This plan may be revised during the study to accommodate protocol amendments. 2 STUDY OBJECTIVE 2.1 Primary Objective The primary object ive is to e valuate the efficacy of CMB305 versus placebo in subjects with synovial sarcoma expressing NY -ESO -1 through the analysis of progression -free survival (PFS) and overall s urvival (OS) .  Progression- free survival (PFS), by investigator assessment, using Response Evaluation Criteria in Solid Tumors (RECIST) v1.1  Overall survival (OS) 2.2 Secondary Objective  To evaluate the efficacy of CMB305 versus placebo using: o Time - to-next treatment (TTNT) o Distant metastasis -free survival (DMFS) o Objective response rate (ORR) (defined by RECIST v1.1)  To evaluate the safety and tolerability of CMB305 versus placebo  To evaluate quality of life (QoL) 2.3 Exploratory Objective  To evaluate the anti -NY-ESO -1 immune response and histologic and molecul ar changes in peripheral blood and tumor tissue and their association with clinical outcomes . 05FPRF Immune Design C orp. IMDZ -04-1702 SAP Draft V1.0 for Protocol V2.0 Version Date: 2018- 05-25 Confidential 10 / 36 3 STUDY DESIGN 3.1 Overall Plan This is a global, randomized, double -blind, placebo- controlled, phase 3 study designed to evaluate the efficacy and safety of the CMB305 vaccine regimen versus placebo in subjects with synovial sarcoma expressing NY -ESO -1. To be eligible, subjects must be receiving a first -line systemic anti- cancer therapy for unresectable locally -advanced or metastatic synovial sarcoma and have no e vidence of progression at the time of randomization. 3.1.1 Study Treatment Subjects who meet eligibility criteria will be randomly assigned in a 1:1 ratio to receive one of the following centrally randomized treatments: placebo and CMB305 Arm A: Placebo Placebo = LV305 placebo + G305 placebo ( NY-ESO -1 placebo + GLA -SE placebo) Matching placebo for LV305 and NY- ESO -1 will be normal saline , and m atching placebo for the GLA -SE component of G305 will be the non- active stable emulsion (SE) . Arm B : CMB305 CMB305 = LV305 + G305 (NY -ESO -1 + GLA -SE)  LV305 is a dose of 4 × 1010 vector genomes (vg) .  G305 is composed of 5 μg GLA -SE admixed with 250 μg of NY -ESO -1 protein. 3.1.2 Treatment Administered The CMB305 or matching placebo dosing regimen is presented in Figure 1 . Figure 1 CMB305 or Matching Placebo Dosing Regimen 05FPRF Immune Design C orp. IMDZ -04-1702 SAP Draft V1.0 for Protocol V2.0 Version Date: 2018- 05-25 Confidential 11 / 36 LV305 or matching placebo is administered as 4 separate 1 -mL SC on Days 1, 22, 50, and 78, each preferably administered in a separate upper or lower limb (or stump if the subject has had a resection), or admin istered at least 3 cm from the neighboring injection site if on the same limb/stump. G305 or matching placebo is administered IM on Days 36, 64, and 92, and then at 8- week intervals up to 1 year or until investigator -determined PD (using RECIST v1.1) is documented or unacceptable toxicity, whichever occurs first.. Three placebos (fully matched to characteristics of LV305, the NY -ESO -1 protein, and GLA -SE) will be provided for this study and will be administered on the same schedule and by the same route as the corresponding experimental therapy components to ensure that the sponsor, site personnel (including pharmacist), and subjects remain blinded to study drug for the duration of the study. 3.2 Study Population Approximately 248 subjects who have synovial sar coma expressing NY -ESO -1 will be enrolled and randomly assigned in a 1:1 ratio to treatment with CMB305 or placebo. The subjects in this study must have documented histologic diagnosis, and unresectable locally - advanced or metastatic synovial sarcoma with at least 6 months l ife expectancy , have IHC test results from tumor biopsy for NY -ESO -1 that are positive , and be no younger than 12 years old without any evidence of disease progression during/after the first -line systemic anti- cancer therapy in Pre -screening period. The subjects are excluded if they have recei ved prior anti -NY-ESO -1 therapy , or have history of brain metastasis , or have inadequate organ function, significant electrocardiog ram (ECG) finding or cardiovascular disease , or have active tuberculosis or hepatitis B (HepB), hepatitis C (HepC), or human immunodeficiency virus (HIV) infection. For the full list of inclusion and exclusion criteria , please refer to section 4.2 and 4.3 of the study protocol. 3.3 Randomization, Stratification and Blinding 3.3.1 Randomization and Stratification Subjects will be randomly allocated in a 1:1 ratio to receive placebo (Arm A) or CMB305 (Arm B) according to a centrally randomized treatment schedule. An IRT system will use the following stratification factors at the time of randomization:  Disease status at screening: locally advanced unresectable (LAUR) vs metastatic  Tumor response during screening: stable disease (SD)/partial response (PR) vs complete response (CR)/no evidence of disease (NED) 05FPRF Immune Design C orp. IMDZ -04-1702 SAP Draft V1.0 for Protocol V2.0 Version Date: 2018- 05-25 Confidential 12 / 36  Baseline presence of anti -NY-ESO -1 antibody (yes vs no) .