Bayer HealthCare has initiated a Phase II trial of riociguatto to treat patients with diffuse cutaneous systemic sclerosis (dcSSc), the most severe form of systemic sclerosis (SSc).

SSc is a rare multisystem, autoimmune disease that results in the overproduction and abnormal growth of collagen, which causes fibrosis of the skin and internal organs.

dcSSc is one of the two major forms of SSc and the most fatal rheumatic disease, which mostly affects people aged in their 40’s and 50’s.

The randomised, double-blind, placebo-controlled RISE-SSc trial is designed to evaluate the efficacy and safety of riociguat against placebo in these patients.

Around 130 patients at over 60 sites in 15 countries will be enrolled in the Phase II RISE-SSc trial.

The development of riociguat to treat dcSSc is part of the company’s worldwide strategic collaboration with Merck in the field of soluble guanylate cyclase (sGC) modulation.

Around 130 patients at over 60 sites in 15 countries will be enrolled in the Phase II RISE-SSc trial, which will evaluate whether 52 weeks of treatment with riociguat in dcSSc is superior to placebo.

The trial will evaluate the effect of riociguat on fibrosis of the skin and the lung, as well as on circulation problems such as digital ulcers.

There are no approved drugs currently available to potentially stop or delay the progression of the fibrotic damage in patients with SSc.

The European Commission and the US Food and Drug Administration (FDA) had granted orphan drug status for riociguat as an oral investigational drug in SSc.

In October 2013, riociguat was approved under the name Adempas in the US for use in inoperable CTEPH or persistent or recurrent CTEPH after surgery and PAH.

In Japan, riociguat was approved in the CTEPH indication in January, while in the EU and US, it has been granted orphan drug designation and was approved by the European Medicines Agency (EMA) under the name Adempas for use in CTEPH and PAH in March.