UNISUS study design: a phase 3 superiority study comparing the efficacy, safety, and tolerability of macitentan 75 mg vs macitentan 10 mg in patients with pulmonary arterial hypertension (PAH)

Background

While advances in PAH-specific therapies have substantially improved survival, there is still an unmet need to improve long-term outcomes in PAH.

Purpose

The UNISUS study is the first head-to-head superiority study in PAH, comparing the time to morbidity or mortality (M/M) with macitentan 75 mg vs macitentan 10 mg in PAH patients.

Methods

UNISUS, an ongoing multicentre, prospective, double-blind (DB), adaptive, event-driven superiority study randomises PAH patients 1:1 to receive macitentan 75 mg or macitentan 10 mg, with a target enrolment of ∼900 patients. Efficacy and safety are continuously assessed by an independent data monitoring committee (IDMC), who advises on pre-specified adaptive changes in study conduct, including expansion of the study population. An independent clinical event committee adjudicates all M/M events. The initial population was restricted to patients in functional class (FC) II/III, aged 18–75 years and excluded those with portopulmonary hypertension (PoPH) and those who were PAH treatment-naïve or receiving a prostanoid analogue. Stable (≥3 months) background PAH-therapy may be maintained, except for endothelin receptor agonists (ERAs), which must be stopped the day before initiating study drug. The study is comprised of a screening period, a 4-week run-in period (if ERA treatment-naïve or on sub-optimal ERA dose), and an event-driven DB treatment period, followed by a 2-year open-label extension with macitentan 75 mg. Initiation of macitentan 75 mg occurs after a 4-week up-titration step with macitentan 37.5 mg (Figure 1). The primary endpoint is time to first on-treatment M/M event, defined as first of: all-cause death, PAH-related hospitalisation, or PAH-related disease progression (confirmed ≥15% decrease in 6-minute walk distance (6MWD) and either FC worsening or addition of PAH therapy). Other endpoints include change from baseline to Week 24 in 6MWD and PAH-SYMPACT symptom scores; time to PAH-related hospitalisation or death; time to all-cause death (may be supplemented with data from an external control arm derived from the CARE PAH study [NCT04955990]); and the safety and tolerability of the study drugs. Figure 2 shows planned assessments and sub-studies. To maximise patient retention, add-on PAH therapies are allowed after a M/M event and, for patients at risk of withdrawing and unable to attend visits, the investigator may consider options for reduced follow-up.

Results

After 60 patients had been exposed for ≥8 weeks, the IDMC reviewed unblinded safety/tolerability data and recommended to expand recruitment from the restricted population to the target population (i.e., including patients: with PoPH, in FC II–IV, from any PAH therapy background [including naïve], aged ≥18 years).

Conclusion

UNISUS is the first head-to-head superiority study in PAH; with over 200 patients enrolled, it is currently recruiting the target population.

Funding Acknowledgement

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

Outcomes associated with modern treatment paradigms in connective tissue disease (CTD)-associated pulmonary arterial hypertension (PAH): a meta-analysis of randomized controlled trials (RCTs)

Background

CTD-PAH has historically represented a PAH subtype with poor prognosis. New therapies, as well as combination therapy approaches targeting multiple pathways have been approved for PAH based on RCTs. CTD-PAH patients comprise a subgroup of the RCT populations and efficacy analyses are based on subgroup analyses which can be less reliable than the overall analysis. We conducted a meta-analysis of RCTs of approved PAH therapies to evaluate outcomes of patients with CTD-PAH.

Purpose

To use meta-analysis to determine response to treatment in patients with CTD-PAH.

Methods

The PubMed and EMBASE databases were searched for English-only articles published between January 1, 2000 and November 25, 2019. Inclusion criteria were multicenter RCTs that enrolled adults with WHO group 1 pulmonary hypertension (PAH); enrollment in 2000 or later; long-term clinical morbidity and/or mortality event or 6-minute walk distance (6MWD) as an efficacy endpoint reported for ≥30 patients with CTD-PAH; and evaluation of a US Food and Drug Administration-approved PAH therapy. The primary outcomes were treatment effect as measured by the study time to first morbidity or morality event and change in 6MWD from baseline to between 3–6 months, per the data provided in each article. Results from individual studies were combined using a random-effects model for overall study population (PAH patients) and the subgroup of CTD-PAH patients.

