Analysis Sets T hree analysis sets are defined for this trial. The Intent -to-Treat set (ITT) includes all subjects who are randomized. The full analysis set (FAS) includes all subject s initiating study intervention. The S afety analysis set includes all subjects initiating study intervention. The FAS and safety analysis set are the same. A ll efficacy analyses will be performed on the ITT set and the FAS. Subjects will be analyzed and summarized based on the arm into which they were randomized. Efficacy analysis performed on the ITT analysis set will be considered to be the primary indicator of efficacy. Analysis performed on the FAS will be considered to be supportive. A ll safety analyses will be performed on the Safety set and subjects will be analyzed and summarized based on the treatment they actually received. 4.4. Changes in Planned Analys is T he analysis as described in the protocol has been expanded to include the analysis of tumor regression and growth rates. Interim analysis has been added. Bavarian Nordic, Inc. Statistical Analysis Plan Amendment 1 Protocol: BNIT -PRV -301 Date Issued: 29 June 2015 C onfidential 9 Revised: June 2015 5.Subject Disposition S ubject enrollment will be summarized for each site by treatment arm and overall for the FAS. S ubject disposition will be summarized by treatment arm and overall for the FAS. Percentages for this table will be based on the total number of subjects in each treatment arm and overall. T he reasons for study treatment discontinuati on will be summarized by treatment arm and overall. The reason s for study treatment discontinuation are listed on the treatment completion eCRFs. 6.Demographics and Baseline Characteristics 6.1. Demographics A summary of demographics and baseline characteristics will be presented by treatment arm and overall for the FAS. The demographic characteristics consist of age, age category, sex, ethnicity, race, and prior smallpox vaccination status. Baseline height and weight will also be presented using descriptive statistics. F or subjects who provide date of birth, age will be calculated as the integer part of (Date of Informed Consent – Date of Birth + 1)/365.25. Age will also be categorized using the categories 18-<25, 25-<45, 45-<65, and 65 or over, and will be presented using frequencies and percentages. The number and percentage of subjects’ ethnicity (Hispanic or Latino, Not Hispanic or Latino, or Not Reported) as well as reported race categories will also be reported. Reported race categories include White, Black, Asian, American Indian or Alaska Native, Native Hawaiian or Other Pacific Islander , and Multiracial. A ll demographic and baseline characteristic data will be listed for each subject.