A longitudinal study by a team of investigators from the Departments of Medicine and Epidemiology at the University of Pittsburgh in Pennsylvania provides insight into the extent to which clinicians can expect to improve chronic anemia in sickle cell disease (SCD) with hydroxyurea alone. They published their findings in Blood Red Cells & Iron.

In written remarks forwarded to Heme Today, the senior author of the published study, Julia Xu, MD, MScGH, stated, “we found that hydroxyurea, the standard of care treatment for SCD, produced only modest improvements in anemia.”

The study cohort included 82 patients with SCD who received hydroxyurea and were subsequently monitored for hemoglobin response. At one month following the start of therapy, the investigators found that the patients’ average hemoglobin level had increased by 0.4 g/dL from baseline and that 26.3% of the cohort had achieved a hemoglobin increase of 1 g/dL or greater.

However, at three months following the start of hydroxyurea, the increase in patients’ average hemoglobin level from baseline was reduced to 0.3 g/dL. At that point, the percentage of the cohort with a hemoglobin increase of 1 g/dL or greater was also smaller at 21.6%.

“These findings highlight that while hydroxyurea remains an essential treatment, it is often insufficient on its own to address the substantial burden of chronic anemia in SCD,” wrote Dr. Xu.

In their study, the investigators also applied univariate linear regression and multivariate linear mixed effects models to identify patient baseline factors associated with response to hydroxyurea. Their multivariate model determined that younger patient age and lower baseline hemoglobin were each independently associated with greater increase of hemoglobin response to hydroxyurea. Male sex and a less severe SCD genotype were also associated with a greater increase in the model, though this did not appear in the unadjusted analyses.

Based on these analysis model findings, the investigators wrote in Blood Red Cells & Iron that “[o]ur study also demonstrates the feasibility of using baseline data to guide therapy selection and create individualized treatment plans for patients with SCD.”