Phase IIIB Extension Clinical Trial of Efficacy and Safety of GST-HG141 (Nairevir) Combined With NAs in Chronic Hepatitis B

A Single-Arm, Open-Label, Multicenter Phase IIIB Extension Clinical Trial to Evaluate the Efficacy and Safety of GST-HG141 (Nairecovir) in Combination With Nucleos(t)Ide Analogs (NAs) in Patients With Chronic Hepatitis B

This is a multicenter, single-arm, open-label, phase IIIb extension clinical trial designed to evaluate the long-term safety and tolerability of GST-HG141 (nerlecovir, 50 mg BID) in combination with nucleos(t)ide analogues (NAs) in patients with chronic hepatitis B (CHB) who completed 48 weeks of treatment in the phase III study (GST-HG141-III-01), did not discontinue prematurely, had an overall medication compliance rate of ≥80%, and were willing to continue treatment.

A maximum of 578 eligible participants will be enrolled at 64 centers, including those who completed the preceding study, had ALT ≤5× upper limit of normal (ULN), and had no severe comorbidities (e.g., decompensated cirrhosis, other viral infections, or malignant tumors)

Study Overview

• Status: Not yet recruiting
• Conditions: Chronic Hepatitis b
• Intervention / Treatment: Drug: GST-HG141

• Study Type: Interventional
• Enrollment (Estimated): 576
• Phase: Phase 3

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Participants who received the study treatment of the phase III clinical trial of GST-HG141 (GST-HG141-III-01) in accordance with the protocol requirements (participants without early withdrawal and with overall medication compliance ≥ 80%), and had ALT ≤ 5×ULN;
2. Participants were willing to participate in the study and were judged by the investigator to be suitable for long-term treatment with GST-HG141 combined with NAs;
3. Male participants with female partners of childbearing potential or female participants of childbearing potential voluntarily adopted effective contraceptive measures from screening to 28 days after study withdrawal ;
4. Signed the informed consent form prior to the trial and were able to complete the study in accordance with the requirements of the trial protocol.

Exclusion Criteria:

1. Presence of severe systemic infection requiring treatment;
2. Suffering from clinically significant acute or chronic liver diseases not caused by HBV infection;
3. Participants with a history of liver cirrhosis; or currently diagnosed or suspected decompensated liver cirrhosis, including but not limited to hepatic encephalopathy, hepatorenal syndrome, esophagogastric variceal bleeding, splenomegaly, ascites, etc.; or participants with significant progression of liver fibrosis;
4. Primary liver cancer; suspected malignant space-occupying liver lesions suggested by imaging examination; combined with other malignant tumors (except cured basal cell carcinoma or squamous cell carcinoma of the skin and carcinoma in situ of the cervix);
5. Impaired gastrointestinal function or gastrointestinal diseases that may affect the absorption of oral drugs as judged by the investigator;
6. Combined with severe diseases of the circulatory, respiratory, urinary, hematological, metabolic, immune, psychiatric, neurological, renal and other systems, and judged by the investigator to be ineligible for continued participation in the study;
7. Participants with major trauma or major surgery within 3 months prior to screening; or those planning to undergo surgery during the study period;

8. Laboratory test abnormalities:

   1. Platelet count < 100×10^9/L;
   2. White blood cell count < 3.0×10^9/L;
   3. Absolute neutrophil count < 1.3×10^9/L;
   4. Serum total bilirubin > 2×ULN;
   5. Albumin < 35 g/L;
   6. Estimated glomerular filtration rate (eGFR) ≤ 60 ml·min-¹·(1.73m²)-¹ ;
   7. International Normalized Ratio (INR) of prothrombin time > 1.5;
9. Lactating females or participants with a positive pregnancy test;
10. Participants with any other conditions deemed inappropriate for participation in this trial by the investigator.

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: GST-HG141; GST-HG141+NAs	Drug: GST-HG141; GST-HG141 50 mg BID + NAs

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate the safety of GST-HG141 combined with NAs treatment	Treatment-emergent AE incidence rate	up to 52 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
The percentage of participants in the experimental group of Study GST-HG141-III-01 with HBV DNA < 20 IU/mL after completing this study and receiving 48 weeks of GST-HG141 combined with NAs treatment.	up to 48 weeks
Among participants of Study GST-HG141-III-01 who had HBV DNA ≥ 20 IU/mL after completing double-blind treatment, the percentage of participants with serum HBV DNA < 20 IU/mL following 48 weeks of treatment in this study.	up to 48 weeks
The percentage of participants with serum HBV DNA < 20 IU/mL at each visit time point.	up to 48 weeks
The percentage of participants with serum HBV DNA < 10 IU/mL at each visit time point.	up to 48 weeks
Changes from baseline in quantitative serum HBV DNA levels at each visit time point.	up to 48 weeks
Time to achieve serum HBV DNA < 20 IU/mL in each group.	up to 48 weeks
The percentage of participants with serum HBsAg seroclearance at each visit time point.	up to 48 weeks
Changes from baseline in quantitative hepatitis B surface antigen (HBsAg) levels at each visit time point.	up to 48 weeks
Changes from baseline in quantitative serum hepatitis B virus pregenomic RNA (HBV pgRNA) levels at each visit time point.	up to 48 weeks

Collaborators and Investigators

• Sponsor: Fujian Akeylink Biotechnology Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): June 26, 2026
• Primary Completion (Estimated): January 11, 2028
• Study Completion (Estimated): March 1, 2028

Study Registration Dates

• First Submitted: April 23, 2026
• First Submitted That Met QC Criteria: May 8, 2026
• First Posted (Actual): May 14, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 8, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Blood-Borne Infections; Pathologic Processes; Chronic Disease; Disease Attributes; Infections; Virus Diseases; Digestive System Diseases; Liver Diseases; Hepatitis, Viral, Human; Communicable Diseases; DNA Virus Infections; Hepadnaviridae Infections; Hepatitis, Chronic; Hepatitis; Pathological Conditions, Signs and Symptoms; Hepatitis B; Hepatitis B, Chronic
• Other Study ID Numbers: GST-HG141-III-EX

Drug and device information, study documents

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