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

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.

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.

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.

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.

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.