The primary objectives of this study:

• To investigate the safety and tolerability of ascending repeated oral doses of BAY1902607 in healthy subjects (Part 1).
• To investigate the effect of BAY1902607 on the pharmacokinetics (PK) of a sub-therapeutic 1 mg dose of midazolam (Part 1).
• To investigate the safety, tolerability and efficacy of BAY1902607 in patients with refractory chronic cough (Part 2).

Inclusion Criteria:

Part 1:

• Male; healthy according to complete medical history, including the physical examination, vital signs (blood pressure, heart rate), 12-lead ECG, clinical laboratory tests
• Age: 18-45 years (inclusive) at the first screening visit
• Non-smoker for at least 6 months and with a pack year history of equal to or less than 5 years
• Subjects, who are sexually active and have not been surgically sterilized, must agree to use two reliable and acceptable methods of contraception simultaneously, when having sexual intercourse with women of childbearing potential (one method used by the subject, one method used by the partner) during the study and for 90 days after receiving the investigational medicinal product, and not to act as sperm donor for 90 days after dosing. [Acceptable methods of contraception include for example: (a) condoms (male or female) with or without a spermicidal agent, (b) diaphragm or cervical cap with spermicide, (c) intrauterine device, (d) hormone-based contraception]

Part 2:

• Age: ≥18 years at the first screening visit
• Refractory chronic cough for at least one year that has been shown to be unresponsive to treatment of cough according to the 2006 British Thoracic Society (BTS) guideline
• Score of ≥ 40 mm on the Cough Severity visual analogue scale (VAS) at screening
• For female patients:

Confirmed post-menopausal woman (defined as exhibiting spontaneous amenorrhea for at least 12 months before screening or as exhibiting spontaneous amenorrhea for 6 months before screening with documented serum follicle-stimulating hormone (FSH) levels > 40 mIU/mL) or Woman without childbearing potential based on surgical treatment at least 6 weeks before screening, such as bilateral tubal ligation, bilateral oophorectomy with or without hysterectomy (documented by medical report verification) or Woman of childbearing potential that agrees to use two reliable and acceptable methods of contraception simultaneously (one method used by the study patient and one method used by the partner) during the study and for at least 31 days (1 average menstrual cycle of 28 days plus approx. 5 half-lives of BAY 1902607) after the last dose. In addition during the study and for at least 31 days after the last dose women of child bearing potential are not allowed to donate oocytes.

Exclusion Criteria:

Part 1:

• Relevant diseases potentially interfering with the study objectives (e.g. respiratory diseases) within the four weeks before screening or between screening and randomization
• Any febrile illness within the four weeks before screening or between screening and randomization
• Medical history of hypogeusia/dysgeusia or the subject has a dysfunction in his ability to taste, as revealed by the taste-disturbance questionnaire during screening and the predose procedures

Part 2:

• FEV1(Forced Expiratory Volume in 1 second) or FVC(Forced Vital Capacity ) of less than 60% of predicted normal, at screening
• History of upper or lower respiratory tract infection or recent significant change in pulmonary status within the 4 weeks before screening
• Current smoking habit or history of smoking within the 6 months before the screening visit
• History of smoking (at any time) for more than 20 pack-years in total (20 cigarettes per pack)

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.