[Treatment by hydroxyurea for adult patients with sickle cell disease: French guidelines 2026]

To update French recommendations for hydroxyurea (HU) prescription in adult patients with sickle cell disease.

Literature synthesis and expert recommendations.

HU is the first-line disease-modifying treatment for patients with HbSS and HbS/β0-thalassemia. Its efficacy has been demonstrated in reducing vaso-occlusive crises, acute chest syndrome, hospitalizations, and transfusion requirements, as well as in improving survival. Its indications are broad and extend beyond the restrictive scope of the current marketing authorization. Early initiation, progressive dose adjustment, and regular monitoring are key to treatment efficacy. Long-term adherence remains a major challenge. Adverse effects, mainly hematological and dermatological, are generally predictable, dose-dependent, and reversible. Potential effects on reproduction require specific and nuanced discussion with patients. Despite extensive evidence supporting its efficacy, HU remains underprescribed, representing a major public health concern. Accordingly, the question facing clinicians is no longer "When should HU be prescribed?" but rather "Is there a reason not to prescribe it?"

Thirty years after its efficacy demonstration, HU remains the cornerstone of medical therapy for HbSS and HbS/β0-thalassemia, and expanding its use to all eligible patients should remain a priority.