S270: LONGER-TERM ANALYSIS OF EFFICACY OF LUSPATERCEPT VERSUS PLACEBO IN PATIENTS WITH TRANSFUSION-DEPENDENT BETA-THALASSEMIA ENROLLED IN THE BELIEVE STUDY - M. D. Cappellini; A. T. Taher; J. B. Porter; K. H. Kuo; T. D. Coates; E. Voskaridou; G. L. Forni; S. Perrotta; A. Khelif; A. Lal; A. Kattamis; A. Piga; et al. (HemaSphere, 2022)