BJT-778 for Chronic hepatitis D infection | Hepatitis D

Inclusion criteria

• {"criterion_text":"- 1. Willing and able to provide written informed consent.\n- 2. Male or female, ≥18 years of age at Screening.\n- 3. Confirmation of chronic HDV infection, defined as positive for anti-HDV antibody test or HDV RNA for at least 6 months prior to Day 1. If prior documentation is not available, then HDV RNA positivity along with evidence of fibrosis (liver stiffness of ≥7 kPa) is acceptable.\n- 4. HDV RNA >500 IU/mL at Screening.\n- 5. ALT >ULN at Screening.\n- 6. Taking or willing to take tenofovir disoproxil fumarate (TDF), tenofovir alafenamide fumarate (TAF), or entecavir (ETV) at baseline, and willing to remain on stable treatment for the duration of the study.\n- 7. In countries where HDV treatment is approved and available, participants must be documented as unwilling or unable to receive treatment."}

Exclusion criteria

• {"criterion_text":"- 1. Pregnant or nursing females.\n- 3. Current, prior history, or is under evaluation for any of the following: a) Difficulty with blood collection and/or poor venous access for the purposes of phlebotomy, b) Clinical hepatic decompensation (i.e., ascites, encephalopathy variceal hemorrhage). Incidental small ascites on imaging without other clinical symptoms/signs of acute decompensation would not exclude the participants, c) Hepatocellular carcinoma; suspected HCC on ultrasound at Screening, d) Vasculitis, e) Extrahepatic disorders possibly related to HBV immune complexes (e.g., glomerulonephritis, polyarteritis nodosa), f) Solid organ or bone marrow transplantation, g) Significant pulmonary disease (e.g., O2-dependent or forced expiratory volume 1 second (FEV1) ≤50% predicted value), h) Significant cardiac disease (e.g., history of myocardial infarctions within 6 months, any history of ventricular tachycardia, congestive heart failure, dilated cardiomyopathy with left ventricular ejection fraction <40%), i)Malignancy diagnosed or treated within 5 years (recent localized treatment of squamous or non-invasive basal cell skin cancers is permitted; cervical carcinoma in situ is allowed if appropriately treated prior to Screening).\n- 4. CTP >6 (B or C)\n- 5. Presence of other liver disease(s) (non-HBV/HDV), such as metabolic dysfunction-associated steatohepatitis (MASH), alcohol associated hepatitis, cholestatic liver disease, other viral (e.g., HCV or HAV) or non-viral hepatitis that has the potential to impact interpretation of data. Exceptions to this criterion include fatty liver without any signs of steatohepatitis or past HCV infection that was successfully treated (HCV RNA negative) ≥6 months prior to Screening.\n- 6. Uncontrolled human immunodeficiency virus (HIV) infection defined as having quantifiable HIV RNA levels in the blood at Screening.\n- 7. History of hypersensitivity to any of the components in the brelovitug formulation.\n- 8. Screening laboratory results as follows, or any other clinically significant abnormalities in Screening laboratory values that would render a participant unsuitable for inclusion: a) Platelet count <50,000/mm3 b) Hemoglobin <10.0 g/dL c) Creatinine clearance by Crockcroft-Gault (CrCl) <30 mL/min d) Alpha fetoprotein (AFP) >100 ng/mL\n- 9.Treatment with another investigational drug, a biological agent, or device within 4 weeks or 5 half-lives, whichever is longer, of Baseline.\n- 10. Use of any interferon within 12 weeks of Screening.\n- 11. Use of any prohibited concomitant medications as described in Study Protocol.\n- 12. Regular alcohol misuse, defined as weekly intake of ≥14 alcoholic drinks per week (average of ≥2 alcoholic drinks per day) within 12 months of Screening.\n- 13. Clinically relevant drug abuse (not including cannabis) within 12 months of Screening.\n- 14. Unwillingness to comply with study procedures as specified by this protocol, or unwillingness to cooperate fully with the Investigator.\n- 15. Have any other conditions (medical, social, psychiatric, or other), which in the opinion of the Investigator would make the participant unsuitable for inclusion or could interfere with the participant participating in or completing the study.\n- 2. Male or female participants of childbearing potential unwilling to comply with contraception requirements during the study."}

Primary endpoints

• {"endpoint_text":"- The proportion of participants who achieve a composite endpoint of virologic response and ALT normalization at Week 24 in brelovitug arms will be compared to response at Week 12 of delayed-treatment arm: •\tVirologic response is defined as HDV RNA ≥2 log10 IU/mL decrease from Baseline or undetectable HDV RNA •\tALT normalization is defined as a decrease in ALT from Baseline to ≤ULN.","definition_or_measurement_approach":"Virologic response is defined as HDV RNA ≥2 log10 IU/mL decrease from Baseline or undetectable HDV RNA; ALT normalization is defined as a decrease in ALT from Baseline to ≤ULN. Measured at Week 24 (brelovitug arms) and compared to Week 12 (delayed-treatment arm)."}

