Trial Outcomes & Findings for Multicenter Study of HGT-1110 Administered Intrathecally in Children With Metachromatic Leukodystrophy (MLD) (NCT NCT01510028)

The study was conducted at 5 main sites for cohorts 1 to 3 in Brazil, Denmark, Germany, France, and Australia and 3 main sites for cohort 4 in Denmark, France, and Germany between 02 February 2012 (first participant first visit) and 20 January 2017 (last participant last visit).

A total of 34 participants were screened and 24 participants were enrolled in the study. Out of which 23 participants completed the study.

Multicenter Study of HGT-1110 Administered Intrathecally in Children With Metachromatic Leukodystrophy (MLD)

An adverse event (AE) was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs were defined as all AEs that occurred at or after the first dose of the investigational product or device implant surgery (whichever occurred earlier) and through the last follow-up date. Drug-related and device-related types of TEAEs were analyzed and reported. The severity of AEs was assessed by the investigator using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) Version 4.0 grading scale. Severity of all AEs or SAEs was recorded as grade 1, 2, 3, 4, or 5 corresponding, respectively, to a severity of mild, moderate, severe, life-threatening, or fatal. Here SDI refers to surgical device implantation.

Clinical laboratory test included serum chemistry, hematology and urinalysis. Clinical laboratory abnormalities were recorded and reported as TEAE. An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs were defined as all AEs that occurred at or after the first dose of the investigational product or device implant surgery (whichever occurred earlier) and through the last follow-up date.

Vital sign assessments included blood pressure, heart rate, respiratory rate and body temperature. Vital sign abnormalities were recorded and reported as TEAE. An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs were defined as all AEs that occurred at or after the first dose of the investigational product or device implant surgery (whichever occurred earlier) and through the last follow-up date. Vital sign abnormalities included pyrexia which was considered as TEAE and was reported.

12-lead ECG was recorded and measured with the participant in rested supine position for at least 10 minutes. ECG abnormalities were recorded and reported as TEAE. An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs were defined as all AEs that occurred at or after the first dose of the investigational product or device implant surgery (whichever occurred earlier) and through the last follow-up date.

Complete physical examination included evaluation of the port and catheter track. Height or length and weight were recorded and used to calculate growth. Body weight and height measurements were used to calculate the body mass index (BMI). Head circumference was measured in uniform manner for all participants. Clinical significance was defined as any variation in physical findings that had medical relevance resulting in an alteration in medical care. Clinically significant abnormalities related to physical examination were recorded and reported as TEAE. An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs were defined as all AEs that occurred at or after the first dose of the investigational product or device implant surgery (whichever occurred earlier) and through the last follow-up date.

CSF chemistry assessments (including cell counts, glucose and protein) was measured. CSF chemistry abnormalities were recorded and reported as TEAE. An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs were defined as all AEs that occurred at or after the first dose of the investigational product or device implant surgery (whichever occurred earlier) and through the last follow-up date.

Number of participants with positive anti-SHP611 antibody results in serum and in CSF were reported. A participant was considered positive if they had at least 1 positive result during the study.

The GMFM-88 was used to measure motor function. The GMFM-88 item scores were used to calculate domain-specific percent score for each of the 5 GMFM-88 dimensions (lying and rolling; sitting; crawling and kneeling; standing; walking, running, and jumping), and a total GMFM-88 (percent) score was calculated based on each dimension score. Each of the 88 items was rated on a 4-point scale: 0=does not initiate; 1=initiates; 2=partially completes; and 3=completes. The GMFM-88 total scores ranged from 0% (no mobility) to a score of 100%, that is (i.e,) the score that can be obtained by an average 5-year-old or older child with normal motor abilities.

The FEES assessment was performed to evaluate the structure and function of the upper throat during swallowing and for an assessment of aspiration risk. Each participant had this assessment performed at the clinical site using transnasal flexible laryngoscopy. FEES for texture utilized was evaluated. Data was presented only for the shifts observed.

The FEES assessment was performed to evaluate the structure and function of the upper throat during swallowing and for an assessment of aspiration risk. Each participant had this assessment performed at the clinical site using transnasal flexible laryngoscopy. Feeding assessment for laryngeal penetration was assessed. Data was presented only for the shifts observed. Here TL refers to thin liquids, THL refers to thickened liquids, PT refers to puree texture, WCC refers to with cough and clearance and WCNC refers to with cough and no clearance.

