| E.1 Medical condition or disease under investigation | 
| E.1.1 | Medical condition(s) being investigated  | 
| Myelofibrosis (MF) is classified as a myeloproliferative neoplasm (MPN) | 
 
 
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| E.1.1.1 | Medical condition in easily understood language  | 
 | 
| E.1.1.2 | Therapeutic area  | Diseases [C] - Cancer [C04] | 
| MedDRA Classification | 
| E.1.2 Medical condition or disease under investigation | 
| E.1.2 | Version  | 18.0 | 
 
| E.1.2 | Level  | PT | 
 
| E.1.2 | Classification code  | 10028537 | 
 
| E.1.2 | Term  | Myelofibrosis | 
 
| E.1.2 | System Organ Class  | 10029104 - Neoplasms benign, malignant and unspecified (incl cysts and polyps) | 
 
 
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| E.1.3 | Condition being studied is a rare disease  |  No  | 
| E.2 Objective of the trial | 
| E.2.1 | Main objective of the trial  | 
| The primary objectives of this study are to evaluate spleen response rate and symptom response rate of 2 dose regimens of imetelstat (9.4 mg/kg and 4.7 mg/kg imetelstat given intravenous [IV] every 3 weeks) in subjects with intermediate-2 or high-risk MF who are relapsed after or refractory to JAK inhibitor treatment. | 
 
 
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| E.2.2 | Secondary objectives of the trial  | 
The secondary objectives are:
 - To assess the safety of imetelstat
 - To assess CR or PR, CI, spleen response, symptoms response, and anemia response per modified 2013 IWG-MRT criteria, duration of responses, and overall survival (OS).
 - To evaluate the pharmacokinetics of imetelstat
 - To evaluate the PK/response and pharmacodynamic (PD) relationships with factors that include hemoglobin concentration, spleen size, and platelet count
 - To evaluate the immunogenicity of imetelstat
 - To assess the effect of treatment on PROs (patient-reported outcomes) | 
 
 
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| E.2.3 | Trial contains a sub-study  |  No  | 
| E.3 | Principal inclusion criteria  | 
- Diagnosis of PMF according to the revised WHO criteria; or PET-MF or PPV-MF according to the IWG-MRT criteria
 - DIPSS intermediate-2 or high risk MF
 - Measurable splenomegaly prior to study entry as demonstrated by palpable spleen measuring greater than or equal to (>=) 5 cm below the left costal margin OR spleen volume of >= 450 cm^3 measured by MRI 
 - Active symptoms of MF as demonstrated by a symptom score of at least 5 points (on a 0 to 10 scale) on at least one of the symptoms or a score of 3 or greater on at least 2 of the symptoms
 - Documented progressive disease during or after JAK inhibitor therapy
 - ECOG performance status 0, 1 or 2 | 
 
 
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| E.4 | Principal exclusion criteria | 
- Peripheral blood blast count of >= 10% or bone marrow blast count of >=10% 
 - Prior treatment with imetelstat
 - Major surgery within 4 weeks of randomization
 - Past or present active hepatitis infection of any type or known acute or chronic liver disease including cirrhosis
 - Prior history of hematopoietic stem cell transplant | 
 
 
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| E.5 End points | 
| E.5.1 | Primary end point(s) | 
- Percentage of participants who Achieve Greater than or equal to 35 percent (%) Reduction in Spleen Volume at Week 24 (Spleen response rate is defined as the percentage of participants who achieve >= 35% reduction in spleen volume at Week 24 from baseline as measured by imaging scans.)
 
 - Percentage of participants who Achieve Greater than or equal to 50 percent (%) Reduction in Total Symptom Score at Week 24 (Symptom response rate is defined as the percentage of participants who achieve >= 50% reduction in TSS at Week 24 from baseline as measured by the modified Myelofibrosis Symptom Assessment Form (MFSAF) version 2.0 diary.) | 
 
 
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| E.5.1.1 | Timepoint(s) of evaluation of this end point | 
 | 
| E.5.2 | Secondary end point(s) | 
- Complete remission (CR) or partial remission (PR) per modified 2013 IWG-MRT criteria
 - Clinical improvement (CI) per modified 2013 IWG-MRT criteria
 - Number of Participants with Responses per 2013 IWG-MRT (Spleen response, symptoms response, and anemia response per modified 2013 IWG-MRT will be assessed.)
 - Duration of Treatment Response and Remission (Duration of spleen response, duration of symptoms response, duration of CR or PR, duration of CI, and duration of anemia response will be reported.)
 - Overall Survival (Overall survival is defined as the time from randomization to date of death from any cause.)
 - European Organization for Research and treatment of Cancer (EORTC) QLQ-C30 Score
 - EuroQol-EQ-5D (EQ-5D-5L) Health Questionnaire Score
 - Brief Pain Inventory- Short Form (BPI) Score
 - Patient’s Global Impression of Change (PGIC)
 - Number of Participants with Adverse Events (AEs)
 - Maximum Plasma Concentration (Cmax) of Imetelstat (The Cmax is the maximum observed plasma concentration.)
 - Time to Reach Maximum Concentration (tmax) of Imetelstat (The tmax is time to reach the maximum observed plasma concentration.)
 - Area Under the Plasma Concentration-Time Curve From Time Zero to 24 Hours (AUC [0-24h]) of Imetelstat (AUC 0-24h is area under the plasma concentration-time curve from time 0 to 24 hours postdose.)
 - Elimination Half-Life (t [1/2] Lambda) of Imetelstat (Elimination half-life (t [1/2] Lambda) is associated with the terminal slope (lambda [z]) of the semi logarithmic drug concentration-time curve, calculated as 0.693/lambda(z).) | 
 
