X-linked Alport syndrome is an inherited kidney disease caused by pathogenic mutations in the COL4A5 gene. Patients develop hematuria, proteinuria and kidney function decline leading to end-stage renal disease. Nionyx Bio Inc. has developed ONYX-101, a novel kidney-targeting therapeutic designed to ensure durable COL4A5 restoration through dual-vector AAV delivery using NYX capsids that were optimized for kidney targeting.

Fabry disease is a lysosomal storage disease tied to the X chromosome and caused by pathogenic variants in the GLA gene encoding galactosidase A. It is characterized by progressive accumulation of galactosidase A substrates, including Gb3 and lyso-Gb3, mainly in the kidney, heart and nervous system.

AAV-based therapies for Duchenne muscular dystrophy (DMD) have shown efficacy, but have limitations such as poor delivery to target tissues and toxicity associated with the vector. Gemma Biotherapeutics Inc. has developed a gene therapy candidate, GB-703, which uses a new myotropic, integrin-binding AAV capsid containing a codon-optimized, deimmunized hybrid payload.

Researchers at UCLA have shown that divergent neuronal signaling in fragile X mice converges on EPAC2, a druggable target whose inhibition restores circuit activity and alleviates core behavioral impairments.

Researchers at the University of London and collaborating institutions have developed a gene and cell therapy approach that enables sustained systemic frataxin protein delivery, improving motor performance and tissue pathology, and supporting a promising translational strategy for long-term disease stabilization in Friedreich’s ataxia patients.

A new strategy aims to improve gene therapy for Pompe disease by optimizing both the genetic component that restores the function of a deficient lysosomal enzyme and the vector that delivers it to the target tissue while avoiding the liver. The findings suggest that combining an optimized transgene with a targeted capsid could significantly enhance the effectiveness of gene therapy for Pompe disease.

Netherton syndrome is a rare disease caused by loss of activity of the lympho-epithelial Kazal-type-related inhibitor (LEKTI) protein, which in turn is caused by mutations in its encoding gene, SPINK5. This deficiency leads to the triggering of the kallikrein (KLK) signaling cascade resulting in skin barrier dysfunction, inflammation and atopy. At the recent Society for Investigative Dermatology meeting, Biocryst Pharmaceuticals Inc. presented early data on BCX-17725, a KLK5/KLK14 inhibitor fusion protein developed to restore LEKTI functioning in patients with Netherton syndrome.

Korro Bio Inc. has announced the selection of KRRO-111 as a development candidate for the treatment of alpha-1 antitrypsin deficiency (AATD), a genetic disorder most commonly caused by a single missense mutation in SERPINA1.

Directed evolution has become a central pillar in gene therapy. This engineering strategy enables the generation of more efficient variants of genetic editors and delivery vectors. Molecular diversification methods are increasingly sophisticated and are now accelerated by machine learning and AI tools, as showcased at the 29th Annual Meeting of the American Society of Gene and Cell Therapy (ASGCT) held in Boston this week.

Gene therapies rely on vectors to reach the target tissue where they act, such as adeno-associated viruses (AAVs) or lipid nanoparticles (LNPs), among other delivery strategies. Each combination is optimized for a specific cell type and indication, aiming to overcome challenges such as efficacy, specificity and toxicity. On May 13, 2026, two sessions included in the scientific symposia of the 29th Annual Meeting of the American Society of Gene and Cell Therapy (ASGCT), being held in Boston this week, addressed AAV-related toxicities, which have led to fatal cases in clinical trials and remain an area for improvement in approved therapies.