Inclusion Criteria:  Age 16 years or older; participants age 16 or 17 years must physically have completed puberty; Documented diagnosis of sickle cell disease (SCD) (HbSS, HbSC, HbS/beta-0thalassemia, HbS/ beta plus thalassemia, or other sickle cell syndrome variants); At least 2 sickle cell pain crises (SCPCs) and no more than 10 SCPCs in the past 12 months; Hemoglobin at least 5.5 and 10.5 gram per deciliter (g/dL) at the most; If taking hydroxyurea, the hydroxyurea dose must be stable for at least 90 days before starting study drug; Women capable of becoming pregnant and men with partners who are women that are capable of becoming pregnant must agree to use 2 forms of contraception.  Exclusion Criteria:  Pregnant or breastfeeding; Receiving regularly scheduled transfusions; Hepatobiliary disorders including but not limited to significant liver disease or gallbladder disease; Severe kidney disease; Prior exposure to gene therapy or prior bone marrow or stem cell transplantation; Currently receiving treatment for SCD (eg, voxelotor, crizanlizumab, L-glutamine), with the exception of hydroxyurea. The last dose of such therapies must have been administered at least 90 days before starting study drug; Currently receiving treatment with hematopoietic stimulating agents; the last dose must have been administered at least 90 days before starting study drug; Received treatment on another investigational trial within 90 days prior to start of study drug or plans to participate in another investigational drug trial; Taking medications that are strong inhibitors of CYP3A4/5 or strong inducers of CYP3A4 that cannot be stopped in an acceptable timeframe before starting study drug (timeframe will be discussed with your doctor).