ABSTRACT
INTRODUCTION APOLLO-B is a Phase 3 study of patisiran in patients with transthyretin (ATTR) cardiac amyloidosis (NCT03997383), which demonstrated a significant benefit in functional capacity (6-MWT), and health status and quality of life (QoL) (KCCQ-OS) with patisiran vs placebo at Month (M) 12. HYPOTHESIS Patisiran improves health status and QoL in the daily lives of patients with ATTR cardiac amyloidosis vs placebo. METHODS Patients were 18-85 years old with ATTR amyloidosis and a medical history of heart failure (HF) due to ATTR cardiomyopathy, with ≥1 prior hospitalization for HF or current clinical evidence of HF. Patients were randomized (1:1) to intravenous patisiran 0.3 mg/kg or placebo every 3 weeks. These post-hoc analyses evaluated percentage of responders reporting ≥5-point improvement in KCCQ-OS, and change from baseline in 4 KCCQ domains and questions within the domains. RESULTS 359 patients received study drug (patisiran, N=181; placebo, N=178): median age (range), 76 (41, 85) years; male, 89%; wild-type ATTR, 80%; 25% were on tafamidis at baseline. At M12, patisiran showed significant benefit vs placebo in KCCQ-OS (LS mean [SEM] change from baseline: patisiran, 0.30 [1.26]; placebo, -3.41 [1.28]; LS mean [SEM] difference: 3.71 [1.80]; p=0.0397). A ≥ 5-point improvement in KCCQ at M12 was more frequent with patisiran vs placebo (34.1 vs 24.0%: difference [95% CI] 10.1% [0.7, 19.5]). Improvement vs placebo was consistent across domains, with LS mean differences [95% CI] in change from baseline (patisiran - placebo) in Physical Limitations (2.75 [-1.24, 6.74]), Total Symptoms (4.55 [0.75, 8.34]), QoL (4.27 [-0.12, 8.65]), and Social Limitations (2.76 [-2.21, 7.73]). Categorical changes from baseline to M12 demonstrated greater percentages of placebo-treated patients reporting worsening for questions in each domain, including activities requiring greater cardiometabolic demand. In patients with values at baseline and M12, notably greater percentages (>5%) of placebo- vs patisiran-treated patients reported worsening (percent difference; n=placebo/patisiran) for questions related to Walking 1 Block on Level Ground (10%; n=159/162), Frequency and Burden of Dyspnea (9.5% and 7.6%; n=164/170), Frequency of Orthopnea (9.6%; n=163/170), Feeling about Spending the Rest of Their Life with HF the Way It Is Right Now (6.4%; n=164/170), and Intimate Relationships (6.3%; n=88/86). Improvement from baseline was reported by greater percentages (>5%) of patisiran-treated patients (percent difference; n=patisiran/placebo) in Enjoyment of Life Limited Due to HF (12.8%; n=170/164) and Hobbies/Recreational Activities (6.0%; n=141/143). CONCLUSIONS In APOLLO-B, improvements in health status and QoL with patisiran vs placebo were apparent across all 4 KCCQ domains. Greater percentages of patisiran-treated patients had KCCQ-OS improved by ≥ 5 points at M12 and they more often reported improvements in QoL, and ability to enjoy life and perform hobbies/recreational activities. More placebo-treated patients reported worsening in walking on level ground, HF symptoms and QoL.