NEW YORK – Alloplex Biotherapeutics on Thursday said it will submit an investigational new drug application to the US Food and Drug Administration to begin a Phase II trial of its autologous peripheral blood mononuclear cell (PBMC)-derived cellular therapy, Suplexa, with immune checkpoint inhibitors in certain colorectal cancers.
Alloplex said in a statement that it will evaluate whether treatment with Suplexa improves patient outcomes by amplifying the effect of immune checkpoint inhibitors in patients with a certain type of colorectal cancer.
The Boston-based company uses its engineered leukocyte stimulator cell lines (ENLIST cells), which are derived from common tumor cell lines, to train PBMCs collected from patients to attack tumor cells. ENLIST cells express immunomodulatory ligands that engage receptors on patients' PBMCs and stimulate them to produce cytokines, proliferate, and thus produce Suplexa cells, which are then returned to the patient.
Alloplex has completed a first-in-human trial of the therapy in patients with advanced cancers, which it plans to present at the Society for Immunotherapy of Cancer conference in November. In the trial, some patients benefited from treatment with Suplexa with no treatment-related serious adverse events, including three patients with colorectal cancer who responded to treatment. One of those patients had a complete response, a second had a partial response, and the third had stable disease. Those responses lasted for up to two years. Among 10 patients with renal cell carcinoma, one had a partial response, six had stable disease, and three had progressive disease.
The firm said the FDA has encouraged it to proceed with an IND submission and it expects to begin the Phase II trial in early 2025.