A hemorrhagic event requiring medical intervention. Medical intervention was defined as any medical attention resulting in therapy or further investigation during the 30-day treatment duration.

Safety population: All randomized participants who took at least 1 dose of study medication. Participants were analyzed according to the treatment they actually received.

TEAEs were defined as AEs that occurred or worsened after receiving the study drug.

Safety population: All randomized participants who took at least 1 dose of study medication. Participants were analyzed according to the treatment they actually received.

Participants recorded the intensity of pain due to SCD each day in the daily pain diaries. A scale of 0 to 9 was used, with 0 indicating no pain, and 9 indicating unbearable pain. A response range of 1 to 9 indicated the participant experienced pain due to SCD, whereas a response of 0 indicated participant did not experience pain due to SCD. The percentage of days with pain (pain rate) was calculated as follows: Pain rate = 100*(Total number of days with pain/number of daily pain diaries completed). Number of daily pain diaries completed was number of nonmissing pain intensity responses.

Intent to treat (ITT) population consisted of all randomized participants. Participants were analyzed according to the treatment they were randomized to. The analysis was performed in the ITT population who recorded pain intensity in at least 1 daily pain diary.

Pain requiring medical attention was defined 2 ways: (1) if the participant attended an unplanned doctor's appointment or clinic visit, visited the emergency room, or was admitted to hospital due to sickle cell pain, or (2) if the participant experienced a vaso-occlusive crisis (VOC), acute chest syndrome, or hepatic sequestration at least once during the treatment period.

Intent to treat (ITT) population consisted of all randomized participants. Participants were analyzed according to the treatment they were randomized to. The analysis was performed in the ITT population who completed at least 1 page of the daily pain diary or with pain endpoint case report form (CRF) data available.

PRI was calculated by VASP phosphorylation assay using flow cytometry. The PRI indicates the level of P2Y12 inhibition. A low PRI reflects strong inhibition of P2Y12, whereas a high PRI reflects weak/absent inhibition of P2Y12. The Least Squares (LS) Mean values were calculated from a mixed-effects model repeated measures (MMRM) analysis with baseline measurement, stratification variable sickle cell genotype, treatment, time, and time*treatment interaction as fixed effects, and participant as a random effect in the model.

All randomized participants who took at least 1 dose of study medication. Participants were analyzed according to the treatment they actually received. The analysis was performed in the safety population who had both baseline and 30-day PRI measurements and a non-missing genotype.

Participants recorded intensity of pain due to SCD each day in daily pain diaries using a pain scale. A scale of 0 to 9 was used, with 0=no pain and 9=unbearable pain. A response range of 1 to 9 indicated participant experienced pain due to SCD, whereas a response of 0 indicated participant did not experience pain due to SCD. Pain intensity was the average of a participant's pain ratings. Average pain intensity=(Sum of all nonmissing pain intensity responses/number of daily pain diaries completed). Number of daily pain diaries completed is number of nonmissing pain intensity responses.

Intent to treat (ITT) population consisted of all randomized participants. Participants were analyzed according to the treatment they were randomized to. The analysis was performed in the ITT population who had recorded the pain intensity in at least 1 daily pain diary.

PRU represents the rate and extent of adenosine (ADP)-stimulated platelet aggregation. The VN P2Y12 assay is a point-of-care device that measures platelet aggregation with single-use, disposable cartridges. A low PRU reflects stronger inhibition of P2Y12, whereas a high PRU reflects weaker inhibition of P2Y12. The Least Squares Mean values were calculated from a mixed-effects model repeated measures analysis with baseline measurement, stratification variable sickle cell genotype, treatment, time, and time*treatment interaction as fixed effects, and participant as a random effect in the model.

Safety population: All randomized participants who took at least 1 dose of study medication. Participants were analyzed according to the treatment they actually received. The analysis was performed in the safety population who had both baseline and 30-day PRU measurements and a non-missing genotype.