Administration of MELPIDA to Determine the Safety and Efficacy for Patients With Spastic Paraplegia Type 50

Phase 1Active Not RecruitingNCT06069687

The Hospital for Sick Children1 enrolled

Overview

This will be a first-in-human Phase I, open-label, single dose clinical study of MELPIDA administered intrathecally (IT) through a lumbar puncture (LP) to a single subject with confirmed pathogenic mutations in the Adaptor Related Protein Complex 4 Subunit Mu 1 (AP4M1) gene. The primary outcome will be the determination of the safety and tolerability of MELPIDA in patients with SPG50, based on development of toxicity. The secondary outcome will be a preliminary exploration of efficacy of the treatment. MELPIDA, is a recombinant serotype 9 adeno-associated virus (AAV) encoding a codon-optimized human AP4M1 transgene and will be administer to the patient via a single intrathecal infusion of 10 mL at 1E14 vg/mL for a total dose of 1E15 vg. The total study duration is 5 years post dosing and the participant will be tested at screening/baseline (-28 to -7 days), return for dosing, and then follow-up visits post-dosing on Days 7 (+/-2), 30 (+/-2), 60 (+/-2), 90 (+/-14), 180 (+/-14), 270 (+/-14), 360 (+/-14), 540 (+/-14), and 720 (+/-14) days, then annually for the last 3 years.

Study Type

INTERVENTIONAL

Allocation

Purpose

OTHER

Masking

NONE

Enrollment

Conditions

Spastic Paraplegia Type 50

Interventions

Eligibility

Sex: MALEMin age: 0 YearsMax age: 4 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age \< 5 years old * Confirmed diagnosis of SPG50 disease by: * Genomic DNA mutation analysis demonstrating homozygous or compound heterozygous, pathogenic and/or potentially pathogenic variants in the AP4M1 gene * Clinical history or examination features consistent with SPG50 and that include neurologic dysfunction * Parent/legal guardian willing to provide written informed consent for their child prior to participation in the study * Subject able to comply with all protocol requirements and procedures Exclusion Criteria: * Inability to participate in study procedures (as determined by the site investigator) * Presence of a concomitant medical condition that precludes lumbar puncture (LP) or use of anesthetics * History of bleeding disorder or any other medical condition or circumstance in which lumbar puncture is contraindicated according to local institutional policy * Inability to be safely sedated in the opinion of the clinical anesthesiologist * Active infection, at the time of dosing, based on clinical observations * Concomitant illness or requirement for chronic drug treatment that in the opinion of the PI creates unnecessary risks for gene transfer * Inability of the patient to undergo MRI according to local institutional policy * Inability of the patient to undergo any other procedure required in this study * The presence of significant non-SPG50 related central nervous system (CNS) impairment or behavioral disturbances that would confound the scientific rigor or interpretation of results of the study * Have received an investigational drug within 30 days prior to screening or plan to receive an investigational drug (other than gene therapy) during the study. * Enrollment and participation in another interventional clinical trial * Contraindication to MELPIDA or any of its ingredients * Contraindication to any of the immune suppression medications used in this study * Clinically significant abnormal laboratory values (GGT, ALT, and AST, or total bilirubin \> 3 × Upper Limit of Normal (ULN), creatinine ≥ 1.5 mg/dL, hemoglobin \[Hgb\] \< 6 or \> 20 g/dL; white blood cell (WBC) \> 20,000 per cmm) prior to gene replacement therapy. Patients with an elevated bilirubin level that is unequivocally the result of neonatal jaundice shall not be excluded

Outcomes

Primary Outcomes

Incidence of unanticipated anticipated treatment-related toxicities, Grade 3 or higher

collection of occurrence and severity of serious adverse events. Incidence of serious adverse events and adverse events throughout the study, as assessed by Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Higher grade values indicated greater severity. Grade 1 - Grade 5.

Time frame: through study completion, an average of 5 years

Change from baseline in nerve conduction velocity

Nerve conduction studies will be used to determine nerve conduction velocity. Nerve conduction studies involve providing a small electrical stimulus to either a motor or sensor nerve and then measuring the resulting action potential at distal point of that nerve (for sensory nerve studies) or at the muscle that the nerve innervates (motor nerve studies). Velocity of conduction (measured between the two points and represented in m/s) will be obtained. The value is compared to standard reference values for age.

Time frame: Screening, Day 21, and Month 3, 6, 12, 24, 36, 48 and 60

Determination of liver safety

Changes in Liver Ultrasound findings from baseline. Incidence of serious adverse events and adverse events throughout the study, as assessed by CTCAE v5.0

Time frame: Screening, Month 6, 12, 24, 36, 48 and 60

Determination of liver safety

Liver laboratory test: alanine transaminase (ALT) in U/L