Safety, Tolerability, and Pharmacokinetics of CSX-1004

Study Overview
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Brief Summary
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This is a Phase 1a, randomized, double-blind, single ascending dose study, designed to assess the safety, tolerability, and PK of a single CSX-1004 injection, administered by IV infusion across a range of doses in healthy adult subjects. The study will have 3 phases: Screening, Inpatient Treatment, and Outpatient Follow-up. The primary objective of the study is to determine the safety and tolerability of CSX-1004 Injection administered by intravenous (IV) infusion across a range of doses in healthy adult subjects. The secondary objective of the study is to determine the pharmacokinetics (PK) of CSX-1004 Injection administered by IV infusion across a range of doses in healthy adult subjects.

Official Title
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A Phase 1a, Randomized, Double-Blind, Placebo-Controlled, Single Site, Single Ascending Dose Study of the Safety, Tolerability, and Pharmacokinetics of CSX-1004 Injection in Healthy Adults

Conditions
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Opioid Overdose, Opioid Use Disorder

Intervention / Treatment
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* Biological: CSX-1004
* Biological: Placebo


Participation Criteria
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Eligibility Criteria
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Major Inclusion Criteria: Healthy male or female subjects, aged 18 to 50 years, inclusive, Minimum weight of 50.0 kg and maximum weight of 100.0 kg Body mass index (BMI) within the range of 18.0 to 32.0 kg/m2, inclusive Major Exclusion Criteria: Positive UDS for substances of abuse (including alcohol) at Screening or admission to the Treatment Phase Current daily cigarette smoker within 3 months of Screening. Social smoking, as defined by non-daily use of nicotine-containing products, is permitted. History or presence of any clinically significant cardiac, psychiatric, endocrine, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, renal, or other major disease or illness at Screening, which in the opinion of the Investigator, might jeopardize the safety of the subject or the validity of the study results.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Sequential Assignment
Interventional Model Description: Single ascending dose study
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CSX-1004<br>Single doses of CSX-1004 Injection | Biological: CSX-1004<br>* Recombinant human immunoglobulin G (IgG) 1λ monoclonal antibody specific for fentanyl and structurally related fentanyl analogs<br>|
| Placebo Comparator: Placebo<br>Sterile saline for injection | Biological: Placebo<br>* Sterile saline for injection<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Treatment-emergent adverse events (AEs), serious AEs, and AEs leading to discontinuation | Incidence, intensity, and causality of adverse events | 5 months | 
| Clinical laboratory assessments | Hematology, biochemistry, and urinalysis | 5 months | 
| Vital signs | Blood pressure and pulse rate | 5 months | 
| 12-Lead electrocardiogram | Variables will include ventricular heart rate and the PR, QRS, QT, QTcB and QTcF intervals | 5 months | 
| Physical examination | Complete physical examination, assessing the subject's overall health and physical condition | 5 months | 
| Infusion site examination | Infusion site will be visually inspected for evidence of erythema, edema, itching, pain, infection, bleeding, abnormal healing, and any other abnormalities | 6 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cmax | Maximum serum concentration | 4 months | 
| AUCinf | Area under the curve from time zero extrapolated to infinity | 4 months | 
| AUClast | Area under the curve from time zero to the last measurable concentration | 4 months | 
| Tmax | Time to maximum serum concentration | 4 months | 
| t1/2 | beta terminal elimination half-life | 4 months |