IgG-cleaving endopeptidase enables in vivo gene therapy in the presence of anti-AAV neutralizing antibodies

Abstract

Neutralizing antibodies (NAbs) to adeno-associated virus (AAV) vectors are highly prevalent in humans 1,2 , block liver transduction 3-5 and vector readministration 6 , thus representing a major limitation to in vivo gene therapy. Strategies aimed at overcoming anti-AAV antibodies are being studied 7 , which often involve immunosuppression and are not efficient in removing pre-existing antibodies. Imlifidase (IdeS) is an endopeptidase able to degrade circulating IgG that is currently being tested in transplant patients 8 . Here we studied if IdeS can eliminate anti-AAV antibodies in the context of gene therapy. We showed efficient cleavage of pooled human IgG (IVIg) in vitro upon endopeptidase treatment. In mice passively immunized with IVIg, IdeS administration decreased anti-AAV antibodies and enabled efficient liver gene transfer.The approach was scaled up to non-human primates, a natural host for wild type AAV.IdeS treatment prior to AAV vector infusion was safe and resulted in enhanced liver transduction, even in the setting of vector readministration. Finally, IdeS reduced anti-AAV antibody levels from human plasma samples in vitro, including plasma from prospective gene therapy trial participants. These results provide a potential solution to overcome pre-existing antibodies to AAV-based gene therapy.

Identification of a myotropic AAV by massively parallel in vivo evaluation of barcoded capsid variants

“…While the sum of our present mouse data does not suggest an enhanced transduction of lymphatic tissues or cells with AAVMYO as compared to AAV9, we consider it pivotal to carefully monitor humoral and cellular immune reactions against AAVMYO in future preclinical work in higher species. If observed and if needed, these could then be modulated, for instance, by the use of IgG-cleaving endopeptidases to overcome pre-existing anti-AAV(MYO) antibodies, as most recently suggested by the Mingozzi lab 32 , or, as noted above, by direct capsid engineering.…”

Immunomodulatory Effects of Hydroxychloroquine and Chloroquine in Viral Infections and Their Potential Application in Retinal Gene Therapy

“…Therefore, adjunctive therapy with hydroxychloroquine might be beneficial in intravitreally delivered retinal gene therapies by reducing the level of AAV neutralising antibody production to facilitate second eye treatment. Alternatively, the endopeptidase imlifidase (IdeS) has been developed as a means of eliminating anti-AAV antibodies [ 125 ]. Cynomologus macaques with pre-existing anti-AAV8 antibodies were intravenously injected with IdeS 24 h prior to AAV8-hFIX injections.…”

“…This led to decreased titres of AAV8-specific IgG and neutralising antibodies and a significant increase in hFIX transgene expression. IdeS also enabled readministration of the novel AAV variant AAV-LK03 in African green monkeys, leading to a significant increase in transgene expression [ 125 ]. It remains to be seen whether such methods would prove effective in retinal gene therapy given that neutralising antibody responses are minimal following subretinal AAV injections [ 17 ].…”

Therapeutic Strategies Targeting DUX4 in FSHD

“…For example, pre-existing immunities to AAV are often found in humans, excluding a large proportion of patients from enrolment [79] and AAV gene transfer triggers an immune response to the AAV capsid, thus preventing the re-administration of the vector. Many laboratories are working on these limitations and proposed solutions include the AAV-specific depletion of neutralizing antibodies using a plasmapheresis column [80], the administration of IgG-cleaving endopeptidases to decrease anti-AAV antibody titers [81], the chemical modification of the AO to improve its pharmacokinetic and pharmacodynamic properties, and the conjugation to antibody or peptide to ameliorate muscle uptake.…”