Results

Ten RCTs (N=4329 PAH patients; n=1263 (29%) with CTD-PAH) met inclusion criteria and were included in the meta-analysis. At baseline, PAH patients had a mean age of 50 years, approximately 78% were female, and approximately 58% had functional class III or IV disease. These characteristics were balanced between treatment and control groups. Baseline 6MWD was 356 m for the overall population and 337 m for patients with CTD-PAH. Five RCTs (N=3172; n=941 with CTD-PAH [30%]) reported hazard ratios (HRs) for time to a morbidity or mortality event by drug treatment and PAH etiology: overall population HR=0.63 (95% confidence interval [CI], 0.56–0.72; P<0.001); CTD-PAH population HR=0.64 (95% CI, 0.51–0.80; P<0.001) (Figure). Nine RCTs reported mean change with drug treatment from baseline to 3 to 6 months in 6MWD for PAH and CTD patients: 33.9 m (95% CI, 21.9–45.9; P<0.001) in the overall population; 20.2 m (95% CI, 10.8–29.7; P<0.001) in CTD-PAH patients.

Conclusions

The improvement in 6MWD in patients with CTD-PAH is smaller than in those with other types of PAH, perhaps reflecting comorbidities and CTD-induced mobility constraints, independent of their cardiopulmonary capacity. Data from long term clinical morbidity/mortality endpoint studies in this large group of patients with CTD-PAH demonstrate that these patients derive significant benefit from currently available PAH therapies which, in many patients, comprised the addition of a drug targeting a second or third pathway involved in the pathophysiology of PAH.

Treatment effect on morbidity/mortality

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Actelion Pharmaceuticals US, Inc.

Characteristics and clinical course of the first 500 patients (pts) from SPHERE (SelexiPag: tHe usErs dRug rEgistry) receiving selexipag in real-world clinical practice

Background

SPHERE is a US, multicentre, prospective registry collecting real-world data from pts with pulmonary arterial hypertension (PAH) treated with selexipag, a selective oral IP prostacyclin receptor agonist.

Methods

SPHERE (planned N=800) included newly initiated (NI, receiving selexipag ≤60 days) and previously initiated (PI) pts. We describe disease characteristics, selexipag dose and clinical course of the first 500 pts and risk assessment based on REVEAL 2.0 risk calculator and COMPERA risk assessment strategy.

Results

Disease characteristics at initiation were: 75.0% female, median age 61.0 years, idiopathic etiology (49.2%) or associated with connective tissue disease (26.4%). Pts were mostly WHO functional class (FC) II (31.0%) or III (49.6%) (unknown for 9.2%). Median time from PAH diagnosis to selexipag initiation was 3.4 years. Of the first 500 pts enrolled, 138 (28%) were NI and 362 (72%) were PI; characteristics were consistent between NI and PI.

Risk classification at initiation differed depending on method used: with REVEAL 2.0, low/intermediate/high risk were 41.8%/29.6%/28.6% (38.4%/26.1%/35.5% for NI and 43.1%/30.9%/26.0% for PI, respectively) and with COMPERA were 22.0%/67.2%/9.6% (13.8%/73.2%/10.9% for NI and 25.1%/64.9%/9.1% for PI), respectively. Note, missing variables in real-world registry data may affect risk assessment.

In both cohorts, median individualised maintenance dose was 1200 μg twice daily (NI 1000 μg, PI 1200 μg); median time to individualised maintenance dose was 8.1 weeks. Median treatment duration was 21.7 months (17.7 months NI, 25.8 months PI). Overall, 32.4% of pts discontinued selexipag (46.4% NI, 27.1% PI), most commonly (22.8%) for adverse events (AEs) (34.8% NI, 18.2% PI). Of note, disease progression is classified as an AE. No selexipag-related deaths were reported.

At 18 months, WHO FC improved/remained stable in the majority of pts (205/235, 87%; improved, 24%; stable, 63%), but worsened in 12.8% of pts. At 18 months, the majority of pts had improved/stable risk by REVEAL 2.0 (265/334, 79% [improved, 22%; stable, 57%]) and by COMPERA (255/316, 81% [improved, 23%; stable, 58%]). This was consistent for NI and PI.

For both risk assessment tools higher risk was associated with increased risk of death. With REVEAL 2.0, risk of death was 2.9 and 9.3 times higher for intermediate and high risk, respectively vs low risk. Similarly with COMPERA, risk of death was 3.2 and 11.4 times higher in intermediate and high risk, respectively vs low risk.

