Real-world effectiveness of voxelotor in individuals with sickle cell disease and history of red blood cell transfusions

Abstract Objectives This non-interventional, real-world study aimed to evaluate the effect of voxelotor on red blood cell (RBC) transfusion burden in individuals with sickle cell disease (SCD) 12 years of age and older in the US, who have a history of RBC transfusions. Methods The study population included patients with a new prescription claim for voxelotor (no use 365 days prior) in the exposed group, and the control group included matched individuals with SCD who did not have a prescription claim for voxelotor during the study period. Propensity score (PS) matching was used to balance baseline confounders between the two groups. Results The voxelotor group and non-voxelotor group consisted of 164 and 289 patients, respectively. Patients in the voxelotor group had 5.26 RBC transfusions per patient per year (PPPY) in baseline and 3.39 RBC transfusions PPPY in follow-up; a change of -1.87 RBC transfusions PPPY, compared to patients in the non-voxelotor group who had 5.54 RBC transfusions PPPY in baseline and 4.89 RBC transfusions PPPY in follow-up; a change of -0.64 RBC transfusions PPPY. The adjusted difference in the rate change was 1.31 RBC transfusions PPPY (p < 0.001). Conclusion In individuals with SCD and a history of RBC transfusions, voxelotor led to a statistically significant reduction in RBC transfusions PPPY compared to matched controls in this real-world study using medical claims data.