The QMG score is a validated outcome comprised of 13 items: ocular (2 items), facial (1 item), bulbar (2 items), gross motor (6 items), axial (1 item), and respiratory (1 item). Each item has a possible score of between 0 and 3 points. The total score range is 0-39 points, with higher score indicating more severe disease.

Outcome measure is reported for the overall population.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

MG-ADL score is an 8-item questionnaire that focuses on relevant symptoms and functional performance of activities of daily living over the previous 7 days. The MG-ADL score assesses disability secondary to ocular (2 items), bulbar (3 items), respiratory (1 item) and gross motor or limb (2 items) impairment related to effects from MG. Each response is graded 0 (normal) to 3 (most severe). The range of total MG-ADL scores is 0-24. A higher score represents more severe disease.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

The QMG score is a validated outcome comprised of 13 items: ocular (2 items), facial (1 item), bulbar (2 items), gross motor (6 items), axial (1 item), and respiratory (1 item). Each item has a possible score of between 0 and 3 points. The total score range is 0-39 points, with higher score indicating more severe disease.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

MG-ADL score is an 8-item questionnaire that focuses on relevant symptoms and functional performance of activities of daily living over the previous 7 days. The MG-ADL score assesses disability secondary to ocular (2 items), bulbar (3 items), respiratory (1 item) and gross motor or limb (2 items) impairment related to effects from MG. Each response is graded 0 (normal) to 3 (most severe). The range of total MG-ADL scores is 0-24. A higher score represents more severe disease.

The protocol-allowed rescue therapy options included intravenous immunoglobulin (IVIg) and therapeutic plasma exchange (PLEX).

Outcome measure is reported for the overall population.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

MG-ADL score is an 8-item questionnaire that focuses on relevant symptoms and functional performance of activities of daily living over the previous 7 days. The MG-ADL score assesses disability secondary to ocular (2 items), bulbar (3 items), respiratory (1 item) and gross motor or limb (2 items) impairment related to effects from MG. Each response is graded 0 (normal) to 3 (most severe). The range of total MG-ADL scores is 0-24. A higher score represents more severe disease.

The protocol-allowed rescue therapy options included IVIg and PLEX.

Outcome measure is reported in Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

MG-ADL score is an 8-item questionnaire that focuses on relevant symptoms and functional performance of activities of daily living over the previous 7 days. The MG-ADL score assesses disability secondary to ocular (2 items), bulbar (3 items), respiratory (1 item) and gross motor or limb (2 items) impairment related to effects from MG. Each response is graded 0 (normal) to 3 (most severe). The range of total MG-ADL scores is 0-24. A higher score represents more severe disease.

The protocol-allowed rescue therapy options included IVIg and PLEX.

Outcome measure is reported for the Anti-AChR-Ab+ population.

The protocol-allowed rescue therapy options included corticosteroids, IVIg and PLEX.

Outcome measure is reported for the Anti-AChR-Ab+ population.

MG-ADL score is an 8-item questionnaire that focuses on relevant symptoms and functional performance of activities of daily living over the previous 7 days. The MG-ADL score assesses disability secondary to ocular (2 items), bulbar (3 items), respiratory (1 item) and gross motor or limb (2 items) impairment related to effects from MG. Each response is graded 0 (normal) to 3 (most severe). The range of total MG-ADL scores is 0-24. A higher score represents more severe disease.

Outcome measure is reported for the Anti-AChR-Ab+ population.

The QMG score is a validated outcome comprised of 13 items: ocular (2 items), facial (1 item), bulbar (2 items), gross motor (6 items), axial (1 item), and respiratory (1 item). Each item has a possible score of between 0 and 3 points. The total score range is 0-39 points, with higher score indicating more severe disease.

Outcome measure is reported for the Anti-AChR-Ab+ population.

The MGC score consists of test items from MG-ADL score and the QMG score, with weighted response options. Scores range from 0-50, with higher scores indicating worse disease manifestations.

