A Study to Assess the Safety, Tolerability and Pharmacokinetics of ABI-6250 in Participants With Mild Hepatic Impairment Compared With Participants With Normal Hepatic Function

A Phase 1, Open-Label, Multiple-Dose Study to Evaluate the Pharmacokinetics, Pharmacodynamics, Safety, and Tolerability of ABI-6250 in Participants With Mild Hepatic Impairment Compared With Participants With Normal Hepatic Function

This study is designed to assess the safety, tolerability and pharmacokinetics of ABI-6250 in participants with mild hepatic impairment compared with participants with normal hepatic function.

Study Overview

• Status: Not yet recruiting
• Conditions: Mild Hepatic Imparement
• Intervention / Treatment: Drug: ABI-6250

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Assembly Biosciences; Phone Number: 833-509-4583; Email: clinicaltrials@assemblybio.com

Study Locations

• New Zealand
  • Auckland, New Zealand
    • New Zealand Clinical Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria (All Participants):

• Participant is willing and able to provide written informed consent, is available for the entire study period, is able to understand and comply with study requirements, procedures and restrictions, able to remain at the clinical research unit (CRU) for the required study duration and return to the CRU for outpatient assessments.
• Participant has a body mass index (BMI) of 18.0 to 45.0 kg/m2, is a non/ex/light-smoker, and is willing and able to swallow whole tablets without breaking, butting or chewing.
• Renal function, as measured by eGFR calculated using the 2009 CKD-EPI equation >60 mL/min at Screening.
• Female participants must be nonpregnant and have a negative serum pregnancy test at Screening and a negative urine pregnancy test on Day -2.
• Participants must agree to comply with protocol-specified contraceptive requirements.
• Suitable venous access for blood sample collection.

Inclusion Criteria for Participants with Mild Hepatic Impairment (Cohort 1):

• Stable mild hepatic impairment designated as Child-Pugh Class A score of 5 to 6 during Screening and Day -2.
• Must meet certain laboratory parameters as Screening.
• Has medical history, clinical lab test results, vital sign measurements and physical examination consistent with stable mild hepatic impairment, as determined by the Investigator.
• On stable medication regiment for at least 14 days before dosing on Day 1.

Inclusion Criteria for Participants with Normal Hepatic Function (Cohort 2):

• Has stable normal hepatic function as determined at Screening and Day -2.
• Medically healthy, as determined by no clinically significant finding from medical history, clinical lab test results, vital sign measurements, 12-lead ECG results, and physical examination results.

Exclusion Criteria (All Participants):

• Child-Pugh score >6 at Screening.
• Female participant who is currently pregnant or lactating, or is planning to become pregnant during the study through EOS.
• Positive test results for HAV IgM, HBcAb IgM, HBsAg, or HIV 1/2 Ab at Screening.
• Positive screen for drugs or alcohol (listed in Table 5) at Screening or on Day -2, with the exception of prescription medication (including THC) as determined by the Investigator to be therapeutic.
• Changes in permitted concomitant medication regimen (defined as starting a new medication[s] or a change in the dosage or frequency of the concomitant medication[s] within 14 days or 5 half-lives [whichever is longer]) before dosing on Day 1.
• History or presence of a clinically significant psychiatric or neurological disease within 1 year of Screening.
• Epilepsy or a history of seizures within the last 2 years (with the exception of febrile seizures).
• Current evidence or history of suicidal behavior in the past 2 years.
• History or presence of uncontrolled cardiac diseases including conduction and structural abnormalities, which may place the participant at increased risk as determined by the Investigator.
• Impairment of GI function or disease that may significantly alter the absorption of ABI-6250 or may predispose the participant to an increased risk of GI toxicity (eg, inflammatory bowel disease, celiac disease, prior gastrectomy, gastric bypass, small bowel resection, etc.).
• Participant has a portal shunt.
• Clinically significant history or evidence of pulmonary, neurologic, psychiatric, cardiovascular, hematologic, dermatologic, immunologic, or metabolic disease; or any other condition or organ system disease that in the opinion of the Investigator would jeopardize the safety of the participant or impact validity of study results.
• Has a malignancy, a history of malignancy, or has received treatment for a malignancy at any time, with the exception of resected and cured basal cell carcinoma or squamous cell carcinoma of the skin (>1 year).
• History or evidence of pancreatic injury or pancreatitis within 6 months of Screening.
• Ongoing history of any medical condition other than mild hepatic impairment as defined by inclusion criteria #12, #13, #14 #15, and #16 that in the opinion of the Investigator would increase the risk to the participant if enrolled in the study or make the participant unsuitable for the study.
• Any clinically significant illness in the 30 days before Day -2.
• Known hypersensitivity or allergy to ABI-6250 or constituent of the formulation.
• Received any investigational drug within 30 days or 5 half-lives of the study drug (whichever is longer) before Screening.
• Participant has had an immunization within 30 days of Screening. Coronavirus disease 2019 vaccine is allowed if the vaccination took place at least 7 days before Screening.
• Donation or significant loss of blood or blood products of 500 mL or more within 56 days before Screening, or donation or loss of plasma within 7 days before Screening, or plans to donate blood or plasma through EOS.
• Participant is unwilling to abstain from consumption of grapefruit, pomelo, or Seville orange whole fruits or juices for 7 days before Day 1 and through EOS.
• Participant is unwilling to abstain from ingesting caffeine- or xanthine-containing products (eg, coffee, tea, cola drinks, and chocolate) for 24 hours before Admission until discharge from the CRU.
• Participant is unwilling to abstain from alcohol for 48 hours before Admission until discharge from the CRU.
• Participant is unwilling or unable to comply with the lifestyle considerations described in this protocol.

