Clinical Research Directory

Investigating the Mechanistic Effects of Mitapivat in Subjects With Sickle Cell Disease

Background: Sickle cell disease (SCD) is an inherited blood disorder. The disease affects the ability of red blood cells to carry oxygen; this in turn can injure organs including the heart, lungs, and kidneys. SCD can lead to serious illness and death. Treatments such as bone marrow transplants and gene therapies can cure SCD, but they are not widely available. Current drug treatments for SCD are not always effective. This natural history study will examine how a study drug (mitapivat) affects red blood cells in people with SCD. Objective: To learn how mitapivat affects red blood cells in people with SCD. Eligibility: People with SCD who are enrolled in the parent study, NIH protocol IRB001565-H. Design: Procedures for this study will be done during visits already scheduled for the parent study. Participants will have additional blood drawn during study visits. The additional amount will be about 3.5 teaspoons. Participants will undergo a test called near infrared spectroscopy (NIRS) up to 9 times. Probes will be placed on their skin. A blood pressure cuff will be placed on their arm. The cuff will be filled with air for up to 5 minutes and then released. Participants may be asked to breathe at a certain rate or to hold their breath during these measurements. NIRS measures oxygen levels, blood flow, and the makeup of skin and muscle. Researchers will draw additional information for this study from participants medical records.

Epidemiology of Silent and Overt Strokes in Sickle Cell Disease

Sickle Cell Disease (SCD) is a rare disease occurring in an estimated 100,000 individuals, often poor and underserved, in the US. Silent and overt strokes contribute significantly to morbidity in adults with SCD, resulting in functional impairment, challenges with school and job performance, and premature death. Five NIH-funded randomized controlled trials have identified therapies to prevent silent and overt strokes in children with SCD, including monthly blood transfusion therapy (for preventing initial and recurrent strokes) and hydroxyurea (for preventing initial strokes). Despite the observation that at least 99% of children with SCD in high-income countries reach adulthood, and approximately 60% of adults will experience one or more strokes (\~50% with silent strokes and \~10% with overt strokes), no stroke trials have established therapeutic approaches for adults with SCD. For adults with SCD, inadequate evidence-based guidelines exist for secondary stroke prevention strategies. Applying stroke prevention strategies in children may not be effective for stroke prevention in adults with SCD, particularly given the high rate of co-morbidities. Identifying subgroups of adults with SCD and higher incidence coupled with the contribution of established stroke risk factors in the general population (smoking, diabetes, obesity, renal disease) will provide the requisite data required for the first-ever phase III clinical trials focused on secondary stroke prevention in adults.

Autologous Testicular Tissue Transplantation

Freezing testicular tissue of prepubertal boys is a method for preserving spermatogonial stem cells (SSCs) in case of imminent gonadotoxic treatment during childhood. In case of total azoospermia in adulthood and presence of a childwish, the investigators intend to perform the first in men autologous testicular tissue transplantation to restore fertility.