Conference: 2014 International PHA Conference and Scientific Sessions
Release Date: 06.22.2014
Presentation Type: Abstracts
File Download: 2014 Conference Abstract - Kim Kerr
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Background: In the Phase III CHEST-1 study, riociguat, a novel soluble guanylate cyclase stimulator, was evaluated in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or persistent/recurrent CTEPH after pulmonary endarterectomy. The study met its primary endpoint, a significant change in 6-minute walking distance (6MWD) at Week 16 and the clinical efficacy of riociguat was also demonstrated across a range of secondary endpoints. Here, we evaluate the impact of riociguat on health-related quality of life (HRQoL) in patients with CTEPH.
Methods: CHEST-1 was a 16-week, double-blind, randomized, placebo-controlled study. The pulmonary arterial hypertension (PAH)-disease-specific (Living with Pulmonary Hypertension [LPH]) questionnaire that has been validated for PAH but not CTEPH, and the generic EuroQol 5-Dimension (EQ-5D) and EQ-5D-Visual Analog Scale (EQ-VAS) questionnaires were completed by patients at baseline and Week 16. The change from baseline to Week 16 for the total population and sub-scores were examined. The relationship between HRQoL and other clinical endpoints (e.g. 6MWD and World Health Organization functional class) were also evaluated.
Results: A total of 173 patients received riociguat (individual dose adjustment up to 2.5 mg three times daily) and 88 patients received placebo. At Week 16, riociguat treatment significantly improved the EQ-5D score, with an increase of +0.06±0.28 (mean±SD) compared with a decrease of −0.08±0.34 in patients receiving placebo (least-squares [LS] mean difference +0.13 [95% CI: 0.06 to 0.21]; p<0.0001). The EQ-VAS score also improved at Week 16 with riociguat treatment, with an increase of +10.5±23.4 in the riociguat group, but remained stable in placebo-treated patients (LS mean difference +10.0 [95% CI: 5.4 to 14.7]; p<0.0001). At Week 16, the LPH total score had improved by –6.7±18.6 in riociguat-treated patients and by –2.1±19.3 in placebo-treated patients compared with baseline (LS mean difference –5.8 [95% CI: –10.5 to –1.1]; p=0.12). Use of the LPH questionnaire in patients with CTEPH needs further validation.
Conclusions: Patients with CTEPH who were treated with riociguat reported significant improvements in HRQoL after 16 weeks of treatment compared with baseline, as measured by the generic EQ-5D and EQ-VAS scores. Smaller differences between riociguat and placebo treatment were observed with the LPH questionnaire.
Type: Clinical Science