Riociguat for Sarcoidosis-Associated Pulmonary Hypertension: Results of a 1-Year Double-Blind, Placebo-Controlled Trial

Abstract

Background: Riociguat is effective in delaying the time to clinical worsening (TCW) in patients with groups 1 and 4 pulmonary hypertension.

Research question: Is riociguat more effective than placebo in prolonging TCW in sarcoidosis-associated pulmonary hypertension (SAPH)?

Study design and methods: This was a double-blind placebo-controlled trial. Patients with SAPH confirmed by right heart catheterization were randomized 1:1 to riociguat or placebo. Patients underwent 6-min walk distance (6MWD) and spirometry testing every 8 weeks. The primary end point was TCW, which was defined by the time to the first of the following: (1) all-cause mortality, (2) need for hospitalization because of worsening cardiopulmonary status attributable to progression of disease, (3) > 50 m decrease in the 6MWD test, or (4) worsening of World Health Organization functional class.

Results: A total of 16 patients were randomized to riociguat (n = 8) or placebo (n = 8). No difference was found in pulmonary artery mean, pulmonary vascular resistance, initial 6MWD, or FVC between the two groups. Five of eight patients who received placebo met TCW criteria, whereas none of the patients who received riociguat experienced a qualifying event. By log-rank analysis, patients who received riociguat were in the study for a significantly longer period (χ ² = 6.259; P = .0124). The 6MWD decreased in the placebo group (median, -55.9 m; range, -176.8 to 60 m), but rose in the riociguat group (median, +42.7 m; range, -7.5 to +91.4 m; P = .0149), with a placebo-corrected difference of 94 m (P < .01). Four of eight patients who received riociguat, but only 1 of 8 patients who received placebo, showed a > 30-m improvement in 6MWD (P > .05). No significant adverse events associated with riociguat occurred.

Interpretation: Over the 1 year of the study, riociguat was effective in preventing clinical worsening and improving exercise capacity in patients with SAPH.

Trial registry: ClinicalTrials.gov; No.: NCT02625558; URL: www.clinicaltrials.gov.

Keywords: 6-min walk distance; pulmonary fibrosis; riociguat; sarcoidosis-associated pulmonary hypertension.