

Drug discovery
2
drugs
With orphan designations
Overview
CLN2 disease is a rare autosomal recessive neurodegenerative lysosomal disorder caused by TPP1 mutations, leading to tripeptidyl peptidase 1 deficiency. Classic presentation involves onset at 2–4 years with language delay, drug-resistant epilepsy, rapid motor/cognitive decline, vision loss, and death by early adolescence. Atypical forms show later onset and slower progression. Diagnosis requires TPP1 enzyme activity testing and genetic confirmation. Enzyme replacement therapy (cerliponase alfa) delays functional decline when initiated early [1][5][6][14].
Burden
Mortality: Median survival 10.1 years; rare survival past teens [8][13].
Caregiver impact: High caregiving hours (>12/day), reduced parental QoL, financial strain, and psychological distress [2][4].
Healthcare systems: Delayed diagnosis (average age 5 years), limited access to diagnostics/therapies in low-resource settings [1][5][18].
Citations: [1][2][3][4][5][6][7][8][9][10][11][13][14][16][18]
Therapies
Enzyme replacement therapy: Intracerebroventricular cerliponase α (approved in 2017) stabilizes motor/language function [1][3][14].
Supportive care: Multidisciplinary management (AEDs for seizures, mobility support, gastrostomy for dysphagia, palliative care) [4][7][16].
Emerging therapies: Gene therapy and substrate reduction therapies in clinical trials [3][11][14].
Categories: rare genetic diseases, rare inborn errors of metabolism, rare neurological diseases
Drug Discovery Landscape
Drug | Therapy type | Regulator | Orphan designation | Approval | Sponsor |
|---|---|---|---|---|---|
AAV composed of an engineered viral capsid variant and a single-stranded DNA (ssDNA) expression cassette containing human tripeptidyl peptidase 1 (hTPP1) cDNA | gene therapies | FDA | 2025-10-16 | — | Latus Bio |
adeno-associated viral serotype 2 vector under the regulatory control of a CMV promoter encoding the human tripeptidyl peptidase-1 (hTPP1) cDNA | gene therapies | FDA | 2016-03-16 | — | Spark Therapeutics, Inc. |