Efficacy and Safety of Tigerase® vs. Pulmozyme® in Patients With Cystic Fibrosis

Inclusion Criteria: 1. Signed Patient Informed Consent Form for participation in the study; 2. Men and women 18 years and older; 3. Diagnosis of cystic fibrosis, defined as the presence of disease symptoms and a positive sweat test and / or detection of 2 mutations of the MVTR gene during genotyping; 4. FEV1 ≥40% and ≤100% of the proper value; 5. The ability to understand the protocol requirements, to give written consent to participate in the study (including the use and transfer of information about the patient's health status related to the study). Exclusion Criteria: 1. Hypersensitivity to any of used study drug, to their components, as well as a history of significant allergic reactions; 2. Acute respiratory infection or exacerbation of chronic pulmonary disease within 4 weeks prior to screening and without corticosteroid or antibiotic therapy; 3. Concomitant diseases and conditions with potential impact the patients safety, including: * Severe renal impairment (serum creatinine more than 1.5 times higher than the upper limit of normal); * Severe liver impairment (alanine aminotransferase (ALT) or aspartate aminotransferase (AST) blood serum activity is 2.5 times or more higher than the upper limit of the laboratory norm); 4. A history of lung transplantation or planned transplantation during this study; 5. The presence of antibodies to HIV, active viral hepatitis B and / or C and / or cirrhosis in the history or detected on Screening; 6. Pregnancy and lactation; 7. Refusal of patients with preserved reproductive potential to use adequate contraception throughout the study and within 30 days after the end of the study; 8. Patients who underwent a blood or blood components transfusion within 10 days prior to screening; 9. Drug or alcohol abuse at the time of Screening or in the past; 10. Patient's participation in any other clinical trials and / or administration of an experimental drug within 30 days prior to the Screening Visit.