Gene Therapy For Fatal Rare Disease-Associated Heart Condition – Lexeo Therapeutics Candidate Shows Improvements In Trials

Lexeo Therapeutics, Inc. LXEO on Monday released interim data across all dose cohorts of LX2006 for Friedreich ataxia (FA) cardiomyopathy, a serious heart condition in FA patients with a rare, inherited neuromuscular disorder. 

In both the Lexeo-sponsored SUNRISE-FA Phase 1/2 trial and the Weill Cornell Medicine investigator-initiated Phase 1A trial, treatment with LX2006 was associated with clinically significant improvements in cardiac biomarkers and functional measures, and increased frataxin protein expression was observed in all participants with cardiac biopsies.

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Left ventricular mass index (LVMI), a surrogate of left ventricular hypertrophy and a predictor of cardiac morbidity and mortality in adults with hypertension:

• 5 of 6 participants achieved >10% improvement by a 12-month visit or sooner
• As of the latest visit, 5 of 6 participants achieved LVMI measurements within the normal range.
• 27% mean improvement in LVMI as of the latest visit
• 25% mean improvement in LVMI by a 12-month visit or sooner
• Participants treated in Cohorts 2 and 3 (mid- and high-dose) demonstrate greater, dose-dependent improvement at earlier time points relative to Cohort 1 (low-dose)

Secondary cardiac biomarkers, functional measures, and patient-reported outcomes:

• 10 of 12 participants achieved a reduction in lateral wall thickness (LWT) at the latest visit.
• 11 of 12 participants achieved >25% reduction in high-sensitivity troponin I at the latest visit.
• The majority of participants showed improvements across functional measures.

Cardiac frataxin expression (assessed in SUNRISE-FA trial only; n=8):

• All participants achieved increases in frataxin protein expression at 3 months
• Dose-dependent increases were observed across cohorts on average, with a 115% mean increase in Cohort 3 (n=4)

In Q2 2025, Lexeo expects to begin enrollment in a prospective natural history study, serving as a concurrent external control arm for the registrational study.

The company expects to initiate a registrational study by early 2026, with a potential efficacy readout in 2027.

Price Action: LXEO stock is up 7.40% at $2.51 during the premarket session at the last check Monday.

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