Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized cancer treatment by harnessing the body's own immune system to identify and eliminate malignant cells. Traditional approaches have relied heavily on ex vivo manipulation of patient T cells, a process involving complex laboratory procedures to extract, engineer, and expand T cells before reinfusion. While this approach has shown remarkable efficacy in hematological cancers, it remains costly, time-consuming, and difficult to scale. To address these limitations, Alfa Chemistry has developed the in vivo CAR-T platform, powered by proprietary lipid nanoparticle (LNP) technology. This platform enables direct engineering of CAR-T cells inside the patient's body, bypassing the cumbersome manufacturing pipeline. Our vision is to provide a scalable, off-the-shelf, and safer immunotherapy solution that expands the reach of CAR-T therapy to more patients and to more cancer types.
Limitations of Current Ex Vivo CAR T Therapies
Although ex vivo CAR-T therapies have produced life-saving outcomes, especially for blood cancers such as B-cell lymphomas and leukemias, significant challenges remain [1]:
- Complex Manufacturing Process: The standard procedure requires harvesting T cells, modifying them with viral vectors, expanding them under controlled conditions, and reinfusing them. This process can take several weeks, which is often unsuitable for patients with aggressive cancers.
- High Costs and Limited Accessibility: Ex vivo CAR-T therapies can cost hundreds of thousands of dollars per patient. The logistics of specialized facilities and individualized processing restrict access to only a fraction of patients worldwide.
- Safety Concerns: Cytokine Release Syndrome (CRS) and neurotoxicity are among the severe adverse effects. Moreover, donor-derived CAR-T therapies (allogeneic) pose risks of graft-versus-host disease and immune rejection.
- Limited Efficacy in Solid Tumors: While hematological cancers have responded well, ex vivo CAR-T therapy shows limited success in solid tumors due to tumor microenvironment barriers, antigen heterogeneity, and trafficking inefficiencies.
These limitations underscore the urgent need for innovative strategies that simplify production, improve safety, and broaden therapeutic scope.
Fig. 1. The process of ex vivo CAR T therapy.
In Vivo CAR T Strategies
To overcome the above challenges, in vivo CAR-T approaches have been developed. Instead of modifying T cells outside the body, these strategies involve delivering CAR constructs directly into patients, where T cells are engineered on-site. This shift transforms CAR-T therapy from a patient-specific, labor-intensive procedure into a streamlined, potentially off-the-shelf solution. Key strategies include [1]:
- Viral Vectors: Lentiviruses, retroviruses, and adeno-associated viruses (AAVs) have been explored for direct in vivo delivery of CAR constructs. While efficient at gene transfer, viral vectors raise concerns regarding immunogenicity, insertional mutagenesis, and scalability.
- Nanocarriers: Synthetic carriers, particularly lipid nanoparticles (LNPs), have emerged as safer, more versatile alternatives. LNPs can encapsulate mRNA or DNA encoding CARs, protect cargo from degradation, and be surface-modified to target T cells specifically. Unlike viral systems, LNPs avoid permanent genetic alterations, reducing long-term risks.
- Hybrid Platforms: Combining biomaterial scaffolds or exosomes with gene delivery systems further improves targeting efficiency and safety profiles.
In vivo strategies have demonstrated promising preclinical outcomes, including effective CAR-T generation, durable anti-tumor activity, and reduced cytokine release toxicity when coupled with immune-modulatory payloads.
Fig. 2. In vivo CAR T therapy.
Our In Vivo CAR-T Platform
Leveraging decades of expertise in nanoparticle engineering and proprietary patents in lipid nanoparticle formulations, we have developed in vivo CAR-T platform. At the center of our in vivo CAR-T platform lies the In Spleen CAR-T therapy powered by mRNA-LNP technology, a breakthrough that redefines how CAR-T therapies are conceived, manufactured, and delivered. This is a spleen-targeted, biodegradable, and non-toxic delivery system that allows CAR-T cells to be generated directly inside the patient's body.
The platform delivers mRNA encoding CAR constructs directly into T cells located in the spleen, one of the body's most important immune reservoirs. Once inside, the mRNA is translated into functional CARs, effectively engineering T cells in situ without the need for ex vivo isolation, culture, or reinfusion. This innovation represents a disruptive shift from traditional CAR-T workflows, enabling faster intervention and expanding patient accessibility. The In Spleen CAR-T therapy incorporates three key innovations that distinguish it from other in vivo CAR-T approaches:
- Biodegradable, spleen-targeted LNPs: Safe and efficient delivery with minimal off-target effects.
- T cell-specific CAR expression technology: Avoids antigen masking by splenic B cells, ensuring accurate and durable CAR function.
- Anti-exhaustion CAR-T design: Enables robust activity where even very low numbers of engineered T cells can effectively clear high tumor burdens.
Advantages of Our Platform
By integrating LNP precision with spleen-targeted delivery, the In Spleen CAR-T strategy offers several transformative advantages:
01Simplicity and Scalability: Streamlined manufacturing eliminates antibody conjugation and ex vivo steps, reducing costs and enabling rapid, large-scale production.
02Rapid Therapeutic Effect: Direct mRNA delivery into T cells ensures fast CAR expression, accelerating time-to-treatment for patients with aggressive disease.
03Safety by Design: Biodegradable, non-toxic LNPs coupled with transient CAR expression minimize long-term risks and improve tolerability.
04Broader Applications: The flexibility of mRNA cargo allows adaptation to multiple cancer antigens, paving the way for applications in both hematologic malignancies and solid tumors.
The In Vivo CAR-T strategy, realized through our In Spleen CAR-T strategy, represents a paradigm shift in cellular immunotherapy. By combining targeted delivery, simplified production, and superior safety, we are building a pathway toward democratizing CAR-T therapy, making it faster, more affordable, and more widely accessible.
Reference
- Bui T. A., et al. Advancements and challenges in developing in vivo CAR T cell therapies for cancer treatment[J]. EBioMedicine, 2024, 106.
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