Bilex Pharma is pleased to announce that BLX-TB01, our novel tuberculosis (TB) vaccine candidate, has received regulatory approval to begin Phase 1 clinical trials. This milestone marks a significant advancement in the company’s efforts to develop an effective vaccine against one of the world’s deadliest infectious diseases.
Addressing a Persistent Global Health Challenge
Tuberculosis remains one of the leading infectious disease killers worldwide, causing approximately 1.6 million deaths annually. Despite the existence of the century-old Bacillus Calmette-Guรฉrin (BCG) vaccine, which provides some protection against severe forms of TB in children, there is currently no highly effective vaccine for preventing pulmonary TB in adolescents and adults โ who account for most TB transmission.
“Tuberculosis continues to impose an enormous burden on global health, particularly in low- and middle-income countries,” said Dr. Andras Ottlik, CEO and Director of Bilex Pharma. “Developing an effective vaccine represents one of the most promising approaches to significantly reducing TB incidence and ultimately working toward elimination of this disease as a public health threat.”
Innovative Approach to a Complex Challenge
BLX-TB01 employs a novel approach to TB vaccination, combining precisely selected Mycobacterium tuberculosis antigens with Bilex Pharma’s proprietary AdaVantโข adjuvant system designed to induce both robust antibody and T-cell responses.
“Our vaccine candidate takes a fundamentally different approach compared to previous TB vaccine efforts,” explained Dr. Eleanor Harrington, Chief Scientific Officer at Bilex Pharma. “BLX-TB01 targets multiple stages of M. tuberculosis infection through a combination of antigens that stimulate diverse immune responses, potentially overcoming limitations of previous vaccine candidates.”
The vaccine incorporates three key M. tuberculosis antigens:
- Ag85B: A secreted antigen that plays a role in mycobacterial cell wall synthesis and has demonstrated strong immunogenicity
- ESAT-6: A virulence factor that induces potent T-cell responses and is absent from the BCG vaccine strain
- Rv2660c: A latency-associated antigen expressed during the dormant phase of infection
These antigens are delivered with Bilex Pharma’s TB-specific adjuvant formulation, designed to direct the immune response toward a balanced Th1/Th17 profile that preclinical research suggests is optimal for TB protection.
Compelling Preclinical Evidence
The advancement to clinical trials follows an extensive preclinical development program that demonstrated promising results across multiple animal models:
- Robust Immunogenicity: BLX-TB01 induced strong antigen-specific CD4+ and CD8+ T-cell responses with a favorable Th1/Th17 profile in both mice and non-human primates.
- Superior Protection: In challenge studies using virulent M. tuberculosis, BLX-TB01 demonstrated significantly greater protection against pulmonary TB compared to BCG vaccination alone.
- Post-Exposure Efficacy: Unlike many vaccine candidates that focus solely on preventing initial infection, BLX-TB01 showed potential efficacy in models of post-exposure vaccination, suggesting possible utility in populations with latent TB infection.
- Potential for BCG Boosting: When administered as a boost to BCG-primed animals, BLX-TB01 significantly enhanced protection compared to BCG alone, supporting its potential use in BCG-vaccinated populations.
“The preclinical data package for BLX-TB01 is particularly strong,” noted Dr. Sophia Chen, Chief Medical Officer at Bilex Pharma. “We observed consistent immunogenicity across species, along with promising efficacy signals in multiple challenge models. These data provide a solid foundation for advancing into human clinical trials.”
Phase 1 Clinical Trial Design
The Phase 1 trial, designated TB-101, will evaluate the safety, reactogenicity, and immunogenicity of BLX-TB01 in healthy adult volunteers. The study will be conducted at three clinical sites in the United Kingdom, with plans for subsequent trials in TB-endemic regions.
Key elements of the study design include:
- Participant Profile: 76 healthy adults aged 18-55 years, with cohorts of both BCG-naรฏve and BCG-vaccinated individuals
- Dose Evaluation: Assessment of three different dose levels (15ฮผg, 50ฮผg, and 150ฮผg total protein)
- Schedule Investigation: Evaluation of both single-dose and two-dose regimens
- Comprehensive Immunological Assessment: Detailed analysis of both humoral and cellular immune responses, including antigen-specific T-cell functionality
- Extended Follow-up: 12-month safety and immunogenicity monitoring
“This first-in-human study is designed to generate a comprehensive dataset on BLX-TB01’s safety profile and immunogenicity,” explained Dr. Chen. “The inclusion of both BCG-naรฏve and BCG-vaccinated participants will help inform future development strategies, whether as a standalone vaccine or as a BCG booster.”
