investigation, etc. Laboratory abnormalities that meet the criteria for Adverse Events should be followed until they have returned to normal or an adequate explanation of the abnormality is found. When an abnormal laboratory or test result corresponds to a sign/symptom of an already reported adverse event, it is not necessary to separately record the lab/test result as an additional event. Laboratory abnormalities that do not meet the definition of an adverse event, should not be reported as adverse events. Whenever possible, a diagnosis, rather than a symptom should be provided (i.e. anemia instead of low hemoglobin). 12.2 Recording of Adverse Events Safety will be assessed by monitoring and recording potential adverse effects of the treatment using the Common T erminology Criteria for Adverse Events (CTCAE) version 5.0 at each study visit. If CTCAE grading does not exist for an adverse event, the severity of mild, moderate, severe, life - threatening, and death, corresponding to Grades 1- 5, will be used whenever possible. Subjects will be monitored through interval medical history evaluations, physical examinations, and clinical laboratory assessments as per the Study Calendar ( Section 10 ). Adverse events will be collected continuously throughout the subject’s participation; using testing/examinations, non-directive questioning (e.g. review of systems), subject self -reporting, etc. Information on all adverse events should be recorded in the source documentation. Information on all adverse events should be recorded in the source documentation. All clearly related signs, symptoms, and abnormal diagnostic procedure results should be recorded in the source document, though should be grouped under one diagnosis. To the extent possible, adverse events should be recorded as a diagnosis and symptoms used to make the diagnosis recorded within the diagnosis event. Do not list symptoms separately if a diagnosis can be assigned. The safety team may require events be reported separately if they occur as SAEs (or in the context of a SAE) even if they can also be considered a constituent of another AE. All adverse events occurring during the adverse event reporting period (defined in Section 12.1 above) must be recorded. If there are no adverse events identified during a study visit occurring after the AE reporting period commences, physician -investigator confirmation of the absence of adverse should be documented. Adve rse events that are ongoing at the time the subject enters the Post -DC Vaccine Surveilliance phase of the study will continue to be followed until: a) the adverse event resolves; b) the subject discontinues participation (i.e. End of Study); or c) there is a change in the adverse event that would normally require the event be captured as a new event (i.e. change in attribution). Please refer to the CRF Completion Guidelines (CCG) for specific instructions on data entry. As much as possible, each adverse event should be evaluated to determine the following information : 1. The severity grade (CTCAE Grade 1 -5) 2. Duration 3. Its relationship to the study treatment (as defined in Section 12.1) 4. Expectedness t o study treatment (as defined in Section 12.1) 5. Action taken with respect to study or investigational treatment 6. Whether medication or therapy was administered 7. Whether it is ser ious (as defined in Section 12.3) DC Vaccine for Colorectal Cancer Page 26 of 34 Version 7.11-11-2021 CONFIDENTIAL This protocol is the property of the University of Pennsylvania. Do not disclose or use except as authorized in writing by the study spons or. Physician -investigator assessment of whether an adverse event is serious (as defined by Section 12.1) must occur within 24 hours from the date of knowledge of the adverse event, in order to meet SAE reporting requirements as described in Section 12.3. Additional assessment of non- serious adverse events, including grade and relationship to study treatment, should occur within 7 days from the date of knowledge of the adverse event or from the date of the study visit where the absence of adverse events was confirmed. Accelerated timelines for adverse event assessments and reporting may be requested in the event of emergent safety concerns and/or to address time-sensitive requests from the FDA. All adverse events should be treated appropriately. If a conco mitant medication or non- drug therapy is given, this action should be recorded. Once an adverse event is detected, it should be followed until its resolution or until it is judged to be permanent, and assessment should be made at each visit (or more frequently, if necessary) of any changes in severity, the suspected relationship to the study treatment, the interventions required to treat it, and the outcome. Adverse events that occur concurrently with the progression of malignancy but that are not related to disease progression (i.e. deep vein thrombosis or hemoptysis) will be reported as an adverse event as described above. Progression of malignancy resultin g in death should be reported as a serious adverse event. Serious adverse events that are still ongoing at the end of the adverse event reporting period must be followed to determine the final outcome. Any serious adverse event that occurs after the adv erse event reporting period and is considered to be possibly related to the study treatment or study participation, should be recorded and reported. 