Immunotherapy for Third Line Metastatic Colorectal Cancer

This is a Phase IIB open label immunotherapy protocol called "StimVax". The protocol design is based upon information obtained from a previous Phase IIA dose level and dose frequency ranging study. The population targeted is MSI-S metastatic colorectal cancer previously treated with two lines of chemotherapy regimens, one containing oxaliplatin and the other containing irinotecan. This population is not considered to be responsive to immunotherapy. The study drug is called "AlloStim". AlloStim is an "off-the-shelf", non-genetically-manipulated, living immune cell immunotherapy. AlloStim is derived from precursors purified from the blood of healthy donors and grown and differentiated in specialized bioreactors in the laboratory. Because the donors are intentionally mis-matched to the host, AlloStim is completely eliminated by the host in a non-toxic rejection response within 24h of administration. Unlike autologous immune cell therapies, like CAR-T cells or TIL cells, AlloStim is allogeneic and is not intended to directly kill tumors. Rather, the novel AlloStim mechanism is designed to modify and train the host immune system to kill tumors and prevent tumor growth and spread. Uniquely, the AlloStim mechanism is also designed to increase Th1/Th2 balance, activate innate effector cells (such as NK and NKT), counter-regulate the immune suppressive and immune evasion mechanisms that tumors use to evade immune elimination both systemically and in the tumor microenvironment. The AlloStim mechanism creates self-amplifying waves of temporal and spatial immune effects that can lead to an initial non-specific cellular innate NK cell immune response followed by a tumor-specific killer T-cell immune response specific for the host tumor through a combination of immune processes called "allo-priming" and "in-situ vaccination".