An Open-Label Uncontrolled Multicenter Study to Evaluate the Pharmacokinetics, Pharmacodynamics, Safety and Activity of Nipocalimab in Children Aged 2 to Less Than 18 Years With Generalized Myasthenia Gravis

Primary

• Change from Baseline in Total Serum Immunoglobulin-G (IgG) Levels

  Change from baseline in total serum IgG levels were reported.

  Time frame: Up to 3 years

• Number of Participants with Infectious Adverse Events (AEs)

  Number of participants with infectious AEs will be reported. An AE is any untoward medical occurrence in a participant participating in a clinical study that does not necessarily have a causal relationship with the pharmaceutical/biological agent under study.

  Time frame: Up to 3 years

• Number of Participants with Serious AEs (SAEs)

  Number of participants with SAEs will be reported. A SAE is any AE that results in: death, persistent or significant disability/incapacity, requires inpatient hospitalization or prolongation of existing hospitalization, is life-threatening experience, is a congenital anomaly/birth defect, is suspected transmission of any infectious agent via a medicinal product, is medically important to prevent one of the outcomes listed above.

  Time frame: Up to 3 years

• Number of Participants with Adverse Events of Special Interests (AESIs)

  Number of participants with AESIs will be reported. Treatment-emergent AEs associated with the following situations are considered an AESI: a) infections that are severe or require intravenous (IV) anti-infective or operative/invasive intervention; b) hypoalbuminemia with albumin less than (\<)20 grams per liter (g/L) \[\<\] 2.0 grams per deciliter \[g/dL\]) c) opportunistic infections and d) Serious and non-serious deep-vein thrombosis (DVT) and/or pulmonary embolism (PE). Any AE occurring at or after the initial administration of study intervention through end of study is treatment emergent.

  Time frame: Up to 3 years

• Number of Participants with Abnormalities in Clinical Laboratory Tests

  Number of participants with abnormalities in clinical laboratory tests (including chemistry, hematology, coagulation, and urinalysis) will be reported.

  Time frame: Up to 3 years

• Number of Participants with Abnormalities in Vital Signs

  Number of participants with abnormalities in vital signs including sitting pulse/heart rate, sitting systolic and diastolic blood pressure, and oral temperature (degrees Celsius) will be reported.

  Time frame: Up to 3 years

• Number of Participants with Abnormalities in Physical Examination

  Number of participants with abnormalities in physical examinations including height, weight, assessments of the skin, head, eyes, ears, nose, throat, neck, thyroid, lungs, heart, abdomen, lymph nodes and extremities will be reported.

  Time frame: Up to 3 years

• Serum Concentration of Nipocalimab over Time

  Serum samples will be analyzed to determine concentrations of nipocalimab using a validated, specific, and sensitive immunoassay method.

  Time frame: Up to 3 years

• Clearance (CL) of Nipocalimab

  CL is defined as the volume of serum from which nipocalimab is completely removed per unit time.

  Time frame: Up to 3 years

• Volume of Distribution (V) of Nipocalimab

  V is defined as the representation of nipocalimab's propensity to either remain in the serum or redistribute to other tissue compartments.

  Time frame: Up to 3 years

• Half-life (t1/2) of Nipocalimab

  t1/2 is defined as the time it takes for nipocalimab's active substance in the body to reduce by half.

  Time frame: Up to 3 years

• Steady-state Peak Concentration (Cpeak,ss) of Nipocalimab

  Cpeak,ss is defined as the peak serum concentration of nipocalimab at steady state.

  Time frame: Up to 3 years

• Steady-state Trough concentration (Ctrough,ss) of Nipocalimab

  Ctrough,ss will be reported. It is defined as the observed serum concentration of nipocalimab just prior to the beginning of a dosing interval at steady state.

  Time frame: Up to 3 years

• Steady-state Area Under the Curve (AUCss) of Nipocalimab

  AUCss is defined as the area under the curve for nipocalimab at steady state.

  Time frame: Up to 3 years