A Clinical Trial to Compare the Efficacy and Safety of 1-week Treatment of Intravenous N-acetylcysteine (NAC) 600 mg Twice Daily, Ambroxol Hydrochloride 30 mg Twice Daily and Placebo as Expectorant Therapies in Adult Chinese Patients With Respiratory Tract Diseases and Abnormal Mucus Secretions

A Phase III, Multi-centre, Randomized, Rater- and Patient-blind, Placebo- and Active-controlled, Parallel Group Clinical Trial to Compare the Efficacy and Safety of 1-week Treatment of Intravenous N-acetylcysteine (NAC) 600 mg Twice Daily (Active Test Treatment), Ambroxol Hydrochloride 30 mg Twice Daily (Active Control Treatment) and Placebo as Expectorant Therapies in Adult Chinese Patients With Respiratory Tract Diseases and Abnormal Mucus Secretions

This is a phase 3, multicenter, randomized, rater- and patient-blind, placebo- and active-controlled, 3-arm parallel group clinical trial. Patients will be randomized to N-acetylcysteine (NAC) or ambroxol or placebo in a 1:1:1 ratio. A total of approximately 333 patients in China will be randomized. The total study duration will be approximately 8 months including the enrolment period of approximately 7 months and the patient participation duration of 1 month or 4 weeks. Each patient will undergo a screening period of up to 1 week, a 1-week treatment period and a 2-week follow-up period. This study will be conducted in approximately 15-25 sites in China.

Inclusion Criteria:

1. Male or female adult (≥18 years old) hospitalized patients with respiratory tract diseases and abnormal mucus secretions such as: acute bronchitis, chronic bronchitis and exacerbations, emphysema, mucoviscidosis and bronchiectasis.
2. Chinese ethnicity and/or Chinese
3. Signed the informed consent form before any study-related procedure
4. Sputum viscosity score ≥ 2 at randomization visit
5. Expectoration difficulty score ≥ 2 at randomization visit
6. Willingness and ability to comply with study procedures

Exclusion Criteria:

1. Intolerance or contra-indication to treatment with NAC or ambroxol or allergy to any component of the study treatments
2. (For female patients) ongoing pregnancy or lactation, or childbearing potential but unwillingness to adopt abstinence or contraception measures during the study
3. Intake of an investigational drug within 1 month before the screening visit
4. Use of expectorants or drugs with expectorant effect within 2 days before randomization visit
5. Diagnosis of active tuberculosis, lung cancer, pulmonary fibrosis, acute pulmonary thromboembolism or any other respiratory condition that might, in the opinion of the investigator, compromise the safety of the patient or affect the interpretation of the results
6. Medical history of and/or illness (including laboratory abnormality) and/or treatment that in the investigator's opinion may interfere with the patient's safety, compliance, or study evaluations
7. Serum alanine aminotransferase and/or aspartate transaminase more than 3 times above the upper limit of normal at screening visit
8. Serum creatinine more than 3 times above the upper limit of normal at screening visit
9. Addiction to alcohol or drugs
10. Mental illness, or other reasons for non-cooperation in the investigator's opinion