Prasugrel Versus Placebo in Adult Sickle Cell Disease

Study Overview
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Brief Summary
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The purpose of this trial is to assess the safety of Prasugrel in adult patients with sickle cell disease (SCD) by monitoring the rate and severity of hemorrhagic events requiring medical intervention compared to placebo for 30 days.

Official Title
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A Double-Blind, Randomized, Multicenter Study of Prasugrel Compared to Placebo in Adult Patients With Sickle Cell Disease

Conditions
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Sickle Cell Anemia

Intervention / Treatment
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* Drug: Prasugrel
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults with Sickle Cell Disease (SCD). Are greater than or equal to 50 kilograms (kg) at time of screening. Are not currently being treated with an investigational drug (use of hydroxyurea, which is not an investigational drug, is permitted under this protocol if the patient has been on a stable dose for at least 30 days prior to randomization and has no signs of hematological toxicity at screening. Agree to use a reliable method of birth control during the study or are women not of child-bearing potential due to surgical sterilization (hysterectomy or bilateral oophorectomy or tubal ligation) or menopause. Exclusion Criteria: Acute painful crisis (requiring medical attention) within 30 days prior to screening. Have a concomitant medical illness (for example, terminal malignancy) that, in the opinion of the investigator, is associated with reduced survival over the expected treatment period (approximately 30 days). Severe hepatic dysfunction (cirrhosis, portal hypertension, or aspartate aminotransferase (AST) greater than or equal to 3x upper limit of normal [ULN]). Renal dysfunction requiring chronic dialysis. Contraindication for antiplatelet therapy. History of intolerance or allergy to approved thienopyridines. Have signs or symptoms of an infection. Hypertension (systolic blood pressure >180 millimeters of mercury (mm Hg) or diastolic blood pressure >110 mm Hg) at the time of screening or randomization. Hematocrit <18%. Any history of bleeding diathesis, bleeding requiring in-hospital treatment, or papillary necrosis. Active internal bleeding. History of spontaneous gastrointestinal (GI) bleeding requiring in-hospital treatment. Gross hematuria. Microhematuria, common in SCD patients, is not a contraindication. Platelet count <100,000 per cubic millimeter. Any history of intraocular hemorrhage. Prior history of transient ischemic attack (TIA), ischemic stroke, hemorrhagic stroke, or other intracranial hemorrhage. Known history of intracranial neoplasm, arteriovenous malformation, or aneurysm. Have clinical findings, in the judgment of the investigator, associated with an increased risk of bleeding. Have an international normalized ratio (INR) of greater than 1.5 at screening. Have had recent surgery (within 30 days prior to screening) or are scheduled to undergo surgery within the next 60 days. History of menorrhagia requiring medical intervention.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 7.5 mg Prasugrel<br>Participants were to receive 7.5 milligrams (mg) of prasugrel orally, once daily if they weighed ≥60 kilograms (kg) and if pharmacodynamic (PD) measures indicated that the 5-mg prasugrel dose did not produce a steady-state PD response equivalent to inhibition of platelet activation (IPA) ≥25%. Because these criteria were not met, no participants received 7.5 mg of prasugrel. | Drug: Prasugrel<br>* Administered orally, once daily for 30 days.<br>* Other names: CS747;|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br>* Administered orally, once daily for 30 days.<br>|
| Experimental: 5 mg Prasugrel<br> | Drug: Prasugrel<br>* Administered orally, once daily for 30 days.<br>* Other names: CS747;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants With Hemorrhagic Events Requiring Medical Intervention During the Treatment Duration | A hemorrhagic event requiring medical intervention. Medical intervention was defined as any medical attention resulting in therapy or further investigation during the 30-day treatment duration. | Baseline through 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants With Hemorrhagic Treatment-Emergent Adverse Events (TEAEs) During the Treatment Duration | TEAEs were defined as AEs that occurred or worsened after receiving the study drug. | Baseline through 30 days | 
| Percentage of Days With Pain Related to Sickle Cell Disease (SCD) During the Treatment Duration | Participants recorded the intensity of pain due to SCD each day in the daily pain diaries. A scale of 0 to 9 was used, with 0 indicating no pain, and 9 indicating unbearable pain. A response range of 1 to 9 indicated the participant experienced pain due to SCD, whereas a response of 0 indicated participant did not experience pain due to SCD. The percentage of days with pain (pain rate) was calculated as follows: Pain rate = 100*(Total number of days with pain/number of daily pain diaries completed). Number of daily pain diaries completed was number of nonmissing pain intensity responses. | Baseline through 30 days | 
| Percentage of Participants With Pain Events Related to Sickle Cell Disease (SCD) Requiring Medical Attention During the Treatment Duration | Pain requiring medical attention was defined 2 ways: (1) if the participant attended an unplanned doctor's appointment or clinic visit, visited the emergency room, or was admitted to hospital due to sickle cell pain, or (2) if the participant experienced a vaso-occlusive crisis (VOC), acute chest syndrome, or hepatic sequestration at least once during the treatment period. | Baseline through 30 days | 
| Platelet Reactivity Index (PRI) Measured by Vasodilator-Associated Stimulated Phosphoprotein (VASP) at 30 Days | PRI was calculated by VASP phosphorylation assay using flow cytometry. The PRI indicates the level of P2Y12 inhibition. A low PRI reflects strong inhibition of P2Y12, whereas a high PRI reflects weak/absent inhibition of P2Y12. The Least Squares (LS) Mean values were calculated from a mixed-effects model repeated measures (MMRM) analysis with baseline measurement, stratification variable sickle cell genotype, treatment, time, and time*treatment interaction as fixed effects, and participant as a random effect in the model. | 30 days | 
| Intensity of Pain Related to Sickle Cell Disease (SCD) During the Treatment Duration | Participants recorded intensity of pain due to SCD each day in daily pain diaries using a pain scale. A scale of 0 to 9 was used, with 0=no pain and 9=unbearable pain. A response range of 1 to 9 indicated participant experienced pain due to SCD, whereas a response of 0 indicated participant did not experience pain due to SCD. Pain intensity was the average of a participant's pain ratings. Average pain intensity=(Sum of all nonmissing pain intensity responses/number of daily pain diaries completed). Number of daily pain diaries completed is number of nonmissing pain intensity responses. | Baseline through 30 days | 
| P2Y12 Reaction Units (PRU) as Measured by Accumetrics VerifyNow® P2Y12 (VN P2Y12) at 30 Days | PRU represents the rate and extent of adenosine (ADP)-stimulated platelet aggregation. The VN P2Y12 assay is a point-of-care device that measures platelet aggregation with single-use, disposable cartridges. A low PRU reflects stronger inhibition of P2Y12, whereas a high PRU reflects weaker inhibition of P2Y12. The Least Squares Mean values were calculated from a mixed-effects model repeated measures analysis with baseline measurement, stratification variable sickle cell genotype, treatment, time, and time*treatment interaction as fixed effects, and participant as a random effect in the model. | 30 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sickle Cell Disease, Sickle Cell Anemia, Adult