Chiesi Global Rare Diseases announced that the FDA is evaluating the regulatory submission for idebenone as a treatment for Leber Hereditary Optic Neuropathy (LHON). The FDA has set February 28, 2026 as its target action date. If approved, idebenone would become the first and only clinically proven therapy for LHON in the United States.

Idebenone is already approved internationally as Raxone, with marketing authorization granted across the European Union (2015), the United Kingdom (2015), Israel (2017), South Korea (2019), Serbia (2019), Switzerland (2014), Chile (2024), Bahrain (2025), and Taiwan (2025).

“LHON changes lives in an instant. This review brings hope of the first-ever approved treatment in the US for LHON, one of the most prevalent mitochondrial diseases,” Malinda Marsh, Chris Marsh, and Lissa Poincenot, parents of children affected by LHON and co-founders of the LHON Collective, stated in a company news release.

“Idebenone is designed to target mitochondrial dysfunction of retinal ganglion cells, the underlying cause of LHON," said Mitch Goldman, Senior Vice President of R&D at Chiesi Global Rare Diseases. Data from our clinical studies and in-market experience suggest that idebenone has a favorable safety profile and the potential to improve vision.”

The FDA’s review includes data from randomized, placebo-controlled trials and real-world observational studies, showing idebenone’s ability to improve or stabilize vision in LHON patients.

  • Phase 3 RHODOS Trial

    • 85 patients (ages 14–65) with disease duration ≤5 years.

    • Idebenone group showed a greater average gain in visual acuity compared to placebo, with a higher proportion achieving clinically meaningful improvements.

  • Phase 4 LEROS Trial

    • Demonstrated sustained benefits in visual acuity at 12 and 24 months.

    • Odds of achieving overall clinical benefit were more than three times higher compared to natural history controls.

  • Safety Profile

    • Most common adverse reactions (≥3% incidence): mild, reversible increases in liver enzymes and diarrhea.