BJT-188

Mirum Pharmaceuticals is set to acquire privately held Bluejay Therapeutics in a deal valued at up to $820 million, adding a late-stage programme for chronic hepatitis delta virus (HDV) to a portfolio already centred on rare liver diseases.Specifically, the transaction gives Mirum worldwide rights to brelovitug, and an opportunity to extend its reach beyond cholestatic liver disorders treated by Livmarli (maralixibat) and Ctexli (chenodiol).Brelovitug (BJT-778) is monoclonal antibody designed to target HBsAg, the surface antigen on hepatitis B virus (HBV) required for HDV to assemble and spread. By binding to that antigen, brelovitug aims to neutralise circulating HBV and HDV virions and deplete HBsAg-containing subviral particles.In mid-stage studies, Bluejay reported that brelovitug could fully suppress detectable HDV RNA, and improve liver enzyme levels, while maintaining a favourable safety profile. Injection-site reactions were the most common side effect. The drug has received breakthrough therapy and PRIME designations in the US and Europe, respectively.The programme is now being tested in the Phase III AZURE-1 and AZURE-2 trials, both of which got under way this year. AZURE-1 will enrol 150 patients in the US and test brelovitug as monotherapy for chronic HDV, while AZURE-2 is running outside the US and will compare brelovitug to Gilead Sciences' antiviral treatment Hepcludex (bulevirtide).Top-line results are expected in the second half of 2026, with Mirum aiming for a potential filing and launch in 2027 if the data hold up.CEO Chris Peetz said the acquisition "fits squarely" into Mirum's mission. Brelovitug in HDV, he said, "leverages our deep expertise in rare liver disease and builds on the relationships we've established with key providers through the volixibat and Livmarli programmes."Under the terms of the agreement, Mirum will pay $250 million in cash and $370 million in stock, with up to $200 million in additional tiered sales-based milestones. To help fund development and future commercial activities, Mirum is also raising about $200 million in a concurrent private placement.The deal, approved by both boards, is expected to close in the first quarter of 2026, after which Mirum says it will reassess Bluejay's other investigational programmes. These include cavrotolimod, a TLR9 agonist oligonucleotide currently in Phase I that is designed to boost innate and adaptive immune responses in chronic HBV infection; BJT-628, a liver-targeted HBV transcript inhibitor that is also in Phase I; and preclinical asset BJT-188, a liver-targeted fatty acid synthase inhibitor for metabolic dysfunction-associated steatohepatitis.

All brelovitug dose regimens studied were well tolerated Results will be presented at The Liver Meeting® 2025 of AASLD Additional preclinical data presented on brelovitug mechanisms of action REDWOOD CITY, Calif., Nov. 10, 2025 (GLOBE NEWSWIRE) -- Bluejay Therapeutics, a clinical-stage biopharmaceutical company dedicated to developing potentially life-changing therapeutics for serious viral and liver diseases, today announced Week 48 treatment data in chronic hepatitis D (CHD) for brelovitug (BJT-778), an investigational, fully human, high-affinity monoclonal antibody (mAb) that targets hepatitis B virus surface antigen (anti-HBsAg). These data will be presented today, Nov. 10, at 8:30am ET in the session Clinical Plenary #2 at The Liver Meeting® 2025 of the American Association for the Study of Liver Diseases (AASLD) in Washington, DC. In this Phase 2 study, brelovitug achieved 100% virologic response across all dose arms and up to 82% of participants reached the combined endpoint of virologic response and ALT normalization. Parallel declines in hepatitis D virus (HDV) viral load and ALT were observed across all doses, indicating a beneficial effect on liver inflammation in addition to viral load reduction. “New therapies are urgently needed to address individuals living with hepatitis D,” said presenting author of the study Kosh Agarwal, BMed Sci (Hons) MD, FRCP, Consultant Hepatologist and Transplant Physician of the Institute of Liver Studies at King’s College Hospital in London, United Kingdom. “The combined virologic and ALT normalization rates achieved with brelovitug monotherapy are promising. We look forward to the continued assessment of brelovitug in Bluejay’s AZURE global Phase 3 clinical program.” CHD, a co-infection occurring in patients with chronic hepatitis B (CHB), is the most aggressive form of viral hepatitis. Individuals coinfected with CHD and CHB have twice the risk of liver cancer and three times the risk of cirrhosis compared to those with CHB alone. There are currently no approved treatments for CHD in the United States and most countries worldwide. Brelovitug CHD Phase 2 Week 48 Study Results Participants with quantifiable HDV RNA and hepatitis B virus suppressed on nucleos(t)ides were assigned to one of three brelovitug dosing regimens: 300 mg weekly (QW) (n=18); 600 mg every week for 12 weeks, then every two weeks (Q2W) (n=11); and 900 mg every four weeks (Q4W) with a loading dose administered at week two (n=18). Participants with compensated cirrhosis and those with well-controlled HIV were eligible for inclusion. Key endpoints of the study include safety and tolerability; virologic response (defined as ≥2 log10 HDV RNA IU/mL reduction from baseline or HDV RNA target not detected (TND)); ALT normalization in those participants with abnormal ALT at baseline; and the combined response of virologic response plus ALT normalization. According to FDA guidance, this combined endpoint is a reliable predictor of clinical benefit and directly supports approval of new drugs in CHD. Brelovitug achieved 100% virologic response across all dose arms. The Week 48 results for each dose were as follows: 300 mg QW (n=18): 100% virologic response, including 56% with HDV RNA below the Lower Limit of Quantification (