Lexeo Therapeutics reports protein expression data from SUNRISE-FA trial

Average pre-treatment FXN level across three subjects was 1.18ng/mg. Compared to FXN levels observed in 29 cadaver tissue samples from 16 individuals without heart disease, we believe the average pre-treatment FXN level represents approximately two percent of healthy individual frataxin levels in the heart. To our knowledge, SUNRISE-FA is the first clinical trial to evaluate frataxin levels in the target organ of FA cardiomyopathy patients via cardiac biopsy. Data to date suggest that FA patients may have lower FXN levels in the heart versus peripheral tissues. Across all three cardiac biopsies, we observed an increase in FXN levels as measured by liquid chromatography mass spectrometry relative to pre-treatment baseline levels. We observed an approximately five-fold increase in protein on average in the second cohort to date, relative to the first cohort ). A dose-dependent response was also seen in our IND-enabling preclinical studies, where a non-linear relationship was observed between dose delivered and frataxin protein expression. Lexeo expects to present additional interim data from SUNRISE-FA Cohorts 1 and 2 in mid-2024, including measures of hypertrophy and other cardiac biomarkers at multiple timepoints. Ahead of this interim readout, Lexeo expects to provide an analysis of baseline characteristics from LX2006-treated patients to characterize the cardiovascular disease phenotype seen in FA as well as baseline levels of hypertrophy and other cardiac biomarkers that will be reported at mid-year.