Effect of etranacogene dezaparvovec on quality of life for severe and moderately severe haemophilia B participants: Results from the phase III HOPE‐B trial 2 years after gene therapy

Abstract

AbstractIntroductionFor people with haemophilia B (PwHB), bleeding may occur despite prophylaxis, negatively affecting health‐related quality of life (HRQoL). The pivotal phase 3 HOPE‐B trial investigating the adeno‐associated virus gene transfer product, etranacogene dezaparvovec (EDZ), demonstrated sustained factor IX (FIX) activity and bleed protection in PwHB with baseline FIX levels ≤2%.AimAssess how EDZ affects HRQoL in HOPE‐B trial participants.MethodsHRQoL was evaluated using generic and disease‐specific patient reported outcomes (PROs) including the EQ‐5D‐5L and the Hem‐A‐QoL questionnaires. Mean domain and total scores were compared 6 months pre‐ and the first 2 years post‐EDZ administration using repeated measures linear mixed models. The percentage of participants with minimal clinically important improvements in HRQoL was also evaluated.ResultsTwo years post‐EDZ, there were nominally significant increases in the least squares (LS) mean score for the EQ‐5D‐5L Index Value (.04; p = .0129), reflecting better HRQoL. Nominally significant decreases in the LS mean scores, reflecting better HRQoL, were also found for the Hem‐A‐QoL total score (−6.0; p < .0001) and the Treatment (−13.94; p < .0001), Feelings (−9.01; p < .0001), Future (−6.45; p = .0004) and Work/School (−5.21; p = .0098) domains. The percentage of participants with ≥15‐point improvement ranged from 45.83% (95% CI: 31.37%, 60.83%) for Treatment to 13.89% (95% CI: 4.67%, 29.50%) for Family Planning. Results were similar for Year 1.ConclusionIn conclusion, gene therapy with EDZ improved HRQoL in the first and second years in several Hem‐A‐QoL domains, including Treatment, Feelings, Work/School and Future domains, whereas improvement in other aspects of HRQoL were not demonstrated.