 
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| E.5.2.1 | Timepoint(s) of evaluation of this end point | 
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| E.6 and E.7 Scope of the trial | 
| E.6 | Scope of the trial | 
| E.6.1 | Diagnosis |  No  | 
| E.6.2 | Prophylaxis |  No  | 
| E.6.3 | Therapy |  No  | 
| E.6.4 | Safety |  Yes  | 
| E.6.5 | Efficacy |  Yes  | 
| E.6.6 | Pharmacokinetic |  Yes  | 
| E.6.7 | Pharmacodynamic |  Yes  | 
| E.6.8 | Bioequivalence |  No  | 
| E.6.9 | Dose response |  No  | 
| E.6.10 | Pharmacogenetic |  No  | 
| E.6.11 | Pharmacogenomic |  No  | 
| E.6.12 | Pharmacoeconomic |  No  | 
| E.6.13 | Others |  Yes  | 
| E.6.13.1 | Other scope of the trial description | 
Immunogenicity
 Biomarker
 Patient Reported Outcome | 
 
 
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| E.7 | Trial type and phase | 
| E.7.1 | Human pharmacology (Phase I) |  No  | 
| E.7.1.1 | First administration to humans |  No  | 
| E.7.1.2 | Bioequivalence study |  No  | 
| E.7.1.3 | Other |  No  | 
| E.7.1.3.1 | Other trial type description |  | 
| E.7.2 | Therapeutic exploratory (Phase II) |  Yes  | 
| E.7.3 | Therapeutic confirmatory (Phase III) |  No  | 
| E.7.4 | Therapeutic use (Phase IV) |  No  | 
| E.8 Design of the trial | 
| E.8.1 | Controlled |  No  | 
| E.8.1.1 | Randomised |  Yes  | 
| E.8.1.2 | Open |  No  | 
| E.8.1.3 | Single blind |  Yes  | 
| E.8.1.4 | Double blind  |  No  | 
| E.8.1.5 | Parallel group |  Yes  | 
| E.8.1.6 | Cross over  |  No  | 
| E.8.1.7 | Other |  No  | 
| E.8.2 |  Comparator of controlled trial | 
| E.8.2.1 | Other medicinal product(s) |  No  | 
| E.8.2.2 | Placebo  |  No  | 
| E.8.2.3 | Other |  No  | 
| E.8.2.4 | Number of treatment arms in the trial | 2 | 
| E.8.3 | 
                                The trial involves single site in the Member State concerned
                             |  No  | 
| E.8.4 |  The trial involves multiple sites in the Member State concerned  |  Yes  | 
| E.8.4.1 | Number of sites anticipated in Member State concerned | 6 | 
| E.8.5 | The trial involves multiple Member States |  Yes  | 
| E.8.5.1 | Number of sites anticipated in the EEA | 47 | 
| E.8.6 Trial involving sites outside the EEA | 
| E.8.6.1 | Trial being conducted both within and outside the EEA |  Yes  | 
| E.8.6.2 | Trial being conducted completely outside of the EEA |  No  | 
| E.8.6.3 | If E.8.6.1 or E.8.6.2 are Yes, specify the regions in which trial sites are planned | 
| Belgium | 
 
| Canada | 
 
| France | 
 
| Germany | 
 
| Israel | 
 
| Italy | 
 
| Korea, Republic of | 
 
| Spain | 
 
| Switzerland | 
 
| Taiwan | 
 
| United Kingdom | 
 
| United States | 
 
 
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| E.8.7 | Trial has a data monitoring committee |  No  | 
| E.8.8 | 
                        Definition of the end of the trial and justification where it is not the last
                        visit of the last subject undergoing the trial
                     | 
| The study is considered completed 18 months after the last subject is enrolled or anytime the sponsor terminates the study, whichever comes first. | 
 
 
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| E.8.9 Initial estimate of the duration of the trial | 
| E.8.9.1 | In the Member State concerned years | 2 | 
| E.8.9.1 | In the Member State concerned months | 8 | 
| E.8.9.1 | In the Member State concerned days | 9 | 
| E.8.9.2 | In all countries concerned by the trial years | 2 | 
| E.8.9.2 | In all countries concerned by the trial months | 8 | 
| E.8.9.2 | In all countries concerned by the trial days | 9 |