Efficacy and dose-response relationship of oral treprostinil in PAH patients on monotherapy or dual background therapy

Background

FREEDOM-C and FREEDOM-C2 were randomized, placebo-controlled, double-blinded international, multicenter studies investigating the use of oral treprostinil (TRE) in subjects on mono or dual background pulmonary arterial hypertension (PAH) therapies. Both had a primary endpoint of change in 6-minute walk distance (6MWD) at Week 16 vs baseline. Previous post-hoc analyses combining mono and dual therapy subjects (PDE-5i and/or ERA) from these studies revealed a TRE dose-dependent increase in 6MWD. (1. White & Rao, 2016)

Purpose

This post-hoc analysis was performed to determine if subjects from FREEDOM-C and FREEDOM-C2 derive improvements in 6MWD with increasing doses of TRE when stratified by mono or dual background therapy and to determine if PAH background therapies (mono or dual) impacted 6MWD.

Methods

All active subjects (n=331) from FREEDOM-C and FREEDOM-C2 were grouped into TRE dose tertiles (low-dose: ≤2 mg BID, mid-dose: >2 mg to ≤3.5 mg BID, and high-dose: >3.5 mg BID). Placebo subjects (n=329) were in a separate 0 mg dose group. No data imputation was implemented.

Comparisons of 6MWD change at Weeks 4, 8, 12, and 16 between mono and dual therapy subgroups at any dose group were performed using a two-sample t-test or nonparametric Wilcoxon rank-sum test. The nonparametric Kruskal-Wallis test was conducted with subsequent pairwise comparisons of 6MWD change at Week 16 between the four dose groups through Dunn's approach. Additionally, the Jonckheere-Terpstra test was used to assess the linear trend for 6MWD improvement with higher doses of TRE.

Results

Baseline characteristics of the combined intention to treat (ITT) population and summary of 6MWD for subjects with both baseline and Week 16 data are in Table 1. 6MWD change improved steadily to Week 16 in subjects at higher TRE doses, regardless of the number of PAH background therapies (Figure 1). No statistical differences were found between mono and dual therapy at any time point or for any dose group. At Week 16, there was a significant difference in 6MWD change between the placebo group and high dose group within both mono and dual background therapy subjects. The difference between the low- and high-dose groups was significant for subjects on dual background therapy. There was a significant positive linear trend for TRE doses in 6MWD improvement at Week 16 for both monotherapy subjects (one-sided p-value = 0.0002) and dual therapy subjects (one-sided p-value = 0.0242).

Conclusions

6MWD improved in PAH patients regardless of their background therapy (monotherapy or dual background) and derive greater 6MWD improvements with higher doses of TRE. The observed dose-dependent 6MWD increase supports the use of TRE in sequential combination with background therapies (mono or dual).

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): United Therapeutics Corporation

Mortality rates and cause of mortality in patients with mildly elevated pulmonary pressures versus PH: insights from the retrospective EVIDENCE-PAH study

Background

Normal mean pulmonary artery pressure (mPAP) does not exceed 20 mmHg and normal pulmonary vascular resistance (PVR) does not exceed 2 Wood Units (WU). The thresholds used to define pre-capillary pulmonary hypertension (PH) – mPAP ≥25 mmHg and PVR >3 WU – are being evaluated. It is unclear if treatment would benefit patients with mildly elevated mPAP (≥21–<25 mmHg).

Purpose

The EVIDENCE-PAH study aims to describe mortality and hospitalisation outcomes, clinical characteristics, therapies, and quality of life during long-term follow-up of a national cohort of patients with different levels of mPAP and PVR. We report preliminary analyses focusing on mortality and its cause in patients stratified by their baseline (BL) mPAP.

Methods

This retrospective analysis included PAH-treatment-naïve patients with suspected PH who received a first right heart catheterisation (RHC) between 2009 and 2017 at any of the 7 UK tertiary PH centres, which assess all PH patients in the UK. A sample of patients with BL mPAP ≥25 mmHg (stratified by PVR and treatable versus non-treatable PH) was used as a control in this analysis. Baseline characteristics, mortality and cause of mortality were stratified by mPAP (<21, ≥21–<25, ≥25 mmHg) at BL (first RHC). Mortality was also stratified by BL PVR (<1, 1–<2, 2–<3, 3–<6, ≥6 WU). Mortality analysis was done without matching cohorts. Mortality data were obtained from the Office for National Statistics, NHS Digital.

Results

In total, 2926 patients were analysed (968, 689 and 1269 with mPAP <21, ≥21–<25, ≥25 mmHg, respectively). Mean observation was 6.1 years. BL characteristics are in Table. Survival worsened with increasing mPAP (p<0.0001) and increasing PVR (p<0.01) (Figure). After 5 years of follow-up, 187 (27.1%) patients with mPAP ≥21–<25 mmHg had died, compared with 162 (16.7%) and 595 (46.9%) patients in the lower and higher mPAP groups, respectively. In patients with mPAP ≥21–<25 mmHg, the most common main cause of death was respiratory disease (36.4%) – with scleroderma lung disease and interstitial lung disease accounting for 69.1% of these deaths – followed by cardiac disease (16.6%) and malignancy (15.0%) (Table). PH was the main cause of death for only 1.6% of patients with mildly elevated mPAP and it was a contributor to death in 6.8% (BL mPAP <21 mmHg), 10.2% (≥21–<25 mmHg), and 40.2% (≥25 mmHg) of cases.

