Abeona Therapeutics announced it is just weeks away from enrolling the first patients in a trial of its gene therapy for the lysosomal storage disease Sanfilippo B.
The new comes as the gene therapy candidate—called ABO-101—has just been awarded orphan status in Europe to go alongside the FDA's orphan designation which was granted last year.
Sanfilippo B syndrome, or mucopolysaccharidosis IIIB (MPS IIIB), is triggered by genetic mutations that shutter N-acetyl-α-D-glucosaminidase (NAGLU) enzyme activity and cause a substance called heparan sulfate to accumulate and cause damage to cells, particularly in the central nervous system.
The disease leads inexorably to neurocognitive decline, speech loss, loss of mobility and premature death, and there is currently no approved treatment that can stabilize or slow the deterioration.
The decision to move ahead with clinical trials for ABO-101 comes after its co-lead program, ABO-102 for related lysosomal storage disease Sanfilippo A/MPS IIIA, showed promising initial data in a phase 1/2 trial.
Additional results from that trial are due to be presented on Feb. 16 at the WORLDSymposium for Lysosomal Storage Diseases in San Diego. According to analysts at Jefferies—who recently started covering the stock—that will likely include six-month data on neurocognition in two of three patients from a low-dose cohort plus initial results from the first patient in a higher-dose cohort.
If the results are positive, the company intends to move swiftly ahead with discussions with the FDA, aiming to get a breakthrough designation and agree to a design for a registration trial.
Jefferies analysts Gena Wang and Xiaobin Gao said that when meeting Abeona's management recently, the company "appeared confident that neurocognitive improvement could possibly be observed with six months' follow-up." All three patients in the low-dose cohort had been weaned off prophylactic steroids within 90 days of receiving the therapy, she added.
Jefferies gave the AB-102 program a 60% chance of success and said the therapy could bring in peak sales of around $190m.
Abeona's one-shot gene therapy approach to Sanfilippo A/B and other lysosomal storage diseases differs from the tack taken by other companies—notably Alexion and Shire—which have focused on developing enzyme replacement treatments that would have to be dosed on an ongoing basis. Until recently, Shire was another potential rival, but dropped development of its SHP610 treatment after failing to show any benefit on neurocognition in a midstage trial.
French gene therapy Lysogene, which is in the throes of planning an initial public offering on the Paris bourse, also has an MPS IIIA candidate called LYS-SAF302 in clinical testing.