A Study to Evaluate the Safety and Efficacy of BIIB104 in Participants With Cognitive Impairment Associated With Schizophrenia (CIAS)

The MCCB is a cognitive battery that assesses 7 domains recommended by the MATRICS initiative (i.e., Working Memory, Verbal Learning, Speed of Processing, Attention/Vigilance, Visual Learning, Social Cognition, and Reasoning and Problem Solving). MCCB was administered via laptop computer and paper-and-pencil assessments. T-scores for the individual tests were calculated according to the developer's recommended scoring algorithms. MCCB composite T scores are between 40 and 60 (normal range). Higher scores indicate better cognitive functioning. The working memory domain score of the MCCB is reported in this outcome measure.

An AE is any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An SAE is any untoward medical occurrence that at any dose results in death, places the participant at immediate risk of death, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, results in a congenital anomaly/birth defect, or is a medically important event.

The SARA is a clinical scale that is based on a semiquantitative assessment of cerebellar ataxia on an impairment level and complements the brief neurological examination. The SARA scale is an eight-item clinical rating scale (gait, stance, sitting, speech, finger-chase test, nose-finger test, fast alternating movements, and heel-shin test) with a total score range of 0-40, where 0 is the best neurological status and 40 is the worst neurological status.

The C-SSRS is an interview-based rating scale to systematically assess suicidal ideation and suicidal behavior. Suicidal ideation is classified on a 5-item scale: 1 (wish to be dead), 2 (nonspecific active suicidal thoughts), 3 (active suicidal ideation with any methods [not plan] without intent to act), 4 (active suicidal ideation with some intent to act, without specific plan), and 5 (active suicidal ideation with specific plan and intent). Suicidal behavior is classified on a 6-item scale: 1 (actual attempt), 2 (interrupted attempt), 3 (aborted attempt), 4 (preparatory acts or behavior), 5 (suicidal behavior), and 6 (suicide). The data analyzed signifies the participants with at least one event of suicidal ideation and/or suicidal behavior.

The UPSA-Bi, international version, an abbreviated version of the UPSA-Validation of Intermediate Measures, is a measure of functional capacity and assesses skills used in community tasks. This assessment measures 2 general skills that were previously identified as essential to functioning in the community: financial skills and communication skills. The UPSA-Bi assessment is scored from 0-100, higher scores indicating higher functional status.

The SCoRS is an interview-based assessment of cognition that involves interviews with participants and informants. The SCoRS includes 20 items designed to specifically assess aspects of cognitive functioning found in each of the seven MCCB cognitive domains including the following: Memory: 4 items; Learning: 2 items; Attention: 3 items; Working memory: 2 items; Problem solving: 3 items; Processing/motor speed: 2 items; Social cognition: 3 items; Language: 1 item. Total score range is 20-80, lower scores indicating higher functional status. The data reported in this outcome measure are for global rating score.

The MCCB is a cognitive battery that assesses 7 domains recommended by the MATRICS initiative (i.e., Working Memory, Verbal Learning, Speed of Processing, Attention/Vigilance, Visual Learning, Social Cognition, and Reasoning and Problem Solving). MCCB was administered via laptop computer and paper-and-pencil assessments. T-scores for the individual tests were calculated according to the developer's recommended scoring algorithms. MCCB composite T scores are between 40 and 60 (normal range). Higher scores indicate better cognitive functioning. The MCCB composite score contains all of the tests and domains of the MCCB.

The MCCB is a cognitive battery that assesses 7 domains recommended by the MATRICS initiative (i.e., working memory, verbal learning, speed of processing, attention/vigilance, visual learning, social cognition, and reasoning and problem solving). MCCB was administered via laptop computer and paper-and-pencil assessments. T-scores for the individual tests were calculated according to the developer's recommended scoring algorithms. MCCB composite T scores are between 40 and 60 (normal range). Higher scores indicate better cognitive functioning. All the domain scores of the MCCB are reported in this outcome measure with the exception of working memory domain.

The PANSS includes 3 subscales and 30 items: 7 items that make up the Positive subscale (e.g., delusions, conceptual disorganization, hallucinatory behaviour); 7 items that make up the Negative subscale (e.g., blunted affect, emotional withdrawal, poor rapport, passive/apathetic social withdrawal); and 16 items that make up the General Psychopathology subscale (e.g., somatic concern, anxiety, guilt feelings, mannerisms and posturing, motor retardation, uncooperativeness, disorientation, poor impulse control, preoccupation). Each item on the positive, negative and general psychopathology subscale is rated from 1 (absent) to 7 (extreme). The score range is 7-49 for positive and negative subscales, score range is 16-112 for the general psychopathology subscale. Total PANSS score (positive+ negative + general psychopathology subscale scores) range from 30 to 210. Higher scores represent more severity in symptoms.

The CGI-S consists of a single 7-point rating score of illness severity. The following question: "Considering your total clinical experience with this particular population, how mentally ill is your participant at this time?" is rated with a score from 1 to 7- 1: Normal, not ill at all; 2: Borderline mentally ill; 3: Mildly ill; 4: Moderately ill; 5: Markedly ill; 6: Severely ill; or 7: Among the most severely ill participants. Lower scores indicate less severity of illness.

The CGI-I consists of a single 7-point rating score total improvement, regardless of whether or not the change is due entirely to drug treatment. The following question: "Compared to your participant's condition at the beginning of treatment, how much has your participant changed?" is rated with a score from 1 to 7- 1: Very much improved; 2: Much improved; 3: Minimally improved; 4: No change; 5: Minimally worse; 6: Much worse; or 7: Very much worse. Lower scores indicate greater improvement.