- Participant must be a minimum of 18 years of age inclusive at the time of signing the informed consent form (ICF) - Participant must have received at least 1 dose of investigational medicinal product (IMP) (rozanolixizumab or placebo) in MG0038 - Participant for whom the investigator considers a favorable benefit/risk for participation - Participant who, alone or with assistance of the caregiver, is considered reliable and capable of adhering to the protocol visit schedule or medication intake according to the judgement of the investigator - Male or female - A female participant is eligible to participate if she is not, not breastfeeding (including pumping breastmilk to feed a child), and at least 1 of the following conditions applies: ◦ Not a woman of childbearing potential (WOCBP) ◦ OR ◦ A WOCBP who agrees to follow the contraceptive guidance for the entire study period - Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the ICF and in the protocol