Note: Patients are not considered to be fully enrolled on this treatment prot ocol unless they meet the eligibility criteria and are registered to Part Two. Abbreviated Title: mRNA-Based, Cancer Vaccine Version Date: January 23, 2019 23 2.3.3 Treatment Assignment Procedures Cohorts Number Name Description 1 Phase I Gastrointestinal Cancer First 12-18 patients enrolled with a diagnosis of gastrointestinal cancer 2a Phase II Melanoma Patients with a diagnosis of melanoma 2b Phase II Gastrointestinal or Genitourinary Cancer Patients with a diagnosis of gastrointestinal or genitourinary cancer Arms Number Name Description 1 Phase I Escalating doses of mRNA vaccine 2 Phase II MTD of mRNA vaccine established in Phase I Randomization and Arm Assignment This is a non-randomized study. All patients will be directly assigned based on cohort as follows: x Subjects in Cohort 1 will be directly assigned to Arm 1.