To evaluate the efficacy and safety of CM9241GRU versus placebo in the treatment of perennial allergic rhinitis.

Inclusion Criteria:

• Participants of both sexes aged 18 and over
• Ability to understand and consent to participate in this clinical research, expressed by signing the Informed Consent Form (ICF)
• Participants with a diagnosis of perennial allergic rhinitis, as determined by a history of symptoms related to non-seasonal allergen exposure for at least 9 months in the 12 months prior to the screening visit.

Exclusion Criteria:

• Participants who have had nasal surgery in the six (6) months prior to the screening visit, or who have obvious external structural abnormalities that interfere with nasal airflow and are considered clinically relevant by the investigator;
• Participants with non-allergic rhinitis (e.g. vasomotor, infectious, medication or drug-induced rhinitis) or seasonal allergic rhinitis;
• Participants with a current diagnosis or history of chronic rhinosinusitis, chronic purulent postnasal drip in the two (2) years prior to the screening visit;
• Participants diagnosed with asthma requiring regular use of systemic or inhaled corticosteroids; uncontrolled asthma (ACT: 5-15); partially controlled asthma (ACT: 16-19);
• Participants with a history of immunotherapy treatment in the 2 years prior to the screening visit;
• Participants with an upper respiratory tract infection or rhinosinusitis requiring antibiotic treatment in the 14 days prior to the screening visit and the randomization visit;
• Participants with an upper respiratory tract viral infection in the 7 days prior to the screening and randomization visits;
• Participants with severe hypertension, severe coronary artery disease, arrhythmias, glaucoma, hyperthyroidism, prostatic hypertrophy.