Alexion Pharmaceuticals has presented new information at the 14th International Symposium on MPS and Related Diseases in Bonn, Germany on the current Phase 1/2 Trial of SBC-103 which is an enzyme replacement therapy in children diagnosed with Sanfillippo syndrome type B also known as mucopolysaccharidosis IIIB.
Assessments were of 24 weeks involving 11 children patients ages 2 to 10 years old split into three parallel dosing groups of 0.3, 1.0, 3.0 mg/kg. The Patients received an IV of SBC-103 dosing every other week. MRI scans of the patients who were dosed at 3 mg showed that 3 out of 4 patients had an increase or no change (-1% to +1%) in CGM volume compared to the baseline which suggests potential stabilization of the disease in the patients.
In the groups diagnosed at 1 mg/kg group 2 out of 3 patients had an increase or no change compared to the baseline and 0.3 mg/kg and 0 out of 3 patients had an increase or no change in CGM volume compared to baseline.
The study also included neurocognitive assessments, in which the 3 mg/kg group, 3 out of 4 patients had an increase in both mental age equivalent (AEq) and developmental quotient (DQ) compared to baseline.
In the 1 mg/kg group, 2 out of 4 patients had an increase in both AEq and DQ compared to baseline, and the 0.3 mg/kg group, 1 out of 3 patients had an increase in both AEq and DQ compared to baseline.
The 3 mg/kg treatment group's response suggest a potential dose effect in comparison to the 0.3 mg/kg and 1 mg/kg group’s response.
In 2015, we spoke with Anthony Quinn, MBChB(MD), PhD, FRCP, chief medical officer and head of research and development at Synagenva Biopharma about SBC-103.
Sanfillipo type B
Sanfillipo B is a lysosomal storage disease is caused by deficiency in the enzyme alpha-N-acetyglucosaminidase (NAGLU), one of the four enzymes required for heparan sulfate (HS) degradation. The first symptoms generally appear between the ages of 2 and 6 years old, with behavior disorders, intellectual deterioration, sleep disorders, and in some cases, very mild dysmorphism. The neurological involvement becomes more prominent with progressive loss of motor milestones and communication problems. Few patients live last their late teens or early twenties.