Study to Assess the Efficacy and Safety of MT-3921 in Subjects With Acute Traumatic Cervical Spinal Cord Injury

Study Overview
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Brief Summary
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The purpose of this study is to compare the efficacy and safety of intravenous (IV) infusions of MT-3921 to placebo in subjects with acute traumatic cervical spinal cord injury. Subjects meeting eligibility criteria will enter the 6-month double-blind period. Subjects will be randomized in a 2:1 ratio to receive MT-3921 or placebo in a double blind manner.

Official Title
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A Phase 2a, Randomized, Double-blind, Placebo-controlled Study to Assess the Efficacy and Safety of MT-3921 in Subjects With Acute Traumatic Cervical Spinal Cord Injury

Conditions
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Spinal Cord Injury

Intervention / Treatment
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* Biological: MT-3921
* Biological: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Additional screening criteria check may apply for qualification: Provide written informed consent prior to beginning any study procedures Cervical spinal cord injury that meet all of the following criteria: Classified as AIS A, AIS B or AIS C ISNCSCI neurological level of injury between C4 and C7 (for C4, the subject must have at least 1 point of motor activity between C5 to C7) UEMS ≤28 at Screening Body mass index (BMI) <40 Exclusion Criteria: Additional screening criteria check may apply for qualification: Any concomitant injury that interferes with the procedures and examinations required by study protocol, including performance, interpretation or validity of neurological examinations Poly-traumatic Injury as defined by Injury Severity Score (ISS) values > 25 Penetrating spinal cord injuries Complete transection of the spinal cord Any other significant pre-existing medical conditions prior to spinal cord injury or current conditions that, in the judgement of the iInvestigator, may increase the risks associated with study participation History of anaphylaxis or clinically significant allergic reactions to any medication History or presence of malignancy within the last 3 years prior to screening Subjects with current SARS-CoV-2 infection (COVID-19) Subjects with hereditary fructose intolerance Psychoactive substance use disorder Participation in any clinical trial of a new chemical entity within 12 weeks prior to Screening Female subjects who are pregnant or lactating

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MT-3921<br>Intravenous (IV) | Biological: MT-3921<br>* Solution for infusion; Intravenous (IV)<br>* Other names: Unasnemab;|
| Placebo Comparator: Placebo<br>Intravenous (IV) | Biological: Placebo<br>* Solution for infusion; Intravenous (IV)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Upper Extremity Motor Score (UEMS) | The UEMS is a subscore of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) that focuses selectively on function of 5 key muscles in the upper limbs. UEMS ranges from 0 to 50 points, where a higher score indicates a better movement. | Baseline and at Day 180 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Spinal Cord Independence Measurement (SCIM) III score | The SCIM III is a comprehensive rating scale that measures the ability of patients with SCI to perform everyday tasks according to their value for the patient. The SCIM III is grouped into four subscales: Self-Care, Respiration and Sphincter Management, Mobility in Room and Toilet, and Mobility Indoors and Outdoors. The total SCIM III score ranges from 0 to 100 points, with 0 point being requiring total assistance and 100 points being completely independent. | Baseline and at Day 180 | 
| Change in Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) score | The GRASSP measures sensorimotor and prehension function through three domains (Strength, Sensation and Prehension) which are important in describing arm and hand function. The total GRASSP score ranges from 0 to 116 points, where a higher score indicates a better outcome. | Baseline and at Day 180 | 
| Change in Spinal Cord Ability Ruler (SCAR) | The SCAR measures voluntary task specific physical actions contributing to independence in ability of daily living. The SCAR uses select items from the upper limb motor assessments of the ISNCSCI and the SCIM III. | Baseline and at Day 180 | 
| Proportion of responders (i.e., subjects with cutoff number or greater increase in the UEMS compared to baseline) |  | Baseline and at Day 180 |