The reversible P2Y12 inhibitor ticagrelor was compared to a placebo in phase 3 HESTIA3 research to see how well it prevented vaso-occlusive crises in young sickle cell disease (SCD) patients.
Weight-based dosages of ticagrelor or a corresponding placebo were randomly allocated 1:1 to patients between the ages of 2 and 17 years. The main outcome was the rate of vaso-occlusive crises, which is a measure of painful crises and/or acute chest syndrome (ACS). The number and length of painful crises, the number of ACS episodes, and the number of vaso-occlusive crises necessitating hospitalization or ER visits were important secondary end objectives. One of the exploratory end objectives was how ticagrelor affected platelet activation.
A total of 193 patients were randomly assigned among 51 locations in 16 different countries (ticagrelor, n = 101; placebo, n = 92). Four months before it was supposed to end, the trial was stopped for lack of effectiveness. The median number of days exposed to ticagrelor was 296.5. The estimated annual incidence of vaso-occlusive crises was 2.74 in the ticagrelor group and 2.60 in the placebo group (rate ratio, 1.06; 95% CI, 0.75-1.50; P =.7597), indicating that the primary end aim was not achieved. For secondary end objectives, there was no proof that ticagrelor was more effective than a placebo. Predose and 2-hour postdose platelet inhibition medians for ticagrelor at 6 months were 34.9% and 55.7%, respectively. At least one bleeding incident occurred in 9 (9%) of the ticagrelor patients and 8 (9%) placebo participants.
In the juvenile SCD patients, there was no difference in the number of vaso-occlusive crises between ticagrelor and placebo.