Estimating Meaningful Differences in Measures of Neuropathic Impairment, Health-Related Quality of Life, and Nutritional Status in Patients With Hereditary Transthyretin Amyloidosis.

Introduction/aims: The degree of change in neuropathic impairment and quality of life (QoL) that is clinically meaningful to patients with hereditary transthyretin amyloidosis with polyneuropathy (ATTRv-PN) is not established. This study aimed to estimate the magnitude of treatment differences that are meaningful to patients in measures of neuropathy and QoL and to determine whether eplontersen achieved a meaningful improvement versus placebo.

Methods: Data from the NEURO-TTRansform trial on patients with ATTRv-PN treated with eplontersen (n = 141) or historical placebo (n = 59) were used. Anchor-based approaches were used to estimate thresholds for meaningful differences in the modified Neuropathy Impairment Score +7 (mNIS+7) composite score, Norfolk QoL-Diabetic Neuropathy (Norfolk QoL-DN) total score, Neuropathy Symptoms and Change (NSC) total score, and modified body mass index (mBMI). Differences between the least squares means of the treatment groups were analyzed.

Results: Meaningful improvement in mNIS+7 was estimated as -4.0 points and deterioration as 1.8 points. The estimated ranges of meaningful improvement and deterioration in Norfolk QoL-DN were -12.8 to -4.0 points, and 5.9 to 14.7 points, respectively. For NSC, ranges were -2.4 to -1.3 points for meaningful improvement, and 0.6 to 5.8 points for deterioration. The estimated meaningful improvement in mBMI was 9.8 kg/m² × g/L and deterioration was -40.9 kg/m² × g/L. Improvements in each measure with eplontersen versus placebo were greater than the estimates of meaningful differences.

Discussion: Eplontersen demonstrated a clinically meaningful effect on neuropathic impairment, QoL, and nutritional status. Such estimates have implications for clinical practice and trials.