Bilex Pharma is pleased to announce the initiation of Phase 1 clinical trials for BLX-CHIK01, our virus-like particle (VLP) vaccine candidate for chikungunya virus. This important milestone follows the successful completion of comprehensive preclinical studies demonstrating the vaccine’s strong immunogenicity and favorable safety profile.

Addressing a Growing Global Health Threat

Chikungunya virus is a mosquito-transmitted pathogen that causes a debilitating disease characterized by severe joint pain, fever, and rash. While rarely fatal, chikungunya can lead to persistent arthralgia lasting months or even years, causing significant disability and economic impact. In recent decades, the virus has spread from its historical range in Africa and Asia to new regions, including the Americas, Europe, and the Pacific Islands, affecting millions of people.

“Chikungunya represents a significant and expanding global health challenge,” said Dr. Andras Ottlik, CEO and Director of Bilex Pharma. “Climate change and increased global travel have expanded the geographical range of the mosquito vectors, putting more populations at risk. An effective vaccine could fundamentally change how we address this growing threat.”

Innovative Virus-Like Particle Approach

BLX-CHIK01 utilizes a virus-like particle (VLP) platform technology, which presents viral structural proteins in a conformation that closely mimics the native virus without any infectious genetic material.

“Our chikungunya vaccine candidate consists of VLPs that display the structural proteins of the virus in their authentic arrangement,” explained Dr. Eleanor Harrington, Chief Scientific Officer at Bilex Pharma. “This approach induces robust neutralizing antibody responses similar to those generated during natural infection, but without the risk of causing disease.”

The VLPs are produced using an advanced mammalian cell expression system that ensures proper protein folding and post-translational modifications, critical factors for generating protective immune responses.

Promising Preclinical Results

The advancement to clinical trials follows an extensive preclinical evaluation program that demonstrated several promising attributes of BLX-CHIK01:

Strong Immunogenicity

• Robust Neutralizing Antibody Responses: The vaccine induced high titers of neutralizing antibodies after a single dose in multiple animal models
• Durable Protection: Antibody responses remained at protective levels for at least 12 months in long-term studies
• Cross-Protection: The vaccine generated antibodies that neutralized diverse chikungunya virus strains from different geographical regions

Favorable Safety Profile

• No Safety Signals: Toxicology studies revealed no significant adverse effects across multiple dose levels
• Well-Tolerated: Local and systemic reactogenicity was mild and transient in animal models
• No Evidence of Antibody Enhancement: Unlike some viral vaccines, BLX-CHIK01 showed no signs of antibody-dependent enhancement of infection

Efficacy in Challenge Models

• Complete Protection: Vaccinated non-human primates were completely protected against viremia following challenge with live chikungunya virus
• Prevention of Joint Inflammation: Animal models showed no evidence of arthritis or joint inflammation after challenge, suggesting protection against the hallmark symptoms of chikungunya disease

“The preclinical data package for BLX-CHIK01 is particularly strong,” noted Dr. Sophia Chen, Chief Medical Officer at Bilex Pharma. “The single-dose protection and durability of the immune response are especially encouraging features that suggest the vaccine could be practical for deployment in affected regions.”

Phase 1 Clinical Trial Design

The Phase 1 trial, designated CHIK-101, is designed to evaluate the safety, tolerability, and immunogenicity of BLX-CHIK01 in healthy adult volunteers. The study has commenced at clinical sites in the United Kingdom, with plans to expand to a site in a chikungunya-endemic region in the second stage of the trial.

Key elements of the study design include:

• Participant Profile: 90 healthy adults aged 18-55 years
• Dose Evaluation: Assessment of three different dose levels (15μg, 45μg, and 90μg of VLP protein)
• Schedule Investigation: Evaluation of both single-dose and two-dose regimens
• Extended Follow-up: 12-month safety and immunogenicity monitoring
• Endemic Region Extension: Planned expansion to include a clinical site in a chikungunya-endemic country for the second stage of the trial

“This first-in-human study is designed to provide comprehensive data on safety and immunogenicity across different dosing regimens,” explained Dr. Chen. “The inclusion of both single and two-dose schedules will help determine the optimal approach for future efficacy trials, while the long-term follow-up will assess the durability of immune responses.”

Manufacturing Advantages

A significant advantage of the BLX-CHIK01 VLP platform is its favorable manufacturing profile, which could facilitate large-scale production and global distribution if the vaccine proves successful in clinical trials.

“Our manufacturing process for BLX-CHIK01 is highly efficient and scalable,” said Dr. Robert Jenkins, Vice President of Manufacturing at Bilex Pharma. “The VLPs are produced with high yield in our mammalian cell system, and the purification process results in a highly stable final product suitable for global distribution.”

