levothyroxine + folinic acid

A combination therapy consisting of levothyroxine (a synthetic thyroid hormone) and folinic acid (a reduced folate, also known as leucovorin). This combination was developed by the Institut Jérôme Lejeune specifically to address potential metabolic and endocrine deficiencies in children with Down syndrome (trisomy 21). Levothyroxine acts as an agonist at thyroid hormone receptors, aiming to correct subclinical hypothyroidism, while folinic acid supports the folate/one-carbon metabolic pathway, which is often hypothesized to be disrupted in individuals with trisomy 21. The combination was evaluated in the Phase 3 ACTHYF trial to determine if it could improve psychomotor development in infants; however, the study results did not demonstrate a significant clinical benefit over placebo, and the program was not pursued further for this indication.

Other names

L-thyroxine + folinic acidlevothyroxine sodium + leucovorinthyroid hormone + folinic acid