• Participant must be 18 years of age or older.

• Participants must have ongoing symptoms of nasal congestion/obstruction at least 12 consecutive weeks before Visit 1 and a Nasal Congestion Score (NCS) ≥2 at Visit 1 (day score) and Visit 2 (weekly average score).

• Participants must have sinus Total Symptom Score (sTSS) (NC, rhinorrhea, facial pain/pressure) ≥5 at Visit 1 (day score) and Visit 2 (weekly average score).

• Participants must have at least one of the following features:

‣ Prior sinonasal surgery (as protocol defined) for chronic rhinosinusitis (CRS).

⁃ Treatment with systemic corticosteroid(s) (SCS) within the prior 2 years before Screening (Visit 1)

⁃ Worsening symptoms of CRS in the past 2 years which would have required treatment with SCS, however participant is intolerant or has a contraindication to SCS.

• Participants must have bilateral inflammation of paranasal sinuses with bilateral ethmoid and maxillary opacification on screening CT scan. Participants must have ≥25% opacification of the ethmoid sinuses and ≥25% opacification of at least 1 maxillary sinus by central reading of CT scan.

• Participants must have a Sino-Nasal Outcome Test-22-Items (SNOT-22) score of ≥20 at Visit 1 and Visit 2.

• Participants who have received a stable dose of mometasone furoate nasal spray (MFNS) for at least 3 weeks before Visit 2.

• A female participant is eligible to participate if she is not pregnant or breastfeeding, and at least 1 of the following conditions applies:

‣ Is not a women of childbearing potential (WOCBP). OR

⁃ Is a WOCBP and agrees to use a contraceptive method that is highly effective, with a failure rate of \<1% during the study (at a minimum until 20 weeks after the last dose of study intervention).