Prophylaxis of Nasal Polyposis After Response to Treatment With Mometasone Furoate Nasal Spray

RATIONALE: Intranasal corticosteroids are the preferred medical treatment for nasal polyposis (NP). This study assesses the efficacy of mometasone furoate nasal spray (MFNS) prophylaxis in preventing NP recurrence after successful MFNS treatment. METHODS: Prospective observational study of 46 subjects ≥18yrs with three phases: treatment (MFNS 200mcg BID/4mo), prophylaxis (MFNS 200mcg QD/4mo), observation (off MFNS 4mo). Subjects followed through all phases unless failed or dropped out. Primary endpoints for each subject/study phase include change in NP and nasal congestion (NC) scores from baseline. NP graded (0-3/side) by monthly nasal endoscopies; NC self-assessed weekly. Improvement=decreased NP size by ≥1, NC by ≥0.5; recurrence=increased NP size by ≥1, NC by ≥0.5. Serum IgE measured at study entry and compared by Student t-test. RESULTS: Treatment phase: 41/46 subjects evaluable; 76%(31/41) responded and entered prophylaxis, 10 failed. No difference in total initial NP size between groups: 22/31(71%) prophylaxis and 8/10(80%) failures had initial NP ≥3. No difference in IgE levels (P>0.5). Prophylaxis phase: 27/31 evaluable; 59%(16/27) responded and entered observation; 11(41%) recurred. No difference in total initial NP score between groups: 12/16(75%) observation and 7/11(64%) failures had initial NP ≥3. No difference in IgE levels (P≤0.2). Observation phase: 14/16 evaluable; 64%(9/14) recurred off prophylaxis; median time to recurrence=1 month. CONCLUSIONS: Seventy-six percent of NP subjects responded to MFNS, regardless of initial NP size or serum IgE levels. Prophylaxis was effective in 59% of subjects after treatment response; 64% recurred off MFNS prophylaxis within 1 month. MFNS prophylaxis prolongs time to NP recurrence, despite initial NP size.