Outcome measure is reported for the overall population.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

The MGC score consists of test items from MG-ADL score and the QMG score, with weighted response options. Scores range from 0-50, with higher scores indicating worse disease manifestations.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

The MGC score consists of test items from MG-ADL score and the QMG score, with weighted response options. Scores range from 0-50, with higher scores indicating worse disease manifestations.

Outcome measure is reported for the Anti-AChR-Ab+ population.

MG-ADL score is an 8-item questionnaire that focuses on relevant symptoms and functional performance of activities of daily living over the previous 7 days. The MG-ADL score assesses disability secondary to ocular (2 items), bulbar (3 items), respiratory (1 item) and gross motor or limb (2 items) impairment related to effects from MG. Each response is graded 0 (normal) to 3 (most severe). The range of total MG-ADL scores is 0-24. A higher score represents more severe disease

Outcome measure is reported for the overall population.

Full Analysis Set (FAS): all participants randomized who received at least one dose of investigational product (IP) in the study and had baseline and at least one post-baseline observations.

MGQOL-15r score is a validated, patient-scored instrument, which measures the impact of MG on health-related quality of life (HRQoL). The 15 items in the questionnaire evaluate mobility (9 items), symptoms (3 items), general contentment (1 item), and emotional well-being (2 items) domains. Each item is rated on a 3-point scale ranging from 0 ("not at all") to 2 ("very much") based on their experience "over the past few weeks." Items scores are summed to generate a total score ranging from 0-45, with higher score indicating worse HRQoL.

Outcome measure is reported for the overall population.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

MGQOL-15r score is a validated, patient-scored instrument, which measures the impact of MG on health-related quality of life (HRQoL). The 15 items in the questionnaire evaluate mobility (9 items), symptoms (3 items), general contentment (1 item), and emotional well-being (2 items) domains. Each item is rated on a 3-point scale ranging from 0 ("not at all") to 2 ("very much") based on their experience "over the past few weeks." Items scores are summed to generate a total score ranging from 0-45, with higher score indicating worse HRQoL.

Outcome measure is reported in Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

MGQOL-15r score is a validated, patient-scored instrument, which measures the impact of MG on health-related quality of life (HRQoL). The 15 items in the questionnaire evaluate mobility (9 items), symptoms (3 items), general contentment (1 item), and emotional well-being (2 items) domains. Each item is rated on a 3-point scale ranging from 0 ("not at all") to 2 ("very much") based on their experience "over the past few weeks." Items scores are summed to generate a total score ranging from 0-45, with higher score indicating worse HRQoL.

Outcome Measure is reported for the Anti-AChR-Ab+ population.

The self-report measure PGIC reflects a participant's belief about the efficacy of treatment. PGIC is a 7 point scale depicting a participant's rating of overall improvement. Participant rate their change as "very much improved", "much improved", "minimally improved", "no change", "minimally worse", "much worse", or "very much worse",

Outcome measure is reported for the overall population.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

The self-report measure PGIC reflects a participant's belief about the efficacy of treatment. PGIC is a 7 point scale depicting a participant's rating of overall improvement. Participants rate their change as "very much improved", "much improved", "minimally improved", "no change", "minimally worse", "much worse", or "very much worse".

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

The self-report measure PGIC score reflects a participant's belief about the efficacy of treatment. PGIC is a 7 point scale depicting a participant's rating of overall improvement. participants rate their change as "very much improved", "much improved", "minimally improved", "no change", "minimally worse", "much worse", or "very much worse".

Outcome measure is reported for the Anti-AChR-Ab+ population.

An exacerbation was defined as one of the following:

• Use of protocol defined rescue therapy, or
• Myasthenic crisis, defined as worsening of myasthenic weakness requiring intubation or non-invasive ventilation to avoid intubation, except when these measures are employed during routine postoperative management, or
• Significant symptomatic worsening to a score of 3 or a 2-point worsening from baseline on any one of the individual MG-ADL items other than double vision or eyelid droop.

