The symptoms of nasal polyposis, especially congestion/obstruction and loss of sense of smell, can have a substantial impact on patients’ quality of life (QoL). Currently, intranasal corticosteroids, including mometasone furoate, are the recommended first-line treatment for mild to moderate nasal polyposis. The benefit of mometasone furoate nasal spray (MFNS) in polyposis has been verified by three large phase III studies, which included almost 1,000 patients. Improvements were seen in all parameters put in relation to the disease.

Aetiological Factors and Epidemiology
Nasal polyposis is often associated with chronic rhinosinusitis (CRS). In the recent European Position Paper on Rhinosinusitis and Nasal Polyps, nasal polyposis is considered to be a subgroup of CRS.¹ The aetiology of nasal polyposis remains unclear; however, there is a clear association with systemic diseases such as asthma and cystic fibrosis as well as intolerance to aspirin. The reported prevalence of nasal polyposis ranges from 2.1% to 4.3% of the general population in European countries.^2-4 Nasal polyposis usually develops in adulthood and its incidence increases with age; it also occurs more frequently in males than in females.⁵ Nasal polyposis is rare in children unless associated with cystic fibrosis, which is a disease dominated by neutrophil infiltration.⁵

Treatment of Nasal Polyposis
The objectives of the management of nasal polyposis are antiinflammatory – i.e., to reduce or eliminate polyps – open the nasal airway, improve or restore the sense of smell, prevent polyp recurrence and improve patient QoL.^6,7 Regular treatment with intranasal corticosteroids is traditionally considered the medical therapy of choice in mild or moderate nasal polyposis, with surgery reserved for more severe cases.^1,8 The cell infiltration with eosinohils, neutrophils and T cells indicates the necessity of anti-inflammatory treatment of changes in the adjacent nasal mucosa in combination with surgery.⁹

Guidelines on the management of nasal polyposis recommend that surgery to remove nasal polyps should be undertaken only in patients with very large polyps or in those who have failed to respond to corticosteroid therapy.^1,10 However, the evidence for this is minute and studies with early surgical intervention are lacking. The addition of endoscopic nasal surgery to a combination of oral and nasal corticosteroid treatment has a clear-cut effect on nasal polyp size, but a limited effect on perceived nasal obstruction and other symptoms.¹¹ Moreover, polyp recurrence rates after endoscopic sinus surgery can be as high as 60%, especially in asthmatic patients or those with aspirin intolerance.^5,12,13 Therefore, it may be more appropriate to consider surgery as an anti-inflammatory treatment in those cases.

MFNS
Currently, no definite cure for nasal polyposis is available, but local corticosteriods are recommended as a basic symptomatic treatment. By reducing inflammation they may reduce polyp size, prevent new polyp formation and delay, or potentially prevent, the need for surgery, although most patients with nasal polyposis may eventually require surgery.^7,14 MFNS (Nasonex^®, Schering-Plough Corporation) is a potent intranasal synthetic corticosteroid that is approved for the treatment of nasal polyps in 15 European countries and in the US. It is indicated for the treatment in patients aged 18 years and older.15 The usual recommended starting dose of MFNS for nasal polyposis in many countries is a once-daily dose (QD) of 200μg that may be increased to twice-daily (BID) if symptoms are inadequately controlled after five to six weeks.

Other indications include prophylaxis and treatment of allergic rhinitis, treatment of non-allergic rhinitis and acute rhinosinusitis in adults.

Clinical Studies with MFNS
The efficacy and safety of MNFS for the treatment of nasal polyps in subjects aged 18 years and older have been demonstrated in phase III clinical studies of four months’ duration. A total of 962 patients with bilateral nasal polyps and clinically significant congestion/obstruction were included for treatment in three studies. Two of the studies were similar large-scale, multicentre, randomised, double-blind, placebocontrolled studies involving a total of 664 adults.^16,17 Subjects were randomly assigned in a 1:1:1 ratio to treatment with MFNS 200μg QD, MFNS 200μg BID or placebo. The third trial, conducted at 12 centres in four Nordic countries (Denmark, Finland, Norway, Sweden), included 298 subjects randomly assigned to receive either MFNS 200μg or placebo.¹⁸