Efficient brain delivery and sustained retention of antibodies via dual targeting of blood-brain barrier and intra-brain proteins.
A dual-targeting strategy shows promise for improving brain delivery and retention of therapeutic antibodies in mice, but human applicability remains to be tested.
Where it sits
this study against the rest of the mgf (mechano growth factor) corpusSummary and findings
The study evaluates a dual-targeting approach for delivering antibodies to the brain using receptor-mediated transcytosis and binding to intra-brain proteins. In a mouse model, the anti-MOG/TfR antibody showed higher brain concentrations and longer retention compared to controls. The technology was also applied to deliver neprilysin, enhancing its brain exposure and pharmacodynamic effects.
Abstract
Efficient delivery of therapeutic antibodies to the brain has been increasingly achieved using receptor-mediated transcytosis (RMT) approaches such as transferrin receptor (TfR)-mediated shuttle systems. Moreover, a strategy for enhancing brain retention has recently emerged as a focus of attention to overcome the rapid clearance of TfR shuttles from the brain. Here, we propose a novel approach that combines binding to intra-brain proteins, such as myelin oligodendrocyte glycoprotein (MOG), cell adhesion molecule 3, and chondroitin sulfate proteoglycan 5, for sustained retention in the brain with binding to blood-brain barrier (BBB) proteins, such as TfR and insulin-like growth factor 1 receptor, for enhanced BBB permeability. A mouse pharmacokinetic study demonstrated that the anti-MOG/TfR antibody reached a higher maximum concentration and maintained higher concentrations in the brain for 4 months than anti-MOG and anti-TfR antibodies. In immunohistochemistry and brain 3D-imaging study, the anti-MOG/TfR antibody distributed throughout the whole brain, suggesting it penetrates the BBB across the whole brain parenchyma and is retained there. Finally, this antibody technology was applied to brain delivery of neprilysin, an enzyme that degrades amyloid beta, demonstrating that it can enhance both the brain exposure and the pharmacodynamic effect of the potential therapeutic molecule. In conclusion, the concept of achieving sustained high brain exposure by combining BBB transport with enhanced brain retention was shown to be broadly applicable. This novel antibody technology platform is expected to deliver and retain various therapeutic molecules efficiently within the brain, addressing critical challenges in drug development for the central nervous system.
Background
The study addresses the challenge of delivering therapeutic antibodies to the brain, a critical issue due to the blood-brain barrier (BBB) limiting drug access. Previous approaches using receptor-mediated transcytosis (RMT) have shown promise but suffer from rapid clearance. This research explores a dual-targeting strategy to enhance both delivery and retention of antibodies in the brain, which could significantly impact treatments for central nervous system disorders.
Methods
The study utilized a mouse pharmacokinetic model to test a dual-targeting approach combining receptor-mediated transcytosis and binding to intra-brain proteins. The anti-MOG/TfR antibody was compared to anti-MOG and anti-TfR antibodies in terms of brain concentration and retention. Immunohistochemistry and brain 3D-imaging were used to assess distribution, and the technology was applied to deliver neprilysin to evaluate pharmacodynamic effects.
Results
The anti-MOG/TfR antibody achieved higher maximum concentrations in the brain and maintained these levels for 4 months, outperforming anti-MOG and anti-TfR antibodies. Imaging studies confirmed whole-brain distribution, indicating effective BBB penetration and retention. The application of this technology to neprilysin delivery resulted in enhanced brain exposure and pharmacodynamic effects, suggesting potential therapeutic benefits.
Interpretation
This study demonstrates a promising approach for enhancing brain delivery and retention of therapeutic antibodies, potentially overcoming significant barriers in CNS drug development. While the findings are statistically significant in the mouse model, clinical significance in humans remains uncertain due to species differences. Further research is needed to assess the safety and efficacy of this technology in human trials.
Key findings
- Higher maximum concentration of anti-MOG/TfR antibody in the brain compared to anti-MOG and anti-TfR antibodies.
- Sustained brain concentrations of anti-MOG/TfR antibody for 4 months.
- Whole brain distribution of anti-MOG/TfR antibody observed in 3D-imaging.
- Enhanced brain exposure and pharmacodynamic effect of neprilysin using the antibody technology.
Limitations
- Mouse model only, no human data
- Potential species differences in BBB and brain protein interactions
- Long-term safety and efficacy in humans untested
- Single-site study