Inclusion Criteria:

Part 1:

• Healthy male or female subjects aged 18 to 55 years old (inclusive);
• Body weight ≥ 50.0 kg for males and ≥ 45.0 kg for females; body mass index (BMI) within the range of 18.5 to 28.0 kg/m2 (inclusive);
• No clinically significant abnormalities at screening or baseline.

Part 2:

• Male or female patients aged 18 to 55 years old (inclusive);
• Clinically confirmed diagnosis of chronic rhinosinusitis with or without nasal polyps;
• Presence of the following symptoms for >4 weeks before screening: nasal obstruction, mucous or mucopurulent rhinorrhea, facial pain/pressure, and reduced or lost sense of smell;
• Modified Lund-Kennedy (MLK) score ≥ 2 in each nostril by nasal endoscopy;
• Lund-Mackay score (LMK) ≥ 2 in each nostril by CT scan;
• Nasal Construction Score (NCS) ≥ 2.

Exclusion Criteria:

Part 1:

• Known hypersensitivity or contraindications to the study drug or its components;
• History or current conditions that affect the safety or absorption of the investigational drug;
• History of drug abuse or drug dependence;
• Participation in any other clinical trials and receiving an investigational drug within 12 weeks before screening or 5 half-lives, whichever is longer;
• If female, is pregnant or lactating, or intends to become pregnant during the study period.

Part 2:

• Known hypersensitivity or contraindications to the study drug or its components;
• Use of prohibited medications prior to screening and during the course of the study; History of drug abuse or drug dependence;
• Participation in any other clinical trials and receiving an investigational drug within 12 weeks before screening or 5 half-lives, whichever is longer;
• If female, is pregnant or lactating, or intends to become pregnant during the study period.