Ataxia Canada is pleased to share an important research milestone for the Friedreich’s ataxia community. Lexeo Therapeutics has announced the publication of Phase I/II clinical data for LX2006, an investigational gene therapy for Friedreich’s ataxia, in the peer-reviewed journal JAMA Cardiology.

The publication combines data from 17 participants enrolled in two independent studies, including Lexeo’s SUNRISE-FA trial. Participants received a single intravenous infusion of LX2006 and were followed for periods ranging from 6 to 36 months.

Key Findings

According to the published results, LX2006 was generally well tolerated and demonstrated encouraging signs of potential benefit across both cardiac and neurological measures of Friedreich’s ataxia.

Highlights from the studies include:

• Most participants experienced either improvement or stabilization of left ventricular mass index (LVMI), an important measure of Friedreich’s ataxia-related cardiomyopathy. Among participants with abnormal baseline LVMI who received mid- or high-dose treatment, mean LVMI improved by 28% at 6 months and 33% at 12 months. Some patients maintained these improvements for up to three years following treatment.
• Improvements or stabilization were also observed in secondary cardiac biomarkers, including high-sensitivity troponin I and lateral wall thickness, supporting the potential of LX2006 across different stages of Friedreich’s ataxia cardiomyopathy.
• Cardiac biopsy data from the SUNRISE-FA study showed increased frataxin protein expression in all evaluated participants three months after treatment, providing evidence that the therapy successfully increased frataxin levels in disease-relevant cardiac tissue.
• LX2006 was associated with stabilization of modified Friedreich Ataxia Rating Scale (mFARS) scores over time, suggesting potential neurological functional benefit.

Safety Profile

The therapy was generally well tolerated across all 17 treated participants. No Grade 3 or higher serious adverse events were reported, and no clinically significant complement activation was observed. Only minimal and transient liver function test elevations were reported. One participant experienced a possibly treatment-related Grade 2 asymptomatic myocarditis approximately one year after treatment.

Looking Ahead

While these findings are from early-stage clinical studies and further research is needed, the publication represents an important step forward in the development of potential new treatments for Friedreich’s ataxia. Cardiomyopathy remains a progressive and life-threatening complication of the disease, and there are currently no approved therapies specifically targeting the cardiac manifestations of Friedreich’s ataxia.

Lexeo Therapeutics plans to continue evaluating LX2006 in the pivotal SUNRISE-FA 2 study, which is expected to be the next major step in determining the therapy’s safety and efficacy.

We remain committed to keeping our community informed as new developments emerge and as promising therapies continue to move through the clinical development process.