 All participants were required to return for safety follow-up SFU assessments at Weeks 4, 12, 24, 36, and 48 after withdrawal or completion of the study. Participants whose peripheral CD20 B cells remained depleted at the end of the SFU periods for the primary and OL portions of the study entered extended safety follow-up ESFU. Assessments for ESFU were performed at 12-week intervals until peripheral B-cell levels returned to within normal range or baseline level whichever was lower. 