Bluejay Therapeutics Presents Positive Preliminary BJT-778 Data from Phase 2 Clinical Trial in Chronic Hepatitis D at EASL 2024 Congress

100% of treated patients in Arm 1 achieved virologic response by Week 28

Most patients also achieved ALT normalization and composite response

BJT-778 was well tolerated across all arms at doses up to 900mg

SAN MATEO, Calif., June 5, 2024 (GLOBE NEWSWIRE) — Bluejay Therapeutics, a private clinical-stage biopharmaceutical company focused on viral and liver diseases, today announced positive preliminary data from the Phase 2 study of BJT-778, a fully human IgG1 monoclonal antibody that acts against hepatitis B surface antigen (anti-HBsAg mAb), in patients with chronic hepatitis D (CHD). The data were presented in a late-breaking poster at the European Association for the Study of the Liver (EASL) Congress 2024.

In the first test arm, 100% of treated patients achieved a virologic response (at least a 2 log reduction in hepatitis D virus (HDV) RNA or becoming HDV RNA undetectable) by Week 28 while receiving treatment with BJT-778. All subjects had reductions of alanine aminotransferase (ALT) from baseline, including two-thirds of subjects whose ALT became normal, reflecting a beneficial effect on liver inflammation. These results highlight the potential of BJT-778 as a monotherapy treatment for CHD.

“We are pleased to present the first look at the safety and clinical activity of BJT-778, which supports the potential for BJT-778 to address unmet needs for the millions of people in the world living with chronic hepatitis D,” said Dr. Keting Chu, Founder and CEO of Bluejay.

As of May 24, 2024, 31 patients have been enrolled in the Phase 2 portion of the study. Patients in Arm 1 (n=10) are receiving 300 mg of BJT-778 subcutaneously (SC) once weekly for 48 weeks, Arm 2 (n=11) are receiving 600 mg SC once weekly for 12 weeks followed by once every two weeks for 36 weeks, and Arm 3 (n=10) are receiving 900 mg SC every two weeks for 4 weeks followed by once every four weeks for 44 weeks. All patients in Arm 1 have reached at least 24 weeks of treatment. All patients in Arm 2 have reached 12 weeks of treatment, while Arm 3 subject data is currently limited to less than 4 weeks. Endpoints include safety and tolerability, changes from baseline in HDV RNA and ALT levels, and proportion of subjects who achieve virologic response (HDV RNA ≥ 2 logs or HDV RNA undetectable), ALT normalization, and composite response (both virologic response and ALT normalization).

Key Findings

Preliminary Efficacy

  • In Arm 1, all 10 (100%) subjects achieved a virologic response by Week 28. ALT declined from baseline in all patients, including 67% (6/9) who achieved ALT normalization, while one subject had a normal ALT at baseline, which declined. 67% (6/9) achieved the approvable endpoint of composite response (virologic response + ALT normalization). Two others were 1 U/L away from the upper limit of normal. The mean reduction of HDV RNA from baseline at Week 24 was 3.6 logs.
  • In Arm 2, 8/10 (80%) patients achieved a virologic response by Week 12. ALT declined in most subjects, even among the 7 patients whose baseline ALT was within the normal range. Three out of four patients with abnormal ALT at baseline normalized by Week 12.

Preliminary Safety

  • Across all 3 treatment arms, BJT-778 at doses up to 900mg has been well tolerated, with no reported serious or Grade 3/4 adverse events, and no discontinuations due to AEs.

About BJT-778

BJT-778 is a high-potency, fully human immunoglobulin G1 (IgG1) mAb antibody against hepatitis B surface antigen (anti-HBsAg mAb). BJT-778 neutralizes and clears hepatitis B and hepatitis D virions and depletes HBsAg-containing subviral particles, which may help to reconstitute antiviral immunity and contribute to functional cure for chronic hepatitis B (CHB) when combined with other agents. BJT-778 has received orphan and PRIME designation from EMA based on early results from the Phase 1/2 study in CHD.

About Bluejay Therapeutics

Bluejay Therapeutics is a private biopharmaceutical company focused on the development of treatments for viral and liver diseases. In addition to BJT-778, Bluejay is also developing and advancing other innovative programs for chronic HBV, including a proprietary TLR9 agonist (Cavrotolimod) and a liver targeted transcript inhibitor (BJT-628), with the goal of finding combinations that achieve functional cure. For more information on Bluejay, please visit the company’s website at