Safety, Tolerability, PK, and Efficacy Evaluation of Repeat Ascending Doses of Olipudase Alfa in Pediatric Patients <18 Years of Age With Acid Sphingomyelinase Deficiency

TEAEs were defined as adverse events (AEs) that occurred or worsened during the on-treatment period (time from the start of investigational medicinal product [IMP]) administration until end of study (i.e. up to 64 weeks).

IARs were defined as AEs that occurred during the infusion or within up to 24 hours after the start of infusion and were considered as related or possibly related to the study treatment by the investigator or the sponsor. Protocol-defined IAR: all AEs that were identified as an IAR by the investigator. Events occurring greater than or equal to (>=) 24 hours after the start of an infusion might had been judged an IAR at the discretion of the investigator or sponsor.

Change from Normal assessment (at Baseline) to Abnormal assessment (at Week 52) was reported. Physical examinations included following observations/measurements: examination of the skin, head, eyes, ears, nose, and throat; lymph nodes; heart, lungs, and abdomen; extremities and joints. Abnormality in physical examinations was based on investigator's discretion.

Change from Normal assessment (at Baseline) to Abnormal assessment (at Week 52) was reported. Neurological examination included: coordination examination, cranial nerve examination, extrapyramidal features, fundoscopy, gait and coordination examination, motor examination, tone peripheral nervous system, reflexes examination, sensory examination, strength examination, mental status.

Abnormal values in alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, and alkaline phosphatase were reported.

• Heart Rate (HR) High: >=120 beats per minute (bpm) (adolescents), >=120 bpm (children), >=140 bpm (early children), >=175 bpm (infants) & increase from baseline (IFB) >=20 bpm for all age categories.
• HR Low: <=50 bpm (adolescents), <=50 bpm (children), <=75 bpm (early children), <=80 bpm (infants) & decrease from baseline (DFB) >=20 bpm for all age categories.
• Systolic BP (SBP) High: >=119 mmHg (adolescents), 108 mmHg (children), 101 mmHg (in early children), 98 mmHg (infants) & IFB >=20 mmHg for all age categories.
• SBP Low: <=90 mmHg (adolescents), <= 80mm Hg (children), <=70 mmHg (early children), <=70 mmHg (infants) & DFB >=20 mmHg for all age categories.
• Diastolic BP (DBP) High:>=78 mmHg (adolescents), >=72 mmHg (children), >=59 mmHg (in early children), >=54 mmHg (infants) & IFB >=10 mmHg for all age categories.
• DBP Low:<=54 mmHg (adolescents), <=48 mmHg (children), <=34 mmHg (early children), <=34 mmHg (infants) & DFB >=10 mmHg for all age categories.

Criteria for potentially clinically significant ECG abnormalities:

• High PR Interval: >=180 milliseconds (ms) in adolescents, 170 ms in children, 160 ms in early children, and 140 ms in infants;
• High QRS Interval: >=110 ms in adolescents, 100 ms in children, 95 ms in early children and 85 ms in infants;
• Prolonged QTc Fridericia (QTc F): >450 ms in male adolescents, children, early children and infants or 470 ms in female adolescents,
• QTc F >500 ms;
• QTc F increase from baseline >60 ms.

Serum samples for immunogenicity assessment were analyzed to detect ADA. ADA response were categorized as: treatment emergent antibody i.e. treatment-induced/treatment-boosted response. A participant whose ADA status was positive anytime post-baseline and was negative or missing at baseline was considered to have treatment induced ADA. A participant whose ADA status was positive at baseline (pre-existing ADA) and the ADA titer level anytime post-baseline was significantly higher than that at baseline is considered to have treatment boosted ADA. Positive samples in the ADA assay were further analyzed in the NAb assay as positive NAb inhibition of catalytic activity and positive NAb inhibition of cellular uptake.

Evidence of portal hypertension was assessed by portal vein direction from liver ultrasound doppler.

Ceoi was defined as the plasma concentration at the end of infusion (EOI). Data collected for child and Infant/child age groups at 0-30 min from end of infusion was considered at end of infusion.

Cmax: maximum plasma concentration observed.

AUClast: Area under the plasma concentration versus time curve calculated using the trapezoidal method from time zero to the time of last measured concentration.

AUC(0-tau): area under the plot of the drug concentration versus the time curve from time "0" to the end of the dosing interval (tau), where dosing interval was 2 weeks.

Half-life is the time measured for the plasma concentration of drug to decrease by one half.

