A Study of Single and Multiple SC Doses of ALXN1830 in Healthy Adult Participants

Study Overview
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Brief Summary
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This study will evaluate the effects of single ascending doses (SAD) and multiple ascending doses (MAD) of ALXN1830 administered subcutaneously (SC) to healthy adult participants.

Detailed Description
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This Phase 1 study will consist of 3 SAD (Cohorts 1 to 3) and 4 MAD (Cohorts 4 to 7) cohorts. Participants will be randomly assigned in a 6:2 ratio to each of the 7 cohorts to receive either single or multiple doses of ALXN1830 (n = 6 per cohort) or single or multiple doses of placebo (n = 2 per cohort).

Official Title
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A Phase 1, Randomized, Double-Blind, Placebo-Controlled, Single and Multiple Ascending Dose Study of Subcutaneous ALXN1830 in Healthy Participants

Conditions
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Healthy

Intervention / Treatment
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* Drug: ALXN1830
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Satisfactory medical assessment. Participants must have had vaccination against pneumococcus (Pneumovax 23 [PPSV23]) at least 28 days, and maximally 4 years prior to Day 1. Participants must have had seasonal influenza vaccination for the current season at least 28 days prior to Day 1. Body weight within 50 to 90 kg, inclusive, and body mass index (BMI) within the range of 18 to 24.9 kg/m^2, inclusive. Must be willing to follow protocol-specified contraception guidance during the study and for up to 3 months after last dose of study drug. Exclusion Criteria: Current/recurrent diseases or relevant medical history. Known exposure to therapeutic proteins, such as monoclonal antibodies, including marketed drugs prior to dosing. Participants who have prior exposure to ALXN1830. Exposure to more than 4 new (small molecule) investigational compounds within 12 months prior to dosing. Current enrollment or past participation within the last 90 days before signing of consent in this or any other interventional clinical study. Presence of hepatitis B surface antigen (HBsAg) at Screening. Positive hepatitis C antibody test result at Screening. Positive human immunodeficiency virus (HIV) antibody test at Screening. Participants who are either immunocompromised or have one of the following underlying medical conditions: anatomic or functional asplenia (including sickle cell disease); primary antibody deficiencies

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cohort 1<br>Participants will receive a single SC dose of ALXN1830 or placebo (750 mg). | Drug: ALXN1830<br>* ALXN1830 will be administered as SC infusion(s).<br>Drug: Placebo<br>* Placebo will be administered as SC infusion(s).<br>|
| Experimental: Cohort 2<br>Participants will receive a single SC dose of ALXN1830 or placebo (1500 mg). | Drug: ALXN1830<br>* ALXN1830 will be administered as SC infusion(s).<br>Drug: Placebo<br>* Placebo will be administered as SC infusion(s).<br>|
| Experimental: Cohort 3<br>Participants will receive a single SC dose of ALXN1830 or placebo (2250 mg). | Drug: ALXN1830<br>* ALXN1830 will be administered as SC infusion(s).<br>Drug: Placebo<br>* Placebo will be administered as SC infusion(s).<br>|
| Experimental: Cohort 4<br>Participants will receive multiple SC doses of ALXN1830 or placebo (300 mg twice weekly; 8 doses total). | Drug: ALXN1830<br>* ALXN1830 will be administered as SC infusion(s).<br>Drug: Placebo<br>* Placebo will be administered as SC infusion(s).<br>|
| Experimental: Cohort 5<br>Participants will receive multiple SC doses of ALXN1830 or placebo (750 mg once weekly; 12 doses total). | Drug: ALXN1830<br>* ALXN1830 will be administered as SC infusion(s).<br>Drug: Placebo<br>* Placebo will be administered as SC infusion(s).<br>|
| Experimental: Cohort 6<br>Participants will receive multiple SC doses of ALXN1830 or placebo (1500 mg once weekly; 4 doses total). | Drug: ALXN1830<br>* ALXN1830 will be administered as SC infusion(s).<br>Drug: Placebo<br>* Placebo will be administered as SC infusion(s).<br>|
| Experimental: Cohort 7<br>Participants will receive multiple SC doses of ALXN1830 or placebo (2250 mg once weekly; 4 doses total). | Drug: ALXN1830<br>* ALXN1830 will be administered as SC infusion(s).<br>Drug: Placebo<br>* Placebo will be administered as SC infusion(s).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number Of Participants With Treatment-emergent Adverse Events | An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study drug, whether or not considered related to the study drug. The incidence and severity of AEs will be determined according to National Cancer Institute Common Terminology Criteria for Adverse Events Version 5.0 (NCI CTCAE v5.0). | Day 1 through Day 141 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area Under The Plasma Concentration Versus Time Curve (AUC) Of Single And Multiple SC Doses Of ALXN1830 | Participants whole blood will be collected to assess the serum concentrations of ALXN1830. | Day 1 through Day 141 | 
| Maximum Observed Plasma Concentration (Cmax) Of Single And Multiple SC Doses Of ALXN1830 | Participants whole blood will be collected to assess the serum concentrations of ALXN1830. | Day 1 through Day 141 | 
| Change From Baseline In Serum Immunoglobulin G (IgG) Of Single And Multiple SC Doses Of ALXN1830 | This outcome measure will assess the change in IgG level from venous blood samples, which is will be used to measure the anti FcRn PD activity of ALXN1830. | Baseline to Day 141 | 
| Change From Baseline In Antidrug Antibody (ADA) And Neutralizing Antibody (Nab) Levels OF Single And Multiple Doses Of ALXN1830 | Participants serum samples will be screened for ADA and Nab to further characterize the immunogenicity of ALXN1830. | Baseline to Day 141 |