Cost-Effectiveness of Dupilumab and Oral Janus Kinase Inhibitors for the Treatment of Moderate-to-Severe Atopic Dermatitis in Singapore

Background: Atopic dermatitis (AD) affects both adults and children, impacting their quality of life and productivity; however, traditional systemic treatments such as cyclosporine have limitations. Emerging novel systemic interventions, including monoclonal antibodies and Janus kinase (JAK) inhibitors, have been shown to improve patient outcomes.

Objective: This study evaluates the cost-effectiveness of novel systemic interventions for moderate-to-severe AD in adults compared with the best supportive care (BSC) in Singapore.

Methods: The economic evaluation used a hybrid model consisting of a decision tree and Markov model. Treatment responses at 16 weeks were based on a network meta-analysis that was developed specifically for this study. Long-term response, discontinuation rates, episodes of flares and treatment-emergent adverse events were obtained from key dupilumab, abrocitinib, baricitinib and upadacitinib trials. The study had a 5-year time horizon and considered the healthcare payer's perspective. Sensitivity and scenario analyses were performed as well.

Results: Baricitinib 4 mg and 2 mg have the lowest incremental cost-effectiveness ratios, at Singapore dollars (S$) 60,730/quality-adjusted life-year (QALY) and S$66,842/QALY, respectively. Upadacitinib 30 mg offers the highest incremental QALY gain, while baricitinib 2 mg offers the least. The cost of the intervention drugs accounted for the highest proportion of the overall expenses (68-93%) for those in the maintenance state. Other influential factors within the model included (1) the incremental utility derived from intervention response; (2) the probability of achieving Eczema Area and Severity Index 75 (EASI-75) with BSC; and (3) the relative risk of achieving EASI-75 with the interventions. In a scenario where the cost of all drugs is matched to the lowest-priced drug, the top three cost-effectiveness interventions are dupilumab, upadacitinib 30 mg and abrocitinib 200 mg, respectively.

Conclusion: The interventions are not found to be cost-effective at their existing prices when compared with BSC. Ideally, a composite score of treatment success and quality-of-life scores ought to be included, but such data were unavailable. Future research should consider conditional discontinuation data and long-term outcomes when such data become accessible.