S270: LONGER-TERM ANALYSIS OF EFFICACY OF LUSPATERCEPT VERSUS PLACEBO IN PATIENTS WITH TRANSFUSION-DEPENDENT BETA-THALASSEMIA ENROLLED IN THE BELIEVE STUDY. (23rd June 2022) - Cappellini, M. D.; Taher, A. T.; Porter, J. B.; Kuo, K. H.; Coates, T. D.; Voskaridou, E.; Forni, G. L.; Perrotta, S.; Khelif, A.; Lal, A.; Kattamis, A.; Piga, A.; et al.