 The entire study consists of a Screening Period, a Run-in Period, and a Study Period which consists of three 3 Clinical Visits. The three 3 Clinical Visits are scheduled with 143 days intervals, as Visit 1 Day 0 of treatment, Visit 2 Day 14, and Visit 3 Day 28. The Clinical Visit 1 will be held within 7-14 days after Screening Visit. Serial FEV1 are performed at Visit 1 and 3. Safety and compliance are evaluated at all 3 Visits. Population PK PPK blood sampling is conducted at Visit 3. 