Acute reactions will be managed as described in Section 4.2.3.1 below. 4.2 General Concomitant Medication and Supportive Care Guidelines In general, concomitant medications and therapies deemed necessary for the supportive care and safety of the subjec t are allowed, provided their use is documented in the subject records and on the appropriate case report form. If toxicity occurs, the appropriate treatment will be used to ameliorate signs and symptoms (including antiemetics for nausea and vomiting, anti-diarrheals for diarrhea and anti- pyretics and anti-histamines for drug feve r). All supportive measures for optimal medical care will be given during the period of study. 4.2.1 Cyclophosphamide (Cy) Cyclophosphamide is commonly used in chemotherapy to treat a variety of cancer diseases. Although cyclophosphamide is administrated at low doses, subjects may still experience the side effects below, but generally the side Phase 2 Study of GVAX (with CY) and pembrolizum ab in MMR-p advanced colorectal cancer J16154/Version 5 / January 17, 2018 21effects tend to be milder than sta ndard dose cyclophosphamide. Side effects that have reported with cyclophosphamide, when it is given at a standard dose, include:  Common toxicities : leucopenia/neutropenia, low appetite, nausea, vomiting, fatigue, and hair loss.  Less common toxicities: hyponatremia, early menopause, hematuria, and pain due to inflammation in the bl adder, liver, lungs, or veins  Rare but clinical important toxicities: hives, blurry vision, numbness and tingling of the mouth and throat, pulmonary fibrosis. Treatment with Cytoxan can also increase the risk of other cancers (bladder and skin cancers, leukemia). Acute reactions will be managed usi ng standard therapy for acute drug reactions as per inst itutional guidelines 4.2.2 GVAX Phase 2 Study of GVAX (with CY) and pembrolizum ab in MMR-p advanced colorectal cancer J16154/Version 5 / January 17, 2018 22 Local skin reactions at v accine sites may be treated with cold packs, topical lotions (e.g. aloe vera or vitamin E).