Notable manufacturing characteristics include:

• Robust Stability: The vaccine has demonstrated stability for at least 24 months at 2-8°C
• Temperature Resistance: Preliminary studies show stability for up to one month at ambient temperature (25°C)
• Scalable Production: The established process is designed for straightforward scale-up to commercial quantities
• Single-Dose Potential: The high immunogenicity after a single dose could simplify vaccination campaigns

Project SAFEGUARD Component

BLX-CHIK01 is a key component of Bilex Pharma’s Project SAFEGUARD, which focuses on developing vaccines against mosquito-borne and neglected tropical diseases that impose substantial burdens in low- and middle-income countries.

“Chikungunya exemplifies the kind of disease our Project SAFEGUARD aims to address—a growing threat with significant impact on affected communities but limited commercial incentives for vaccine development,” said Dr. Ottlik. “We believe that innovative approaches and strategic partnerships can overcome these challenges to develop vaccines that make a real difference in global health.”

The program has received partial funding support from the Wellcome Trust as part of its efforts to advance vaccines against neglected diseases.

Collaboration with Endemic Region Partners

The development of BLX-CHIK01 has benefited from collaboration with research partners in chikungunya-endemic regions:

• Clinical Expertise: Partnership with the Federal University of Bahia, Brazil, which will host the endemic region portion of the Phase 1 trial
• Epidemiological Insights: Collaboration with the National Institute of Virology, India, for surveillance and strain diversity assessment
• Implementation Planning: Engagement with the Pan American Health Organization (PAHO) on deployment strategies for affected regions

“Local expertise is invaluable for developing vaccines against diseases like chikungunya,” noted Dr. Chen. “Our collaborators provide critical insights into disease burden, circulation patterns, and implementation challenges that help ensure our vaccine candidate is optimized for the contexts where it’s most needed.”

Addressing a Gap in Preventive Measures

Currently, no vaccines for chikungunya are widely approved or available globally, leaving affected communities to rely on mosquito control measures and supportive care for those who become infected. One vaccine received approval in the United States in late 2023 but is not yet widely available internationally.

“The lack of widely available preventive options for chikungunya represents a significant gap in our ability to control this disease,” said Dr. Harrington. “An effective, single-dose vaccine that can be produced at scale could transform the approach to chikungunya control, particularly in endemic regions with limited healthcare resources.”

Clinical Development Pathway

Following the Phase 1 trial, Bilex Pharma has outlined a comprehensive development plan for BLX-CHIK01:

• Phase 2 Studies: Planned to commence in early 2025, evaluating safety and immunogenicity in broader populations, including adolescents and older adults in endemic regions
• Phase 3 Efficacy Trial: A large-scale study in chikungunya-endemic regions to assess protection against natural infection, tentatively scheduled to begin in late 2025
• Alternative Approval Pathways: Exploration of accelerated approval based on immunological endpoints if traditional efficacy trials are challenging due to unpredictable outbreak patterns

“We recognize that developing vaccines for diseases with unpredictable outbreak patterns presents unique challenges,” said Dr. Chen. “We’re working closely with regulatory authorities to design a development program that can accommodate these realities while generating robust evidence of safety and effectiveness.”

Broader Impact on Vector-Borne Disease Prevention

Beyond its potential impact on chikungunya, the successful development of BLX-CHIK01 could have implications for approaches to other mosquito-borne viral diseases:

• Platform Validation: Demonstrating the effectiveness of the VLP approach for chikungunya could support its application to other arboviruses
• Implementation Models: Developing deployment strategies for chikungunya vaccination could inform approaches to other vector-borne diseases
• Manufacturing Capabilities: Building production capacity for BLX-CHIK01 could facilitate rapid response to other emerging arboviral threats

“Vector-borne viral diseases represent some of the most significant emerging infectious threats globally,” noted Dr. Ottlik. “The lessons we learn from developing BLX-CHIK01 will inform our broader efforts to address these challenges through innovative vaccine approaches.”

Statement from Leadership

“The initiation of clinical trials for our chikungunya vaccine candidate represents an important milestone in our efforts to address neglected but significant global health threats,” concluded Dr. Ottlik. “While more established markets tend to drive much of vaccine development, we believe that innovative biotechnology companies have a responsibility to also address diseases that predominantly affect lower-resource settings.”

Dr. Ottlik added, “BLX-CHIK01 exemplifies our commitment to this broader mission of global health impact. We look forward to advancing this candidate through clinical development and, if successful, working with global health partners to ensure it reaches the populations who need it most.”

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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 Chikungunya

Chikungunya is a viral disease transmitted to humans by infected mosquitoes, primarily Aedes aegypti and Aedes albopictus. It causes fever and severe joint pain, along with muscle pain, headache, fatigue, and rash. While most patients recover fully, some experience persistent joint pain for months or years. The disease has spread rapidly since 2004, with outbreaks reported in over 110 countries across Africa, Asia, Europe, the Americas, and the Pacific Islands. The name “chikungunya” derives from a word in the Kimakonde language, meaning “to become contorted” or “to walk bent over,” describing the stooped appearance of sufferers with joint pain.