HUMx Gateway™ — Platform-Addressable Ceiling

While more than 30 lysosomal storage disorders involve the central nervous system, only a subset are realistically addressable through an in vivo HSC-lentiviral approach. Humvira estimates that approximately 12–18 CNS-LSD indications fall within the long-term platform ceiling, defined by diseases where durable microglial replacement and continuous enzyme delivery can meaningfully modify disease progression. Our prioritized pipelines as below:

CNS-LSD (HUMx Gateway™) Pipelines

HUMx Gateway™ — Platform-Addressable Ceiling

While hundreds of genetically defined inborn errors of immunity have been described, only a subset are realistically addressable through an in vivo HSC-lentiviral approach. Humvira estimates that approximately 40–80 severe PID/CID indications fall within the long-term platform ceiling, defined by disorders where hematopoietic stem cell–level correction can drive durable, multi-lineage immune rebuilding and clinically meaningful outcomes. Our prioritized pipelines as below:

Primary Immunodeficiencies (HUMx Gateway™) Pipelines

Durable Factor VIII Expression Through Next-Generation AAV Gene Therapy

While Humvira’s core platform focuses on in vivo lentiviral hematopoietic stem cell (HSC) gene therapy for diseases requiring hematopoietic or microglial rebuilding, hemophilia A represents a complementary genetic disease context in which durable systemic protein expression can be achieved directly through targeted AAV delivery.

Hemophilia A is a severe inherited bleeding disorder caused by deficiency or dysfunction of coagulation factor VIII (FVIII). Patients experience recurrent bleeding episodes, progressive joint damage, and significant long-term morbidity, often requiring lifelong prophylactic treatment. With current standard-of-care therapies, annual treatment costs in developed markets frequently reach several hundred thousand U.S. dollars per patient, making hemophilia A one of the most economically burdensome chronic genetic diseases.

AAV-mediated gene therapy offers the potential for sustained FVIII expression following a single administration. Importantly, the liver is a clinically validated and well-characterized target tissue for AAV gene delivery, making hemophilia A particularly well suited for an AAV-based therapeutic approach. However, first-generation AAV gene therapies have faced key limitations, including inconsistent delivery of intact functional genomes and the need for high vector doses.

Against this backdrop, Humvira is developing a next-generation AAV-mediated gene therapy program for hemophilia A designed to enhance functional genome integrity and delivery efficiency in support of durable FVIII expression.

To support long-term development flexibility, Humvira has established both AAV5 and AAV8 delivery formats incorporating the same optimized therapeutic transgene design. This dual-serotype strategy provides development optionality while preserving a unified molecular framework and a consistent product rationale.

In preclinical studies, the AAV8 version of Plenacogene parvovec demonstrated substantially enhanced full-length vector genome delivery relative to prior-generation AAV approaches, supporting the potential for more efficient and durable FVIII expression at clinically practical doses.