A Single Arm, Open Label, Phase 1/2 Study to Evaluate the Pharmacokinetics and Safety of Etavopivat in Pediatric Patients With Sickle Cell Disease
This study is being done to learn about etavopivat, a once a day medicine taken by mouth in adolescents with sickle cell disease. The main goals are to study safety and how long etavopivat stays in the bloodstream, while also studying if there are benefits from taking etavopivat. Eligible participants who enter the study will start a 96-week treatment period. At the end of the 96 weeks, participants will have an end of study visit that occurs 4 weeks later. The participants will receive etavopivat every day throughout the treatment period.
• Type of Participant and Disease Characteristics
‣ Patient has confirmed diagnosis of SCD
‣ • Documentation of SCD genotype (HbSS, HbSβ0-thalassemia or other sickle cell syndrome variants) based on prior history of laboratory testing. Molecular genotyping is not required. SCD genotype may be determined from the results of Hb electrophoresis, high-performance liquid chromatography (HPLC), or similar testing. Note that Hb electrophoresis is performed by the local laboratory at Screening.
⁃ Hemoglobin greater than or equal to (≥) 5.5 and less than (\<) 10.5 grams per deciliter (g/dL)
⁃ Adolescent patients with severe SCD, as defined by at least 1 of the following:
• Two or more VOCs in the past 12 months, defined as a previously documented episode of acute chest syndrome (ACS) or acute painful crisis (for which there was no explanation other than VOC) which required prescription or healthcare professional-instructed use of analgesics for moderate to severe pain
∙ Hospitalization for any SCD-related complication in the last 12 months
∙ Proteinuria, defined as an albumin:creatinine ratio (ACR) \> 100 milligrams per gram (mg/g) on 2 measures (separated by ≥ 1 month) as an indicator of early renal disease
∙ History of a conditional TCD in the last 12 months, but not currently being treated with chronic transfusion therapy. Conditional TCD is defined as a TAMMV of 170-199 centimeters per second (cm/s) by TCD or 155-184 cm/s by imaging TCD (TCDi).
⁃ For participants taking hydroxyurea (HU), the dose of HU (mg/kg) must be stable (no more than a 20% change in dosing) for at least 90 days prior to start of study treatment with no anticipated need for dose adjustments during the study, in the opinion of the Investigator
⁃ Patients on crizanlizumab or L-glutamine treatment at the time of consent may be eligible if they:
• Have been on a stable dose for ≥ 12 months at the time of consent (ie, no changes to the dose except for changes to weight or for safety reasons)
∙ For patients on crizanlizumab, have been ≥ 80% compliant with the planned regimen during the 12 months prior to the time of consent