Trofinetide and Rett Syndrome: A Comprehensive Review of the First FDA-Approved Therapy

Abstract: 

Rett syndrome is a rare, X-linked neurodevelopmental disorder predominantly affecting females, characterized by early developmental regression, loss of purposeful hand use, severe cognitive impairment, and autonomic dysfunction. It is most commonly caused by de novo mutations in the MECP2 gene, which disrupts normal synaptic development and function. Until recently, management strategies were limited to supportive care, with no disease-modifying options available. In 2023, Trofinetide, a synthetic analog of glycine-proline-glutamate (GPE) designed to modulate synaptic integrity and reduce neuroinflammation, became the first FDA-approved pharmacologic therapy specifically for Rett syndrome. This literature review synthesizes evidence from preclinical models, randomized clinical trials (LAVENDER, LILAC, DAFFODIL), pharmacokinetic studies, and systematic reviews to assess Trofinetide’s therapeutic mechanism, efficacy, safety profile, and clinical utility. Across studies, Trofinetide consistently demonstrated statistically and clinically meaningful improvements in core Rett syndrome symptoms, particularly in behavioral and functional domains, with a tolerable side-effect profile primarily involving mild to moderate gastrointestinal events. While questions remain regarding long-term efficacy, early intervention potential, and applicability to broader patient populations, Trofinetide represents a landmark advancement in the treatment landscape for Rett syndrome and sets a precedent for future targeted therapies in rare neurodevelopmental disorders.