• Participant is 18 to 65 years of age, inclusive at the time informed consent is obtained.

• Documented SCD at the time of screening (S/S, S/β0, S/β+, and S/C only) as confirmed through review of medical records or HPLC.

• Participants who meet at least one the following criteria:

‣ ≥4 to 10 episodes of SCD pain crisis over 12 months, or ≥2 to 5 over 6 months prior to screening

⁃ ≥2 episodes of SCD pain crisis plus at least one of the following over previous 12 months: i) Acute chest syndrome (ACS) ii. Hepatic or splenic sequestration iii. Priapism

⁃ ≥2 of the following events over the previous 12 months:i. ACS ii. Hepatic or splenic sequestration iii. Priapism

⁃ Tricuspid regurgitant jet velocity (TRV) ≥ 3.0 meter/second(m/s) OR TRV ≥ 2.5 m/s + N-terminal pro b-type natriuretic peptide (NT-proBNP) plasma level ≥ 160 picogram per milliliter; OR documented ongoing pulmonary hypertension diagnosed from previous echocardiogram or right-sided heart catheterization with mean pulmonary artery pressure \> 25 millimeter of mercury;

⁃ SCD-related chronic kidney disease (CKD)

⁃ Meet medical criteria to receive (e.g., post-cerebrovascular accident) but are contraindicated for chronic transfusions (e.g., alloimmunization, transfusion reactions)

• Previous experience with Hydroxyurea (HU) but have shown to be unresponsive and/or intolerant or ineligible AND

• Previous experience with a stable dose of voxelotor, crizanlizumab, and/ or L-glutamine but have shown to be unresponsive and/or intolerant or ineligible

• Per Investigator's recommendation, participants may continue crizanlizumab and/or L-glutamine but must be on a stable dose for at least 6 months

• HbF ≤ 20% of total Hb

• Total Hb ≥ 5.5 g/dL and ≤ 12 g/dl (males) or ≤ 10.6 g/dl (females) at screening.

• Participant must meet both of the following laboratory values at screening:

‣ Absolute neutrophil count ≥ 1.5 × 10\^9 per liter (/l)

⁃ Platelets ≥ 80 × 10\^9/l

⁃ Absolute reticulocyte count at screening ≥ 100 x 10\^9/l.