Drug clearance is a quantitative measure of the rate at which a drug substance is removed from the blood. Total body clearance of a drug from the plasma calculated using equations below: CL = Dose / AUC after the first dose.

Volume of distribution is defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired plasma concentration of a drug.

tmax: time to reach maximum plasma concentration observed.

Spleen and liver volumes was assessed by abdominal magnetic resonance imaging (MRI).

Pulmonary imaging of chest using HRCT was obtained to quantitate the degree of possible infiltrative lung disease. Lung fields were assessed by a central reader & scored subjectively for the degree of interstitial lung disease on a scale ranges from 0 =normal, 1 =mild, 2=moderate and 3 =severe, where higher scores indicate more severity.

Z-score for height of participants was evaluated. Height Z-Score, i.e., the height-for-age Z Score, is the number of standard deviations of the actual height of a child from the median height of the children of the corresponding age and sex as determined from the standard sample. A height Z-score of 0 is equal to the median and is considered normal. Negative numbers indicate values lower than the median and positive numbers indicate values higher than the median. For analysis, mean Z-score was calculated and an increase of mean height Z-score from baseline indicates an improvement on growth.

Percent predicted Hemoglobin-adjusted DLco was calculated as: 100*Adjusted DLco/Predicted DLco in unit of mL CO/min/mmHg where, adjusted DLco = Observed DLco (in mL CO/min/mmHg) divided by Hemoglobin-adjusted factor. Per planned analysis, pulmonary function testing (PFT) was to be performed only on participants >=5 years of age therefore, data for participants in "age cohort: infant/early child" were not collected.

Hand X-ray was performed on participant's left hand, fingers and wrist to assess bone age of participants. At each visit (Baseline and Week 52), difference between the bone age and actual age at that visit was calculated. Difference in age in months was calculated as bone age in months minus real age at time of assessment (in months) at specified time points. In this outcome measure change from baseline at Week 52 in the difference between actual age and bone age (in months) is reported.

Cardiopulmonary status was assessed using a stationary one-wheeled cycle used as an ergometer to measure a person's work output under controlled conditions. Participants were asked to ride the cycle at increasing workload levels until they could no longer proceed. The workload at which participant stopped and cannot proceed was considered as maximum workload (in watt). As per the planned analysis, this assessment was not to be performed on participants that were <=6 years of age or <120 cm in height on day 1/week 0, therefore infant/early child cohort was not evaluable.

Physician assessed participant's current clinical status (refers to clinical status at Week 52 in comparison to Baseline) was evaluated by marking 1 of the following 7 categories: • marked improvement, • moderate improvement, • mild improvement, • no change, • mild worsening, • moderate worsening, or • marked worsening. These 7 categories were converted to scores as follows: 3 = marked improvement of daily activities, 2 = moderate improvement of daily activities, 1 = mild improvement of daily activities, 0 = no change, -1 = mild worsening of daily activities, -2 = moderate worsening of daily activities, -3 = marked worsening of daily activities where higher score indicated improvement in daily activities as compared to baseline. In this outcome measure, observed scores of participant's clinical status at Week 52 are reported.

Efficacy biomarkers included chitotriosidase, chemokine ligand 18 (CCL18), angiotensin-converting enzyme (ACE).

Lipid profile parameters included low density lipoprotein (LDL)-cholesterol, high density lipoprotein (HDL)-cholesterol and triglycerides.

Bone biomarkers included bone specific alkaline phosphatase, C-Telopeptide.

PedsQL includes a child self-report (CS-R) for participants 5 to 18 years and parents' report (PR) of participants 2 to 18 years. CS-R: 23-item PedsQL Generic Core Scales report includes 4 scales, Physical (P), Emotional (E), Social (S), and School Functioning (SF). PR: 21-item PedsQL Generic Core Scales report includes P, E, S, and SF scales. Each item used a 5-point rating scale ( from 0=never to 4=almost always). Items are reverse scored and linearly transformed to a 0 (almost always) -100 (never) scale. Higher score indicates better Health Related Quality of Life (HRQoL). P, E, S and SF summary scores are calculated as mean of respective functioning items. Psychosocial Health Summary Score is calculated as mean of 13 or 15 items (E, S and SF). Generic core total scale score is calculated as the mean of all the 21 or 23 items (P, E, S and SF). All summary/total scores are mean of specific items and they all have values ranges from 0 to 100, where higher score=better HRQoL.

Sphingomyelin and Lyso-sphingomyelin levels were assessed in plasma. Lyso-sphingomyelin is a metabolite of sphingomyelin.