Brelovitug Receives FDA Breakthrough Therapy Designation for Chronic Hepatitis Delta

The US Food and Drug Administration has granted Breakthrough Therapy designation to Bluejay Therapeutics’ brelovitug (BJT-778) for the treatment of chronic hepatitis delta (CHD).1

Announced on January 21, 2025, the designation comes just 2 months after phase 2 data demonstrating 100% virologic response and up to 78% combined virologic response and alanine aminotransferase (ALT) normalization with brelovitug monotherapy were presented at The Liver Meeting 2024 of the American Association for the Study of Liver Diseases.1,2

"Chronic hepatitis delta is the most aggressive form of viral hepatitis and the lack of approved treatments in the United States creates a major unmet need for patients," Keting Chu, MD, PhD, founder and chief executive officer of Bluejay Therapeutics, said in a press release.1 "Breakthrough Therapy designation recognizes the potential of brelovitug to transform the lives of people living with CHD. We look forward to initiating a global pivotal trial as soon as possible to meet our goal of improving patients’ lives."

A high potency, fully human immunoglobulin G1 monoclonal antibody, brelovitug targets the surface antigen (anti-HBsAg) of the hepatitis B virus. It is designed to neutralize and remove hepatitis B and hepatitis D virions and deplete HBsAg-containing subviral particles, making brelovitug a potentially safe and highly efficacious treatment for CHD.1

According to a release from Bluejay, brelovitug has also shown immunomodulatory functions in patients with chronic hepatitis B (CHB), which may help to reconstitute antiviral immunity and contribute to functional cure for CHB when combined with other agents.1

In the phase 2 study for CHD, participants with quantifiable hepatitis D virus (HDV) RNA and hepatitis B virus (HBV) suppressed on nucleos(t)ides were assigned to 1 of 3 doses of BJT-778: 300 mg weekly (n = 18); 600 mg every week for 12 weeks, then every 2 weeks (n = 11); or 900 mg every 4 weeks after a loading dose administered at week 2 (n = 18).2

Key endpoints included 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 participants with abnormal ALT at baseline; and a combined response of virologic response plus ALT normalization.2

Results showed BJT-778 achieved 100% virologic response across all dose arms and up to 78% of participants reached the combined endpoint of virologic response and ALT normalization. Parallel declines in HDV viral load and ALT were observed across all doses, indicating a beneficial effect on liver inflammation as a result of viral load reduction.2

Additionally, BJT-778 demonstrated a favorable safety profile, and all doses were safe and well tolerated with no ≥ grade 3 adverse events, no severe adverse events, and no treatment discontinuations due to adverse events.2

According to a press release from Bluejay at the time of the phase 2 data, the company expected longer-term, 48-week data across all dose arms to be shared in the second half of 2025.2

References

1. Bluejay Therapeutics. Bluejay Therapeutics Receives U.S. FDA Breakthrough Therapy Designation for Brelovitug (BJT-778) for the Treatment of Chronic Hepatitis Delta. January 21, 2025. Accessed January 21, 2025. https://bluejaytx.com/bluejay-therapeutics-receives-u-s-fda-breakthrough-therapy-designation-for-brelovitug-bjt-778-for-the-treatment-of-chronic-hepatitis-delta/
2. Bluejay Therapeutics. Bluejay Therapeutics Reports Best-in-Class Monoclonal Antibody BJT-778 Achieved 100% Virologic Response and Up To 78% Combined Virologic Response and ALT Normalization as Monotherapy in Participants With Chronic Hepatitis D (CHD). November 15, 2024. Accessed January 21, 2025. https://bluejaytx.com/bluejay-therapeutics-reports-best-in-class-monoclonal-antibody-bjt-778-achieved-100-virologic-response-and-up-to-78-combined-virologic-response-and-alt-normalization-as-m/