Medicines that are not part of the study treatment will not generally be provided or paid for by the NIH Clinical Center. 3.5.2 Compensation Participants will not be compensated on this study. 3.5.3 Reimbursement The NCI will cover the costs of some expenses associated with protocol participation. Some of these costs may be paid directly by the NIH and some may be reimbursed to the participant/guardian as appropriate. The amount and form of these payments are determined by the NCI Travel and Lodging Reimbursement Policy. 3.6 CRITERIA FOR REMOVAL FROM PROTOCOL THERAPY AND OFF STUDY C RITERIA 3.6.1 Criteria for removal from protocol therapy Disease progression as evidenced by radiographic or clinical progression (defined in section 5.3.5). Intercurrent illness or medical circumstances: if at any time the constraints of this protocol are detrimental to the patient’s health, the patient may be removed from protocol therapy. In this event, the reasons for withdrawal will be documented. Patient’s request to be taken off study. In this event, the reasons for withdrawal will be documented. If patients are non-compliant with the protocol guidelines, they may be removed from the study at the discretion of the principal investigator. Any Grade 4 toxicity that is possibly, probably or definitely related to the protocol treatment will require a patient to be off-treatment. Grade >3 autoimmune toxicity while on vaccine, will require a patient to be off- treatment. Any Grade 3 non-autoimmune toxicity that does not resolve to Grade 1 or baseline within 60 days and is possibly, probably or definitely related to the protocol treatment will require a patient to be off-treatment. Any grade of seizure will require discontinuation of enzalutamide but patients may continue vaccine at the discretion of the investigator. Prior to documenting removal from protocol therapy, effort must be made to have all subjects complete a safety visit approximately 30 days following the last dose of study therapy. 3.6.2 Off-Study Criteria Patient is off-treatment including an approximately 30 day follow up visit (when logistically feasible) Patient’s request to be withdrawn from the study 31 Short Title: Enzalutamide Vaccine in mCRPC Version Date: 03/29/2022 Death 3.7 POST-STUDY EVALUATION Patients treated at the NCI will be offered enrollment in the 04-C-0274 “Follow-Up Study of Subjects Previously Enrolled in Immunotherapy Studies Utilizing Gene Transfer” once off study. 3.8 CONCOMITANT TREATMENT Patients will be on concomitant androgen suppression therapy with a GnRH agonist or GnRH antagonist (unless they have had a prior orchiectomy).