Effect of Roxadustat on Thyroid Function in Patients With Renal Anemia

Context: Roxadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, a recently developed class of drugs for treatment of anemia in chronic kidney disease (CKD), is reported to have a structure unlike that of other HIF-PH inhibitors but similar to that of triiodothyronine and bind to the thyroid hormone receptor in vitro. However, reports on the effects of roxadustat on thyroid function are limited and not detailed, and it remains unknown whether other HIF-PH inhibitors also affect thyroid function. Objective: To compare the effect of roxadustat with daprodustat, another HIF-PH inhibitor, on thyroid function in patients with renal anemia in CKD. Methods: This retrospective observational study included a total of 26 patients with anemia in CKD who were treated with roxadustat or daprodustat; thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were measured before and after treatment with the drugs. Results: After initiation of roxadustat, TSH showed a significant decrease (2.4732 [1.7858-4.9016] μIU/mL before treatment and 0.659 [0.112-2.005] μIU/mL after treatment, P < .05); FT4 showed a significant decrease (0.93 [0.84-1.05] ng/dL before treatment and 0.70 [0.53-0.85] ng/dL after treatment, P < .01). After daprodustat initiation, neither TSH nor FT4 showed a significant change (TSH: 3.044 [1.853-4.171] μIU/mL before treatment and 2.893 [1.866-4.894] μIU/mL after treatment, P = .635; FT4 was 0.93 [0.81-1.00] ng/dL before treatment and 0.97 [0.87-1.05] ng/dL after treatment, P = .328). Conclusion: Roxadustat decreases TSH and FT4 levels while daprodustat does not.