Periodic Reporting for period 1 - POLYBRAINT (Versatile Polypeptide-based Intranasal Drug Delivery Platform(s) to Tackle CNS Disorders.)
Reporting period: 2022-06-01 to 2023-11-30
Current challenges in delivering large-molecule biologics to the central nervous system (CNS) impede the development of effective treatments for conditions such as stroke, brain cancer, Alzheimer's disease, Parkinson's, and neuro-AIDS. Despite successful therapies for depression, schizophrenia, chronic pain, and epilepsy, delivering therapeutics to the CNS remains a significant bottleneck affecting both clinical needs and the pharmaceutical industry. CNS drug development is more expensive and has a 45% higher failure rate compared to drugs targeting other organs. The blood-brain barrier (BBB) presents a significant obstacle, blocking a substantial percentage of small-molecule drugs and completely preventing the entry of water-soluble drugs or large-molecule biotherapeutics. The limited success in achieving therapeutic concentrations in the CNS through peripheral administration hampers the effective treatment of related disorders. Existing solutions, such as invasive administration or BBB disruption, come with associated health risks.
To address this challenge, POLYBRAINT aimed to innovate an intranasal drug delivery platform for delivering biologics to the brain, advancing the development of nanotherapies for CNS disorders. This platform, based on crosslinked star-shaped polyglutamates (CSS-PGA) (WO2017025298A1, EU and US granted patent), was developed during the ERC consolidator MyNano (ID 648831). We selected two model biologics, a clinically relevant peptide (Oxytocin, an endocrine neuropeptide produced in the hypothalamus and released by the posterior pituitary) and an antibody (anti-PD-L1, expressed in microglia with neuroimmunomodulator properties) to conjugate to two selected nanocarriers that showed accumulation in different brain areas as proof of concept and demonstrated that our nanocarriers can reach and diffuse through the brain in wild-type mice after intranasal administration, even targeting specific areas of interest. More notably, we explored a more complex protein, GBA, in a Parkinson's disease model in collaboration with VHIR and Univ Barcelona (Spain). GBA encodes the lysosomal enzyme glucocerebrosidase that breaks down glucosylceramide and glucosylsphingosine within the lysosome. Recent research has shown that a mutation in the GBA gene is now the main genetic risk factor for PD, and 10-15% of PD patients carry GBA mutations.
To address this challenge, POLYBRAINT aimed to innovate an intranasal drug delivery platform for delivering biologics to the brain, advancing the development of nanotherapies for CNS disorders. This platform, based on crosslinked star-shaped polyglutamates (CSS-PGA) (WO2017025298A1, EU and US granted patent), was developed during the ERC consolidator MyNano (ID 648831). We selected two model biologics, a clinically relevant peptide (Oxytocin, an endocrine neuropeptide produced in the hypothalamus and released by the posterior pituitary) and an antibody (anti-PD-L1, expressed in microglia with neuroimmunomodulator properties) to conjugate to two selected nanocarriers that showed accumulation in different brain areas as proof of concept and demonstrated that our nanocarriers can reach and diffuse through the brain in wild-type mice after intranasal administration, even targeting specific areas of interest. More notably, we explored a more complex protein, GBA, in a Parkinson's disease model in collaboration with VHIR and Univ Barcelona (Spain). GBA encodes the lysosomal enzyme glucocerebrosidase that breaks down glucosylceramide and glucosylsphingosine within the lysosome. Recent research has shown that a mutation in the GBA gene is now the main genetic risk factor for PD, and 10-15% of PD patients carry GBA mutations.
Following the established objectives during Polybraint, first, the validation of the technical feasibility and effectiveness of our nanocarrier platform for the i.n. delivery of biologics was achieved. We conjugated the antibody PD-1, fully characterized, and studied its efficacy and safety in a wild-type murine model after intranasal administration, demonstrating that the presence of the polymeric nanocarrier, as well as the vehicle (a permeation enhancer hydrogel), are key to achieving enhanced performance compared with the standard of care (free PD-1 antibody in the clinics intranasally as well as intraperitoneally, a normal administration route for this antibody in preclinical studies). For oxytocin transportation, conjugation was not possible due to oxytocin stability issues, and an alternative PGA nanocarrier with capabilities for drug encapsulation was developed. Studies in vivo (biodistribution as well as pharmacological activity) are ongoing. Alternatively to oxytocin and through an extended collaboration with research teams at VHIR and Univ Autonoma Barcelona, the conjugation with the protein GBA with an adapted strategy and the demonstration of its effectiveness as enzyme replacement therapy in a Parkinson's disease murine model were also achieved (patent filed). Again, as in the case of PD-1, demonstrating the need for the use of both components, the polypeptidic nanocarriers and the hydrogel acting as a vehicle for intranasal delivery.