Secondary endpoints

• {"endpoint_text":"- Safety endpoint will evaluate: •Incidence and severity of treatment-emergent adverse events (TEAE) •Proportion of participants who permanently discontinue treatment due to an adverse event Comparison with delayed treatment will include data through Week 12 (Predose).","definition_or_measurement_approach":"Incidence and severity of TEAEs and proportion permanently discontinuing due to AE; comparison with delayed treatment includes data through Week 12 (predose)."}
• {"endpoint_text":"- The proportion of participants who achieve the following at Week 24, 48, and 96 of treatment unless otherwise specified: • Virologic response defined as ≥2 log10 IU/mL decline from baseline or undetectable HDV RNA • HDV RNA","definition_or_measurement_approach":"Virologic response measured as ≥2 log10 IU/mL decline from baseline or undetectable HDV RNA at Weeks 24, 48, and 96; additional HDV RNA categories (e.g., <LLOQ, TND) as specified in protocol."}
• {"endpoint_text":"- Proportion of subjects who achieve HDV RNA","definition_or_measurement_approach":"Proportion achieving specified HDV RNA thresholds (detailed measures in protocol)."}
• {"endpoint_text":"- Change from Baseline in liver stiffness as determined by transient elastography at Weeks 24, 48, and 96 of brelovitug treatment","definition_or_measurement_approach":"Liver stiffness measured by transient elastography (e.g., FibroScan) at Weeks 24, 48, 96; change from baseline recorded."}
• {"endpoint_text":"- Change from Baseline in AST-to-platelet ratio index (APRI) at Weeks 24, 48, and 96 of brelovitug treatment","definition_or_measurement_approach":"APRI score calculated from AST and platelet count at specified timepoints; change from baseline recorded."}
• {"endpoint_text":"- Change from Baseline in CTP score in cirrhotic participants at Weeks 24, 48, and 96 of brelovitug treatment","definition_or_measurement_approach":"Child-Turcotte-Pugh (CTP) score assessed in cirrhotic participants at Weeks 24, 48, 96; change from baseline recorded."}
• {"endpoint_text":"- Change from Baseline in Model for End-Stage Liver Disease (MELD) score in cirrhotic participants at Weeks 24, 48, and 96 of brelovitug treatment","definition_or_measurement_approach":"MELD score assessed in cirrhotic participants at Weeks 24, 48, 96; change from baseline recorded."}
• {"endpoint_text":"- Proportion of participants with clinical disease progression from Baseline in HDV-associated liver disease at Weeks 24, 48 and 96 of brelovitug treatment. Progression will be determined by the Independent Data Monitoring Committee (IDMC).","definition_or_measurement_approach":"Clinical disease progression in HDV-associated liver disease assessed at Weeks 24, 48, 96; determination adjudicated by the IDMC."}

Methods

• Site-based recruitment via participating hospitals/clinics (Gastroenterology/Hepatology and Infectious Diseases departments) in Belgium, Hungary, Bulgaria.
• Participant-facing materials: brochures, posters and patient brochures (documents include K2_Recruitment material_Poster_BE-NL, K2_Recruitment material_Poster_BE-FR, Participant Brochure_Redacted, Participant Poster_public).
• Referral letters and Dr-to-Dr letters to local physicians (documents: Referral Letter_BE-NL/BE-FR_Redacted; Dr to Dr letter_Redacted).
• Patient cards and dosing diaries (documents: L2_Patient Card_EN_public; D4_Patient facing documents Dosing diary_Placeholder).
• Country-specific recruitment arrangements documents submitted (K1_Recruitment arrangements for Belgium, Hungary, Bulgaria indicated in document list).

Belgium

Earliest CTIS Part Ii Submission Date

28-11-2025

Latest Decision Or Authorization Date

15-04-2026

Processing Time Days

138

Number Of Sites

3

Number Of Participants

20

Hungary

Earliest CTIS Part Ii Submission Date

08-07-2025

Latest Decision Or Authorization Date

17-04-2026

Processing Time Days

283

Number Of Sites

2

Number Of Participants

10

Bulgaria

Earliest CTIS Part Ii Submission Date

19-12-2025

Latest Decision Or Authorization Date

15-04-2026

Processing Time Days

117

Number Of Sites

1

Number Of Participants

5

Primary sponsor

Full Name

Bluejay Therapeutics Inc.

Organisation Type

Pharmaceutical company

Country Of Registered Address

United States

Third parties

• {"country":"Netherlands","full_name":"DDL Diagnostic Laboratory B.V.","duties_or_roles":"code:4","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"United States","full_name":"Medidata Solutions Inc.","duties_or_roles":"code:7","organisation_type":"Non-Pharmaceutical company"}
• {"country":"United States","full_name":"Suvoda LLC","duties_or_roles":"code:3","organisation_type":"Non-Pharmaceutical company"}
• {"country":"Australia","full_name":"Resolian","duties_or_roles":"code:4","organisation_type":"Industry"}
• {"country":"Belgium","full_name":"CluePoints","duties_or_roles":"code:15; Risk based monitoring","organisation_type":"Pharmaceutical company"}
• {"country":"Germany","full_name":"Catalent Germany Schorndorf GmbH","duties_or_roles":"code:14","organisation_type":"Pharmaceutical company"}
• {"country":"Switzerland","full_name":"Psi Cro AG","duties_or_roles":"codes:1,10,12,2,5,6,8,9","organisation_type":"Pharmaceutical company"}
• {"country":"Australia","full_name":"VIDRL","duties_or_roles":"code:4","organisation_type":"Health care"}
• {"country":"United Kingdom","full_name":"Acm Global Central Laboratory Limited","duties_or_roles":"code:4","organisation_type":"Laboratory/Research/Testing facility"}
• {"country":"United States","full_name":"B2s Life Sciences LLC","duties_or_roles":"code:4","organisation_type":"Pharmaceutical company"}