Number Needed to Treat and Cost-per-Responder Analysis of Dupilumab and Mepolizumab in Chronic Rhinosinusitis With Nasal Polyps

OBJECTIVES: We compared the number needed to treat (NNT) to achieve one additional responder versus standard of care (SoC) and the cost per additional responder (CPR) of dupilumab versus mepolizumab at week 24 after treatment initiation (baseline) in patients with chronic rhinosinusitis with nasal polyps (CRSwNP).

METHODS: An existing NNT model was adapted to a Portuguese healthcare perspective to analyze the week 24 NNT versus SoC of dupilumab and mepolizumab, considering the following response rates: reduction from baseline in Nasal Polyp Score (NPS) ≥1; reduction in NPS ≥2; and reduction in Sino-Nasal Outcome Test (SNOT-22) score ≥8.9. Efficacy data for mepolizumab were based on response rates derived from a post-hoc analysis of "mepolizumab-like" patients (at least one prior surgery, non-smoker, or former smoker >6 months, VAS >7 at baseline) in placebo-controlled SINUS trials (NCT02912468 and NCT02898454), along with published findings from a Bucher indirect treatment comparison. Treatment costs were multiplied by the NNT to obtain the corresponding 24-week CPR for each response criterion. Treatment costs (acquisition and training costs related to administration) were sourced from published contracts with hospitals and the official gazette.

RESULTS: In the base case, for NPS improvement ≥1, the NNT versus SoC was 1.8 for dupilumab and 7.6 for mepolizumab. For NPS improvement ≥2, the NNT versus SoC was 3.1 for dupilumab and 10.0 for mepolizumab. For SNOT-22 improvement ≥8.9, the NNT versus SoC was 3.7 for dupilumab and 19.8 for mepolizumab. Relative to mepolizumab, the 24-week incremental CPR for dupilumab for NPS improvement ≥1 and ≥2 was €27,614 and €31,678 lower, respectively. Similarly, for SNOT-22 improvement ≥8.9 from baseline, the incremental CPR for dupilumab was €79,154 lower compared to mepolizumab.

CONCLUSIONS: Achieving an equivalent number of additional responders (reduction in NPS, reduction in SNOT-22) after 24 weeks of treatment was less costly with dupilumab than mepolizumab in CRSwNP.