Conclusions

Of the first 500 pts in SPHERE, the vast majority were prevalent PAH cases in FC II or III. Around one-quarter of pts had improved FC and/or risk; the majority of pts remained stable risk. Higher risk was associated with increased mortality risk. Over 50% of pts completed 18 months of selexipag. Discontinuations were most commonly for AEs and/or PAH progression.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Actelion Pharmaceuticals US, 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

P3671Selexipag dosing and titration in the first 500 patients enrolled in SPHERE (SelexiPag: tHe UsErs dRug rEgistry)

Introduction

SPHERE is an ongoing US-based, multicentre, prospective, registry collecting data on use of the oral selective IP prostacyclin receptor agonist selexipag in real-world settings. Here, we report selexipag dosing and titration in the first 500 patients.

Methods

SPHERE, initiated in November 2016, will enrol 800 patients newly initiated on or already treated with selexipag at enrolment who have a documented titration regimen. Patients are followed for up to 18 months. Patients were considered “newly initiated” on selexipag if they were enrolled in SPHERE ≤60 days after starting selexipag and were considered “previously initiated” if they enrolled >60 days after starting selexipag. The highest dose is the maximum dose reached during up-titration within 6 months since initiation. Selexipag “maintenance dose” is defined as the first dose received for ≥14 days without interruption or change; “titration speed” is defined as the highest dose reached within the first 6 months after initiation divided by the time (in weeks) to reach it.

Results

The data cut-off for this analysis was December 20, 2018. Most patients had Group 1 pulmonary hypertension (PH) (95.4%), which was primarily idiopathic (49.6%) or connective tissue disease associated (26.0%). At selexipag initiation 49.8% of patients had functional class III symptoms. At the time of selexipag initiation, 19.2% of patients were on PH therapy containing a prostacyclin pathway agent (PPA) (8.5% with a parenteral PPA). The median maintenance dose of selexipag was 1200 μg BID (IQR: 800–1600 μg BID) and the median time to reach it was 8.1 wks (IQR: 5.3–11.0 wks). Low (≤400 μg BID), medium (600–1000 μg BID), and high (≥1200 μg BID) maintenance doses were attained by 15.1%, 30.8%, and 49.5% of patients, respectively (and in 23.2%, 31.2%, and 36.2%, respectively, in GRIPHON). The median titration speed was 175 μg BID/wk (IQR: 110.5–195.3 μg BID/wk), slower than the protocol-outlined 200 μg BID/wk in GRIPHON. In SPHERE, most patients titrated at speeds <200 μg BID/wk, regardless of whether they were newly (175 μg BID/wk; IQR 118.6, 195.3) or previously (175 μg BID/wk; IQR 109.8, 195.3) initiated. As expected, more patients discontinued due to adverse events in the newly (29.0%) versus previously (14.1%) initiated groups. The most common adverse events leading to selexipag discontinuation were worsening pulmonary hypertension (2.2%), headache (2.0%), myalgia (1.4%), and nausea (1.0%).

Conclusion

The median maintenance selexipag dose in SPHERE was 1200 μg BID. While the median titration speed was 175 μg BID/wk, there was marked variation and the vast majority of patients titrated slower than 200 μg BID/wk. No new safety signals were observed.

Acknowledgement/Funding

Actelion Pharmaceuticals US, Inc.

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

Cardiac complications of systemic sclerosis

The majority of patients with SSc are believed to have subclinical primary cardiac involvement. Overt cardiac manifestations of SSc are associated with poor prognosis and can be difficult to manage. Primary myocardial disease, i.e. without systemic or pulmonary hypertension and without significant pulmonary or renal disease, is postulated to be due to microvascular ischaemia. Undetected early cardiac manifestations can progress silently to myocardial fibrosis. Symptoms may manifest without warning and can rapidly lead to arrhythmia and left and right heart dysfunction and failure. Of the currently practical screening methods, annual echocardiography and/or evaluation of N-terminal portion of pro-B-type natriuretic peptide concentrations should therefore be employed in SSc patients, in order to anticipate the development of cardiac symptoms. Although there is limited evidence in respect of specific therapeutic options, treatment of early abnormalities with calcium channel blockers and angiotensin-converting enzyme inhibitors may improve myocardial perfusion and function, while standard management of overt cardiac disease is equally appropriate in the SSc population. However, it remains to be seen if early intervention can limit the progression of these life-threatening complications.

