Omaveloxolone

The mechanism of action of omaveloxolone has not been fully elucidated; however, its therapeutic effect in patients with Friedreich's ataxia may be linked to its ability to activate the Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. Nrf2 is a transcription factor that mitigates oxidative stress. In normal conditions, Nrf2 levels are regulated by Kelch-like ECH-associated protein 1 (KEAP1), which binds to Nrf2, prevents Nrf2 translocation to the nucleus, and degrades it by ubiquitination. In the presence of oxidative stress, the ubiquitination system is disrupted. Nrf2 accumulates and translocates to the nucleus, where it promotes the expression of genes against oxidative stress. In patients with Friedreich's ataxia, the Nrf2 signaling pathway is dysfunctional. In Friedreich's ataxia models, Nrf2 has a lower activity; therefore, Nrf2 activators such as omaveloxolone represent a therapeutic opportunity. A study has shown that omaveloxolone binds to KEAP1, inhibiting its interaction with Nrf2 and promoting the translocation of Nrf2 to the nucleus. Aside from activating Nrf2, omaveloxolone also inhibits the NF-κB signalling pathway, promoting antioxidative, anti-inflammatory, and antiapoptotic mechanisms.