Whole Recombinant Saccharomyces cerevisiae Yeast Expressing Ras Mutations as Treatment for Patients With Solid Tumors Bearing Ras Mutations: Results From a Phase 1 Trial.

We are developing whole, heat-killed, recombinant Saccharomyces cerevisiae yeast, engineered to encode target proteins, which stimulate immune responses against malignant cells expressing those targets. This phase 1 trial, enrolling patients with advanced colorectal or pancreas cancer, was designed to evaluate safety, immunogenicity, response, and overall survival of ascending doses of the GI-4000 series of products, which express 3 different forms of mutated Ras proteins. The study enrolled 33 heavily pretreated subjects (14 with pancreas and 19 with colorectal cancer), whose tumors were genotyped before enrollment to identify the specific ras mutation and thereby to identify which GI-4000 product to administer.

GI-19007, a Novel Saccharomyces cerevisiae-Based Therapeutic Vaccine against Tuberculosis.

As yet, very few vaccine candidates with activity in animals against infection have been tested as therapeutic postexposure vaccines. We recently described two pools of mycobacterial proteins with this activity, and here we describe further studies in which four of these proteins (Rv1738, Rv2032, Rv3130, and Rv3841) were generated as a fusion polypeptide and then delivered in a novel yeast-based platform (Tarmogen) which itself has immunostimulatory properties, including activation of Toll-like receptors. This platform can deliver antigens into both the class I and class II antigen presentation pathways and stimulate strong Th1 and Th17 responses.

Construction and Immunogenicity Testing of Whole Recombinant Yeast-Based T-Cell Vaccines.

GlobeImmune's Tarmogen(®) immunotherapy platform utilizes recombinant Saccharomyces cerevisiae yeast as a vaccine vector to deliver heterologous antigens for activation of disease-specific, targeted cellular immunity. The vaccines elicit immune-mediated killing of target cells expressing viral and cancer antigens in vivo via a CD8(+) CTL-mediated mechanism. Tarmogens are not neutralized by host immune responses and can be administered repeatedly to boost antigen-specific immunity.

Fas ligand based immunotherapy: A potent and effective neoadjuvant with checkpoint inhibitor properties, or a systemically toxic promoter of tumor growth?

Fas ligand (FasL, CD95L) is a 40-kDa type II transmembrane protein that binds to Fas (CD95) receptors and promotes programmed cell death. Fas receptors are expressed at higher levels in many tumors than in normal cells; however, systemic administration of FasL or agonistic anti-Fas antibodies to mice with tumors caused lethal hepatitis. Somewhat paradoxically, elimination of Fas or FasL from tumors also leads to death induced by CD95 receptor/ligand elimination (DICE).