Pulmonary arterial hypertension: the most devastating vascular complication of systemic sclerosis

Pulmonary arterial hypertension (PAH) is a devastating vascular complication of a number of CTDs. In patients with SSc, PAH has a dramatic impact on prognosis and survival and is the single most common cause of disease-related death.Yearly echocardiographic screening for PAH is recommended in patients with SSc. If suspected, confirmation of PAH diagnosis by right heart catheterization is necessary. Treatment goals for patients with PAH associated with SSc (PAH-SSc) aim to slow disease progression and improve quality of life. Some measures used to gauge the effect of treatment in patients with PAH-SSc remain to be fully validated; the 6-min walk distance, for example, is a simple and reproducible means of assessing exercise capacity, but there exists a need to understand what constitutes a clinically relevant change in this specific patient population. Currently, pharmacological intervention in PAH-SSc may target one or more of three pathophysiological pathways in PAH. The prostacyclin analogue epoprostenol has been shown to improve exercise capacity and haemodynamics in PAH-SSc patients and similar data are available from smaller studies on trepostinil and iloprost. The dual endothelin receptor antagonist bosentan has been shown to improve exercise capacity and haemodynamics in PAH-SSc, and similar data have been obtained in small numbers of patients treated with the endothelin receptor A antagonists sitaxsentan and ambrisentan. Impaired production of nitric oxide may be addressed by inhibiting phosphodiesterase type-5 with sildenafil or possibly tadalafil. Combinations of multiple targeted therapies may be beneficial to this patient population.

The 6-min walk test (6MW) as an efficacy endpoint in pulmonary arterial hypertension clinical trials: Demonstration of a ceiling effect

BACKGROUND

PAH trials traditionally use 6MW as the primary endpoint. Concerns regarding a "ceiling effect" masking efficacy have led to exclusion of patients with milder disease from most trials (BL 6MW>450 m). STRIDE I evaluated the selective endothelin A receptor antagonist, sitaxsentan (SITAX), in a 12-week randomized, double-blind, trial (178 patients) employing placebo (PBO), 100 mg or 300 mg SITAX orally once daily in PAH and included patients with NYHA class II, congenital heart disease and a BL 6MW>450 m, groups often excluded from previous trials.

METHODS

We analyzed 6MW effects For All Pts (intention-to treat) and those meeting Traditional enrollment criteria, defined as patients with NYHA class III or IV and 6MW< or =450 m at BL with idiopathic PAH or PAH related to connective tissue disease. The 100 mg and 300 mg SITAX arms are pooled based on similar treatment effects on 6MW.

CONCLUSION

Existence of a "ceiling effect" is supported by these data. The magnitude of the treatment effect and statistical power when using 6MW as the endpoint. Comparisons between PAH trials that do not adjust for the effects of differing enrollment criteria require caution.

Molecular and functional analysis identifies ALK-1 as the predominant cause of pulmonary hypertension related to hereditary haemorrhagic telangiectasia

BACKGROUND

Mutations of the transforming growth factor beta (TGFbeta) receptor components ENDOGLIN and ALK-1 cause the autosomal dominant vascular disorder hereditary haemorrhagic telangiectasia (HHT). Heterozygous mutations of the type II receptor BMPR2 underlie familial primary pulmonary hypertension.

OBJECTIVE

To investigate kindreds presenting with both pulmonary hypertension and HHT.

METHODS

Probands and families were identified by specialist pulmonary hypertension centres in five countries. DNA sequence analysis of ALK-1, ENDOGLIN, and BMPR2 was undertaken. Cellular localisation was investigated by heterologous overexpression of mutant constructs in both BAEC and HeLa cells. The impact of a novel sequence variant was assessed through comparative analysis and computer modelling.

RESULTS

Molecular analysis of 11 probands identified eight missense mutations of ALK-1, one of which was observed in two families. Mutations were located within exons 5 to 10 of the ALK-1 gene. The majority of ALK-1 mutant constructs appeared to be retained within the cell cytoplasm, in the endoplasmic reticulum. A novel GS domain mutation, when overexpressed, reached the cell surface but is predicted to disrupt conformational changes owing to loss of a critical hydrogen bond. Two novel missense mutations were identified in ENDOGLIN.

CONCLUSIONS

The association of pulmonary arterial hypertension and HHT identifies an important disease complication and appears most common among subjects with defects in ALK-1 receptor signalling. Future studies should focus on detailed molecular analysis of the common cellular pathways disrupted by mutations of ALK-1 and BMPR2 that cause inherited pulmonary vascular disease.