Global Collaboration for TB Vaccine Development
The advancement of BLX-TB01 to clinical trials represents the culmination of a collaborative effort involving multiple partners committed to TB vaccine development:
- Academic Expertise: Research collaboration with the University of Oxford’s Jenner Institute, which provided specialized knowledge in TB immunology
- Funding Support: Partial funding from the Global Health Innovative Technology Fund (GHIT) and the UK Department of Health and Social Care
- Clinical Partnership: Trial implementation in collaboration with the Oxford Vaccine Group with consultative input from the TB Vaccine Initiative (TBVI)
“Developing an effective TB vaccine requires expertise across multiple disciplines and sectors,” said Dr. Ottlik. “We’re grateful for the support and collaboration of our partners, whose contributions have been instrumental in advancing BLX-TB01 to this important milestone.”
Significance for TB Control Efforts
The development of an effective TB vaccine could transform global TB control efforts. Mathematical modeling suggests that a vaccine with 50% efficacy could prevent approximately 33 million TB cases over 15 years if delivered to just 20% of adults in countries with high TB burdens.
“While improvements in diagnosis and treatment have contributed to reducing TB mortality, vaccination represents the most sustainable approach to dramatically reducing TB incidence,” explained Dr. Chen. “An effective vaccine would complement existing TB control strategies and potentially accelerate progress toward TB elimination.”
Manufacturing and Access Considerations
In parallel with clinical development, Bilex Pharma is addressing manufacturing and access considerations to ensure that BLX-TB01 could be made widely available in TB-endemic regions if proven effective:
- Scalable Manufacturing Process: Development of a highly efficient production system capable of large-scale, cost-effective manufacturing
- Thermostability Focus: Formulation work aimed at creating a product with reduced cold chain requirements
- Access Planning: Early engagement with global health organizations to develop deployment strategies for high-burden settings
“From the outset, we’ve designed BLX-TB01 with global access considerations in mind,” noted Dr. Robert Jenkins, Vice President of Manufacturing at Bilex Pharma. “Our process development work has focused on creating a vaccine candidate that could be manufactured at scale and deployed in resource-limited settings.”
Next Steps in Development
Following the Phase 1 trial, Bilex Pharma has outlined a comprehensive development pathway for BLX-TB01:
- Phase 2a Studies: Planned for late 2024 in a TB-endemic region, evaluating safety and immunogenicity in local populations
- Prevention of Infection Trial: A Phase 2b study to assess the vaccine’s ability to prevent TB infection, with primary completion targeted for 2026
- Efficacy Trials: Large-scale Phase 3 assessment of efficacy against active TB disease, to be conducted in partnership with international research networks
“While we recognize that TB vaccine development presents significant challenges, we’re committed to advancing BLX-TB01 through a comprehensive clinical development program,” said Dr. Ottlik. “The initiation of Phase 1 trials represents an important first step in determining whether our approach can contribute to addressing this critical global health need.”
Broader TB Efforts at Bilex Pharma
BLX-TB01 is the lead candidate in Bilex Pharma’s tuberculosis program, which also includes earlier-stage research on next-generation approaches:
- Mucosal Delivery Platforms: Investigating respiratory delivery systems that might enhance protection against pulmonary TB
- Innovative Antigen Combinations: Evaluating additional M. tuberculosis antigens that could broaden immune coverage
- Therapeutic Vaccination: Exploring vaccine approaches that could enhance treatment outcomes for active TB
“Our commitment to addressing TB extends beyond BLX-TB01,” explained Dr. Harrington. “We’re continuing to advance our understanding of TB immunology and exploring multiple approaches that could contribute to global TB control efforts.”
Statement from Leadership
“The advancement of BLX-TB01 to clinical trials represents a significant milestone for Bilex Pharma and for TB vaccine development more broadly,” concluded Dr. Ottlik. “While we recognize that the path to an effective TB vaccine is challenging, the potential impact on global health makes this effort incredibly important. We look forward to reporting the results from this first clinical trial and continuing to advance our TB vaccine program.”
About Bilex Pharma
Bilex Pharma is a UK-based biotechnology company dedicated to advancing human health through groundbreaking research and innovative vaccine development. Our mission is to protect communities worldwide by combating infectious diseases and emerging health threats with safe, effective, and accessible vaccines.
About Tuberculosis
Tuberculosis (TB) is a bacterial infection caused by Mycobacterium tuberculosis that primarily affects the lungs. TB is transmitted through the air when infected individuals cough, sneeze, or speak. Approximately one-quarter of the world’s population has latent TB infection, with the risk of progression to active disease highest in those with compromised immune systems. In 2021, an estimated 10.6 million people fell ill with TB worldwide, and 1.6 million died from the disease, making it the second leading infectious killer after COVID-19.