New Medicines

Mucopolysaccharidosis IIIA (MPS IIIA - Sanfilippo syndrome)


New molecular entity
Abeona Therapeutics
Abeona Therapeutics

Development and Regulatory status

Phase II Clinical Trials
Phase II Clinical Trials
Mar 22Abeona announces it will pursue a strategic partner to take over development activities for ABO-102 for MPS IIIA, while it focuses on development of EB-101 and preclinical eye gene therapy programs. It has ceased build-out of additional AAV manufacturing space. As part of the FDA feedback on the Transpher A Statistical Analysis Plan (SAP) in Jan 22, the agency recommended that all participants be followed to an age of at least 60 months, which would shift timing of the neurocognitive outcomes data readout to late-2024/early-2025, as compared to the prior projection of Q2 23 [11].
Aug 21Upcoming milestones for Abeona include making first lot of Abeona-produced ABO-102 clinical grade product [8].
Jul 21Abeona completes a successful Type B meeting with the FDA regarding the pivotal trial to support filing and approval for ABO 102. It was agreed that the ongoing PI/II Transpher A study will serve as the pivotal study for ABO 102 and could potentially support a Biologics License Application (BLA) submission. In addition, Abeona also agreed with the FDA on acceptance of neurocognitive assessment using the raw score from the Bayley Scales of Infant and Toddler Development (BSITD) and the Kauffman Assessment Battery for Children (KABC-2) as the primary endpoint for Transpher A study [7].
Nov 20Abeona anticipates submitting a marketing authorisation application for EU conditional approval of ABO-102 for MPS IIIA in 2023. The Company is also seeking guidance from the US FDA regulatory path for ABO 102 in MPS IIIA [5].
Nov 20Abeona continues process development activities at its manufacturing facility in Cleveland, Ohio to enable in-house manufacturing of commercial supply of ABO-102 and ABO-101 [6].
Nov 20ABO-102 has orphan drug status in US and FDA, plus rare pediatric disease, fast track and regenerative medicine advanced therapy (RMAT) status in US and PRIME status in EU [2].


An adeno-associated viral (AAV9)-based gene therapy involving a one-time intravenous infusion of a genetically modified adeno-associated virus (AAV) to deliver a normal copy of the defective gene to cells of the central nervous system + peripheral organs
Mucopolysaccharidosis III is considered the most common of the mucopolysaccharidosis genetic disorders, occurring with an incidence of 1 in 70,000 newborns. Sanfilippo syndrome results from the deficiency or absence of 4 different enzymes that are necessary to degrade the GAG heparan sulfate. Each enzyme deficiency defines a different subtype of Sanfilippo syndrome, as follows: type IIIA (Sanfilippo A), type IIIB (Sanfilippo B), type IIIC (Sanfilippo C), and type IIID (Sanfilippo D) [1].
Mucopolysaccharidosis IIIA (MPS IIIA - Sanfilippo syndrome)
Intravenous infusion

Trial or other data

Feb 22PI/II ABT-003 study (NCT04088734) is recruiting, and still expects to complete collection of primary outcome data in Dec 23. PI/II ABT-001 study (NCT02716246) is also recruiting, and primary outcome data collection should finish Dec 24 [10].
Feb 21Abeona announces updated data from the ongoing PI/II Transfer A study. 19 patients treated as of January 2021 with a clear dose-response and sustained reduction of heparan sulfate levels in CSF. Also sustained reduction in liver volume, positive neurocognitive signals seen in younger, higher functioning patients enrolled in cohort 3. As of Jan 21, mean follow-up in cohort 1 (55 months); cohort 2 (47 months); and cohort 3 (24 months). ABO-102 has been well tolerated to date with no deaths and no infusion-related/serious drug-related adverse events. The second PI/II study that Abeona initiated was to treat patients who do not qualify for participation in the Transfer A study because of their more advanced cognitive impairment caused by MPS IIIA [9].
Nov 20Target enrolment in the ABO-102 Transpher A study for MPS IIIA (15 to 22 patients) has been achieved. To date, 18 patients have been dosed in the Transpher A study, including 12 patients dosed in cohort 3. Abeona intends to continue enrolling patients into the study through Q1 21 given the lack of treatment options for MPS IIIA and encouraging efficacy and safety data from cohort 3 [6].
Sep 20PI/II studies (ABT001 and ABT003) are recruiting. There are no UK trial sites [3].
May 19PI/II gene therapy trial of ABO 102 in patients with middle and advanced phases of the Mucopolysaccharidosis IIIA disease starts (NCT04088734; ABT-003). The primary end point of the trial is to determine the safety by the incidence, type and severity of treatment-related adverse events and serious adverse events, change from baseline in CSF heparan sulfate levels after treatment and change from baseline in liver and/or spleen volumes after treatment, as measured by magnetic resonance imaging (MRI). The open-label trial is recruiting 12 patients in Spain, Australia and the US. Collection of primary outcome data is expected to complete Dec 23 [3].
Dec 18Abeona will expand the PI/II Transpher A trial to enrol patients at earlier stages of disease [5].
May 18Abeona announces clinical data from the ongoing PI/II Transpher A trial demonstrating robust and durable clinical effects achieved throughout various timepoints post-administration. To date, 11 patients have been dosed with a single intravenous injection of ABO-102. A supportive natural history study (Truxal et. al., 2016, Mol. Genet. Metab.) in MPS IIIA demonstrated that subjects showed, on average, 2.2 times increased liver volumes over normal. ABO-102 is well-tolerated in all subjects to date, with no drug-related serious adverse events (SAE) reported through over 4,200 cumulative days post-injection [4].
Mar 16PI/II Transpher A trial to assess the safety, tolerability and potential efficacy of ABO 102 in children with MPS IIIA starts (ABT001; MPS-IIIA; NCT02716246). The open-label trial intends to enrol 22 patients in the US, Spain and Australia. The trial will enrol patients six months to two years of age, or patients exceeding two years with a cognitive Developmental Quotient of 60% or above. Primary outcomes are safety and change from baseline in age equivalent developmental score; collection of these data is due to complete Dec 22 [3].