153 In vivo polymeric gene delivery platform for targeted cell reprogramming in hematological malignancies
Year: 2026
Type: conference-abstract
Abstract: Background Over the past two years, in vivo CAR T therapies have emerged as a promising alternative to ex vivo manufacturing and its intrinsic limitation. Targeting lipid nanoparticles (LNPs) and modified lentiviral vectors (LVVs) have achieved rapid clinical development and triggered increasing industrial interest, including strategic acquisitions by major pharmaceutical compagnies. However, these approaches still face challenges related to immunogenicity, delivery specificity or LVV bioproduction yields.Methods Alaya.bio is a preclinical-stage company developing a scalable in situ gene delivery hybrid platform combining the advantages of both LVVs and LNPsto target and reprogram cells in situ. A transduction-deficient LVV lacking the immunogenic VSV-G envelope protein is functionalized with shielding lipid polymers conjugated via click chemistry to an anti-CD3 scFv, and subsequently coated with biodegradable cationic polymers. This design confers T-cell targeting specificity, reduced immunogenicity and enhanced tolerability. Lead nanoparticles (NPs), encoding the CD19-CAR 1XX construct, have been successfully formulated through a GMP-compatible process including microfluidics, tangential flow filtration and a sterile final filtration step.Results The resulting targeting cationic NPs exhibited monodispersity, different surface potentials, excellent batch-to-batch consistency, and stable gene delivery in relevant human cell models. Their CD3-mediated internalization, associated with a long-term, dose-dependent CAR expression, was also demonstrated in vitro. The biodistribution and toxicity of non-targeting and CD3-targeting nanoparticles were investigated in immunodeficient NCG mice engrafted with human CD34-positive hematopoietic stem cells after a single intravenous administration The tested doses were safe and well tolerated, with no body weight loss, hepatotoxicity or changes in cytokine levels following the injections, supporting the feasibility of repeat dosing compared with other technologies. The exclusive tropism to blood cells demonstrated an obvious advantage for CAR-T cell therapy in blood malignancies. Finally, the in vivo functionality was demonstrated in NSG mice engrafted with human PBMCs and challenged with NALM6 B-cell leukemia, showing tumor burden control and prolonged survival over 28 days. Longitudinal in vivo CAR-T cell generation and B-cell depletion are currently being investigated in a CD34-positive humanized NCG mice model.Conclusions Efficient systemic gene delivery and functional CAR-T cell generation with sustained antitumor activity were achieved with our targeting lentiviral vector-based polymeric nanoparticles. Their favorable safety profile after repeat administration opens new treatment options at recurrence/relapse and shows great potential for further preclinical and clinical development of in situ universal CAR-T cell therapies. This versatile technology is amenable to reprograming a broader range of therapeutic cells beyond immuno-oncology with therapeutic applications to autoimmune diseases and genetic disorders.
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,490
OpenAlex ID: W7225173700