COST EFFECTIVENESS ANALYSIS OF SONPIRETIGENE ISTEPARVOVEC FOR RETINITIS PIGMENTOSA WITH SEVERE VISION LOSS
Author(s)
Andrew Davies, MSc1, Anish Patel, PharmD2, Jessica S. Dunne, MSc3, Karissa M. Johnston, BSc, MSc, PhD3, Samar Mohanty, PhD2, Ramesh V. Arjunji, PhD2;
1Stockbridge Economic Appraisal Ltd, Edinburgh, United Kingdom, 2Nanoscope Therapeutics, Inc., Dallas, TX, USA, 3Broadstreet HEOR, Vancouver, BC, Canada
1Stockbridge Economic Appraisal Ltd, Edinburgh, United Kingdom, 2Nanoscope Therapeutics, Inc., Dallas, TX, USA, 3Broadstreet HEOR, Vancouver, BC, Canada
OBJECTIVES: Sonpiretigene isteparvovec (hereafter sonpiretigene) is an optogenetic therapy for retinitis pigmentosa (RP) patients with severe vision loss. RESTORE, a phase 2b/3 trial randomized 27 participants to sonpiretigene or sham over 100 weeks. Treated participants demonstrated statistically significant and clinically meaningful improvements in best corrected visual acuity versus sham. This analysis aimed to evaluate the cost-effectiveness of a one-time, unilateral injection of sonpiretigene versus supportive care (SC), and highlights the importance of alternative assumptions around durability of treatment effects.
METHODS: A Markov cohort model was adapted from a recent Institute for Clinical and Economic Review (ICER) cost-effectiveness analysis, which was based on baseline characteristics and treatment effectiveness data from the RESTORE trial. Health state assignment after 52 weeks (better than counting fingers to no light perception) and progression through worsening states followed ICER’s approach. Treatment was assumed to halt progression while effects persisted. Health state utilities were also applied in line with the ICER analysis; health state costs were not considered as these had been assumed not to differ meaningfully in ICER’s analysis. A lifetime durability of treatment effect was assumed as the base case. Sensitivity analysis explored use of a stable effect duration of 5 years, with subsequent rates of progression returning linearly to natural history levels but retaining prior cumulative treatment benefits. This differs from ICER’s model which aimed to impose equivalency of sonpiretigene to SC in absolute terms after 10 years.
RESULTS: Under a lifetime durability of treatment effect, sonpiretigene had a cost/QALY of $270,000 compared with SC. Gradually reverting to natural history progression rates over years 6-10 resulted in an incremental cost-effectiveness ratio of $435,000 per QALY.
CONCLUSIONS: Sonpiretigene is expected to maintain visual gains over a lifetime, resulting in a robust and highly cost-effective intervention for a rare disease with high unmet need.
METHODS: A Markov cohort model was adapted from a recent Institute for Clinical and Economic Review (ICER) cost-effectiveness analysis, which was based on baseline characteristics and treatment effectiveness data from the RESTORE trial. Health state assignment after 52 weeks (better than counting fingers to no light perception) and progression through worsening states followed ICER’s approach. Treatment was assumed to halt progression while effects persisted. Health state utilities were also applied in line with the ICER analysis; health state costs were not considered as these had been assumed not to differ meaningfully in ICER’s analysis. A lifetime durability of treatment effect was assumed as the base case. Sensitivity analysis explored use of a stable effect duration of 5 years, with subsequent rates of progression returning linearly to natural history levels but retaining prior cumulative treatment benefits. This differs from ICER’s model which aimed to impose equivalency of sonpiretigene to SC in absolute terms after 10 years.
RESULTS: Under a lifetime durability of treatment effect, sonpiretigene had a cost/QALY of $270,000 compared with SC. Gradually reverting to natural history progression rates over years 6-10 resulted in an incremental cost-effectiveness ratio of $435,000 per QALY.
CONCLUSIONS: Sonpiretigene is expected to maintain visual gains over a lifetime, resulting in a robust and highly cost-effective intervention for a rare disease with high unmet need.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EE210
Topic
Economic Evaluation
Topic Subcategory
Trial-Based Economic Evaluation
Disease
SDC: Sensory System Disorders (Ear, Eye, Dental, Skin), STA: Genetic, Regenerative & Curative Therapies