Bluejay Therapeutics
Bluejay Therapeutics is a clinical-stage biopharmaceutical company developing monoclonal antibody therapies for viral hepatitis, with lead asset brelovitug in Phase 3 trials for chronic hepatitis delta virus. Acquired by Mirum Pharmaceuticals in January 2026 for up to $820 million.
- Company typePrivate
- Founded2019
- HeadquartersSan Mateo, United States
- Headcount11–50
- GTM typeB2B
- OfferingHardware or Manufacturing
What Bluejay Therapeutics does
Bluejay Therapeutics was a privately-held clinical-stage biopharmaceutical company founded in 2019 and headquartered in San Mateo, California, focused on developing treatments for viral hepatitis and other serious liver diseases. The company's pipeline centered on brelovitug, a fully human monoclonal antibody targeting chronic hepatitis delta virus (HDV) — the most severe form of viral hepatitis — which received both FDA Breakthrough Therapy designation and EMA PRIME designation. Brelovitug demonstrated 100% HDV RNA response in Phase 2 trials and was advancing through the Phase 3 AZURE registrational program with topline data expected in H2 2026. Bluejay's secondary program was an HBsAg inhibitor targeting chronic hepatitis B virus (HBV), intended as part of a combination approach to achieve functional cure for chronic HBV infection. Peak sales potential for brelovitug was estimated at over $750 million.
Bluejay operated as a pre-commercial R&D entity with no product revenue. Its business model relied on venture capital funding and clinical development execution. Across three equity rounds (2021 seed ~$19M, $41M Series B in August 2022 led by Arkin Bio Ventures, and $182M Series C in May 2024 led by Frazier Life Sciences), the company raised approximately $242 million from a syndicate including Novo Holdings, RA Capital Management, T. Rowe Price, Wellington Management, HBM Healthcare Investments, and RiverVest. The company was led by Founder, CEO, and Chairman Dr. Keting Chu, an experienced biotech executive whose prior roles included VP of Biology and Head of R&D at Five Prime Therapeutics and Head of Immunotherapy and Antibody Therapeutics at Chiron Corporation.
In January 2026, Mirum Pharmaceuticals completed its acquisition of Bluejay Therapeutics for up to $820 million, comprising $620 million upfront and up to $200 million in potential milestone payments. The transaction added brelovitug to Mirum's rare liver disease commercial portfolio, transferring future commercialization, distribution, and revenue mechanics to Mirum's established hepatology infrastructure. Bluejay now operates as a wholly-owned subsidiary of Mirum Pharmaceuticals.
Bluejay Therapeutics firmographics
Firmographics- Name
- Bluejay Therapeutics
- Legal name
- Bluejay Therapeutics, Inc.
- Website
- https://bluejaytx.com
- Company type
- Private
- Founded year
- 2019
- Operating status
- Acquired
- Headcount range
- 11–50 employees
- Short description
- Bluejay Therapeutics is a clinical-stage biopharmaceutical company developing monoclonal antibody therapies for viral hepatitis, with lead asset brelovitug in Phase 3 trials for chronic hepatitis delta virus. Acquired by Mirum Pharmaceuticals in January 2026 for up to $820 million.
- Ownership category
- akta.pro rank
Bluejay Therapeutics industry classification
Industry- Product category
- Biopharmaceuticals — Hepatitis Therapeutics
- NAICS
- Biological Product (except Diagnostic) Manufacturing (325414)
- SIC
- Biological Products, (No Disgnostic Substances) (2836)
- akta.pro primary industry
- Hepatology (Viral Hepatitis) (HLAKAGAC)
Keywords
Where Bluejay Therapeutics is headquartered
LocationHeadquarters
- HQ city
- San Mateo
- HQ country
- United States
- HQ region
- North America
Markets served
Bluejay Therapeutics business model
Business model- GTM type
- B2B
- Offering type
- Hardware or Manufacturing
- Cost components
- Technology or R&D, Personnel, Operations
Bluejay Therapeutics product offering
Product offeringCore offering
Bluejay Therapeutics develops biologic therapeutics for chronic viral hepatitis, with its lead asset brelovitug being a late-stage fully human monoclonal antibody targeting chronic hepatitis delta virus (HDV) that has received FDA Breakthrough Therapy and EMA PRIME designations. The company also pursues a functional cure for chronic hepatitis B virus (HBV) through an HBsAg inhibitor program combined with monoclonal antibody approaches.
Product overview
Bluejay Therapeutics was a biotech company focused on viral hepatitis and serious liver diseases. Its lead product was brelovitug, a late-stage monoclonal antibody for chronic hepatitis delta virus (HDV), which received FDA Breakthrough Therapy and EMA PRIME designations. The company was also developing an HBsAg inhibitor as part of its hepatitis B virus programs. Bluejay was acquired by Mirum Pharmaceuticals in January 2026 for up to $820 million.
Differentiator
Problem solved
Functional benefit
Products and services
- Brelovitug A late-stage fully human monoclonal antibody targeting chronic hepatitis delta virus (HDV), with FDA Breakthrough Therapy and EMA PRIME designations. Demonstrated 100% HDV RNA response in Phase 2 trials and is being developed for the treatment of patients with chronic hepatitis D infection — the most severe form of viral hepatitis.
