Credit: National Institutes of Health

New research shows the efficacy and safety of hydroxyurea treatment for sickle cell anemia at four low-income sites in Africa, with no increase in clinically diagnosed infections.

Hydroxyurea is a drug taken once daily by mouth that works to reduce the complications of sickle cell anemia by encouraging the body to produce more fetal hemoglobin. This form of hemoglobin, normally made by babies in the womb, stops red blood cells from sickling.

While hydroxyurea is a recommended treatment in high-income countries, doctors have been cautious in low-income settings because it reduces the number of infection-fighting neutrophils and could therefore lead to an increased risk of infections where access to clinical services is limited.

The study, part of the Realizing Effectiveness Across Continents with Hydroxyurea (REACH) trial, showed that there was no increase in the incidence or severity of infections, including malaria, in children receiving hydroxyurea treatment.

Living with sickle cell

Sickle cell anemia is the most common and severe inherited blood disease in humans, with approximately 80% of cases occurring in sub-Saharan Africa. Around 550,000 children are born with sickle cell anemia every year. The disease results in complications such as pain, vulnerability to infections and chronic ill health.

Bacterial and viral infections, including life-threatening infections, are common complications of sickle cell anemia. In theory, treatment with hydroxyurea could worsen infections, including malaria, because it dampens the immune system; however, this has not been studied in detail previously.

Treatment of sickle cell anemia

The study, published today in The Lancet Haematology, was carried out at four sites in Africa: Angola, the Democratic Republic of the Congo, Kenya and Uganda. It involved the treatment of 606 children and young adults living with sickle cell anemia.

Recruitment of children ages 1 to 10 took place between 2014 and 2016, and patients have been followed every two to three months since then.

The children who participated in the multicenter trial began hydroxyurea treatment at a fixed dose for six months, after which their doses were increased to the maximum they could tolerate. During the trial, most infections were reported retrospectively, usually through clinical history alone rather than through real-time testing for infection.

The incidence of malarial and nonmalarial infections decreased with increasing hydroxyurea doses. The researchers found that the risk of infection dropped by 51% for malaria and 38% for nonmalarial infections.

REACH has been running for more than 10 years and has already shown that hydroxyurea therapy is both safe and highly effective in reducing most sickle cell–related complications. Through this extended analysis, the latest research shows that hydroxyurea treatment does not increase the risk of serious infections in low-income settings in Africa.

Study lead Tom Williams, a professor at Imperial College London's Institute of Global Health Innovation, said, "Many doctors are cautious about using hydroxyurea because they are worried that it will increase the risks of severe or fatal infections. This is particularly true in low-income settings with limited medical resources.

"In this huge study covering more than 5,000 patient-years of follow-up, we found no increase in illness or death from infections, even when hydroxyurea is used at the maximum tolerated dose."

Senior author Russell Ware, a professor at Cincinnati Children's Hospital Medical Center, said, "These findings provide long-awaited data regarding the long-term safety of hydroxyurea used at the maximum tolerated dose in low-income settings. Over 10 years of treatment, the incidence and severity of infections did not increase and, in many cases, decreased."

The study authors recommend that children with sickle cell anemia living in low-resource settings receive treatment with hydroxyurea at the maximum tolerated dose.

Williams added, "The results of this study provide strong reassurance that the incidence and severity of infections are not increased with long-term or maximum-dose hydroxyurea treatment. These findings support the wider use of hydroxyurea as standard care."

More information: Incidence of clinically diagnosed infections in children with sickle cell anaemia treated with oral hydroxyurea in Angola, DR Congo, Kenya, and Uganda: a cohort study from the REACH trial, The Lancet Haematology (2026).

Provided by Imperial College London

Source: MedicalXpress

Original article: https://medicalxpress.com/news/2026-10-children-sickle-cell-safely-hydroxyurea.html