Safety and Preliminary Efficacy of Intravenous Allogeneic Adipose-Derived Mesenchymal Stem Cells (GXIPC1) in Patients with Type 1 Diabetes Mellitus: A Phase 1, Single-Arm, Open-Label Clinical Trial

Background Type 1 diabetes mellitus (T1DM) results from autoimmune β-cell destruction and requires lifelong insulin therapy. This study aimed to evaluate the safety and preliminary efficacy of intravenous allogeneic adipose-derived mesenchymal stem cells (MSCs, GXIPC1) in children with recent-onset T1DM. Methods In this single-arm, open-label phase 1 trial, ten children (aged ≥ 5 years) diagnosed with T1DM within the previous 12 months received a single intravenous infusion of GXIPC1 at a dose of 1×10⁶ cells/kg. The primary endpoint was safety over 6 months. Secondary endpoints included changes in HbA1c, fasting glucose, C-peptide, and daily insulin requirements at 1, 3, and 6 months after infusion. Results No treatment-related serious adverse events occurred. Six participants experienced eight mild-to-moderate adverse events (mainly mild hypoglycemia managed by insulin adjustment), none related to GXIPC1. Vital signs and laboratory parameters remained stable. Median fasting glucose decreased from 15.3 mmol/L at baseline to 5.8 mmol/L at 1 month. Daily insulin requirements decreased by 44% at 3 months (median 22.5 to 12.5 IU/day), and one participant achieved insulin independence between months 3 and 6. Median HbA1c remained stable at 3 months (7.41%) and increased slightly at 6 months (8.27%), with 30% of participants showing values below baseline and 20% below 7.5%. C-peptide levels remained stable, suggesting preserved endogenous β-cell function. Conclusions Intravenous GXIPC1 was safe and well tolerated in children with recent-onset T1DM and demonstrated encouraging signals of improved glycemic control and reduced insulin dependence. Further evaluation in randomized phase 2 trials is warranted.