12.3 Reporting of Serious Adverse Events Every SAE , UADE , and PDSAE (during post- DC vaccine surveillance), regardless of suspected causality , occurring during the adverse event reporting period defined in Section 12.1 must be reported to the Sponsor Team within 24 hour s of learning of its occurrence. The original SAE notification may take place by email to meet the 24 hour reporting window. Within 3 business days of initial knowledge of the event, the investigator must submit a complete SAE form to the Sponsor along with any other diagnostic information that will assist the understanding of the event. The Investigator will keep a copy of this SAE Form on file at the study site. New or follow- up information on SAEs /UADEs/PDSAEs should be promptly reported as updates become available. At a minimum follow -up SAE Forms should be submitted: • Within 1 week of ICU admission or any life- threatening event • Within 2 weeks of hospital discharge Follow-up information should be submitted as an amendment to the initial SAE form, and should include both the follow -up number and report date. The follow -up information should describe whether the event has resolved or continues, if there are any changes in assessment, if and how it was treated, and whether the subject continued or withdrew from study participation. Report serious adverse events to: DC Vaccine for Colorectal Cancer Page 27 of 34 Version 7.11-11-2021 CONFIDENTIAL This protocol is the property of the University of Pennsylvania. Do not disclose or use except as authorized in writing by the study spons or. Attention: Clinical Safety Manager or designee Center for Cellular Immunotherapies University of Pennsylvania At the time of the initial notification, the following information should be provided: • Study identifier • Subject number • A description of the event • Date of onset • Current subject status • Whether study treatment was discontinued • The reason the event is classified as serious • Investigator assessment of the association between the event and study treatment • Expectedness relative to investigational product(s) 12.3.1 Investigator Reporting: Local Regulatory Review Committees Report events to local regulatory review committ ees per institutional policy. 12.4 Pregnancies To ensure subject safety, each pregnancy occurring while the subject is on study treatment must be reported to protocol sponsor within 24 hours of learning of its occurrence. The pregnancy should be followed up to determine outcome, including spontaneous or voluntary termination, details of the birth, and the presence or absence of any birth defects, congenital abnormalities, or maternal and/or newborn complications. If a pregnancy occurs on study, this will be reported as an SAE using an SAE Report Form. Pregnancy outcomes must be collected for the female partners of any males who took study treatment in this study. Consent to report information regarding these pregnancy outcomes should be obtained from the mother. 12.5 Protocol Exceptions/Deviations Exception: A one time, intentional action or process that departs from the IRB-approved study protocol, intended for one occurrence. If the action disrupts the study progress , such that the study design or outcome (endpoints) may be compromised, or the action compromises the safety and welfare of study subjects , advance documented approval from the Regulatory Sponsor and local regulatory review committees per institut ional guidelines is required. Approval from the Regulatory Sponsor must be received prior to submission to local regulatory review committees for approval. Deviation: A one time, unintentional action or process that departs from the approved study protocol, involving one incident and identified retrospectively , after the event occurred. If the impact on the protocol disrupts the study design , may affect the outcome (endpoints) or compromises the safety and welfare of the subjects, the deviation must be reported to the Regulatory Sponsor within 10 business days of PI knowledge, and to local regulatory review committees per institutional DC Vaccine for Colorectal Cancer Page 28 of 34 Version 7.11-11-2021 CONFIDENTIAL This protocol is the property of the University of Pennsylvania. Do not disclose or use except as authorized in writing by the study spons or. guidelines. Acknowledgement from the Regulatory Sponsor must be received prior to submission to local regulatory review committees. Other deviations should be appropriately documented per site policies/procedures (such as a subject missing a visit is not an issue unless a critical/im portant treatment or procedure was missed and must have been done at that specific time). Include the following information on the Sponsor supplied exception/deviation form: protocol number, subject study number, comprehensive description of the excepti on/deviation from the protocol, rationale , and corrective and preventative action plan (deviations only) . Ensure all completed exception/deviation forms are signed by the Principal Investigator (or physician sub- investigator) and submitted to the Sponsor Project Manager for review. Attention: Sponsor Project Manager Center for Cellular Immunotherapies (CCI) University of Pennsylvania Once approval of the exception request or acknowledgement of the deviation has been granted by the Regulatory Sponsor, the exception or deviation will be submitted to all applicable committees for review and approval /acknowledgement per institutional guidelines . 