NEW YORK – Cambridge, Massachusetts-based Repertoire Immune Medicines on Monday announced preliminary clinical and biomarker data from an ongoing Phase I/II study of its autologous T-cell therapy, PRIME IL-15, as a treatment for patients with relapsed or refractory metastatic solid tumors.
PRIME IL-15 is an autologous cell product loaded with a cytokine IL-15Fc nanogel designed to target solid tumors while limiting systemic exposure. According to preliminary data from the ongoing trial, which will be presented in a poster session during the Society of Immunotherapy for Cancer's virtual annual meeting this week, 10 out of 17 patients treated with PRIME IL-15 achieved stable disease following treatment, four of whom remained stable for more than six months. The investigators did not note any serious immune-related toxicities.
In addition to the safety and preliminary anti-tumor activity, the investigators assessed the treatment's biologic activity according to clinical biomarker data and reported persistent T-cell clones in both patients' tumors and blood. After obtaining solid tumor biopsies from seven patients treated with the cell therapy, the investigators observed tumor-infiltrating T-cell lymphocytes for CD8-positive T cells in five out of the seven patients, and tumor-infiltrating T-cell lymphocytes for CD4-positive T cells in four out of the seven patients.
As a next step, the investigators are using Repertoire's discovery platform, DECODE, to assess the antigen specificity of the T-cell clones. Â
"We are encouraged to see both CD4-positive and CD8-positive T cells infiltrating into solid tumors following the administration of PRIME IL-15," Anthony Coyle, Repertoire's president of research and development, said in a statement. "The use of our proprietary IL-15 nanogel technology coupled with antigen-activated T cells supports a favorable safety profile and our ability to increase dosing going forward."