Bayer recently announced that the company will immediately terminate its Phase 2 clinical trial of riociguat in patients with pulmonary hypertension associated with idiopathic interstitial pneumonias (PH-IIP), following the recommendation of an independent Data Monitoring Committee (DMC) that observed data suggesting that patients on riociguat had an increased risk for death or adverse effects. For safety purposes, the patients will be continuously monitored for at least four months after ceasing treatment.
PH-IIP is a rare disease in which patients suffer from both pulmonary hypertension and idiopathic interstitial pneumonias, a type of pneumonia characterized by shortness of breath and various degrees of interstitial inflammation and fibrosis. Because there are no currently approved treatments for PH-IIP, it is a disease with a poor prognosis and an estimated mortality rate of more that 20 percent in one year, revealing an urgent need for new effective therapies.
PH-IIP belongs to Group 3 of a five-group classification system of pulmonary hypertension. Riociguat, licensed in the U.S. as Adempas, is a stimulator of soluble guanylyl cyclase (sGC) involved in vasodilation, and the only approved treatment for two other types of pulmonary hypertension from Group 1 and Group 4.
Particularly, Adempas is indicated for the treatment of adults with pulmonary arterial hypertension (PAH) — included in the first group of the classification system — or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH, Group 4) following surgical treatment, or inoperable CTEPH.
The terminating Phase 2 trial (NCT02138825) was investigating riociguat efficacy in PH-IIP patients. However, the DMC, an independent committee that monitors patient safety during trials, found that patients receiving the drug could have an increased risk for death or other serious adverse events. The only common feature found among the patients who died was a more advanced lung disease, when compared to the study population as a whole.
“We understand that the need to terminate the study in PH-IIP is very disappointing for patients suffering from this disease, as well as for their doctors and healthcare providers. There is a significant unmet medical need for PH-IIP patients as there are no approved treatments, and finding an effective treatment remains a challenge,” said Dr. Joerg Moeller, member of the Bayer Pharmaceuticals Executive Committee and Head of Global Development, in a press release.
“Bayer remains committed to identifying new therapeutic options and to improving the lives of patients in disease areas where there is a high unmet medical need such as pulmonary hypertension,” he said.