TLR9 x HBsAg

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 05, 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 . Contacts Investors & Media: Argot Partners bluejay@argotpartners.com

SAN MATEO, Calif., May 29, 2024 (GLOBE NEWSWIRE) -- Bluejay Therapeutics, a private clinical-stage biopharmaceutical company focused on viral and liver diseases with unmet medical needs, today announced that the European Medicines Agency (EMA) has issued a positive opinion on the Company’s application for orphan designation for BJT-778 for the treatment of chronic hepatitis D (CHD). “We are delighted that the EMA has issued a positive opinion for orphan designation for BJT-778. This recognition underscores the urgent need for new treatment options for people living with this devastating chronic infection,” said Keting Chu, Founder and CEO of Bluejay Therapeutics. “We are eager to accelerate the development of BJT-778 and make it available to patients as soon as possible. We look forward to continuing our collaboration with the EMA and other regulatory agencies to expedite the availability of this promising treatment for patients with CHD.” In addition to orphan designation, BJT-778 has also been granted Priority Medicines (PRIME) designation by the EMA for the treatment of chronic HDV, an endorsement to the therapy’s potential to address a high unmet need in patients with these serious conditions. About BJT-778 BJT-778 is a high-potency, fully human immunoglobulin G1 (IgG1) monoclonal antibody (mAb) 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 a functional cure for chronic hepatitis B (CHB). BJT-778’s preclinical safety and efficacy profiles make it an ideal candidate for combination therapies with existing and emerging treatments for CHB and chronic hepatitis D (CHD). BJT-778 is currently being evaluated for the treatment of CHD and as a functional cure for chronic HBV. About Bluejay Therapeutics Bluejay Therapeutics is a private biopharmaceutical company focused on the development of treatments for viral and liver diseases. The Company’s lead program, BJT-778, is a potentially best-in-class fully human IgG1 anti-HBsAg mAb, being developed for both chronic HBV and HDV. 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 achieving higher rates of functional cure. For more information on Bluejay, please visit the company’s website at www.bluejaytx.com. Contacts Investors & Media: Argot Partners bluejay@argotpartners.com

Presentations include late-breaking abstract highlighting preliminary results from Phase 2 study of BJT-778 in chronic hepatitis D (CHD)SAN MATEO, Calif., May 22, 2024 (GLOBE NEWSWIRE) -- Bluejay Therapeutics today announced it will present new data from its ongoing Phase 2 trial evaluating the potential of BJT-778, an investigational anti-HBsAg monoclonal antibody (mAb) that acts against hepatitis B surface antigen, for the treatment of chronic hepatitis D (CHD) at the European Association for the Study of the Liver (EASL) conference taking place June 5-8, in Milan, Italy. Bluejay will also present several posters describing the preclinical profile of BJT-778, its mechanisms of action, and its pharmacokinetics and safety profile in healthy volunteers. Four abstracts have been selected for presentation, including a late-breaker poster presentation that will highlight the safety, tolerability, and antiviral activity data from the Phase 2 trial evaluating BJT-778 for the treatment of chronic hepatitis delta virus (HDV). Additional presentations will focus on the safety and pharmacokinetic profile of BJT-778 in healthy volunteers, the preclinical profile of BJT-778, including its affinity against HBsAg, neutralizing activity against hepatitis B and D viruses, and its pan-genotypic activity, and BJT-778’s preclinical immunomodulatory activity, showcasing its potential for enhancing antiviral T cells functions to potentially clear HBV infection. Presentation details for EASL are as follows: Late-Breaker Poster Presentation – Phase 2 Title: Rapid reductions of HDV RNA and ALT with the monoclonal antibody, BJT-778: results from a phase 2 study (Abstract #LBP-001)Date: Wednesday, June 5 at 8:30 am CESTPresenter: Kosh Agarwal, M.D., Institute of Liver Studies, King's College Hospital, Denmark Hill, London, UK Poster Presentation – Phase 1 Title: Safety, tolerability, and pharmacokinetics of BJT-778, a monoclonal antibody for treatment of chronic hepatitis B and chronic hepatitis D, following single ascending doses in healthy volunteers (Abstract #WED-374)Date: Wednesday, June 5 at 8:30 am CESTPresenter: Edward Gane, M.D., Professor of Medicine at the University of Auckland, New Zealand, and Chief Hepatologist, Transplant Physician, and Deputy Director of the New Zealand Liver Transplant Unit at Auckland City Hospital Poster Presentation – Preclinical Title: Characterization of BJT-778, an anti-HBsAg neutralizing monoclonal antibody for treatment of hepatitis B virus and hepatitis D virus infections (Abstract #WED-366)Date: Wednesday, June 5 at 8:30 am CESTPresenter: Hilario Ramos, Ph.D., Bluejay Therapeutics Poster Presentation – Preclinical Title: Uptake and T cell stimulation by anti-HBs monoclonal antibody BJT-778-rHBsAg immune complexes (Abstract #SAT-536)Date: Saturday, June 8 at 8:30 am CESTPresenter: Loghman Salimzadeh, Ph.D., Schwartz-Reisman Liver Research Centre, University Health Network, Toronto, Ontario, Canada About BJT-778 BJT-778 is a high-potency, fully human immunoglobulin G1 (IgG1) monoclonal antibody (mAb) 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 a functional cure for chronic hepatitis B (CHB). BJT-778’s preclinical safety and efficacy profiles make it an ideal candidate for combination therapies with existing and emerging treatments for CHB and chronic hepatitis D (CHD). BJT-778 is currently being evaluated for the treatment of CHD and as a functional cure for chronic HBV. About Bluejay Therapeutics Bluejay Therapeutics is a private biopharmaceutical company focused on the development of treatments for viral and liver diseases. The Company’s lead program, BJT-778, is a potentially best-in-class fully human IgG1 anti-HBsAg mAb, being developed for both chronic HBV and HDV. 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 achieving higher rates of functional cure. For more information on Bluejay, please visit the company’s website at www.bluejaytx.com. Contacts Investors & Media: Argot Partners bluejay@argotpartners.com