To establish the safety, tolerability, and feasibility of intradermal (id, MS-tolDC) and intranodal (in, TOLERVIT-MS) administration of tolDC in active MS patients, we conducted two phase I, open-label, dose-escalation, single-center clinical trials.
Clinical-grade vitamin D3-treated autologous tolDC were manufactured under GMP conditions, starting from leukapheresis. Following loading with seven myelin-derived peptides (MBP13-32, MBP111-129, MBP154-170, PLP139-154, MOG1-20, MOG35-55, and MBP83-99), cell aliquots were cryopreserved. In a dose escalation study, three cohorts received a total of six administrations of 5, 10, or 15x106 tolDC per vaccine. The first four tolDC products were administered with a 2-week interval, while the last two had a 4-week interval. Safety assessments included recording adverse events (AE), relapses, neurological disability, and magnetic resonance imaging (MRI) endpoints. Secondary outcome measures included additional clinical and MRI endpoints, with exploratory outcomes involving immunological monitoring and quality of life assessments.
In Belgium (NCT02618902) and Spain (NCT02903537), 18 patients were included and treated with id (n=9) or in (n=9) tolDC, respectively. Each cohort exhibited a similar number of AE, with no statistically significant differences observed between sites or cohorts. Importantly, no serious adverse events were reported.
In conclusion, both intradermal (id) and intranodal (in) administration of tolDC proved to be safe, feasible, and well-tolerated. Regulatory authorities have approved a phase II clinical trial, and as of now, all approvals for the phase 2 clinical trial application have been obtained. This positive response has been affirmed by National competent authorities and institutional review boards in Spain and Belgium. Patient inclusion and treatment for the phase 2 clinical trial are anticipated to commence in Q1 2024.
In addition to the clinical trial efforts, ReSToRe has focused on organising meetings for researchers and stakeholders, data management, dissemination, exploitation of results, and the establishment of legal agreements. The findings from the phase I clinical trial were disseminated through presentations at reputable international meetings, including the 18th International Congress of Immunology 2023 and the 9th Joint ECTRIMS-ACTRIMS Meeting 2023.