Page last updated: May 5, 2026
Page reviewed by: Dr. Cara O’Neill, FAAP
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Summary Information
The SNG-101 (formerly ABO-101) gene therapy uses an adeno-associated virus serotype 9 carrying the human NAGLU gene under the control of a CMV enhancer/promoter (rAAV9.CMV.hNAGLU). This therapy was developed by Haiyan Fu, PhD, and Doug McCarty, PhD, during their tenures at Ohio State University/Nationwide Children’s Hospital. The therapy was then licensed to Abeona Therapeutics for further development.
This experimental gene therapy is designed to be delivered one-time through a venous catheter inserted into a peripheral limb vein. A tapering course of prophylactic oral prednisone or prednisolone will be administered for a period of at least two months to reduce potential immune response to the gene therapy.
There were two studies under Abeona Therapeutics regarding the ABO-101 gene therapy product. In October 2017, the clinical trial for ABO-101 began and enrolled 11 patients, ending in April 2022. A multicenter, non-interventional, long-term follow-up study in participants who have been treated with ABO-101 in the prior trial was conducted from October 2020 to April 2022. Eligible participants were planned to undergo clinical evaluations at prespecified intervals for 3 years from the last visit in the prior clinical trial (up to 5 years post-treatment).
The program was discontinued in 2022 by Abeona Therapeutics due to a lack of drug supply and for business reasons unrelated to the product safety profile and/or signs of efficacy.
In May 2025, Sangrail Biologics announced its formation and that SNG-101 (formerly Abeona’s ABO-101) for Sanfilippo Syndrome Type B (MPS IIIB) as its lead clinical asset.
Our community is grateful to the patients and families who chose to participate in clinical trials. Their participation is essential to the advancement of science that brings us closer to an approved treatment for Sanfilippo Syndrome.
Clinical Trial Information
Study Title: “Phase I/II Gene Transfer Clinical Trial of rAAV9.CMV.hNAGLU for Mucopolysaccharidosis (MPS) IIIB” ClinicalTrials.gov ID NCT03315182
Trial Listing: Read this clinical trial’s information on ClinicalTrials.gov, for more details about the study.
Status: Completed (October 2017-April 2022)
Number of patients enrolled: 11
Study design: Open label dose escalation study
Dosing cohorts (groups):
- Cohort 1 (Low Dose): 2 x 10e13 vg/kg (vector genomes per kilogram of body weight). Two patients were enrolled in this cohort.
- Cohort 2 (Medium Dose): 5 x 10e13 vg/kg. Four to Five planned enrollees in this cohort.
- Cohort 3 (High Dose): 1 x 10e14 vg/kg. Four to Eight participants were planned in this cohort.
As the study progressed, the inclusion criteria were revised to a narrowed group of children: ages 0-2 years of age or >2 years of age with a developmental quotient of >60. This youngest group of patients receiving the highest dose of gene therapy are considered to be part of the updated study name “Transpher A.”
Information about this and other clinical trials for Sanfilippo Syndrome
You may also find information about this and other clinical trials for Sanfilippo Syndrome in the downloadable .PDF created by Cure Sanfilippo Foundation. See the link below to access.
Long-Term Follow-up Information
Study Title: “A Long-term Follow-up Study of Patients With MPS IIIB Treated With ABO-101” (ClinicalTrials.gov ID NCT04655911)
Trial Listing: Read this study’s information on ClinicalTrials.gov for more details about the study.
Study Status: Terminated (October 2020-April 2022)
Patients enrolled: 1
Publications associated with this experimental therapeutic
- Murrey DA, Naughton BJ, Duncan FJ, Meadows AS, Ware TA, Campbell KJ, Bremer WG, Walker CM, Goodchild L, Bolon B, La Perle K, Flanigan KM, McBride KL, McCarty DM, Fu H. Feasibility and safety of systemic rAAV9-hNAGLU delivery for treating mucopolysaccharidosis IIIB: toxicology, biodistribution, and immunological assessments in primates. Hum Gene Ther Clin Dev. 2014 Jun;25(2):72-84. doi: 10.1089/humc.2013.208. Epub 2014 Apr 10.
- Truxal KV, Fu H, McCarty DM, McNally KA, Kunkler KL, Zumberge NA, Martin L, Aylward SC, Alfano LN, Berry KM, Lowes LP, Corridore M, McKee C, McBride KL, Flanigan KM. A prospective one-year natural history study of mucopolysaccharidosis types IIIA and IIIB: Implications for clinical trial design. Mol Genet Metab. 2016 Nov;119(3):239-248. doi: 10.1016/j.ymgme.2016.08.002. Epub 2016 Aug 18.
Study Updates and Announcements
May 2026
Sangrail Biologics, a clinical-stage gene therapy company focused rare pediatric genetic diseases, announced the launch of the company today and highlighted the company’s lead clinical asset, SNG-101 (formerly known as ABO-101 under Abeona Therapeutics), a potential first-in-class AAV gene therapy designed to treat the underlying cause of disease in children with Sanfilippo syndrome type B (MPS IIIB).
Read the press statement
Cure Sanfilippo Foundation was proud to be early supporters of this program, when it was run by Abeona and Nationwide Children’s Hospital. The new company Sangrail Biologics is led by the former CEO of Abeona (and subsequently Forge Biologics), so brings significant history and experience with Sanfilippo syndrome and gene therapy drug production. While managed by Abeona, 14 children were treated with this intravenous AAV9 gene therapy across 3 dose levels. Like other enzyme replacement and gene therapies in Sanfilippo to date, the most robust effects on neurological development occur the earlier that treatment is given. Importantly, meaningful benefit has also been reported by families even when treatment was initiated after Sanfilippo cognitive symptoms were evident.