Conclusion

Long-term survival in patients with mPAP ≥21–<25 mmHg was worse than in those with normal mPAP, and better than in those with the current definition of PH. While the main cause of death was mostly unrelated to PH and further analysis is needed to understand the impact of underlying disease, mildly elevated mPAP appears to confer a worse prognosis and should be closely monitored. These data show the relevant disease burden in patients with mPAP ≥21–<25 mmHg and the need to understand if they could benefit from treatment. PVR may be key in determining patients who might benefit.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Actelion Pharmaceuticals Ltd., a Janssen pharmaceutical company of Johnson & Johnson.

Effect of macitentan on left ventricular (LV) function in pulmonary arterial hypertension (PAH): results from REPAIR

Introduction

PAH impacts right ventricular (RV) structure and function but also leads to changes in the LV due to RV/LV interaction and underfilling. REPAIR, the first PAH study to use a primary endpoint assessed by cardiac MRI (cMRI), reported that RV stroke volume (RVSV) increased by 12 mL and pulmonary vascular resistance (PVR) decreased by 38% from baseline (BL) to Week 26 with macitentan.

Purpose

To assess the effect of macitentan on LV function in patients with PAH.

Methods

REPAIR (NCT02310672) was a 52-week, multicentre, open-label, single-arm, phase 4 study assessing the effect of macitentan primarily on RV structure and function, determined by cMRI and right heart catheterisation. Macitentan 10 mg was initiated in treatment-naïve patients, in patients receiving stable background phosphodiesterase type-5 inhibitor (PDE5i) at BL, or in initial combination with PDE5i. Exploratory LV endpoints were assessed by cMRI at Weeks 26 and 52. Safety was assessed up to end of study treatment +30 days in all patients who received ≥1 dose of macitentan (N=87). Patients with BL and Week 26 assessments for both PVR and RVSV were included in the modified Full Analysis Set (mFAS; N=71).

Results

In the mFAS, 57 (80%) patients were female. At BL, median age was 45 years; median (Q1, Q3) six-minute walk distance was 395 (323, 483) m; 48%/51% of patients were WHO functional class II/III; 59% had idiopathic PAH. Compared to BL, at Weeks 26 and 52 there were significant changes in LV cMRI parameters (table). The most common AEs were peripheral oedema (22%), headache (21%) and dizziness (14%).

Conclusions

Macitentan led to improvements in LV mass, volume and function, including clinically-relevant increases in LV stroke volume, at both 26 and 52 weeks in patients with PAH. Safety was consistent with other macitentan clinical trial data.

Funding Acknowledgement

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

Importation of Polish trichinellosis cases to Ireland, June 2007

A Polish national in his late 20s presented in June to the emergency department of a hospital in Dublin.

Renal artery embolisation in the palliative treatment of renal carcinoma

The aim of this study is to review the role and technique of renal artery embolisation (RAE), and assess its effectiveness in the palliative treatment of unresectable or inoperable renal cell carcinoma (RCC) in our institution. The study group consisted of 19 consecutive patients (16 male, 3 female; age range 47-87 years) who underwent palliative RAE for the treatment of renal carcinoma between January 2000 and December 2005. Unresectable disease was present in 11 patients (3 stage IVa, 8 stage IVb). Potentially resectable disease was present in 8 patients (4 stage II, 1 stage IIIa, 1 stage IIIb, 2 stage IIIc); however, these patients were unfit for surgery for other reasons. 13 patients presented with haematuria, which was gross in 7 patients. Nine patients complained of flank pain. RAE was performed using polyvinyl alcohol or embosphere particles, metallic coils and, in some cases, absolute alcohol was necessary. At the time of analysis, 12 patients had died while 7 patients were still alive, with an overall median survival for the study group of 6 months. In the 7 patients with transfusion dependant gross haematuria, there was stabilization of the haemoglobin level post-embolisation. In the 9 patients who presented with flank pain, symptoms improved or resolved in 8 patients. The median length of hospital stay for the 18 patients who were discharged was 5.0 days. RAE is a safe and tolerable management option for patients with inoperable or unresectable renal carcinoma as a means of palliation of local symptoms and improving clinical status, with low morbidity and shorter hospital stay.

Local involvement of the urinary bladder in primary colorectal cancer: outcome with en-bloc resection

BACKGROUND

Colorectal cancers that adhere to the urinary bladder require en-bloc partial or total cystectomy to achieve negative tumor margins.

METHODS

This prospective study evaluated the outcome of combined bladder resection for carcinoma of the colon or rectum at a unit specializing in gastrointestinal cancer.

