Periodic Reporting for period 1 - e-FabRIC (enhanced manufacturing of broadly potent equine polyclonal Fab with a Rational Immunization strategy against Coronaviruses)
Periodo di rendicontazione: 2023-12-01 al 2025-05-31
The e-FabRIC project aligns with the EU’s pandemic preparedness plan by supporting the development of broad-spectrum antiviral therapies to address unmet public health needs. Its goal is to provide a ready-to-use therapeutic solution capable of tackling major societal and health challenges.
e-FabRIC will implement a novel hyperimmunization strategy to produce high-titer equine immunoglobulins with broad neutralizing specificity against viruses in the sarbecovirus subfamily. These antibodies will be processed as purified F(ab’)2 fragments, a well-established pharmaceutical product with a strong safety record in humans.
The broad neutralizing activity results from immunizing horses with a nanoparticle “mosaic antigen” displaying up to eight different sarbecovirus receptor-binding domain (RBD) subunits, combined with the natural immunogenetic diversity of horses. Polyclonal antibodies produced this way have intrinsic advantages, such as high avidity and recognition of multiple adjacent epitopes on the nanoparticle, offering broader coverage compared to monoclonal antibodies.
Unlike monoclonal antibodies, which bind only a few precise epitopes and are prone to viral escape, the polyclonal F(ab’)2 fragments provide a multivalent approach that is more cost-effective and resilient against mutations.
To ensure European sovereignty, the entire production chain—including antigen manufacturing, hyperimmunization, and GMP processing—will take place within the EU. e-FabRIC will also establish a comprehensive regulatory pathway by developing all necessary analytical methods early in the process.
The project aims to collaborate closely with regulatory authorities to define the best approval strategy. The FBT manufacturing platform will produce GMP-grade therapeutic F(ab’)2 fragments for stockpiling, enabling immediate clinical deployment during epidemics or pandemics with a safe, effective, and rapidly available treatment option.
e-FabRIC will implement a novel hyperimmunization strategy to produce high-titer equine immunoglobulins with broad neutralizing specificity against viruses in the sarbecovirus subfamily. These antibodies will be processed as purified F(ab’)2 fragments, a well-established pharmaceutical product with a strong safety record in humans.
The broad neutralizing activity results from immunizing horses with a nanoparticle “mosaic antigen” displaying up to eight different sarbecovirus receptor-binding domain (RBD) subunits, combined with the natural immunogenetic diversity of horses. Polyclonal antibodies produced this way have intrinsic advantages, such as high avidity and recognition of multiple adjacent epitopes on the nanoparticle, offering broader coverage compared to monoclonal antibodies.
Unlike monoclonal antibodies, which bind only a few precise epitopes and are prone to viral escape, the polyclonal F(ab’)2 fragments provide a multivalent approach that is more cost-effective and resilient against mutations.
To ensure European sovereignty, the entire production chain—including antigen manufacturing, hyperimmunization, and GMP processing—will take place within the EU. e-FabRIC will also establish a comprehensive regulatory pathway by developing all necessary analytical methods early in the process.
The project aims to collaborate closely with regulatory authorities to define the best approval strategy. The FBT manufacturing platform will produce GMP-grade therapeutic F(ab’)2 fragments for stockpiling, enabling immediate clinical deployment during epidemics or pandemics with a safe, effective, and rapidly available treatment option.
As part of RP1, the design and production of mosaic antigens were successfully completed. These antigens met the expected quality control standards and demonstrated the anticipated antigenic activity. Therefore, WP1 was completed successfully.
The produced antigens were subsequently used in WP2 to carry out the hyperimmunisation of several horses using two different adjuvants. The immunisation protocol proceeded smoothly, and an increase in antibody titres targeting the viruses represented in the mosaic antigens was observed during the immunisation period.
Following immunisation, plasma was collected and small-scale pilot batches were processed to purify immunoglobulins and produce F(ab')2 fragments. The plasma was evaluated in vitro through seroneutralisation assays.