In parallel, we have studied brain distribution by optical imaging, showing differences depending on the brain area, mainly due to the different cell population (deeper understanding in this line is ongoing). In addition, to overcome the resolution limitation of this technique, the conjugates were labeled with DTPA-Gd, and their brain biodistribution is being explored also by MRI at Univ Barcelona with our collaborators. Both immunoconjugates tested in vivo maintain cargo functionality: in PD-1 in the wild-type animal and now it is being explored in a glioblastoma model (Univ Barcelona); and the GBA protein in a Parkinson's disease model (VHIR). Additional experiments not planned but enriching those results obtained include the implementation of microfluidics to control crosslinking strategies and optimized biologic conjugate synthesis towards industrial scale-up and cost-effective manufacture. With all these experiments, it is believed that the readiness of the technology moves from TRL 2-3 to TRL 5-6.
Work performed under objectives/tasks 2 and 3 include a patentability report for the hydrogel/nanocarrier as an i.n. platform and a Freedom to Operate study, both of them positive. Together with a possible market study for i.n. strategies, we are currently discussing possibilities to advance towards translation.
In summary, In Polybraint, we have (1) confirmed the transportation of the biologic cargo with pharmacological functionality; (2) conducted benchmark studies with the parent biologics after intranasal and also intravenous (GBA) and intraperitoneal (PD-1) administration; (3) established an IP strategy, acquired IP protection for GBA derivatives and performed freedom to operate analysis as well as started to assess the future commercialization feasibility to move this interesting technology forward as the vehicle as well as the nanconjugate part of the intranasal formulation are key elements to effectively deliver biologics to the brain.
In parallel, we have studied brain distribution by optical imaging, showing differences depending on the brain area, mainly due to the different cell population (deeper understanding in this line is ongoing). In addition, to overcome the resolution limitation of this technique, the conjugates were labeled with DTPA-Gd, and their brain biodistribution is being explored also by MRI at Univ Barcelona with our collaborators. Both immunoconjugates tested in vivo maintain cargo functionality: in PD-1 in the wild-type animal and now it is being explored in a glioblastoma model (Univ Barcelona); and the GBA protein in a Parkinson's disease model (VHIR). Additional experiments not planned but enriching those results obtained include the implementation of microfluidics to control crosslinking strategies and optimized biologic conjugate synthesis towards industrial scale-up and cost-effective manufacture. With all these experiments, it is believed that the readiness of the technology moves from TRL 2-3 to TRL 5-6.
Work performed under objectives/tasks 2 and 3 include a patentability report for the hydrogel/nanocarrier as an i.n. platform and a Freedom to Operate study, both of them positive. Together with a possible market study for i.n. strategies, we are currently discussing possibilities to advance towards translation.
In summary, In Polybraint, we have (1) confirmed the transportation of the biologic cargo with pharmacological functionality; (2) conducted benchmark studies with the parent biologics after intranasal and also intravenous (GBA) and intraperitoneal (PD-1) administration; (3) established an IP strategy, acquired IP protection for GBA derivatives and performed freedom to operate analysis as well as started to assess the future commercialization feasibility to move this interesting technology forward as the vehicle as well as the nanconjugate part of the intranasal formulation are key elements to effectively deliver biologics to the brain.
Polybraint is propelling forward an innovative, non-invasive, and patient-friendly intranasal platform designed for the effective delivery of various active principles, including biologics. The breakthroughs achieved under the ERCPoC grant, involving the successful demonstration with both an antibody and a protein, transcend current standards in the field.
The project is now venturing into uncharted territories, exploring a spectrum of biologics, such as oligonucleotides, with the ambitious goal of enabling gene transfection in the brain. Overcoming this hurdle is a pivotal advancement, addressing a critical challenge in the treatment of numerous pathologies. The team recognizes that this pursuit necessitates structural modifications to the nanocarrier, paving the way for complexation—a strategic move that represents the next frontier.
This progression not only marks a paradigm shift in the capabilities of the Polybraint platform but also opens up a myriad of possibilities for the future. As the project evolves, the potential impact on patient care and treatment efficacy is substantial.
The discussions around potential industry partnerships and entrepreneurial initiatives underscore the project's intent to transition from successful demonstrations in controlled environments to real-world validations. This strategic move aims to enhance the likelihood of success and bring Polybraint's cutting-edge technology to the forefront of transformative healthcare solutions.
The project is now venturing into uncharted territories, exploring a spectrum of biologics, such as oligonucleotides, with the ambitious goal of enabling gene transfection in the brain. Overcoming this hurdle is a pivotal advancement, addressing a critical challenge in the treatment of numerous pathologies. The team recognizes that this pursuit necessitates structural modifications to the nanocarrier, paving the way for complexation—a strategic move that represents the next frontier.
This progression not only marks a paradigm shift in the capabilities of the Polybraint platform but also opens up a myriad of possibilities for the future. As the project evolves, the potential impact on patient care and treatment efficacy is substantial.
The discussions around potential industry partnerships and entrepreneurial initiatives underscore the project's intent to transition from successful demonstrations in controlled environments to real-world validations. This strategic move aims to enhance the likelihood of success and bring Polybraint's cutting-edge technology to the forefront of transformative healthcare solutions.