Khanna D, Allanore Y, Denton CP, et al. - In view of the approval of riociguat for pulmonary arterial hypertension and its antiproliferative, anti-inflammatory and antifibrotic effects in animal models of tissue fibrosis, researchers sought to evaluate riociguat for its efficacy and safety in patients with early diffuse cutaneous systemic sclerosis (dcSSc) at high risk of skin fibrosis progression. They conducted a randomized, double-blind, placebo-controlled, phase IIb trial including adults with dcSSc of < 18 months' duration and a modified Rodnan skin score (mRSS) 10–22 units. Participants were administered riociguat 0.5 mg to 2.5 mg orally three times daily (n = 60) or placebo (n = 61). Participants well tolerated riociguat. No significant benefit of riociguat in terms of mRSS was observed when compared with placebo at the predefined p < 0.05. Potential efficacy signals were gained in secondary and exploratory analyses that required confirmation in in further trials.