PII-063 - COST EFFECTIVENESS OF INDIVIDUALIZED DOSING FOR A HYPOTHETICAL NEW DRUG IN ATOPIC DERMATITIS: A PHARMACOMETRIC-PHARMACOECONOMIC SIMULATION STUDY.

M. Gastonguay¹, M. Johnson¹, D. Polhamus¹, E. Anderson¹, K. Barrett²; ¹Metrum Research Group, Boston, MA, USA, ²Metrum Research Group, Boston, MA.

Background: This study assessed the cost effectiveness (CE) of reducing interindividual variability (IIV) in efficacy response and therapy discontinuation rate (TDR) via a dose individualization strategy (DIS) for a hypothetical new drug (ND) in atopic dermatitis (AD) relative to a reference treatment, dupilumab (DU).

Methods: A pharmacometric (PM) - pharmacoeconomic (PE) model was developed for DU. The PM-PE model for ND was based on the same structure, with select modifications of PM model parameters, relative to the DU reference. PM model data sources included digitized longitudinal meta-data from published studies. The PM model described longitudinal eczema area and severity index (EASI) score as a fractional decrease from baseline EASI score, including effects for placebo response, topical corticosteroids (TCS), and drug effects. The PE model was characterized as a Markov model with health states: non-responder, responder (EASI 50, EASI 75, EASI 99), and associated quality adjusted life years (QALYs). An effective DIS was emulated as a reduction in ND efficacy response IIV and as a reduction in TDR, which was assumed to be related to a decrease in side effects, relative to DU. The cost of implementing the DIS was assumed to be negligible. Replicate simulations were implemented at various levels of IIV and TDR in an interactive tool developed in R and Shiny, running on the Metworx platform. Results were summarized for each scenario as the difference in (ND-DU) QALYs and the probability of CE vs. willingness to pay (WTP).

Results: Reductions in IIV expected from a DIS for ND did not provide a CE benefit relative to standard DU therapy. Improvements in TDR that might result from a DIS resulted in an increase of approximately 1 QALY and improved probability of CE for ND relative to DU (30% vs 15%, respectively, at a WTP of $100,000).

Conclusion: In AD, DIS focused on reducing side effects may be more impactful than those aimed at reducing variability in efficacy.