Evaluation of Nitric Oxide Nasal Spray (NONS) for Treatment of Recurrent Acute Rhinosinusitis

Inclusion Criteria:

1. At least aged 18 years old at the time of consent (19 years depending on the age ofmajority in the Canadian province/territory).

2. History of recurrent acute bacterial sinusitis (ABS) with at least three episodes inthe previous 12 months with at least two episodes requiring ATB therapy (withsymptom-free periods between infections).

3. History of at least two moderately severe symptoms of acute rhinosinusitis (anterior (nasal) and posterior (postnasal drip) secretions, nasal obstruction (congestion),headache or facial pain/pressure during a typical RARS episode.

4. If female, be surgically sterile or post-menopausal (no menses for at least 12months), or if of childbearing potential, must be using an acceptable method ofcontraception such as a combination estrogen/progestin hormonal contraceptive (oralor injected) for at least 1 month prior to Screening, or such items as anintrauterine device (IUD), intrauterine system (IUS), transdermal hormonal implant,vaginal hormonal ring, or 2 forms of the following: diaphragm, cervical cap, patch,condom, spermicide, or sponge. Total abstinence is permitted. Must agree to agreecontinue using contraception for the duration of the study medication treatment.

5. If male, be surgically sterile, or agree to use appropriate contraception (latexcondom with spermicide) when engaging in sexual activity and agree to not donatesperm for the duration of the study medication treatment.

6. Be reasonable stable health (i.e., diagnosed chronic illnesses that are not deemedstable by the participant's primary care physician), or in the opinion of theInvestigator, based on medical history (i.e., absence of any clinically relevantabnormality) during Screening.

7. Be able to understand and provide written, informed consent.

8. Must be able to attend on-site and virtual study visits.

Exclusion Criteria:

1. Complicated RARS (orbital or intracranial involvement).

2. Symptoms attributed to sinus disease for longer than 4 weeks.

3. RARS with multiple courses of antimicrobial therapy failures (in previous 2 years, 3or more episodes treated with 2 or more ATBs).

4. Disease history consistent with severe allergic or seasonal rhinitis (requiring oralcortico-steroids to manage intractable nasal symptoms).

5. Isolated frontal and sphenoidal clinical disease (given the differentpathophysiology and etiologic pathogens).

6. History of nasal polyposis.

7. History of abnormal sinus pathology.

8. Previous sinus surgery.

9. Participants with cystic fibrosis.

10. Recurrent moderate epistaxis.

11. Participants with chronic obstructive pulmonary disease (COPD).

12. Participants with severe asthma (per European Respiratory Society (ERS)/AmericanThoracic Society (ATS) 2014).

13. Immunocompromised participants or participants with other medical conditions thatmay affect interpretation of the effect of trial drugs.

14. Allergic to any of the trial drugs.

15. Females who are breastfeeding, pregnant, or attempting to become pregnant.

16. Participants who have conditions that participation is not in their best interest.

17. Participants whose participation in the study, in the opinion of the Investigator,have a condition which would interfere with their ability to adhere to the protocol (e.g., participants whom are mentally or neurologically disabled and whom areconsidered not fit to their participation in the study), interfere with theassessment of the investigational product, or compromise the safety of theparticipant or the quality of the data.

18. Participants who are unable to sign the informed consent.