponding negative control, were orthotopically injected into the mammary fat pads of female immune-deficient NSG mice. The growth rates of these tumors, measured serially with caliper, and final tumor weights were compared between GRB7 knock down and the negative control. The proliferation rate and apoptosis of these tumors were studied with ki-67 staining and Tunel assay.The effects of GRB7 knock down on signaling were investigated with a proteome profiler receptor tyrosine kinase kit (R&D). The role of signaling molecules differentially activated in the growth of breast cancer cells by GRB7 knock down was examined utilizing siRNA mediated knock down, and antibody and small molecule inhibitors.

Results- GRB7 knock down decreased the growth of HCC-1954, 21MT1 and JimT1 cells in vitro and the growth of tumor xenograft these cells formed in animal models. When assayed by ki67 staining and Tunel assay, the mechanism of reduced tumor xenograft growth appeared to be distinct. Reduced proliferation and increased apoptosis were seen in 21MT1 cells, while reduced proliferation was seen in HCC-1954 cells and increased apoptosis in JimT1 cells. Protein profiling found that tyrosine phosphorylation of candidate signaling molecules was reduced with GRB7 knock down in JimT1 cells. Immuno-blotting and immuno-precipitation experiments were performed to evaluate these effects in other cell lines. The effect of targeting these molecules in breast cancer cell growth by siRNA and inhibitors is being examined.

Discussion- GRB7 has essential growth promoting function in therapy resistant HER-2 positive human breast cancer cells. GRB7 knock down has pleiotropic effects on signaling in various cellular contexts. The potential of targeting GRB7 signaling in treating therapy resistant HER-2 positive breast cancer merits further study.

Citation Format: Luoh S-W, Wagoner W, Lai X, Hu Z, Chin K, Ramsey B. An essential role of GRB7 in promoting the growth of therapy resistant HER-2 positive human breast cancer cells in culture and animal models [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-08-03.

Failure of neoadjuvant chemotherapy for resectable esophageal squamous cell carcinoma

Neoadjuvant treatment has become standard care for patients with resectable esophageal cancer. However, some patients cannot undergo surgery or curative resection because of disease progression during neoadjuvant treatment. The aim of this study is to identify the pretreatment characteristics of patients in whom neoadjuvant treatment failed. The study enrolled 231 patients who underwent chemotherapy with cisplatin and 5-fluorouracil (CF) as neoadjuvant therapy for T1N1-3 or T2-3 any-N esophageal squamous cell carcinoma (ESCC). Of these patients, 201 (87.0%) underwent curative resection (R0) and 30 (13.0%) could not undergo curative resection; 19 patients (8.2%) underwent incomplete resection (R1 or R2), and 11 patients (4.8%) could not undergo surgery because of disease progression. We compared clinical characteristics and survival between patients who underwent curative resection (curative group) and those who could not undergo curative resection (noncurative group) to determine the factors predicting noncurative treatment. The noncurative group had significantly worse disease-specific survival than the curative group (P < 0.001). All patients in the noncurative group had cT3 tumors. In 141 patients with cT3 tumors, those in the noncurative group were more likely to have higher serum SCC antigen concentration (P = 0.021), location of the main tumor in the upper to the middle third of the esophagus (P = 0.071), intramural metastases (P < 0.001), advanced N category (P = 0.016), and bulky lymph node metastases (P = 0.060). Multivariate logistic regression analysis identified location of the main tumor in the upper to the middle third of the esophagus (P = 0.047), intramural metastases (P = 0.002), and nodal metastases (N1, P = 0.014; N2, P = 0.015, respectively) as independent predictors of treatment failure in patients with cT3 tumors. Neoadjuvant CF therapy alone may not be effective for patients with cT3 tumors accompanied by these risk factors, and the efficacy of alternative strategies, such as triplet chemotherapy or chemoradiotherapy, should be evaluated.