Outcome measure is reported for the overall population.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

An exacerbation was defined as one of the following:

• Use of protocol defined rescue therapy, or
• Myasthenic crisis, defined as worsening of myasthenic weakness requiring intubation or non-invasive ventilation to avoid intubation, except when these measures are employed during routine postoperative management, or
• Significant symptomatic worsening to a score of 3 or a 2-point worsening from baseline on any one of the individual MG-ADL items other than double vision or eyelid droop.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

An exacerbation was defined as one of the following:

• Use of protocol defined rescue therapy, or
• Myasthenic crisis, defined as worsening of myasthenic weakness requiring intubation or non-invasive ventilation to avoid intubation, except when these measures are employed during routine postoperative management, or
• Significant symptomatic worsening to a score of 3 or a 2-point worsening from baseline on any one of the individual MG-ADL items other than double vision or eyelid droop.

Outcome measure is reported for the Anti-AChR-Ab+ population.

MSE was defined as MG-ADL= 0 or 1.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

Outcome measure is reported for the overall population.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

Outcome measure refers to participants with baseline steroids> 5 mg.

Outcome measure is reported in Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

Outcome measure refers to participants with baseline steroids> 5 mg.

Outcome measure is reported for the Anti-AChR-Ab+ population.

Outcome measure is reported for the overall population.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

Outcome Measure refers to participants with baseline steroids> 5 mg.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

FAS: all participants randomized who received at least one dose of IP in the study and had baseline and at least one post-baseline observations.

Outcome Measure refers to participants with baseline steroids> 5 mg.

Outcome measure is reported for the Anti-AChR-Ab+ population.

An AE is any untoward medical occurrence associated with the use of the IP, whether or not it is considered related. Clinically significant changes from baseline in clinical laboratory results, vital signs and ECGs were also reported as AEs.

An AESI is an event of medical interest specific to the understanding of the IP and which may require close monitoring and collection of additional information.

A SAE is considered "serious" if it results in any of the following outcomes:

• Death;
• A life-threatening AE. An event is considered "life-threatening" if its occurrence places the patient or subject at immediate risk of death;
• Inpatient hospitalization or prolongation of existing hospitalization;
• A persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions;
• A congenital anomaly/birth defect;
• May require medical or surgical intervention to prevent one of the outcomes listed in this definition.

Safety Analyses Set: all participants who received any dose of IP during the RCP.

Treatment emergent ADA were defined as ADA positive post-baseline only or boosted pre-existing ADA titer.

Outcome measure is reported for the overall population.

Safety Analyses Set: all participants who received any dose of IP during RCP.

Treatment emergent ADA were defined as ADA positive post-baseline only or boosted pre-existing ADA titer.

Outcome measure is reported in Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

Safety Analyses Set: all participants who received any dose of IP during RCP.

Treatment emergent ADA were defined as ADA positive post-baseline only or boosted pre-existing ADA titer.

Outcome measure is reported for the Anti-AChR-Ab+ population.

On inebilizumab dosing days, inebilizumab pharmacokinetic (PK) serum samples were collected pre-dose and approximately 15 minutes (± 5 minutes) after completion of the IP infusion.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

PK Analysis Set: all participants who received IP and had at least one quantifiable serum PK observation post first dose.

On inebilizumab dosing days, inebilizumab PK serum samples were collected pre-dose and approximately 15 minutes (± 5 minutes) after completion of the IP infusion.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

PK Analysis Set: all participants who received IP and had at least one quantifiable serum PK observation post first dose.

On inebilizumab dosing days, inebilizumab PK serum samples were collected pre-dose and approximately 15 minutes (± 5 minutes) after completion of the IP infusion.

Outcome measure is reported for the Anti-AChR-Ab+ and Anti-MuSK-Ab+ populations.

PK Analysis Set: all participants who received IP and had at least one quantifiable serum PK observation post first dose.