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Selecta Biosciences Presents New Preclinical Data from its Gene Therapy Program at the American Society of Gene & Cell Therapy (ASGCT) 22nd Annual Meeting
“The development of antibodies against the viral vectors used to deliver gene therapy has thus far impeded the ability to re-dose patients. These preclinical data highlight how the co-administration of our ImmTOR technology with AAV-based vectors suppresses the immune response to the vector, potentially enabling re-treatment to provide sustained therapeutic efficacy over time,” said
Details of the five data presentations and key highlights include:
Oral Presentation Title: ImmTOR™ Tolerogenic Nanoparticles Enhance Transgene Expression after Both Initial and Repeat Dosing in a Mouse Model of Methylmalonic Acidemia Treated with an Anc80 AAV Vector
Authors: Ilyinskii, et al.
Abstract #: 24
- In a methylmalonic acidemia (MMA) mouse model, the repeated co-administration of Anc80-Mut, a rationally engineered AAV vector encoding the methylmalonic CoA transgene, and ImmTOR™ was well-tolerated and led to complete inhibition of IgG antibodies.
- Higher liver cell viral DNA copy number, sustained reduction of serum MAA levels, and normalized weight gain were seen in MMA mice treated with the combination of ImmTOR™ and Anc80-Mut.
Oral Presentation Title:Tolerogenic ImmTOR Nanoparticles Enhance Vector Transduction, mRNA Synthesis and Transgene Expression after Initial and Repeated Administrations of AAV-based Gene Therapy Vectors through Immunological and Non-immunological Mechanisms
Authors: Ilyinskii, et al.
Abstract #: 146
- In naïve mice models, co-administration of ImmTOR™ and AAV-based vectors enhanced transgene expression after the first dose of AAV vector, with rapid and enhanced transgene expression, which may enable therapeutic benefit at lower doses, potentially avoiding toxicities associated with larger doses.
Oral Presentation Title:Development of a Novel AAV-based Therapy in Combination with Tolerogenic SVP Nanoparticles for a Sustained Treatment of Ornithine Transcarbamylase Deficiency
Authors: De Sabbata, et al.
Abstract #: 25
- In a mouse model of Ornithine TransCarbamylase deficiency (OTCd), a monogenic urea cycle disease that results in the accumulation of ammonia in the blood, ssAAV8-OTC in combination with ImmTOR™ was shown to effectively restore the physiological levels of urinary orotic acid and serum ammonia, correcting disease. These data demonstrate a new opportunity to treat pediatric patients with the possibility to re-dose to maintain therapeutic levels.
Poster Title:Characterization of pre-existing antibodies to Anc80 vector in adult and pediatric donors, and the Impact of ImmTOR technology on restoring antibody-compromised transgene activity in vivo
Authors: Leung, et al.
Abstract #: 294
- Using a murine passive antibody transfer mouse model, the addition ImmTOR to Anc80-Mut enabled transgene expression even in the presence of moderately neutralizing antibodies (NAbs) against the Anc80 AAV vector.
Oral Presentation Title:The Combination Therapy of ImmTOR™ with AAV Anc80 is Therapeutic, Safe, and Repeatable in Mice with Methylmalonic Acidemia, and Compatible with the Low Seroprevalence of Anc80 NAbs in the Patient Population
Authors: Li, et al.
Abstract #: 425
- In a mouse model of the severe childhood form of isolated MMA, ImmTOR treatment was well tolerated and enabled repeat dosing of Anc80-Mut vector.
- A survey of sera from Mut-deficient MMA patients showed only 2/27 patients were seropositive for neutralizing antibodies (NAb) against the Anc80 vector.
- The low seroprevalence of pre-existing Anc80 NAbs in the MMA patient population, and the ability to mitigate formation of new NAbs with ImmTOR, has the potential to make this combination therapy versatile and amenable for repeat dosing.
Full poster abstracts are available on the ASGCT conference website at https://annualmeeting.asgct.org/am19/abstracts.
This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding Selecta’s plans to present at the
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Source: Selecta Biosciences, Inc.