Bayer HealthCare has started a Phase III trial of riociguat, a soluble guanylate cyclase (sGC) stimulator, to treat children suffering from pulmonary arterial hypertension (PAH).

Since 2013, riociguat has been approved to treat adults suffering from this life-threatening lung disorder.

Riociguat is being developed and commercialised as part of Bayer’s worldwide strategic collaboration with Merck in the field of soluble guanylate cyclase (sGC) modulation.

Bayer HealthCare Executive Committee member and Global Development head Dr Joerg Moeller said: “Taking into account the poor prognosis for children with pulmonary arterial hypertension, new medications are needed.

“In clinical studies riociguat has proven to be effective and well tolerated for adults, and now with our new study we will investigate its safety profile in children suffering from pulmonary hypertension.”

Pulmonary hypertension (PH) can occur at any age, from infancy to adulthood, and data on paediatric epidemiology remains rare and the exact incidence and prevalence of PH in children is not known.

“Taking into account the poor prognosis for children with pulmonary arterial hypertension, new medications are needed.”

Currently, there are only two approved treatment options available for children with PAH.

The international, multicentre, single-arm, open-label PATENT-CHILD trial will evaluate the safety, tolerability and pharmacokinetics of a body-weight adjusted, riociguat regimen in children aged between six years and less than 18 years of age.

The drug will be evaluated in children who have been diagnosed with idiopathic, hereditary, or PAH associated with connective tissue disease or congenital heart disease with shunt closure.

Riociguat is the first member of a distinct class of compounds discovered and developed by Bayer as an oral treatment to target a key molecular mechanism underlying PH.

In October 2013, riociguat (Adempas) was approved in the US for use in inoperable chronic thromboembolic pulmonary hypertension (CTEPH) or persistent or recurrent CTEPH after surgery and in PAH.

In March 2014, riociguat was been granted orphan drug designation in the EU and US. It was also approved by the European Medicines Agency (EMA) under the name Adempas for use in CTEPH and PAH.

In Japan, the drug has been granted orphan drug designation in the CTEPH indication and was approved in CTEPH in January 2014 and in PAH in February this year.