A Phase 3 Open-label, Multicenter, Randomized Study of ASP2215 versus Salvage Chemotherapy in Patients with Relapsed or Refractory Acute Myeloid Leukemia (AML) with FLT3 Mutation ISN/Protocol 2215-CL-0301 ClinicalTrials.gov Identifier: NCT02421939 Date of Protocol Version 9.1: 16 May 2018 Sponsor: Astellas Pharma Global Development, Inc. (APGD) 1 Astellas Way Northbrook, IL 60062 Sponsor: APGD ISN/Protocol 2215-CL-0301 EudraCT 2015-000140-42 - CONFIDENTIAL - A Phase 3 Open-label, Multicenter, Randomized Study of ASP2215 versus Salvage Chemotherapy in Patients with Relapsed or Refractory Acute Myeloid Leukemia (AML) with FLT3 Mutation Protocol for Phase 3 Study of ASP2215 ISN/Protocol 2215-CL-0301 Version 9.1 [JP] Incorporating Country-specific Non-Substantial Amendment 3 [See Attachment 1] 16 May 2018 IND 117,548 EudraCT 2015-000140-42 Sponsor: Astellas Pharma Global Development, Inc. (APGD) 1 Astellas Way Northbrook, IL 60062 Protocol History: Version 1.0 [24Mar2015] Version 2.0 Incorporating Substantial Amendment 1 [22Jun2015] Version 2.1 [JP] Incorporating Country-specific Non-Substantial Amendment 1 [06Aug2015] Version 3.0 Incorporating Substantial Amendment 2 [13Aug2015] Version 3.0 [JP] Incorporating Substantial Amendment 2 [13Aug2015] Version 4.0 [KR] Incorporating Country-specific Substantial Amendment 3 [08Oct2015] Version 5.0 Incorporating Substantial Amendment 4 [09Dec2015] Version 5.0 [KR] Incorporating Substantial Amendment 4 [09Dec2015] Version 5.0 [JP] Incorporating Substantial Amendment 4 [09Dec2015] Version 6.0 [KR] Incorporating Substantial Amendment 5 [31Mar2016] Version 7.0 [FR] Incorporating Country-specific Substantial Amendment 6 [22Jun2016] Version 8.0 Incorporating Substantial Amendment 7 [08Aug2016] Version 8.1 Incorporating Non-substantial Amendment 2 [27Sep2016] Version 9.0 Incorporating Substantial Amendment 8 [20Sep2017] Version 9.0 [KR] Incorporating Country-specific Substantial Amendment 8 [20Sep2017] Version 9.0 [FR] Incorporating Country-specific Substantial Amendment 8 [20Sep2017] This confidential document is the property of the Sponsor. No unpublished information contained in this document may be disclosed without prior written approval of the Sponsor. 16 May 2018 Astellas Page 1 of 122 Version 9.1 [JP] Incorporating Country-specific Non-Substantial Amendment 3 Sponsor: APGD ISN/Protocol 2215-CL-0301 EudraCT 2015-000140-42 - CONFIDENTIAL - Table of Contents I. SIGNATURES ······················································································ 8 II. CONTACT DETAILS OF KEY SPONSOR’S PERSONNEL····························10 III. LIST OF ABBREVIATIONS AND DEFINITION OF KEY TERMS ··················12 IV. SYNOPSIS··························································································16 V. FLOW CHART AND SCHEDULE OF ASSESSMENTS ·································30 1 INTRODUCTION·················································································38 1.1 Background ····················································································38 1.2 Nonclinical and Clinical Data ·······························································39 1.2.1 Nonclinical Data·········································································39 1.2.2 Clinical Data ·············································································40 1.3 Summary of Key Safety Information for Study Drugs ···································42 1.3.1 ASP2215··················································································42 1.3.2 Comparative Chemotherapy Regimens ···············································45 1.4 Risk-Benefit Assessment·····································································45 2 STUDY OBJECTIVES, DESIGN AND ENDPOINTS·····································46 2.1 Study Objectives ··············································································46 2.1.1 Primary Objectives ······································································46 2.1.2 Secondary Objectives ···································································46 2.1.3 Exploratory Objectives ·································································46 2.2 Study Design and Dose Rationale···························································47 2.2.1 Study Design·············································································47 2.2.2 Dose Rationale···········································································48 2.3 Endpoints·······················································································49 2.3.1 Co-Primary Endpoints ··································································49 2.3.2 Secondary Endpoints····································································49 2.3.3 Exploratory Endpoints ··································································49 2.3.4 Safety Endpoints·········································································50 2.3.5 Pharmacokinetics········································································50 3 STUDY POPULATION··········································································50 3.1 Selection of Study Population ·······························································50 3.2 Inclusion Criteria··············································································50 3.3 Exclusion Criteria ·············································································52 16 May 2018 Astellas Page 2 of 122 Version 9.1 [JP] Incorporating Country-specific Non-Substantial Amendment 3 Sponsor: APGD ISN/Protocol 2215-CL-0301 EudraCT 2015-000140-42 - CONFIDENTIAL - 4 TREATMENT(S)··················································································53 4.1 Identification of Investigational Products ··················································53 4.1.1 ASP2215··················································································53 4.1.2 Comparative Drug(s)····································································54 4.2 Packaging and Labeling ······································································55 4.3 Study Drug Handling ·········································································55 4.4 Blinding ························································································56 4.5 Assignment and Allocation ··································································57 5 TREATMENTS AND EVALUATION························································57 5.1 Dosing and Administration of Study Drugs and Other Medications····················57 5.1.1 Dose/Dose Regimen and Administration Period ····································57 5.1.2 Interruption, Reduction or Escalation in Dose of the Study Drug ·················58 5.1.3 Previous and Concomitant Treatment (Medication and Nonmedication Therapy) ··················································································60 5.1.4 Resumption of Treatment After Hematopoietic Stem Cell Transplantation······61 5.1.5 Treatment Compliance··································································61 5.2 Demographics and Baseline Characteristics ···············································62 5.2.1 Demographics············································································62 5.2.2 Medical History··········································································62 5.2.3 Diagnosis of the Target Disease, Severity and Duration of Disease ··············62 5.2.4 FLT3 Mutation Status···································································62 5.2.5 Performance Status······································································63 5.3 Efficacy Assessment··········································································63 5.3.1 Response Definitions ···································································63 5.3.2 Survival Time, Duration and Other Efficacy Endpoints····························65 5.3.3 Bone Marrow Aspiration and/or Biopsy··············································66 5.3.4 Survival Status and Subsequent Antileukemic Treatments and Their Outcomes·················································································67 5.4 Safety Assessment ············································································67 5.4.1 Vital Signs················································································67 5.4.2 Adverse Events ··········································································68 5.4.3 Laboratory Assessments································································68 5.4.4 Physical Examination ···································································69 5.4.5 Electrocardiogram·······································································69 16 May 2018 Astellas Page 3 of 122 Version 9.1 [JP] Incorporating Country-specific Non-Substantial Amendment 3 Sponsor: APGD ISN/Protocol 2215-CL-0301 EudraCT 2015-000140-42 - CONFIDENTIAL - 5.4.6 Chest X-ray or Computed Tomography Scan········································70 5.4.7 Multigated Acquisition Scan or Echocardiogram ···································70 5.4.8 Ophthalmologic Exam ··································································70 5.5 Adverse Events and Other Safety Aspects ·················································70 5.5.1 Definition of Adverse Events ··························································70 5.5.2 Definition of Serious Adverse Events·················································71