12.6 Medical Monitoring It is the responsibility of the Principal Investigator to oversee the safety of the study at the clinical site. This safety monitoring will include careful assessment and appropriate reporting of adverse events as noted above. Medical monitoring will include a regular assessment of the number and type of serious adverse events. 12.7 Study Stoppin g Rules This trial will be paused if the following events occur, pending further discussion with the Sponsor Medical Director, IRB and FDA: • Any death that may be related to the investigational products. • DLT is observed in 2 out of the first 2 subjects, 3 out of the first 4 subjects, 4 out of the first 7, 5 out of the first 10 and 6 at any time The above statistical stopping rule was developed such as the rule will be triggered if the lower limit of the two -sided 90% confidence interval of the event rate exceeding 20%. Under this rule, we would stop the study early with a probability of 1.6%, 8.8%, and 23.8% if the true event rate is 10%, 20%, and 30%, respectively. These probabilities were calculated from a simulation study. The study may be discontinued at any time by the IRB, the Sponsor, the FDA, or other government agencies as part of their duties to ensure that research subjects are protected. 13.0 STATISTICAL CONSIDERATIONS Approximately 12 evaluable subjects will be enrolled in this study. All subjects who receive at least one Dendritic Cell Vaccine at the minimum acceptable dose for infusion will be considered evaluable for primary endpoint analysis. Subjects who fail apheresis or who do not receive vaccine due to other reasons will not be considered evaluable and will be replaced. The sample size is determined based on availability of the funding. Early stopping rules will be implemented as described in Section 12.7. DC Vaccine for Colorectal Cancer Page 29 of 34 Version 7.11-11-2021 CONFIDENTIAL This protocol is the property of the University of Pennsylvania. Do not disclose or use except as authorized in writing by the study spons or. The primary end point of the study is to determine the post -vaccine immune response based on measuring increased numbers of peptide -specific CD8+ T cells as calculated by the flow cytometric -based intracellular cytokine or tetramer staining15. For each peptide, the intracellular cytokine and tetramer assays are performed on blood samples obtained at the indicated tim e points. Data are presented as the absolute number or percentage of CD8+ T cells positive for IFN -y, IL-2, TNF -alpha and granzyme B secretion when stimulated with peptide or tetramer binding based on gating variables set using the iMASC reagent kit (Beckm an Coulter). The lower limit of detection (LLD) is 0.03% per 100,000 cells for flow cytometric assays. For the analysis, a negative control peptide or tetramer (e.g. HIV gag peptide) will be used to normalize each assay. Each sample is incubated or stained with control peptide or tetramer and the number of positive CD8+ T cells are subtracted from each experimental point . The mean and SD at baseline are obtained for each subject . Based on our prior experience, the expected analytical CV (standard deviation/mean) is 10%. A positive intracellular cytokine or tetramer response is defined as an increase greater than 3SD above the baseline value. For each peptide, the proportions of CD8+ T cell response s (positive or negative) and the associated 90% exact confidence intervals (CI) will be reported for each time point. With 12 subjects, the width of the 90% exact CI will be no more than 25 % away from the observed proportions. The primary endpoint will also include evaluating the safety and tolerability of the mature dendritic cell vaccine using proportions and exact 90% confidence intervals. Safety data from all subjects will be analyzed together regardless of the actual infusi on dose received. Adverse events will be tabulated by grades and body system. The frequency of grade 3 and 4 AEs will be summarized separately. With 12 evaluable subjects, the half- width of the exact 90% confidence interval (CI) will be no more than 26%. The probability of observing at least one DLT will be 72%, 93% , and 99% if the true DLT rate is 10%, 20%, and 30%, respectively. For the secondary objective, the percentage of CD8 + T-cell responses are expected to be approximately Gaussian on the original or a transformed scale (e.g., log transformation). Linear mixed models will be used to describe the change in counts by time, dose and the time by dose interaction and pattern over time will be