In this trial the effects of the inhaled drug BAY1237592 will be studied in patients with high blood pressure in the pulmonary blood vessels due to Pulmonary Arterial Hypertension (PAH) and due to Chronic Thromboembolic Pulmonary Hypertension (CTEPH). Pulmonary hypertension is characterized by the elevation of pressure in the pulmonary arteries (PAP) and of the pulmonary vascular resistance (PVR) leading to increased workload of the right chamber of the heart to eject blood against this elevated resistance. The goal of this study is to measure the safety and tolerability of the drug as well as the reduction of the PVR at different doses

In Part A patients without specific treatment for PH (untreated patients) will be tested. In Part B also patients stably pre-treated with specific PH drugs will be studied in combination with the new inhaled drug

Main Inclusion Criteria:

• Patients with PAH or CTEPH undergoing medically indicated routine invasive diagnostics
• Men and women aged 18 to 80 years

Part A:

- Untreated patients: Therapy-naïve patients (defined as off treatment with PDE-5 inhibitors, endothelin receptor antagonists, prostanoids, or other sGC stimulators/activators) with PAH or CTEPH or patients pre-treated with these medications who have to undergo a drug specific wash-out period at the discretion of the investigator for least 24 h prior to Day -1 if medically safe

Part B:

• Untreated patients with PAH or CTEPH:

  -- Group 1 (total will be summed up with corresponding dosage group from Part A)

• Pre-treated patients with PAH or CTEPH:

  • Group 2: Pre-treated patients with any kind of monotherapy* for PAH/CTEPH
  • Group 3: Pre-treated patients with any kind of double combination therapy* for PAH/CTEPH * patients receiving inhaled Iloprost, and patients who are known responders to iNO are excluded

Main Exclusion Criteria:

- Medical history indicating a different cause for PH than PAH or CTEPH according to the guidelines of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS), such as significant left heart disease, valvular disease, or structural heart defects, as assessed by the investigator, significant pulmonary disease or clinical suspicion of pulmonary venoocclusive disease

Availability of this study's data will later be determined according to Bayer's commitment to the EFPIA/PhRMA "Principles for responsible clinical trial data sharing". This pertains to scope, timepoint and process of data access.

As such, Bayer commits to sharing upon request from qualified researchers patient-level clinical trial data, study-level clinical trial data, and protocols from clinical trials in patients for medicines and indications approved in the US and EU as necessary for conducting legitimate research. This applies to data on new medicines and indications that have been approved by the EU and US regulatory agencies on or after January 01, 2014.

Interested researchers can use www.clinicalstudydatarequest.com to request access to anonymized patient-level data and supporting documents from clinical studies to conduct research. Information on the Bayer criteria for listing studies and other relevant information is provided in the Study sponsors section of the portal.