Phase 3 Efficacy and Safety Study of BG00012 in Pediatric Participants With Relapsing-Remitting Multiple Sclerosis (RRMS)

Participants who were free of new or newly enlarging T2 hyperintense lesions were assessed on Brain MRI scans.

An adverse event (AE) was any unfavorable and unintended sign (including an abnormal assessment such as an abnormal laboratory value), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. An SAE was any untoward medical occurrence that at any dose resulted in death, in the view of the Investigator, placed the participant at immediate risk of death, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, resulted in a birth defect. TEAEs were defined as AEs occurring or worsening after beginning study treatment (after the first dose).

An AE was any unfavorable and unintended sign (including an abnormal assessment such as an abnormal laboratory value), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product.

The number of new or newly enlarging T2 hyperintense lesions that developed in each participant was assessed on Brain MRI scans.

Participants who were free of new or newly enlarging T2 hyperintense lesions were assessed on Brain MRI scans.

Participants free of Gd-enhancing MRI lesions and new or newly enlarging T2 MRI lesions were assessed on Brain MRI Scans.

Relapses are defined as new or recurrent neurologic symptoms not associated with fever or infection, lasting at least 24 hours, and accompanied by new objective neurological findings upon examination by the examining neurologist. The time to first relapse was defined as the time from the first dose in Part 1 up to the first relapse. Time to First Relapse was estimated by Kaplan-Meier method.

Relapses are defined as new or recurrent neurologic symptoms not associated with fever or infection, lasting at least 24 hours, and accompanied by new objective neurological findings upon examination by the examining neurologist. The proportion of relapse-free participants was estimated using the Kaplan-Meier method.

ARR is calculated as the total number of relapses that occurred during the study divided by the total number of participant-years. ARR was analyzed using negative binomial regression model.

An AE was any unfavorable and unintended sign (including an abnormal assessment such as an abnormal laboratory value), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. An SAE was any untoward medical occurrence that at any dose resulted in death, in the view of the Investigator, placed the participant at immediate risk of death, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, resulted in a birth defect. TEAEs were defined as AEs occurring or worsening after beginning study treatment (after the first dose).

Negative change from baseline indicated reduction in temperature.

Negative change from baseline indicated reduction in pulse rate.

Negative change from baseline indicated reduction in blood pressure.

Negative change from baseline indicated reduction in respiratory rate.

Clinical significance of abnormalities in ECG was determined based on the investigator's discretion. Shift to abnormal indicated values that were normal or unknown at baseline and shifted to abnormal values post-baseline.

Hematology parameters included leukocytes, erythrocytes, hemoglobin, hematocrit, platelets, eosinophils, lymphocytes, monocytes and neutrophils. These parameters were flagged as low, normal, or high relative to parameter's normal range or as unknown if no result was available. Here, shift to low indicated values that were normal, high or unknown at baseline and shifted to low values postbaseline. Shift to high indicated values that were normal, low or unknown at baseline and shifted to high postbaseline values. The categories with at least one participant with shift from baseline in these parameters are reported.

A negative change from baseline indicated a reduction in aPTT.

A negative change from baseline indicated a reduction in PT.

A negative change from baseline indicated a reduction in clotting time.

Parameters included sodium, potassium, chloride, bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma glutamyl transferase, urea nitrogen, creatinine, bicarbonate, calcium, magnesium, phosphate, urate and glucose. These parameters were flagged as low, normal or high relative to parameter's normal range or as unknown if no result was available, by Investigator. Here, shift to low indicated values that were normal, high or unknown at baseline and shifted to low values postbaseline. Shift to high indicated values that were normal, low or unknown at baseline and shifted to high values postbaseline. Categories with at least one participant with shift from baseline in these parameters are reported.

Urinalysis included assessments of glucose, ketones, occult blood, protein, specific gravity. These parameters were flagged as low, normal, or high relative to parameter's normal range or as unknown if no result was available, by the Investigator. Here, shift to low indicated values that were normal, high or unknown at baseline and shifted to low values postbaseline. Shift to high indicated values that were normal, low or unknown at baseline and shifted to high postbaseline. The categories with at least one participant with shift from baseline in these parameters are reported.

The PedsQL multidimensional fatigue questionnaire was answered by the participant (self-assessment) and parent. The fatigue scale contains 18 questions in 3 fatigue dimensions: general fatigue, sleep/rest fatigue and cognitive fatigue. Each item was scored on 5-point Likert scale (0=never to 4=almost always). Each individual score was then reversed (subtracted from 4) and linearly transformed as follows: 0=100, 1=75, 2=50, 3=25, 4=0. For each dimension, total score was calculated as the sum of all the items/number of items answered. A higher total score indicated fewer problems.

The PedsQL QOL questionnaire was answered by the participant (self-assessment) and parent. The QoL scale contains 23 questions in 4 dimensions: Physical Functioning, Emotional Fatigue, Social Fatigue and School Fatigue. Each item was scored on 5-point Likert scale (0=never to 4=almost always). Each individual score was then reversed (subtracted from 4) and linearly transformed as follows: 0=100, 1=75, 2=50, 3=25, 4=0. For each dimension, total score was calculated as the sum of all the items/number of items answered. A higher total score indicated better quality of life.

The EDSS measures the disability status of participants with multiple sclerosis on a scale that ranges from 0 to 10. The first levels 1.0 to 4.5 refer to people with a high degree of ambulatory ability and the subsequent levels 5.0 to 9.5 refer to the loss of ambulatory ability. The range of main categories include (0) = normal neurologic exam; to (5) = ambulatory without aid or rest for 200 meters; disability severe enough to impair full daily activities; to (10) = death due to MS with higher scores indicating more disability. A negative change from baseline indicated an improvement in the disability.