examined graphically. Dose is treated as a fixed effect as the doses to be administered cover the range about which conclusions will be drawn. We will explore whether Time should be treated as a random effect, as the time points represent a sample from an ongoing process. In addition, clustered logistic regression will be u sed to model the probability of tetramer positivity versus negativ ity by time, dose and time by dose interaction. These models are intended to be descriptive, and no preliminary data exist which estimate longitudinal trends, so no power calc ulation is attempted. For the exploratory aim, the association between treatment outcomes and tumor/immune biomarkers will be examined by t -test. The treatment outcomes are binary variables including immune response rate as measured by dextrameter/tetramer assay as described previously and any grade 3 or higher AEs. Tumor and immune biomarkers are primarily continuous variables. Due to exploratory nature of the analyses, no adjustment of multiple testing will be performed. Additional correlative assays will be performed (Cr 51 release); however, these data will be not be used to determine the primary end point but may be used as surrogate assays to evaluate the functionality of neoantigen peptide -specific CD8 + T cells. These assays will be performed using CD8+ T cells from baseline and post -vaccination blood samples. A positive Cr51 assay is defined as an increase in specific lysis > 15% above background at effector:target ratio of 5:1. DC Vaccine for Colorectal Cancer Page 30 of 34 Version 7.11-11-2021 CONFIDENTIAL This protocol is the property of the University of Pennsylvania. Do not disclose or use except as authorized in writing by the study spons or. 14.0 DATA HANDLING AND RECORDKEEPING 14.1 Confidentiality Information about st udy subjects will be kept confidential and managed according to the requirements of the Health Insurance Portability and Accountability Act of 1996 (HIPAA). Those regulations require a signed subject authorization informing the subject of the following: • What protected health information (PHI) will be collected from subjects in this study • Who will have access to that information and why • Who will use or disclose that information • The rights of a research subject to revoke their authorization for use of their PHI. In the event that a subject revokes authorization to collect or use PHI, the investigator and Sponsor , by regulation, retain the ability to use all information collected prior to the revocation of subject authorization. For subjects that have revok ed authorization to collect or use PHI, attempts should be made to obtain permission to collect at least vital status (i.e. that the subject is alive) at the end of their scheduled study period. 14.2 Source Documents Source data is all information, original records of clinical findings, observations, or other activities in a clinical trial necessary for the reconstruction and evaluation of the trial. Source data are contained in source documents. Examples of these original documents, and data records include: hospital records, clinical and office charts, laboratory notes, memoranda, subjects’ diaries or evaluation checklists, pharmacy dispensing records, recorded data from automated instruments, copies or transcriptions certified after verification as being accurate and complete, microfiches, photographic negatives, microfilm or magnetic media, x- rays, subject files, and records kept at the pharmacy, at the laboratories, and at medico -technical departments involved in the clinical trial. The investigator must maintain source documents for each subject in the study, consisting of case and visit notes (hospital or clinical medical records) containing demographic and medical information, laboratory data, and the results of any other tests or assessments. All information recorded on the eCRFs must be traceable to source documents in the subject’s file. The investigator must also keep the original signed informed consent form, and a signed copy must be given to the subject . 14.3 Case Report Forms The study case report form (CRF) is the primary data collection instrument for the study. All data requested on the CRF must be recorded. All entries will be entered into an electronic data capture system (EDC). The Principal Investigator is responsible fo r assuring that the data entered into eCRF is complete, accurate, and that entry and updates are performed in a timely manner. 14.4 Records Retention It is the Investigator’s responsibility to retain study essential documents for at least 2 years after the la st approval of a marketing application in their country and until there are no pending or contemplated marketing applications in their country or at least 2 years have elapsed since the formal discontinuation of clinical development of the investigational product. These documents may be retained for a longer period if required. DC Vaccine for Colorectal Cancer Page 31 of 34 Version 7.11-11-2021 CONFIDENTIAL This protocol is the property of the University of Pennsylvania. Do not disclose or use except as authorized in writing by the study spons or.