An Investigative Report on GI-4000 (DB05698): A Yeast-Based Immunotherapy Targeting RAS-Mutated Cancers — From Promising Signal to Strategic Repurposing

Executive Summary & Critical Disambiguation

Overview of GI-4000 (DB05698)

GI-4000 (DrugBank ID: DB05698) is an investigational, off-the-shelf therapeutic cancer vaccine developed to treat solid tumors harboring mutations in the Ras oncogene.[1] It is a complex biologic product, classified as a biotech drug, that originates from GlobeImmune's proprietary Tarmogen® immunotherapy platform.[3] The vaccine consists of whole, heat-inactivated recombinant

Saccharomyces cerevisiae (common baker's yeast) that has been genetically engineered to express specific mutated forms of the human Ras protein.[1] The foundational therapeutic hypothesis of GI-4000 is to leverage the yeast vehicle as a natural adjuvant to deliver the mutated Ras antigens to the patient's immune system, thereby stimulating a robust and highly specific cytotoxic T-lymphocyte (CTL) response capable of recognizing and eliminating cancer cells that express these oncogenic proteins.[1] GI-4000 is not a single entity but a series of four distinct products, each expressing a unique combination of Ras mutations, designed to collectively target the seven most common mutations observed in human cancers.[2] This design necessitates the genotyping of a patient's tumor to administer the corresponding matched vaccine product.[2]

Synopsis of Clinical Development and Corporate Trajectory