ARR is calculated as the total number of relapses that occurred during the study divided by the total number of participant-years. ARR was analyzed using negative binomial regression model.

The EDSS measures the disability status of participants with multiple sclerosis on a scale that ranges from 0 to 10. The first levels 1.0 to 4.5 refer to people with a high degree of ambulatory ability and the subsequent levels 5.0 to 9.5 refer to the loss of ambulatory ability. The range of main categories include (0) = normal neurologic exam; to (5) = ambulatory without aid or rest for 200 meters; disability severe enough to impair full daily activities; to (10) = death due to MS. A negative change from baseline indicated an improvement in the disability.

BVMT-R is used to assess learning/memory. In this test, six abstract designs are presented for 10 sec. The display is removed from view, and participants render the stimuli via pencil on paper, manual responses. Each design receives from 0 to 2 points, representing accuracy and location. There are three Learning Trials, and the score is reported as the total number of points earned over the trials. Thus, scores range from 0 to 12 per trial; total score range is 0 to 36 for all three trials. Scores were converted to standardized scores using normative data, ranging from 2-86. The lower the score, the more severe the cognitive impairment while higher scores reflect better visuospatial memory.

SDMT is used to assess processing speed. It consists of 9 abstract symbols. Each symbol is paired with a single digit. The participant is provided with a key, showing each symbol digit pair. In addition, the participants are shown several rows of the 9 symbols, which are arranged pseudo-randomly, without the digit. Participants are asked to voice the digit associated with each symbol as rapidly as possible for 90 seconds. The SDMT score ranges from 0 to 110, where higher scores indicate improvement in cognitive functioning and lower scores indicate worsening.

Participants or caregivers were posed the following question: "During the past year, did [you/the participant] progress from one [class/grade-level] to the next in school?" Responses were recorded as Yes (participant advanced to the next grade) or No (participant did not advance).

Negative change from baseline indicated reduction in temperature.

Negative change from baseline indicated reduction in pulse rate.

Negative change from baseline indicated reduction in blood pressure.

Negative change from baseline indicated reduction in respiratory rate.

Clinical significance of abnormalities in ECG was determined based on the investigator's discretion. Shift to abnormal indicated values that were normal or unknown at baseline and shifted to abnormal values post-baseline.

Hematology parameters included leukocytes, erythrocytes, hemoglobin, hematocrit, platelets, eosinophils, lymphocytes, monocytes and neutrophils. These parameters were flagged as low, normal, or high relative to parameter's normal range or as unknown if no result was available. Here, shift to low indicated values that were normal, high or unknown at baseline and shifted to low values postbaseline. Shift to high indicated values that were normal, low or unknown at baseline and shifted to high postbaseline values. The categories with at least one participant with shift from baseline in these parameters are reported.

Parameters included potassium, bilirubin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase, urea nitrogen, creatinine, bicarbonate, calcium, magnesium, phosphate, urate and glucose. These parameters were flagged as low, normal or high relative to parameter's normal range or as unknown if no result was available, by Investigator. Here, shift to low indicated values that were normal, high or unknown at baseline and shifted to low values postbaseline. Shift to high indicated values that were normal, low or unknown at baseline and shifted to high values postbaseline. Categories with at least one participant with shift from baseline in these parameters are reported.

Urinalysis included assessments of erythrocytes, leukocytes and specific gravity. These parameters were flagged as low, normal, or high relative to parameter's normal range or as unknown if no result was available, by the Investigator. Here, shift to low indicated values that were normal, high or unknown at baseline and shifted to low values postbaseline. Shift to high indicated values that were normal, low or unknown at baseline and shifted to high postbaseline. The categories with at least one participant with shift from baseline in these parameters are reported.

Bone age was tested until the participant reached a bone age of 16 years.

Tanner pubertal staging in males was assessed for testes and scrotum development and pubic hair growth, progressing from stage 1 (prepubertal) to stage 5 (adult). Assessments ended when bone age reached ≥16 years. Testes and scrotum stages were: 1-prepubertal; 2-enlargement of testes, scrotum reddens, texture change; 3-Enlargement of penis, further growth of testes; 4-Increased size of penis with growth in breadth and development of glans; testes and scrotum larger, scrotum skin darker; 5-adult genitalia. Pubic hair stages were: 1-prepubertal; 2-Sparse growth of long, slightly pigmented hair, straight or curled; 3-Darker, coarser and more curled hair, spreading sparsely over junction of pubes; 4-Hair adult in type, but covering smaller area than in adult; no spread to medial surface of thighs; 5-Adult in type and quantity, with horizontal distribution.

Tanner pubertal staging in females was assessed for breast development and pubic hair growth, progressing from stage 1 (prepubertal) to stage 5 (adult). Assessments ended when bone age reached ≥16 years or the participant was post-menarche. Breast development stages: 1-prepubertal; 2-breast bud stage with elevation of breast and papilla; enlargement of areola, 3-further enlargement of breast and areola; no separation of their contour; 4-areola and papilla form secondary mound above level of breast; 5-mature stage: projection of papilla only, related to recession of areola. Pubic hair stages: 1-prepubertal (can see velus hair similar to abdominal wall); 2-sparse growth of long, slightly pigmented hair, straight or curled, mainly on labia; 3-Darker, coarser and more curled hair, spreading sparsely over junction of pubes; 4-hair adult in type, but covering smaller area than in adult; no spread to medial surface of thighs; 5-adult in type and quantity, with horizontal distribution.