A technical challenge was encountered during quality control of the pilot batches: the results did not meet the expected standards. Further analyses and an additional filtration step were performed. The refined batches have been re-tested in vitro, and the results are currently under evaluation.
The produced antigens were subsequently used in WP2 to carry out the hyperimmunisation of several horses using two different adjuvants. The immunisation protocol proceeded smoothly, and an increase in antibody titres targeting the viruses represented in the mosaic antigens was observed during the immunisation period.
Following immunisation, plasma was collected and small-scale pilot batches were processed to purify immunoglobulins and produce F(ab')2 fragments. The plasma was evaluated in vitro through seroneutralisation assays.
A technical challenge was encountered during quality control of the pilot batches: the results did not meet the expected standards. Further analyses and an additional filtration step were performed. The refined batches have been re-tested in vitro, and the results are currently under evaluation.
Results and potential impacts, and identification of key needs for further uptake and success
The project successfully achieved the design and production of mosaic antigens with validated quality and antigenic activity, enabling the completion of WP1. These antigens demonstrated their utility in triggering a specific immune response during the horse hyperimmunisation campaign conducted in WP2, leading to a measurable increase in virus-specific antibody titres. Plasma collected from immunised animals was used to produce small-scale pilot batches of F(ab')2 fragments. Initial in vitro seroneutralisation results are promising, although quality control of the first batches revealed technical issues that required additional processing.
Potential impacts include the development of a novel class of equine-derived immunoglobulin fragments targeting multiple viral pathogens simultaneously, based on a mosaic antigen strategy. This approach may provide a scalable and flexible platform for rapid response to emerging viral threats.
Key needs for further uptake and success involve:
Further optimisation and scale-up of the production and purification process to consistently meet GMP quality standards.
Additional preclinical evaluation to confirm efficacy and safety of the final F(ab')2 product.
Demonstration studies in relevant in vivo models or potential target populations.
Regulatory pathway clarification and support, including engagement with authorities for alignment on quality and safety criteria.
Commercial and industrial partnerships to facilitate access to manufacturing infrastructure, financing, and eventual market deployment.
Exploration of intellectual property protection to support future exploitation and internationalisation of the product.
An overview of current results indicates solid progress in technical feasibility and proof-of-concept stages. Continued development will focus on process robustness, efficacy demonstration, and preparation for regulatory and commercial pathways.
The project successfully achieved the design and production of mosaic antigens with validated quality and antigenic activity, enabling the completion of WP1. These antigens demonstrated their utility in triggering a specific immune response during the horse hyperimmunisation campaign conducted in WP2, leading to a measurable increase in virus-specific antibody titres. Plasma collected from immunised animals was used to produce small-scale pilot batches of F(ab')2 fragments. Initial in vitro seroneutralisation results are promising, although quality control of the first batches revealed technical issues that required additional processing.
Potential impacts include the development of a novel class of equine-derived immunoglobulin fragments targeting multiple viral pathogens simultaneously, based on a mosaic antigen strategy. This approach may provide a scalable and flexible platform for rapid response to emerging viral threats.
Key needs for further uptake and success involve:
Further optimisation and scale-up of the production and purification process to consistently meet GMP quality standards.
Additional preclinical evaluation to confirm efficacy and safety of the final F(ab')2 product.
Demonstration studies in relevant in vivo models or potential target populations.
Regulatory pathway clarification and support, including engagement with authorities for alignment on quality and safety criteria.
Commercial and industrial partnerships to facilitate access to manufacturing infrastructure, financing, and eventual market deployment.
Exploration of intellectual property protection to support future exploitation and internationalisation of the product.
An overview of current results indicates solid progress in technical feasibility and proof-of-concept stages. Continued development will focus on process robustness, efficacy demonstration, and preparation for regulatory and commercial pathways.