Eplontersen reduces serum TTR in patients with hereditary transthyretin amyloidosis with polyneuropathy

BACKGROUND: This exploratory analysis of the NEURO-TTRansform Phase 3 trial evaluated the efficacy of eplontersen in patients with hereditary transthyretin (ATTRv) amyloidosis with polyneuropathy by genetic variant. METHODS: Changes from baseline in NEURO-TTRansform primary endpoints serum transthyretin (TTR) at Week 65, modified Neuropathy Impairment Score+7 (mNIS+7) composite score, and Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QoL-DN) total score at Week 66 were evaluated in patients with early-onset (aged < 50 years) and late-onset (aged ≥ 50 years) Val30Met (p.Val50Met) or non-Val30Met ATTRv amyloidosis with polyneuropathy. Secondary endpoints from NEURO-TTRansform were also evaluated by genetic variant. RESULTS: In total, 144 patients with early-onset (n = 54) or late-onset (n = 31) Val30Met or non-Val30Met (n = 59), ATTRv amyloidosis with polyneuropathy were randomized to eplontersen. A further 60 patients from NEURO-TTR with early-onset (n = 16) or late-onset (n = 17) Val30Met or non-Val30Met (n = 27), served as a historical placebo group. The mean percentage difference (95% confidence interval) in serum TTR was -79.9 (-87.8, -72.0), -85.0 (-93.3, -76.6), and -70.6 (-77.7, -63.5) with eplontersen versus placebo in the early- and late-onset Val30Met, and non-Val30Met groups, respectively. Across subgroups, the change from baseline to Week 66 in mNIS+7 composite score was generally well maintained, and the Norfolk QoL-DN total score improved with eplontersen versus worsening with placebo. The Polyneuropathy Disability score was maintained in most patients. From baseline to Week 65, the modified body mass index was maintained with eplontersen compared to a marked reduction (worsening) for placebo. CONCLUSIONS: Findings were suggestive of consistent benefits in reducing neuropathy impairment and improving QoL with eplontersen versus historical placebo, across TTR variants. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04136184, NCT01737398.