A Study to Evaluate Rozanolixizumab in Study Participants With Generalized Myasthenia Gravis

The purpose of this study is to assess the safety, tolerability and efficacy of additional 6-week treatment cycles with rozanolixizumab in study participants with generalized myasthenia gravis (gMG).

Inclusion Criteria: * Study participant must meet one of the following: 1. completed MG0003 \[NCT03971422\] 2. required rescue therapy during the Observation Period in MG0003 or 3. completed at least 6 visits in MG0004 \[NCT04124965\] * Body weight ≥35 kg at Baseline (Day 1) * Study participants may be male or female Exclusion Criteria: * Study participant has a known hypersensitivity to any components of the study medication or other anti-neonatal Fc receptor (FcRn) medications * Study participant with a known tuberculosis (TB) infection, at high risk of acquiring TB infection, or latent tuberculosis infection (LTBI), or current/history of nontuberculous mycobacterial infection (NTMBI) * Study participant met any mandatory withdrawal or mandatory study drug discontinuation criteria in MG0003, or MG0004, or permanently discontinued study drug in either study * Study participant intends to have a live vaccination during the course of the study or within 8 weeks following the final dose of rozanolixizumab * Study participant with severe (defined as Grade 3 on the Myasthenia Gravis-Activities of Daily Living (MG-ADL) scale) weakness affecting oropharyngeal or respiratory muscles, or who has myasthenic crisis or impending crisis