Lexeo Therapeutics has posted updated data in Friedreich ataxia (FA) patients, linking a gene therapy to improvements on outcomes the biotech plans to use as co-primary endpoints in a registrational trial.
An earlier cut of the data last year disappointed investors when Lexeo revealed it was unable to assess the effect of the candidate on fitness. However, the biotech is planning to start a registrational trial in early 2026 on the strength of the latest results.
The fresh data come from a pooled analysis of two studies of LX2006, a gene therapy designed to treat cardiac dysfunction in FA by increasing expression of the heart muscle protein frataxin. Lexeo said the FDA has agreed to the use of frataxin expression and left ventricular mass index (LVMI) as co-primary endpoints in the planned registrational trial.
Five of the six people with abnormal LVMI at baseline experienced a 10% or greater improvement within 12 months. Lexeo reported improvements in three out of four patients in its earlier cut of the data. LVMI predicts cardiac morbidity and mortality.
The biotech saw increased frataxin expression in all patients with cardiac biopsies. The level of increase was dose dependent, with Lexeo reporting a 115% jump in the four patients in the third dose cohort.
Lexeo said the LVMI and frataxin results topped the target thresholds for its planned registrational study. The biotech expects to reach final alignment with the FDA on the statistical plan this year, Lexeo CEO Nolan Townsend said on a call with investors to discuss the data. Townsend added that “the [FDA] team that we've been working with has not changed and they continue to work in the same way.”
Last month, Lexeo said it expects its existing cash to give it a runway into 2027. Townsend told analysts “we would anticipate obviously having the study enrolled within '26 and then data in 2027.”