The FEES assessment was performed to evaluate the structure and function of the upper throat during swallowing and for an assessment of aspiration risk. Each participant had this assessment performed at the clinical site using transnasal flexible laryngoscopy. Feeding assessment for aspiration through vocal cords were assessed. Data was presented only for the shifts observed. Here TL refers to thin liquids, THL refers to thickened liquids, PT refers to puree texture, WCC refers to with cough and clearance and WCNC refers to with cough and no clearance.

The FEES assessment was performed to evaluate the structure and function of the upper throat during swallowing and for an assessment of aspiration risk. Each participant had this assessment performed at the clinical site using transnasal flexible laryngoscopy. FEES for dose residue clear after subsequent swallowing was assessed. Data was presented only for the shifts observed. Here TL refers to thin liquids, THL refers to thickened liquids, PT refers to puree texture.

The FEES assessment was performed to evaluate the structure and function of the upper throat during swallowing and for an assessment of aspiration risk. Each participant had this assessment performed at the clinical site using transnasal flexible laryngoscopy. FEES for aspiration risk was assessed. Data was presented only for the shifts observed. Here TL refers to thin liquids, THL refers to thickened liquids, PT refers to puree texture, WCC refers to with cough and clearance and WCNC refers to with cough and no clearance.

Evaluation of peripheral nerve function by ENG studies was performed to measure nerve conduction velocity (NCV), amplitude (AMP),distal latency (DL), and F-wave latency. Categorized amplitude values were assessed. Data was presented only for number of participants who reported change in amplitude greater than (\>) 0.

Evaluation of peripheral nerve function by ENG studies was performed to measure nerve conduction velocity (NCV), amplitude (AMP),distal latency (DL), and F-wave latency. Categorized nerve conduction velocity values were assessed. Data was presented only for number of participants who reported change in nerve conduction velocity \> 0. Here MME refers to median motor elbow, WCV for wrist conduction velocity, PMA for peroneal motor ankle, FHCV to fibular head conduction velocity, TMA for tibial motor ankle, KCV for knee conduction velocity and UME for ulnar motor elbow,

Evaluation of peripheral nerve function by ENG studies was performed to measure nerve conduction velocity (NCV), amplitude (AMP),distal latency (DL), and F-wave latency. Categorized amplitude values were assessed. Data was presented only for number of participants who reported change in distal latency \> 0. Here MMW refers to median motor wrist, APB for abductor pollicis brevis, MSW for median sensory wrist, DDL for digit distal latency, PMA for peroneal motor ankle, EDB for extensor digitorum brevis, SSB-point DL for sural sensory B-point distal latency, TMA for tibial motor ankle, abductor hallucis for AH distal latency and, UMW for ulnar motor wrist.

The VABS-II test measures adaptive behaviors, including the ability to cope with environmental changes, to learn new everyday skills, and to demonstrate independence. This test measures the following 4 key domains: communication, daily living skills, socialization, motor skills, and the adaptive behavior composite (ABC) (a composite of the other 4 domain). Items in each domain are rated as either 0 (does not), 1(sometimes) or 2(independently) performs a given behavior or skill. The 4 domain standard scores range from 20-160 and higher scores indicate a higher level of functioning. ABC scores have a mean of 100 and a standard deviation of 15 (range = 20 to 160) and higher scores indicate a higher level of functioning. A positive change value indicates improvement in adaptive functioning.

COMFORT questionnaire was used to assess health status and the impact of disease on the ability of participants with MLD to carry out activities of daily life. The questionnaire was organized by 8 domains (ie, personal care; positioning, transfer, or mobility; eating; pain and discomfort during the day; sleep; emotions; communication; and play and leisure activities). The COMFORT scores range from 0 to 100, with higher scores indicating a decline in the functioning.

Cmax is the maximum observed serum concentration of SHP611.

Tmax is the time to reach maximum observed drug concentration of SHP611 during a dosing interval.

The AUC0-inf is the area under the concentration-time curve from time zero to infinity of SHP611.

AUC0-last is the area under the concentration-time curve from the time of dosing to the last measurable concentration of SHP611.

Area under the concentration-time curve over the interval from 0 to 24 hours after dosing of SHP611.

Lambda z is first order elimination rate constant associated with the terminal portion of the curve, determined as the negative slope of the terminal log-linear phase of the drug concentration-time curve.

The t1/2 is the time in hours required for the concentration of the drug to reach half of its original value.

CL/F was defined as the total body clearance of the drug for extravascular administration divided by the fraction of dose absorbed.

Volume of distribution was associated with the terminal slope following extravascular administration of SHP611 divided by the fraction of dose absorbed.

Concentration of SHP611 in CSF was determined using validated enzyme-linked immunosorbent assay (ELISA) method.