825-P: Novel Autologous Dendritic Cell Therapy AVT001 for Type 1 Diabetes
Authors: GAGLIA JASON L. , MACKEY MIKAYLA , DALEY HEATHER L. , BRYANT NORA , KIM DAVID Y. , DONG TUOCHUAN , FAN ERMEI E. , VORA JITEN , SKYLER JAY S. , RITZ JEROME , JIANG HONG 
Published: June 2023

Studies in several animal models and of humans with type 1 diabetes (T1D) have suggested that Qa-1/HLA-E restricted CD8+ T regulatory cells (Tregs) are important in maintaining self-tolerance and a defect thereof playing a key role in T1D pathogenesis. To evaluate the safety and efficacy of targeting this pathway in T1D we undertook a first in human, phase 1/2 study of AVT001, an investigational autologous dendritic cell-based vaccine designed to address this immunologic mechanism. This double-blind, randomized (2:1 treated vs placebo) trial enrolled individuals (n=25) who were 16 years and older, within 1 year of clinical diagnosis of T1D, and with an ex-vivo correctable defect in the function of HLA-E-restricted CD8+ Tregs. All participants underwent leukapheresis, the first step in the generation of AVT001. AVT001 treatment (n=16) or placebo (n=9) was delivered as a series of three-monthly intravenous infusions. The primary endpoint of the study was safety/tolerability at day 150. AVT001 was safe and well tolerated with all participants completing treatment, no peri-infusion reactions noted, and adverse events reported as being mild or moderate in the AVT001 treated group, with rates similar to placebo. A pre-specified efficacy endpoint was change from baseline in C-peptide area under the curve (AUC) during a 4-hour mixed meal tolerance test utilizing a mixed-effect model for repeated measurements (MMRM). The baseline mean (SD) AUCs were treated 0.531 (0.363) and placebo 0.611 (0.178) nmol/L. At day 150, the C-peptide AUCs were significantly different between groups, namely 0.518 (0.430) and 0.472 (0.134) respectively. Per MMRM, the least square mean difference between AVT001 and placebo at day 150, is estimated to be 0.172 (p=&lt;.0001). There was an increase in AUC or no change for 6 (37.5%) in the AVT001 treated group and 1 (11.1%) in the placebo group. These results indicate that AVT001 treatment was safe and well tolerated with evidence of significant preservation of endogenous insulin secretion.

Disclosure
J.L.Gaglia: Advisory Panel; Dompé, Consultant; Vertex Pharmaceuticals Incorporated, Abata Therapeutics, Avotres Inc., Current Health, Research Support; Avotres Inc., Dompé, Imcyse, Stock/Shareholder; Vertex Pharmaceuticals Incorporated. J.Ritz: Advisory Panel; Novartis, Taleris, AvroBio, Clade Therapeutics, LifeVault Bio, Smart Immune, Garuda, Tscan, Research Support; Gilead Sciences, Inc., Novartis. H.Jiang: Employee; Avotres Inc. M.Mackey: None. H.L.Daley: None. N.Bryant: None. D.Y.Kim: None. T.Dong: Employee; Avotres Inc., Novartis. E.E.Fan: None. J.Vora: Other Relationship; Avotres Inc., Glyscend Inc. J.S.Skyler: Advisory Panel; Adocia, Altheia Sciences, Arecor, Avotres Inc., Bayer Inc., COUR Pharmaceuticals, Dance Biopharm/Aerami, Diasome, Enthera, Immnomolecular Therapeutics, Kriya Therapeutics, Oramed Pharmaceuticals, Orgenesis Inc., Precigen, Inc., ViaCyte, Inc., Board Member; Applied Therapeutics Inc., Dexcom, Inc., Consultant; Novo Nordisk, Sanofi, Signos, 4Immune, Other Relationship; Imcyse, Provention Bio, Inc.

Funding
Avotres Inc.