PBI55 Patient Preferences for GENE Therapy in Hemophilia: Results from the Paving Threshold Technique Survey

Abstract

The aim of the Patient preferences to Assess Value IN Gene therapies (PAVING) study was to investigate trade-offs that adult Belgian hemophilia A and B patients are willing to make when choosing between prophylactic factor replacement therapy (PFRT) and gene therapy. The threshold technique was used to quantify the minimum acceptable benefit (MAB) of a switch from PFRT to gene therapy for ‘Annual bleeding rate’ (ABR), ‘Chance to stop prophylaxis’ (STOP), and ‘Quality of life’ (QOL). ‘Time that side effects have been studied’ was also included as an attribute. An educational tool provided patients with information on gene therapy. The design was supported by stakeholder (including HTA, payers and patients) involvement. Threshold intervals were analyzed using interval regression models in Stata 16. A total of 117 patients completed the survey. Mean thresholds were identified for all benefits (ABR, STOP and QOL), but substantial preference heterogeneity was observed. Heterogeneity in STOP thresholds was found to be most extreme and the majority of patients could be classified in two opposite groups. Time spent on the educational tool and residence were found to impact MAB thresholds. Most patients (88%) would accept gene therapy if it would result in 0 bleeds per year (vs. 6 for PFRT), 90% chance to stop prophylaxis, had no impact on QOL, and if there was 10 years of follow-up on side effects (vs. 30 for PFRT). Results from this study confirmed the value of educating patients on novel treatments (e.g. through educational tools) prior to measuring their preferences. Moreover, preference heterogeneity for novel treatments can be expected and was confirmed in this study. In making decisions on gene therapy, regulators, HTA and payers should consider preference heterogeneity and the impact of patient education on acceptance.