Modelling Natural History and Cost-Effectiveness of Gene-Agnostic Treatment in Retinitis Pigmentosa

Purpose: Treatment options for Retinitis pigmentosa (RP) have been limited. A new generation of innovative but potentially expensive treatments under development may halt or reverse disease progression. Methods: Using an existing database, a closed-cohort microsimulation model of all genetic subtypes of RP was conducted from a US societal perspective. A hypothetical gene-agnostic therapy was compared to standard care at age 30. Outcomes included: VF and VA progression; Incremental cost-effectiveness ratio (ICER: dollars per quality-adjusted life-year (QALY) gained); lifetime medical and productivity-related costs. Results: Baseline cohort (age 30, N=381; mean VA logMAR, 0.26 (20/36); mean VF sum total degrees (III4e), 749). By age 45, 79% of untreated RP patients reached legal blindness or worse, compared to significantly delayed progression with treatment. ICER of gene-agnostic therapy was $158,554/QALY, yielding better outcomes compared to untreated RP (20.5 vs. 16.7 QALYs) and substantial indirect cost savings ($691,961) if a drug price of $1.5 million was assumed. Conclusions: A gene-agnostic treatment for RP with drug price of $1.5 million (both eyes) may be cost-effective for most types of RP, particularly with earlier initiation. These findings can inform clinical, economic, and health policy decisions, potentially supporting early intervention strategies and resource allocation for novel RP treatments.