Severe pulmonary hypertension associated with COPD

Pulmonary hypertension can be associated with chronic obstructive pulmonary disease (COPD). Mild to moderate elevations in pulmonary artery pressures are commonly reported. Previous studies included patients initially diagnosed with COPD and subsequently evaluated for pulmonary hypertension. The occurrence of COPD in patients being evaluated for pulmonary hypertension has not been reported. We performed a retrospective chart review of approximately 600 patients evaluated in a large tertiary care pulmonary hypertension clinic. Subjects were included if they were older than 40 years, had no other secondary causes of pulmonary hypertension and had evidence of COPD by pulmonary function studies or thoracic computed tomography. Criteria was met by five subjects (3 males and 2 females, mean age = 65 years) all of whom were past smokers. The average mean pulmonary artery pressure (MPAP) was 59 +/- 7 mm Hg. The mean pulmonary vascular resistance (PVR) was 15.2 +/- 5 mmHg/liter/min. Only one patient had a fall in MPAP of more than 10% and a greater than 30% decline in PVR following infusion of adenosine to test vasodilator responsiveness. COPD is rare in a population referred primarily for evaluation of pulmonary hypertension. Although infrequent, severe pulmonary hypertension may be associated with COPD.

Development of nonspecific interstitial pneumonitis associated with long-term treatment of primary pulmonary hypertension with prostacyclin

A young woman with primary pulmonary hypertension presented with interstitial lung disease approximately 5 years after successful treatment with IV prostacyclin. The pathology was consistent with nonspecific interstitial pneumonitis and was unresponsive to steroids and immunosuppressive medications. We speculate that further cases of this syndrome may be reported as more patients are living beyond 5 years with prostacyclin.

The short-term effects of digoxin in patients with right ventricular dysfunction from pulmonary hypertension

OBJECTIVE

Studies on the effects of digoxin in patients with right ventricular failure and normal left ventricular function have not been performed. We evaluated the short-term effects of digoxin administration in patients with primary pulmonary hypertension on hemodynamics, neurohormones, and baroreceptor responsiveness.

DESIGN

This was a prospective study with patients serving as their own controls.

SETTING

University Hospital Intensive Care Unit with central monitoring.

PATIENTS

Seventeen patients with primary pulmonary hypertension and symptomatic heart failure were enrolled.

INTERVENTIONS

Following baseline hemodynamics, neurohormonal samples were drawn and the heart rate response to change in blood pressure following a challenge of phenylephrine and nitroprusside were recorded. One mg of intravenous digoxin was given and the measurements repeated after 2 hours.

RESULTS

Following digoxin there was a significant increase in cardiac output (3.49+/-1.2 to 3.81+/-1.2 L/min., p=0.028), a significant fall in norepinephrine (680+/-89 to 580+/-85 pg/ml, p=.013), and a significant increase in atrial natriuretic peptide (311+/-44 to 421+/-9 pg/ml, p=0.01). All of the patients had changes in heart rate and blood pressure following phenylephrine and nitroprusside challenge, but there was no significant difference in the change in heart rate response to change in blood pressure when rechallenged after digoxin treatment.

CONCLUSION

Digoxin produces a modest increase in cardiac output in patients with pulmonary hypertension and right ventricular failure, as well as a significant reduction in circulating norepinephrine. No detectable effects of digoxin on baroreceptor responsiveness were apparent. The use of digoxin in pulmonary hypertension is warranted.

Knowledge of disease and dietary compliance in patients with end-stage renal disease

Noncompliance is a common problem in patients with end-stage renal disease. In this study, we assessed the relationship between knowledge of disease and dietary compliance in a cohort of 56 dialysis patients. Based on a health belief model of adherence, we predicted that dialysis patients who knew more about kidney disease and its treatment would be more complaint than those who knew less about these matters. We also examined the relationship between dietary compliance and patients' emotional well-being. We used a composite measure of compliance consisting of serum K, P, and interdialytic weight gain. A 30-item "Kidney Disease Questionnaire" was used to assess patients' knowledge of their illness. Contrary to prediction, compliers did not score higher on the knowledge questionnaire; in fact, the observed correlation of .32 was in the opposite direction. In the same vein, we found no relationship between compliance and emotional well-being. These results, although somewhat surprising, add to a growing body of research which indicates that medical compliance involves more than educating patients about the mechanisms and treatment of their illness.

Invasive Streptococcus pneumoniae in Perth teaching hospitals, 1990 to 1994

Streptococcus pneumoniae causes pneumonia, otitis media and meningitis. Reports of penicillin resistance and the development of vaccines highlight the need for baseline information about pneumococcal disease in Australia. We surveyed Perth teaching hospital laboratory records for the period 1990 to 1994 for isolates of S. pneumoniae recovered from normally sterile sites, and obtained isolate and patient demographic information. Highest rates of invasive disease were found at the extremes of age and were associated with Aboriginality. Isolates were rarely penicillin resistant. Surveillance of invasive pneumococcal disease will be of importance in monitoring the emergence of penicillin resistance and the impact of conjugate vaccines.