Arbutus Receives FDA Fast Track Designation for Hepatitis B RNAi Therapeutic Imdusiran
核心洞察
The FDA has granted Fast Track designation to Arbutus Biopharma's imdusiran (AB-729), an RNAi therapeutic for chronic hepatitis B treatment.
Clinical trials show imdusiran achieved functional cure in 10 patients to date, with six maintaining cure for over two years.
The designation facilitates development and expedites FDA review for this therapy targeting over 250 million chronic hepatitis B patients worldwide.
Arbutus Biopharma Corporation (搜索) announced that the U.S. Food and Drug Administration has granted Fast Track designation for imdusiran (AB-729), an investigational RNAi therapeutic for the treatment of chronic hepatitis B. The designation recognizes the significant unmet medical need in chronic hepatitis B, which affects over 250 million people worldwide and causes approximately 1.1 million deaths annually from complications including cirrhosis and liver cancer.
"We are excited about the potential of imdusiran, which in trials has achieved functional cure for 10 chronic hepatitis B patients to date and allowed many others to live medication-free, to address significant unmet medical need," said Lindsay Androski, President and CEO of Arbutus. "The FDA grant of Fast Track designation validates imdusiran as an important drug candidate, and we look forward to working collaboratively and closely with the FDA during the remaining stages of the development process."
Clinical Trial Results Demonstrate Promising Efficacy
In Arbutus' Phase 2a clinical trials, eight patients with chronic hepatitis B achieved functional cure following treatment with imdusiran and nucleos(t)ide analogue (搜索) therapy in combination with either pegylated interferon alfa-2a or low dose nivolumab plus an immunotherapeutic. Notably, six out of the eight patients have continued to sustain functional cure for over two years, demonstrating the durability of the therapeutic response.
The clinical data extends beyond functional cure achievements. An additional 41 patients across the company's Phase 2a clinical trials were able to remain off nucleos(t)ide analogue (搜索) therapy for at least 48 weeks following treatment with imdusiran. Two additional patients who discontinued nucleos(t)ide analogue therapy in their Phase 2a clinical trials have now achieved functional cure during their participation in long-term follow-up.
Functional cure is defined as sustained hepatitis B surface antigen seroclearance and hepatitis B virus DNA less than the lower limit of quantification after 24 weeks off treatment, with or without anti-hepatitis B surface antibodies. Clinical data generated thus far has shown imdusiran to be generally safe and well-tolerated, while also providing meaningful reductions in hepatitis B surface antigen and hepatitis B virus DNA.
Novel RNAi Mechanism Targets Viral Proteins
Imdusiran is an RNAi therapeutic specifically designed to reduce all hepatitis B viral proteins and antigens, including hepatitis B surface antigen, which is thought to be a key prerequisite to enable reawakening of a patient's immune system to control the virus. The therapeutic targets hepatocytes (搜索) using Arbutus' novel covalently conjugated N-Acetylgalactosamine delivery technology enabling subcutaneous delivery.
Fast Track Benefits and Development Pathway
The FDA's Fast Track program is designed to facilitate the development and expedite the review of investigational therapies to treat serious conditions with unmet medical need. A drug granted Fast Track designation may be eligible for several benefits, including earlier and more frequent meetings and communications with the FDA and, if relevant criteria are met, the potential for Accelerated Approval, Priority Review or Rolling Review of a Biologics License Application or New Drug Application.
Addressing Global Health Burden
Hepatitis B represents a significant global health challenge. The World Health Organization estimates that over 250 million people worldwide suffer from chronic hepatitis B infection, while other estimates indicate that approximately 2 million people in the United States suffer from chronic hepatitis B infection. The disease is a potentially life-threatening liver infection that can cause chronic infection leading to a higher risk of death from cirrhosis and liver cancer.
Arbutus Biopharma Corporation (搜索) is a clinical-stage biopharmaceutical company focused on infectious disease. The company is currently developing imdusiran and an oral PD-L1 (搜索) inhibitor (AB-101) for the treatment of chronic hepatitis B infection.