Lexeo's Gene Therapy Shows Early Promise for Friedreich Ataxia Cardiomyopathy

Lexeo Therapeutics has reported encouraging preliminary data from its gene therapy candidate LX2006 for treating Friedreich ataxia (FA) cardiomyopathy. Despite the promising results, the company's shares fell by nearly 20% in premarket trading on Monday.

The data comes from eight participants who have been followed for at least six months in Lexeo’s Phase I/II SUNRISE-FA trial and a Phase Ia study initiated by investigators at Weill Cornell Medicine. LX2006, an AAV-based gene therapy designed to deliver a functional copy of the frataxin gene, was found to be well tolerated with no serious treatment-related adverse events in either study.

Regarding efficacy, the results showed that in four participants with elevated left ventricular mass index (LVMI) at baseline, the mean reduction in LVMI was 11.4% at 12 months. This reduction increased to 18.3% in two patients who had reached 18 months. Prior to the data release, analysts at Baird had suggested that a sustained decline in LVMI over time, particularly approaching 20%, would be highly favorable. Lexeo reported that 75% of participants with elevated LVMI at baseline achieved over a 10% reduction at 12 months.

Additionally, there were clinically meaningful improvements in cardiac biomarkers and increased frataxin levels compared to baseline. Specifically, the left ventricular (LV) lateral wall thickness, an early sign of left ventricular hypertrophy, was reduced by an average of 13.6%. Troponin I, a biomarker for myocardial injury, decreased by an average of 53.3% in all patients after 12 months.

Eric Adler, Lexeo's chief medical officer, stated, "Based on the favorable safety profile and clinical benefits observed to date, we are excited to explore expedited clinical development of LX2006, including potential for accelerated approval." As of July 15, 13 participants had been dosed with LX2006 across three dose cohorts in the two ongoing trials.

In the latter part of last year, Lexeo completed an initial public offering (IPO), raising just over $110 million. The funds will be utilized to advance LX2006 and the company's other pipeline candidates, including LX1001, a gene therapy for APOE4-associated Alzheimer's disease.