Exclusion Criteria for Participants With Mild Hepatic Impairment (Cohort 1):

• Any finding that, in the judgment of the Investigator, is a clinically significant laboratory abnormality unrelated to the participant's hepatic impairment, including serum chemistry, hematology, coagulation, and urinalysis test results (abnormal test may be repeated for confirmation).
• Vital sign abnormality after at least 5 minutes resting in the supine position at Screening, Day -2, Day -1, or predose on Day 1.
• Abnormal standard 12-lead ECG after at least 5 minutes resting in the supine position at Screening, Day -2, or predose on Day 1.
• Positive test for drugs of abuse, including alcohol at Screening or Admission (Day -2), with the exception of medications under prescription and verified by the Investigator as used for therapeutic management.

Exclusion Criteria for Participants With Normal Hepatic Function (Cohort 2):

• History or presence of hepatic disease indicated by medical history or abnormal hepatic function.
• Abnormal vital sign measurements after at least 5 minutes resting in the supine position at Screening, Day -2, Day -1, or predose on Day 1.
• Abnormal standard 12-lead ECG after at least 5 minutes resting in the supine position at Screening, Day -2, or predose on Day 1.
• Any finding that, in the judgment of the Investigator, is a clinically significant laboratory abnormality, including serum chemistry, hematology, coagulation, and urinalysis test results (abnormal test results may be repeated for confirmation).
• Use of any prescription medication or OTC medication, including multivitamins, dietary and herbal supplements within 14 days or 5 half-lives, whichever is longer, before dosing on Day 1 and until the EOS.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cohort 1 & 2, ABI-6250	Drug: ABI-6250; Participants will receive ABI-6250 0.5 mg QD over 10 days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum Observed Plasma Concentration (Cmax) of ABI-6250.		From Day 1 to Day 35, at pre-specified timepoints.
Apparent Terminal Elimination Half Life (t 1/2) of ABI-6250.		From Day 1 to Day 35, at pre-specified timepoints.
Time to Cmax (Tmax) of ABI-6250.		From Day 1 to Day 35, at pre-specified timepoints.
Area Under the Plasma Concentration-Time Curve (AUC) from time zero to 24 hours postdose (AUC0-24) of ABI-6250 on Days 1 and 10.		From Day 1 to Day 35, at pre-specified timepoints.
Apparent Systemic Clearance (CL/F) of ABI-6250.		From Day 1 to Day 35, at pre-specified timepoints.
Apparent Volume of Distribution (Vz/F) of ABI-6250.		From Day 1 to Day 35, at pre-specified timepoints.
Adverse events (AEs).		From enrollment to Day 35.
Incidence of Clinically Significant Clinical Laboratory Parameters Abnormality.	Number of participants with at least one clinically significant laboratory parameters abnormality. The following parameters will be measured: Serum Chemistry: ALT, ALB, Alk phos, AST, BUN, Ca, Co2, Cl, Creatinine kinase, eGFR, GGT, Total Cholesterol, Trig, Glucose, LDH, Potassium, Sodium, T. Bili, D. Bili and I. Bili, Total protein. Hematology: HCT, HGB, MPV, Platelet count, RBC count, RBC indices (MCH, MCHC, MCV, RDW), WBC count, WBC differential (BASO, EOS, LYMPH, MONO, NEUT). Urinalysis: UCLA, UBILQL, UCOL, UGLUQ, UKET, UWEST, UNIT, UOCULT, pH, protein, Specific gravity. Coagulation: aPTT, PT, FIB, INR.	From enrollment to Day 35, at pre-specified timepoints.
Incidence of Clinically Significant Vital Signs Abnormality.	Number of participants with at least one clinically significant vitals abnormality. The following clinical signs will be measured: systolic blood pressure (mmHg), diastolic blood pressure (mmHg), heart rate (beats/min), respiratory rate (breaths/min), and body temperature (C°).	From enrollment to Day 35, at pre-specified timepoints.
Incidence of Clinically Significant 12-lead Electrocardiogram (ECG) Abnormality.	Number of participants with at least one clinically significant electrocardiogram abnormality. The following standard 12-lead ECG will be recorded: PR interval (msec), QRS duration (msec), QT interval (msec), QTCF interval (msec), heart rate (beats/min), RR (msec), and interpretation.	From enrollment to Day 35, at pre-specified timepoints.
Incidence of Clinically Significant Physical Examination Abnormality.	Number of participants with at least one clinically significant physical abnormality. A complete physical examination, including at a minimum, assessments of the general appearance, respiratory, cardiovascular, gastrointestinal, musculoskeletal, and dermatological systems, in addition to examinations of the head, eyes, ears, nose, throat, neck, and lymph nodes, as well as height and weight measurement to calculate BMI.	From enrollment to Day 35, at pre-specified timepoints.

Secondary Outcome Measures

Outcome Measure	Time Frame
Bile acid levels in plasma.	From Day 1 to Day 35, at pre-specified timepoints.
Coproporphyrin 1 (CP-1) levels in plasma.	From Day 1 to Day 35, at pre-specified timepoints.

Other Outcome Measures

Outcome Measure	Time Frame
Unbound Cmax (Cmax,u) of ABI-6250.	Day 1 and Day 10, at pre-specified timepoints.
Unbound AUC0-24 (AUC0-24,u) of ABI-6250.	Day 1 and Day 10, at pre-specified timepoints.
Amount of bile acids excreted in urine.	From Day 1 to Day 14, at pre-specified timepoints.

Collaborators and Investigators

• Sponsor: Assembly Biosciences

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: September 14, 2026
• First Submitted That Met QC Criteria: September 24, 2026
• First Posted (Actual): October 1, 2026

Study Record Updates

• Last Update Posted (Actual): October 16, 2026
• Last Update Submitted That Met QC Criteria: October 14, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: ABI-6250-102

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No