- HBsAg Inhibitor An HBsAg (hepatitis B surface antigen) inhibitor program targeting hepatitis B virus (HBV), part of Bluejay Therapeutics' pipeline for developing a functional cure for chronic HBV infection, intended for use in combination with monoclonal antibody approaches.
Quantifiable outcome
- 100% HDV RNA response demonstrated in Phase 2 trials
- +1 more outcomes
Companies that use Bluejay Therapeutics
Customer profileSegments2 records
Ideal customer profiles2 records
Bluejay Therapeutics technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature2 records
Bluejay Therapeutics partnerships and signals
Strategic signalPartnerships
One partnership is on record.
- Mirum PharmaceuticalscoreMirum Pharmaceuticals acquired Bluejay Therapeutics for up to $820 million (including $620M upfront and up to $200M in milestone payments). The acquisition added brelovitug, a late-stage monoclonal antibody for chronic hepatitis delta virus with FDA Breakthrough Therapy and EMA PRIME designations, to Mirum's rare liver disease portfolio. The deal was completed in January 2026.
Scale indicators4 records
Recent moves6 records
Expansion highlights5 records
Bluejay Therapeutics competitors and assessment
Company assessmentDirect peers
- Vir Biotechnology: Clinical-stage immunology company developing therapies for chronic hepatitis B and hepatitis D, including monoclonal antibody and siRNA approaches. Direct competitor to Bluejay's brelovitug in chronic HDV and HBV functional cure strategies.
- Arbutus Biopharma: Biotech focused on chronic HBV functional cure using RNAi (AB-729) and oral capsid inhibitor approaches. Directly comparable to Bluejay in target indication (chronic HBV) and combination cure strategy.
- Brii Biosciences: China- and US-based biotech developing siRNA, monoclonal antibody, and combination therapies for chronic HBV, including functional cure strategies. Directly comparable target indication and modality mix.
- Assembly Biosciences: Clinical-stage biotech developing a portfolio of HBV core inhibitors and other small molecules aimed at functional cure of chronic hepatitis B. Directly comparable pipeline and indication overlap.
- Aligos Therapeutics: Developer of oligonucleotide and small molecule therapies for chronic hepatitis B and hepatitis D, with multiple programs targeting functional cure. Comparable preclinical/clinical pipeline and target indications.
Broad incumbents
- Gilead Sciences: Major biopharmaceutical company with established HBV franchise (Vemlidy/tenofovir) and active R&D efforts toward functional cure. Larger incumbent overlapping in chronic hepatitis B market.
- Roche: Global biopharma with diagnostics and therapeutics presence in viral hepatitis, including HBV programs. Broad incumbent with overlapping capability in hepatology indications.
- AstraZeneca: Global biopharma with established presence in liver and infectious disease therapeutics, including chronic HBV pipeline investments. Broad incumbent overlapping in viral hepatitis.
- GlaxoSmithKline: Global biopharma with hepatitis R&D programs including TLR agonists and entry inhibitors for chronic HBV. Broad incumbent with overlapping hepatology therapeutic interests.
- Johnson & Johnson: Diversified biopharma with hepatitis programs through Janssen, including investigational therapies for chronic HBV and HDV. Larger incumbent with hepatology footprint.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat3 records
Key risks6 records
Key highlights7 records
Customer concentration
Bluejay Therapeutics social profiles
Digital presenceBluejay Therapeutics financial estimates
Financial estimateRevenue estimate
Valuation estimate
Bluejay Therapeutics leadership team
Management profileNumber of profiles
Profiles6 records
Bluejay Therapeutics funding detail
Funding detailFunding overview
Funding rounds3 records
Investors12 records
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Bluejay Therapeutics M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Bluejay Therapeutics
What does Bluejay Therapeutics do?
Bluejay Therapeutics develops biologic therapeutics for chronic viral hepatitis, with its lead asset brelovitug being a late-stage fully human monoclonal antibody targeting chronic hepatitis delta virus (HDV) that has received FDA Breakthrough Therapy and EMA PRIME designations. The company also pursues a functional cure for chronic hepatitis B virus (HBV) through an HBsAg inhibitor program combined with monoclonal antibody approaches.
Is Bluejay Therapeutics a public or private company?
Bluejay Therapeutics is a private company. It is classified as corporate owned and is currently acquired.
When was Bluejay Therapeutics founded?
Bluejay Therapeutics was founded in 2019. It employs 11 to 50 people.
Where is Bluejay Therapeutics based?
Bluejay Therapeutics is headquartered in San Mateo, United States, in the North America region.
Who are Bluejay Therapeutics's main competitors?
Direct peers on record are Vir Biotechnology, Arbutus Biopharma, Brii Biosciences, Assembly Biosciences and Aligos Therapeutics. Broad incumbents are Gilead Sciences, Roche, AstraZeneca, GlaxoSmithKline and Johnson & Johnson.
Does Bluejay Therapeutics have an API?
No public API is recorded for Bluejay Therapeutics.
What industry is Bluejay Therapeutics in?
Bluejay Therapeutics's product category is Biopharmaceuticals — Hepatitis Therapeutics. Its primary akta.pro industry code is HLAKAGAC, Hepatology (Viral Hepatitis). Its NAICS code is 325414 and its SIC code is 2836.