A Phase IIb, Randomised, Double-blind, Placebo-controlled, Multicentre Study to Evaluate the Efficacy and Safety of Concomitant Use of Eplontersen and ALXN2220 Compared With Eplontersen and Placebo in Adult Participants With Transthyretin-Mediated Amyloid Cardiomyopathy (ATTR-CM) | Arctuva