1 = Mild Macular or papular eruption, erythema, or induration that is asymptomatic or mildly symptomatic. 2 = Moderate Macular or papular eruption, erythema or induration with pruritus, or other associated moderate symptoms. 3 = Severe Ulceration, superinfection, blistering, or phlebitis. 4 = Potentially Life -Threatening Necrosis of the skin. If the subject develops a potentially life -threatening (Grade 4) local reaction thought to be probably or definitely related to vaccination , the safety review team must be notified within 24 hours. The safety review team will determine whether local reactions are due to the vaccine. 5.5.2 Systemic Reactions Systemic reactions will be graded according to the World Allergy Organization Subcutaneous Immunotherapy Systemic Reaction Grading System ( Cox 2010) ( Appendix B ). The safety review team should be contacted within 48 hours for any non- local Grade 3 or 4 reactions (i.e., elevated temperature following vaccination s) thought probably or definitel y related to vaccination. The safety review team will determine whether systemic reactions are due to the vaccine. 5.5.3 Anticancer Drugs Unanticipated and anticipated toxicities from the anticancer maintenance therapy regimen will be graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 ( https://ctep.cancer.gov/protocoldevelopment/electronic_applications/ctc.htm ). Any Grade 3 or 4 toxicities that result in a temporary or permanent change in an anticancer therapy must be reported to the safety review team within 4 days of knowledge of the change. Treos Bio ZRT OBERTO -101 Amendment 3 Product: PolyPEPI 1018 Colorectal Cancer Vaccine Page 45 of 81 CONFIDENTIAL Anticipated toxicities resulting from components of the anticancer maintenance therapy regimen will be managed by the subject's clinician according to best clinical practice including dose reductions when indicated. Subjects who change and/or permanently discontinue their anticancer maintenance therapy will be handled on a case- by-case basis through discussions with the safety review team to decide whether they can remain on study treatment/on study. 5.5.4 Dose Limiting Toxicity (DLT) DLT is defined as any of the following occurring any time from Day 1 (Visit 2) until 21 days after administration o f the vaccine (according to NCI CTCAE version 4.0, (https://ctep.cancer.gov/protocoldevelopment/electronic_applications/ctc.htm ): Hematologic • Grade 4 hematologic toxicity which lasts at least 5 days • Grade 3 or higher thrombocytopenia which lasts at least 5 days Non-hematologic: • Grade 4 or greater non -hematological local (at the site of vaccine injection) adverse events • Grade 3 or greater non -hematological syst emic adverse events with the exception of alopecia, anorexia, nausea, vomiting and fatigue, constipation and dehydration Treos Bio ZRT OBERTO -101 Amendment 3 Product: PolyPEPI 1018 Colorectal Cancer Vaccine Page 46 of 81 CONFIDENTIAL 6 DESCRIPTION OF STUDY ASSESSMENTS AND PRO CEDURES The timing of the study assessments and procedures are summarized in the SoA in Appendix A . The investigator and sponsor will conduct the study in accordance with International Council for Harmonisation ( ICH) Good Clinical Practice (GCP) and local regulations.