Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Pociredir

Key Inclusion Criteria:

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

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

• Participants who meet at least one the following criteria:

1. ≥4 to 10 episodes of SCD pain crisis over 12 months, or ≥2 to 5 over 6 monthsprior to screening

2. ≥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 sequestrationiii. Priapism

3. ≥2 of the following events over the previous 12 months:i. ACS ii. Hepatic orsplenic sequestration iii. Priapism

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

5. SCD-related chronic kidney disease (CKD)

6. Meet medical criteria to receive (e.g., post-cerebrovascular accident) but arecontraindicated for chronic transfusions (e.g., alloimmunization, transfusionreactions)

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

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

• Per Investigator's recommendation, participants may continue crizanlizumab and/orL-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:

1. Absolute neutrophil count ≥ 1.5 × 10^9 per liter (/l)

2. Platelets ≥ 80 × 10^9/l

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

Key Exclusion Criteria:

• Sickle cell complication requiring care from a medical provider in hospital oremergency care setting in the 14 days prior to starting study drug.

• History of bone marrow transplant or human stem cell transplant or gene therapies.

• • Participants with a history of severe renal disease defined as estimatedglomerular filtration rate < 30 mL/min/1.73m^2. Participants on dialysis of any kindare excluded.

• Participants receiving regularly scheduled transfusions or therapeutic phlebotomies,or any participant who has been transfused within 60 days prior to initiating studydrug.

• Participant with active malignancy, or history of cancer (except for squamous cellskin cancer, basal cell skin cancer, and stage 0 cervical carcinoma in situ, with norecurrence for the last 5 years), or has an immediate family member with known orsuspected familial cancer syndrome. Known presence of a chromosomal abnormality orgenetic mutation that may put the participant at an increased risk ofmyelodysplastic syndrome (MDS) or acute myeloid leukemia (AML).

• Participant currently on HU, or have received HU, within 60 days prior to initiatingstudy drug.