A Study of AEB1102 (Pegzilarginase) in Patients With Arginase 1 Deficiency

Change in plasma arginine concentrations from study Baseline

Change in plasma argininic acid concentrations from study Baseline

Change in plasma guanidinoacetic acid concentrations from study Baseline

Change in plasma α-keto-δ-guanidinovaleric acid concentrations from study Baseline

Change in plasma α-N-acetylarginine concentrations from study Baseline

Change in 6MWT distance from study Baseline

Change from study Baseline. The GMFM-D evaluates the patient's ability to stand via assessment of 13 activities, each of which is scored on a scale of 0 to 3, with a scale range of 0-39 points. An increase in GMFM-D score indicates improvement in standing.

Change from study Baseline. The GMFM-E evaluates a subject's ability to walk, run, and jump via assessment of 24 activities, each of which is scored on a scale of 0 to 3, , with a scale range of 0-72. A higher GMFM-E score indicates greater ability, with increasing scores indicating improvement in walking, running, and jumping.

Spasticity improvement for lower body muscle groups based on MAS from study Baseline. The MAS is used to measure the resistance to passive movement about a joint due to spasticity using a 6-point scoring scale with possible values of 0, 1, 1+ (scored as 1.5), 2, 3, and 4, where 0 is no increase in muscle tone (no spasticity) and 4 is affected part(s) rigid in flexion or extension (total rigidity). Thus, a decrease in MAS score indicates improvement in spasticity.

Change from study Baseline. The BBS, a measure of balance, utilizes a 5-point scoring scale of 0 (indicating the lowest level of function) to 4 (indicating the highest level of function) for 14 tasks, giving a scale range of 0-56, with a higher score representing better balance.

Change from study Baseline. The Purdue Pegboard Test evaluates manipulative dexterity and bimanual coordination, measuring performance speed in a fine motor task via gross movements of the arms, hands, and fingers, as well as fine motor extremity dexterity. A higher Purdue Pegboard Test score indicates better dexterity and coordination. Scores were compared to normative data, compiled from healthy individuals, to produce a Z-score (0 being population mean). A positive Z-score indicates the raw score is higher than the mean average; a negative Z-score indicates the raw score is below the mean average.

Change from study Baseline. The Purdue Pegboard Test evaluates manipulative dexterity and bimanual coordination, measuring performance speed in a fine motor task via gross movements of the arms, hands, and fingers, as well as fine motor extremity dexterity. A higher Purdue Pegboard Test score indicates better dexterity and coordination. Scores were compared to normative data, compiled from healthy individuals, to produce a Z-score (0 being population mean). A positive Z-score indicates the raw score is higher than the mean average; a negative Z-score indicates the raw score is below the mean average.

Hyperammonemic episodes" are defined as either an AE for which an Investigator observed symptoms considered to be consistent with a "hyperammonemic episode", or an AE in a patient meeting all 3 of the following criteria: 1. Confirmed ammonia level ≥100 μM, 2. One or more symptoms related to hyperammonemia, 3. Requiring hospitalization or emergency room management.