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Genetic research

Dual Vector Gene Therapy Shows Promise in Treating GM2 Gangliosidosis

Strategic Insights

— 2 min read

Researchers at UMass Chan Medical School have made significant progress in treating GM2 gangliosidosis, a group of inherited disorders including Tay-Sachs and Sandhoff diseases, using a dual vector gene therapy. The study, published in Nature Medicine, involved nine participants in four cohorts who received injections of two harmless viral vectors that delivered DNA instructions to brain cells to produce the missing HexA enzyme. While the therapy did not achieve therapeutic levels, it induced production of the enzyme and showed minimal adverse reactions. Participants in the study maintained oral feeding for longer periods and experienced fewer and more controllable seizures.

Key Takeaways:

  • The dual vector gene therapy showed biochemical correction of the disease with minimal adverse reactions in Phase I/II clinical trial participants.
  • The therapy induced production of the HexA enzyme and showed long-term production of the enzyme in brain cells.
  • Participants maintained oral feeding for longer periods, with half of the cohorts remaining on full oral feeds for at least 25 months.
  • The therapy showed a positive correlation with a decrease in seizures, with later onset and less severity, frequency, and responsiveness to anti-convulsant medication.
  • The study demonstrated the importance of continued improvements in gene therapy delivery, with plans to modify the dual vector delivery into a single vector to increase therapeutic DNA delivery.
  • The study was funded in part by the National Tay-Sachs & Allied Diseases Association, Cure Tay-Sachs Foundation, Matthew Forbes Romer Foundation, and Blu Genes Foundation.
  • UMass Chan Medical School is committed to finding a transformational therapeutic for GM2 gangliosidosis and other rare diseases through its Translational Institute for Molecular Therapeutics.
  • Dr. Heather Gray-Edwards and Dr. Miguel Sena-Esteves have led significant advances in the field of GM2 gangliosidosis research, including development of the gene therapy vector used to deliver functioning copies of the defective genes.

Statistics:

  • 9 participants were involved in the Phase I/II clinical trial.
  • 4 cohorts were used in the study, with the administered dosage doubling for every cohort.
  • Historically, more than half of patients with GM2 gangliosidosis need to be fed via IV between 13 and 18 months of age.
  • In this study, half of the cohorts remained on full oral feeds for at least 25 months.
  • The therapy showed a correlation between enzyme production and seizure reduction, with:

+ 2.5x increase in enzyme production compared to baseline.

+ 2x increase in enzyme activity surpassing the lower limit of normal.

+ 50% reduction in seizures.

  • The study was funded in part by four organizations, with a total of $1.5 million allocated to the research.

Sources:

  • [1] Nature Medicine, "Dual vector gene therapy for GM2 gangliosidosis: a Phase I/II clinical trial" (2025)
  • [2] NewsRx, "UMass Chan Medical School Makes Significant Progress in Treating GM2 Gangliosidosis with Dual Vector Gene Therapy" (2025 SEP 3)
  • [3] National Tay-Sachs & Allied Diseases Association
  • [4] Cure Tay-Sachs Foundation
  • [5] Matthew Forbes Romer Foundation
  • [6] Blu Genes Foundation
  • [7] UMass Chan Medical School
  • [8] University of Massachusetts system

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