• Documented SCD at the time of screening, as confirmed through review of medical records or high-performance liquid chromatography (HPLC)/electrophoresis. - Participant, who if female and of childbearing potential, agrees to use 2 effective methods of contraception, one which must be highly effective, or practice abstinence starting at the time of the ICF signing to 90 days after the last dose of study drug, and, who if male, agrees to use condoms or practice abstinence from the time of ICF signing to 90 days after the last dose of study drug. - Total Hb ≥ 5.5 grams/deciliter (g/dL) and ≤ 12 g/dL (males) or ≤ 10.6 g/dL (females) at screening - Participant must meet all of the following laboratory values at screening: 1. Absolute neutrophil count ≥ 1.5 × 10^9/L (cells/liter) 2. Platelets ≥ 80 × 10^9/L 3. Absolute reticulocyte count > 100 × 10^9/L - Participants who meet all other inclusion and

for this study, and per Investigator's recommendation may continue crizanlizumab, and/or L-glutamine, must be on a stable dose for at least 6 months Exclusion Criteria: - Participant has had any of the following in the 14 days prior to dosing: major surgery, serious illness, infection (clinically significant bacterial, fungal, parasitic or viral infection which requires therapy), fever not resolved within 3 days and requiring treatment, or sickle cell complication requiring care from a medical provider in a hospital or emergency care setting. - Participant has a serious medical condition other than SCD that, in the opinion of the Investigator, would preclude them from participating in the study, or which is unresolved or requiring ongoing treatment. - Elective surgery planned for the time period of the study. - Use of any medications that induce or inhibit cytochrome P450 (CYP) 3A4, inhibit P-glycoprotein, breast cancer resistance protein, or multidrug and toxin extrusion protein 2-K, or are substrates of CYP2B6 within 14 days prior to first dose of study drug or anticipated need for any of these medications during the study. - Participation in any other study with an investigational agent within the past 30 days or 5 half-lives, whichever is longer, prior to the first dose of study drug. - For Fed Cohort Only: Participant has special dietary restrictions or inability to consume standard meals as required in the study. Note: Other protocol specified criteria may apply.