RESULTS

Patients (n = 63) with colorectal tumors adherent to the bladder at operation and without distal metastases were followed. Fifty-eight patients (92%) had tumors of the sigmoid colon or upper rectum. Operative morbidity and mortality rates were 18% and 1.5%, respectively. Histological staging demonstrated bladder adherence in 46% (29/63) and invasion in 54% (34/63). Overall disease-specific survival was 54% with a mean follow-up of 7.6 years (range 5-12). Five-year survival for margin-negative patients was 72% (26/36) and 27% (4/15) for node-negative and -positive tumors, respectively. The bladder was closed primarily in 48 patients and reconstructed by enterocystoplasty in 5, with 10 patients requiring urinary diversion.

CONCLUSIONS

En-bloc bladder resection for adherent or invading tumors of the colon and rectum achieves good local control, but an infiltrative extravesical margin denotes poor prognosis. The potential for cure in completely excised node-negative tumors is good. Bladder reconstruction is achievable in most patients.

Local Involvement of the Urinary Bladder in Primary Colorectal Cancer: Outcome with En Bloc Resection

BACKGROUND

Colorectal cancers that adhere to the urinary bladder require en bloc partial or total cystectomy to achieve negative tumor margins.

METHODS

This prospective study evaluated the outcome of combined bladder resection for carcinoma of the colon or rectum at a unit specializing in gastrointestinal cancer.

RESULTS

Patients (n = 63) with colorectal tumors adherent to the bladder at operation and without distal metastases were followed. Fifty-eight patients (92%) had tumors of the sigmoid colon or upper rectum. Operative morbidity and mortality rates were 18% and 1.5%, respectively. Histological staging demonstrated bladder adherence in 46% (29/63) and invasion in 54% (34/63). Overall disease-specific survival was 54%, with a mean follow-up of 7.6 (range 5-12) years. Five-year survival for margin negative patients was 72% (26/36) and 27% (4/15) for node negative and positive tumors, respectively. The bladder was closed primarily in 48 patients and reconstructed by enterocystoplasty in five, with ten patients requiring urinary diversion.

CONCLUSIONS

En bloc bladder resection for adherent or invading tumors of the colon and rectum achieves good local control, but an infiltrative extravesical margin denotes poor prognosis. The potential for cure in completely excised node negative tumors is good. Bladder reconstruction is achievable in most patients.

Vasomotor instability preceding tilt-induced syncope: does respiration play a role?

This study aimed to determine whether alterations in cardiovascular dynamics before syncope are related to changes in spontaneous respiration. Fifty-two healthy subjects underwent continuous heart rate (HR), arterial blood pressure (BP), and respiratory measurements during 10-min periods of spontaneous and paced breathing (0.25 Hz) in the supine and 60 degrees head-up tilt positions. Data were evaluated by power spectrum and transfer function analyses. During tilt, 27 subjects developed syncope or presyncope and 25 remained asymptomatic. Subjects with tilt-induced syncope had significantly greater increases in low-frequency (0.04-0. 15 Hz) systolic BP, diastolic BP, and HR power during tilt than the asymptomatic subjects (P </= 0.01). This difference was present during spontaneous but not paced breathing. However, average tidal volume, respiratory rate, minute ventilation, proportion of breaths below 0.15 Hz, and low-frequency respiratory power during tilt did not differ between syncopal and nonsyncopal subjects. Transfer magnitudes between low-frequency respiration and BP, and between BP and interbeat interval, were also similar between groups. Thus vasomotor instability before syncope is not related to alterations in respiration or the cardiovagal baroreflex but may reflect oscillating central sympathetic outflow to the vasculature.

School nutrition survey

Food we eat has an important influence on health and well-being. Many eating habits are established in childhood. 456 children aged eight to 12 years participated in this survey of food eaten at school. Of all the food items eaten as a snack, 48.6% were categorised as junk. 75.8% of the sandwiches brought to school for lunch were made with white bread. Of the remaining food items brought for lunch 63.5% were of the junk variety. Compared with those who brought a snack or lunch from home, those given money to buy their own were more likely to eat junk (p < 0.01). Food eaten at school reflects approximately one third of a child's daily food intake but health food practises for even a third of food intake may be of a value for health and long term eating habits. Nutritional education with the reinforcement of high nutritional standards in schools could improve the situation.

An outbreak of cryptosporidiosis associated with a swimming pool

In August 1988 an increase was noted in the number of cases of cryptosporidiosis identified by the microbiology laboratory at Doncaster Royal Infirmary. By 31 October, 67 cases had been reported. Preliminary investigations implicated the use of one of two swimming pools at a local sports centre and oocysts were identified in the pool water. Inspection of the pool revealed significant plumbing defects which had allowed ingress of sewage from the main sewer into the circulating pool water. Epidemiological investigation confirmed an association between head immersion and illness. The pools were closed when oocysts were identified in the water and extensive cleaning and repair work was undertaken. The pool water was retested for cryptosporidial oocysts and found to be negative before the pool reopened.