Serious side effects were observed during phase II clinical trials of riociguatum (INN) by Bayer, for therapy of arterial pulmonary hypertension with idiopathic interstitial pneumonia. Independent committee for data monitoring, having studied the information obtained, has concluded, that the drug may be associated with increased mortality. However, the committee members did not specify the reason for increased mortality in CT participants, having remarked that the deceased patients had suffered more severe forms of arterial pulmonary hypertension. But as doubts in safety of the drug did emerge, Bayer announced early termination of the clinical trial program.
Note, that currently riociguatum (INN) has been approved in a number of countries (including Russia) for treatment of pulmonary arterial hypertension (WHO groups 1 and 4). It is marketed under the trademark of Adempas.