A Study to See How BIIB122 Works in the Human Body, and to Evaluate it's Safety, and Tolerability in Healthy Adult Japanese, Chinese, and Caucasian Participants

Study Overview
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Brief Summary
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The study will be looking at an investigational drug, BIIB122, in healthy adult Japanese, Chinese, and Caucasian participants. The main goal of the study is to compare the drug level achieved in the body, between the different ethnic groups, after single and multiple doses of BIIB122. Researchers also want to see if single and multiple doses of BIIB122 are safe and if healthy participants can tolerate given doses of BIIB122.

Official Title
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An Open-Label, Parallel-Group, Phase 1 Study to Evaluate the Pharmacokinetics, Safety, and Tolerability of BIIB122 in Healthy Adult Japanese, Chinese, and Caucasian Participants

Conditions
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Healthy Volunteer

Intervention / Treatment
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* Drug: BIIB122


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: Have a body mass index (BMI) between 18 and 30 kilograms per square meter (kg/m^2), inclusive. Body weight (BW) ≥50 kg and ≤100 kg at Screening Negative polymerase chain reaction (PCR) test result for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at Screening and Day -1 For Japanese healthy volunteers: Participant was born in Japan, and biological parents and grandparents were of Japanese origin; if living outside of Japan for more than 10 years, must not have significantly modified diet since leaving Japan For Chinese healthy volunteers: Participant was born in China, and biological parents and grandparents were of Chinese origin; if living outside of China for more than 5 years, must not have had a significantly modified diet since leaving China. Additionally, Chinese healthy volunteers must be of the same gender and have a screening weight within ±15% of their matched Caucasian healthy volunteer For Caucasian healthy volunteers: Participant must be a white person of European descent, which may include participants of Hispanic descent. Additionally, Caucasian healthy volunteers must be of the same gender and have a screening weight within ±15% of their matched Japanese healthy volunteer Key Exclusion Criteria: History of any clinically significant cardiac, endocrinologic, hematologic, hepatic, immunologic, infectious, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, and renal, or other major disease, as determined by the Investigator History of severe allergic or anaphylactic reactions, or of any allergic reactions that in the opinion of the Investigator are likely to be exacerbated by any component of the study treatment Current enrollment in any other drug, biological, device, or clinical study, or treatment with an investigational drug or approved therapy for investigational use within 30 days prior to Day -1, or 5 half-lives, whichever is longer Immunization or vaccinations are not allowed from Screening to safety follow-up (SFU)/ early termination (ET) Visit NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cohort 1: Low-Dose<br>Participants will receive Dose 1 of BIIB122, orally, once on Day 1. | Drug: BIIB122<br>* Administered as specified in the treatment arm.<br>* Other names: DNL151;|
| Experimental: Cohort 2: Mid-Dose<br>Participants will receive Dose 2 of BIIB122, orally, once on Day 1. | Drug: BIIB122<br>* Administered as specified in the treatment arm.<br>* Other names: DNL151;|
| Experimental: Cohort 3: High-Dose<br>Participants will receive Dose 3 of BIIB122, orally, once on Day 1. | Drug: BIIB122<br>* Administered as specified in the treatment arm.<br>* Other names: DNL151;|
| Experimental: Cohort 4: High-Multi-Dose<br>Participants will receive Dose 3 of BIIB122, orally, once daily (QD), for 10 days. | Drug: BIIB122<br>* Administered as specified in the treatment arm.<br>* Other names: DNL151;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum Observed Plasma Concentration (Cmax) of BIIB122 |  | Cohorts 1,2 and 3: At multiple time points post-dose on Days 1 to 4, and at Day 10; Cohort 4: At multiple time points post-dose on Day 1, Pre-dose on Days 2 to 9, Pre-dose and at multiple time points post-dose on Days 10 to 13, and at Day 20 | 
| Time to Reach Maximum Observed Plasma Concentration (Tmax) of BIIB122 |  | Cohorts 1,2 and 3: At multiple time points post-dose on Days 1 to 4, and at Day 10; Cohort 4: At multiple time points post-dose on Day 1, Pre-dose on Days 2 to 9, Pre-dose and at multiple time points post-dose on Days 10 to 13, and at Day 20 | 
| Area Under the Concentration-Time Curve From Time 0 to 24 Hours (AUC0-24h) of BIIB122 |  | Cohorts 1,2 and 3: At multiple time points post-dose on Days 1 to 4, and at Day 10; Cohort 4: At multiple time points post-dose on Day 1, Pre-dose on Days 2 to 9, Pre-dose and at multiple time points post-dose on Days 10 to 13, and at Day 20 | 
| Cohorts 1,2 and 3: Area Under the Concentration-Time Curve From Time 0 to Time of the Last Measurable Concentration (AUClast) of BIIB122 |  | Cohorts 1,2 and 3: At multiple time points post-dose on Days 1 to 4, and at Day 10 | 
| Cohorts 1,2 and 3: Area Under the Concentration-Time Curve From Time 0 to Infinity (AUCinf) of BIIB122 |  | Cohorts 1, 2 and 3: At multiple time points post-dose on Days 1 to 4, and at Day 10 | 
| Cohort 4: Cmax of BIIB122 at Steady State (Cmax,ss) |  | Cohort 4: Pre-dose and at multiple time points post-dose on Days 10 to 13 | 
| Cohort 4: Tmax of BIIB122 at Steady State (Tmax,ss) |  | Cohort 4: Pre-dose and at multiple time points post-dose on Days 10 to 13 | 
| Cohort 4: AUC of BIIB122 Within a Dosing Interval at Steady State (AUCtau,ss) |  | Cohort 4: Pre-dose and at multiple time points post-dose on Days 10 to 13 | 
| Cohort 4: Accumulation Ratio (AR) for AUC Within a Dosing Interval (AUCtau) |  | Cohort 4: Pre-dose and at multiple time points post-dose on Days 10 to 13 | 
| Cohort 4: AR for Cmax |  | Cohort 4: Pre-dose and at multiple time points post-dose on Days 10 to 13 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) | An AE is any untoward medical occurrence in a participant or clinical investigation participant (healthy volunteer) administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. An SAE is any untoward medical occurrence that at any dose results in death, in the view of the investigator, places the participant at immediate risk of death (a life-threatening event), requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, results in a congenital anomaly/birth defect or is a medically important event. | Cohorts 1,2 and 3: Up to Day 10; Cohort 4: Up to Day 20 |