January 6, 2021 -- Selecta Biosciences has achieved preclinical data validating its ImmTOR platform to enhance the efficacy, safety, and durability of adeno-associated viral (AAV) vector gene therapies. The company plans to present these data at the annual meeting of the American Society of Gene & Cell Therapy (ASGCT) in May.
In the study, the company found that co-administration of an AAV vector and ImmTOR, a selective immune tolerance compound, in nonhuman primates enabled higher and more durable transgene expression, as well as robust inhibition of anti-AAV8 immunoglobulin G (IgG) and neutralizing antibodies.
The researchers administered a single intravenous infusion of a widely used reporter gene transgene -- recombinant adeno-associated serotype eight capsid directing expression of a transgene encoding secreted embryonic alkaline phosphatase (AAV8-SEAP). It was administered alone or co-administered with ImmTOR.
These findings suggest the potential for dosing lower levels of AAV gene therapies, thereby improving patient safety and lowering costs. Moreover, currently AAV gene therapies cannot be redosed due to the formation of neutralizing antibodies to the AAV vectors. The study found that ImmTOR mitigated the formation of neutralizing antibodies, potentially allowing for redosing.
Selecta, in partnership with Asklepios BioPharmaceuticals, expects to initiate a phase I clinical trial of MMA-101 and ImmTOR for patients with methylmalonic acidemia in the first half of 2021, with preliminary data expected by the end of 2021.